page_title
stringlengths
1
91
page_text
stringlengths
0
34.2k
Nilutamide
Nilutamide, sold under the brand names Nilandron and Anandron, is a nonsteroidal antiandrogen (NSAA) which is used in the treatment of prostate cancer. It has also been studied as a component of feminizing hormone therapy for transgender women and to treat acne and seborrhea in women. It is taken by mouth.Side effects in men include breast tenderness and enlargement, feminization, sexual dysfunction, and hot flashes. Nausea, vomiting, visual disturbances, alcohol intolerance, elevated liver enzymes, and lung disease can occur in both sexes. Rarely, nilutamide can cause respiratory failure and liver damage. These unfavorable side effects, along with a number of associated cases of death, have limited the use of nilutamide.Nilutamide acts as a selective antagonist of the androgen receptor (AR), preventing the effects of androgens like testosterone and dihydrotestosterone (DHT) in the body. Because most prostate cancer cells rely on these hormones for growth and survival, nilutamide can slow the progression of prostate cancer and extend life in men with the disease.Nilutamide was discovered in 1977 and was first introduced for medical use in 1987. It became available in the United States in 1996. The drug has largely been replaced by newer and improved NSAAs, namely bicalutamide and enzalutamide, due to their better efficacy, tolerability, and safety, and is now rarely used.It is on the World Health Organizations List of Essential Medicines. Medical uses Prostate cancer Nilutamide is used in prostate cancer in combination with a gonadotropin-releasing hormone (GnRH) analogue at a dosage of 300 mg/day (150 mg twice daily) for the first 4 weeks of treatment, and 150 mg/day thereafter. It is not indicated as a monotherapy in prostate cancer. Only one small non-comparative study has assessed nilutamide as a monotherapy in prostate cancer.Nilutamide has been used to prevent the effects of the testosterone flare at the start of GnRH agonist therapy in men with prostate cancer. Transgender hormone therapy Nilutamide has been studied for use as a component of feminizing hormone therapy for transgender women. It has been assessed in at least five small clinical studies for this purpose in treatment-naive subjects. In these studies, nilutamide monotherapy at a dosage of 300 mg/day, induced observable signs of clinical feminization in young transgender women (age range 19–33 years) within 8 weeks, including breast development, decreased body hair (though not facial hair), decreased morning erections and sex drive, and positive psychological and emotional changes. Signs of breast development occurred in all subjects within 6 weeks and were associated with increased nipple sensitivity, and along with decreased hair growth, were the earliest sign of feminization.Nilutamide did not change the size of the prostate gland (which is the same as with high-dosage cyproterone acetate and ethinylestradiol treatment for as long as 18 months), but was found to alter its histology, including increased stromal tissue with a significant reduction in acini and atrophic epithelial cells, indicating glandular atrophy. In addition, readily apparent histological changes were observed in the testes, including a reduction in tubular and interstitial cells.Nilutamide was found to more than double luteinizing hormone (LH) and testosterone levels and to triple estradiol levels. In contrast, follicle-stimulating hormone levels remained unchanged. A slight but significant increase in prolactin levels was observed, and levels of sex hormone-binding globulin increased as well. The addition of ethinylestradiol to nilutamide therapy after 8 weeks abolished the increase in LH, testosterone, and estradiol levels and dramatically suppressed testosterone levels, into the castrate range. Both nilutamide alone and the combination of nilutamide and estrogen were regarded as resulting in effective and favorable antiandrogen action and feminization in transgender women. Skin conditions Nilutamide has been assessed in the treatment of acne and seborrhea in women in at least one small clinical study. The dosage used was 200 mg/day, and in the study, "seborrhea and acne decreased markedly within the first month and practically disappeared after 2 months of [nilutamide] treatment." Available forms Nilutamide is available in the form of 50 and 150 mg oral tablets. Side effects General side effects of NSAAs, including nilutamide, include gynecomastia, breast pain/tenderness, hot flashes (67%), depression, fatigue, sexual dysfunction (including loss of libido and erectile dysfunction), decreased muscle mass, and decreased bone mass with an associated increase in fractures. Also, nausea (24–27%), vomiting, constipation (20%), and insomnia (16%) may occur with nilutamide. Nilutamide monotherapy is known to eventually induce gynecomastia in 40 to 80% of men treated with it for prostate cancer, usually within 6 to 9 months of treatment initiation.Relative to other NSAAs, nilutamide has been uniquely associated with mild and reversible visual disturbances (31–58%) including delayed ocular adaptation to darkness and impaired color vision, a disulfiram-like alcohol intolerance (19%), interstitial pneumonitis (0.77–2.4%) (which can result in dyspnea (1%) as a secondary effect and can progress to pulmonary fibrosis), and hepatitis (1%), and has a higher incidence of nausea and vomiting compared to other NSAAs. The incidence of interstitial pneumonitis with nilutamide has been found to be much higher in Japanese patients (12.6%), warranting particular caution in Asian individuals. There is a case report of simultaneous liver and lung toxicity in a nilutamide-treated patient.There is also a risk of hepatotoxicity with nilutamide, though occurrence is very rare and the risk is significantly less than with flutamide. The incidence of abnormal liver function tests (e.g., elevated liver enzymes) has been variously reported as 2 to 33% with nilutamide. For comparison, the risk of elevated liver enzymes has been reported as 4 to 62% in the case of flutamide. The risk of hepatotoxicity with nilutamide has been described as far less than with flutamide. Fulminant hepatic failure has been reported for nilutamide, with fatal outcome. Between 1986 and 2003, the numbers of published cases of hepatotoxicity for antiandrogens totaled 46 for flutamide, 21 for cyproterone acetate, 4 for nilutamide, and 1 for bicalutamide. Similarly to flutamide, nilutamide exhibits mitochondrial toxicity in hepatocytes by inhibiting respiratory complex I (NADH ubiquinone oxidoreductase) (though not respiratory complexes II, III, or IV) in the electron transport chain, resulting in reduced ATP and glutathione production and thus decreased hepatocyte survival. The nitro group of nilutamide has been theorized to be involved in both its hepatotoxicity and its pulmonary toxicity. Pharmacology Pharmacodynamics Antiandrogenic activity Nilutamide acts as a selective competitive silent antagonist of the AR (IC50 = 412 nM), which prevents androgens like testosterone and DHT from activating the receptor. The affinity of nilutamide for the AR is about 1 to 4% of that of testosterone and is similar to that of bicalutamide and 2-hydroxyflutamide. Similarly to 2-hydroxyflutamide, but unlike bicalutamide, nilutamide is able to weakly activate the AR at high concentrations. It does not inhibit 5α-reductase.Like other NSAAs such as flutamide and bicalutamide, nilutamide, without concomitant GnRH analogue therapy, increases serum androgen (by two-fold in the case of testosterone), estrogen, and prolactin levels due to inhibition of AR-mediated suppression of steroidogenesis via negative feedback on the hypothalamic–pituitary–gonadal axis. As such, though nilutamide is still effective as an antiandrogen as a monotherapy, it is given in combination with a GnRH analogue such as leuprorelin in prostate cancer to suppress androgen concentrations to castrate levels in order to attain maximal androgen blockade (MAB).Like flutamide and bicalutamide, nilutamide is able to cross the blood–brain barrier and has central antiandrogen actions. Cytochrome P450 inhibition Nilutamide is known to inhibit several cytochrome P450 enzymes, including CYP1A2, CYP2C9, and CYP3A4, and can result in increased levels of medications that are metabolized by these enzymes. It has also been found to inhibit the enzyme CYP17A1 (17α-hydroxylase/17,20-lyase) in vitro and thus the biosynthesis of androgens. However, nilutamide monotherapy significantly increases testosterone levels in vivo, so the clinical significance of this finding is uncertain. Pharmacokinetics Nilutamide has an elimination half-life of 23 to 87 hours, with a mean of 56 hours, or about two days; this allows for once-daily administration. Steady state (plateau) levels of the drug are attained after two weeks of administration with a dosage of 150 mg twice daily (300 mg/day total). It is metabolized by CYP2C19, with at least five metabolites. Virtually all of the antiandrogenic activity of nilutamide comes from the parent drug (as opposed to metabolites). Chemistry Nilutamide is structurally related to the first-generation NSAAs flutamide and bicalutamide as well as to the second-generation NSAAs enzalutamide and apalutamide. History Nilutamide was developed by Roussel and was first described in 1977. It was first introduced for medical use in 1987 in France and was the second NSAA to be marketed, with flutamide preceding it and bicalutamide following it in 1995. It was not introduced until 1996 in the United States. Society and culture Generic names Nilutamide is the generic name of the drug and its INN, USAN, BAN, and DCF. Brand names Nilutamide is marketed under the brand name Nilandron in the United States and under the brand name Anandron elsewhere in the world such as in Australia, Canada, Europe, and Latin America. Availability Nilutamide is or has been available in the United States, Canada, Australia, Europe, Latin America, Egypt, and Lebanon. In Europe, it is or has been available in Belgium, Croatia, the Czech Republic, Finland, France, the Netherlands, Norway, Poland, Portugal, Serbia, Sweden, Switzerland, and Yugoslavia. in Latin America, it is or has been available in Argentina, Brazil, and Mexico. Research The combination of an estrogen and nilutamide as a form of combined androgen blockade for the treatment of prostate cancer has been studied in animals.Nilutamide has been studied in the treatment of advanced breast cancer. References Further reading Raynaud JP, Bonne C, Moguilewsky M, Lefebvre FA, Bélanger A, Labrie F (1984). "The pure antiandrogen RU 23908 (Anandron), a candidate of choice for the combined antihormonal treatment of prostatic cancer: a review". Prostate. 5 (3): 299–311. doi:10.1002/pros.2990050307. PMID 6374639. S2CID 85417869. Moguilewsky M, Bertagna C, Hucher M (1987). "Pharmacological and clinical studies of the antiandrogen Anandron". J. Steroid Biochem. 27 (4–6): 871–5. doi:10.1016/0022-4731(87)90162-2. PMID 3320565. Du Plessis DJ (1991). "Castration plus nilutamide vs castration plus placebo in advanced prostate cancer. A review". Urology. 37 (2 Suppl): 20–4. doi:10.1016/0090-4295(91)80097-q. PMID 1992599. Creaven PJ, Pendyala L, Tremblay D (1991). "Pharmacokinetics and metabolism of nilutamide". Urology. 37 (2 Suppl): 13–9. doi:10.1016/0090-4295(91)80096-p. PMID 1992598. Harris MG, Coleman SG, Faulds D, Chrisp P (1993). "Nilutamide. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy in prostate cancer". Drugs Aging. 3 (1): 9–25. doi:10.2165/00002512-199303010-00002. PMID 8453188. Dole EJ, Holdsworth MT (1997). "Nilutamide: an antiandrogen for the treatment of prostate cancer". Ann Pharmacother. 31 (1): 65–75. doi:10.1177/106002809703100112. PMID 8997470. S2CID 20347526. Iversen P, Melezinek I, Schmidt A (2001). "Nonsteroidal antiandrogens: a therapeutic option for patients with advanced prostate cancer who wish to retain sexual interest and function". BJU Int. 87 (1): 47–56. doi:10.1046/j.1464-410x.2001.00988.x. PMID 11121992. S2CID 28215804.
Lodine
Lodine (Sardinian: Lodìne) is a town and comune in the province of Nuoro, Sardinia, Italy. == References ==
Ganirelix
Ganirelix acetate (or diacetate), sold under the brand names Orgalutran and Antagon among others, is an injectable competitive gonadotropin-releasing hormone antagonist (GnRH antagonist). It is primarily used in assisted reproduction to control ovulation. The drug works by blocking the action of GnRH upon the pituitary, thus rapidly suppressing the production and action of LH and FSH. Ganirelix is used in fertility treatment to prevent premature ovulation that could result in the harvesting of eggs that are too immature to be used in procedures such as in vitro fertilization.GnRH agonists are also sometimes used in reproductive therapy, as well as to treat disorders involving sex-steroid hormones, such as endometriosis. One advantage of using GnRH antagonists is that repeated administration of GnRH agonists results in decreased levels of gonadotropins and sex steroids due to desensitization of the pituitary. This is avoided when using GnRH antagonists such as ganirelix. The success of ganirelix in reproductive therapy has been shown to be comparable to that when using GnRH agonists. Medical uses Ganirelix is used as a fertility treatment drug for women. Specifically, it is used to prevent premature ovulation in people with ovaries undergoing fertility treatment involving ovarian hyperstimulation that causes the ovaries to produce multiple eggs. When such premature ovulation occurs, the eggs released by the ovaries may be too immature to be used in in-vitro fertilization. Ganirelix prevents ovulation until it is triggered by injecting human chorionic gonadotrophin (hCG).Ganirelix is administered by a subcutaneous injection of 250 µg once per day during the mid to late follicular phase of a patients menstrual cycle. Treatment should start on the 5th or 6th day after the start of ovarian stimulation, and the mean duration for its use is five days. Preferably, the subcutaneous injections are delivered in the upper leg, and the patient can be trained to do this themself. Continued use of the drug should take place until the administration of hCG begins. hCG administration is begun when a sufficient number of follicles have developed due to the effects of endogenous and or exogenously administered follicle stimulating hormone. Contraindications Ganirelix should not be used in women who are already pregnant, and because of this the onset of pregnancy must be ruled out before it is administered. Women using ganirelix should not breast feed, as it is not known whether ganirelix is excreted in breast milk. Side effects Clinical studies have shown that the most common side effect is a slight reaction at the site of injection in the form of redness, and sometimes swelling. Clinical studies have shown that, one hour after injection, the incidence of at least one moderate or severe local skin reaction per treatment cycle was 12% in 4 patients treated with ganirelix and 25% in patients treated subcutaneously with a GnRH agonist. The local reactions generally disappear within 4 hours after administration. Other reported side effects are some that are known to be associated with ovarian hyperstimulation, including gynecological abdominal pain, headache, vaginal bleeding, nausea, and gastrointestinal abdominal pain. In some rare cases, less than 1 user in 10,000, hypersensitivity to ganirelix can cause anaphylactoid reactions, most likely due to allergy. Birth defects A follow-up analysis for ganirelix done by the Marketing Authorisation Holder compared the number of congenital malformations between individuals whose mothers were treated with ganirelix compared with individuals whose mothers were treated with a GnRH agonist. The total number of congenital malformations was higher in the ganirelix group than in the GnRH agonist group (7.6% vs. 5.5%). This falls within the range for the normal incidence of congenital malformations, and current data do not suggest that ganirelix increases the incidence of congenital malformations or anomalies. No important differences in the frequency of ectopic pregnancies and miscarriage were noted with the use of ganirelix. Interactions Currently, no studies have been done to assess the possible drug-drug interactions between ganirelix and other drugs. Pharmacology Pharmacodynamics Ganierlix is a synthetic peptide that works as an antagonist against gonadotropin-releasing hormone (GnRH) ("Ganirelix acetate injection," 2009). Ganirelix competitively blocks GnRH receptors on the pituitary gonadotroph, quickly resulting in the suppression of gonadotropin secretion. This suppression is easily reversed by discontinuation of ganirelix administration. Ganirelix has a significantly higher receptor binding affinity (Kd = 0.4 nM) than GnRH (Kd = 3.6 nM). Pharmacokinetics When ganirelix is given to healthy adult females, steady-state serum concentrations are reached, on average, after three days ("Ganirelix acetate injection," 2009). A study administering ganirelix to healthy adult females (n=15) found the mean (SD) elimination half-life (t1/2) to be 16.2(1.6) hours, volume of distribution/absolute bioavailability (Vd/F) 76.5(10.3) liters, maximum serum concentration (Cmax) 11.2(2.4) ng/mL, and the time until maximum concentration (tmax) 1.1(0.2) hours. One 250 µg injection of ganirelix resulted in a mean absolute bioavailability of 91.1%. Chemistry Ganirelix is derived from GnRH, with amino acid substitutions made at positions 1, 2, 3, 6, 8, and 10. History The European Commission gave marketing authorization for ganirelix throughout the European Union to N.V. Organon in May 2000. See also Gonadotropin-releasing hormone receptor § Antagonists References External links "Ganirelix". Drug Information Portal. U.S. National Library of Medicine. "Ganirelix acetate". Drug Information Portal. U.S. National Library of Medicine.
Ceftazidime/avibactam
Ceftazidime/avibactam, sold under the brand name Avycaz among others, is a fixed-dose combination medication composed of ceftazidime, a cephalosporin antibiotic, and avibactam, a β-lactamase inhibitor. It is used to treat complicated intra-abdominal infections, urinary tract infections, and pneumonia. It is only recommended when other options are not appropriate. It is given by injection into a vein.Common side effect include nausea, fever, liver problems, headache, trouble sleeping, and pain at the site of injection. Severe side effects may include anaphylaxis, seizures, and Clostridioides difficile-associated diarrhea. While use appears to be safe in pregnancy the medication has not been well studied in this group. Doses should be adjusted in those with kidney problems. Ceftazidime works by interfering with the building of the bacterial cell wall while avibactam works by preventing ceftazidimes breakdown.The combination was approved for medical use in the United States and the European Union in 2015. It is on the World Health Organizations List of Essential Medicines. Resistances are increasingly been reported with United States, Greece and Italy accounting for 80% of cases. Medical use Ceftazidime/avibactam is used to treat certain multidrug-resistant gram-negative infections.Ceftazidime/avibactam is used for the treatment of: complicated intra-abdominal infections. In these cases it is often used in combination with metronidazole, which provides coverage for anaerobic pathogens. complicated urinary tract infections, including acute pyelonephritis, in adults. hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia. Bacterial activity For many bacterial infections, it offers little or no advantage over ceftazidime monotherapy, due to the widespread expression of resistance mechanisms other than β-lactamase production. These include Haemophilus, Moraxella and Neisseria pathogens, and infections caused by Acinectobacter baumannii.The antibacterial spectrum of ceftazidime/avibactam includes nearly all Enterobacteriaceae, including ceftazidime-resistant strains. The activity of ceftazidime/avibactam against the important hospital pathogen Pseudomonas aeruginosa is variable, due to the potential presence of other resistance mechanisms in addition to β-lactamase production. Synergy was observed for avibactam with ceftazidime in the Burkholderia cepacia complex. Adverse events When used to treat life-threatening infections, ceftazidime/avibactam is more likely than carbapenem antibiotics to cause serious adverse events, including worsening kidney function and gastrointestinal adverse effects. Mechanism of action Bacterial resistance to cephalosporins is often due to bacterial production of β-lactamase enzymes that deactivate these antibiotics. Avibactam inhibits some (but not all) bacterial β-lactamases. Also, some bacteria are resistant to cephalosporins by other mechanisms, and therefore avibactam doesnt work. Avibactam is not active against New Delhi metallo-β-lactamase 1 (NDM-1). Avibactam inhibits Klebsiella pneumoniae carbapenemases (KPCs), and AmpC-type β-lactamases, which are resistant to the other clinically-available β-lactamases, tazobactam and clavulanic acid. Regulatory It was granted approval for marketing in the United States by the Food and Drug Administration (FDA) in February 2015. It was granted approval for marketing in Europe by the European Medicines Agency in 2016. During its clinical development, ceftazidime/avibactam was designated as a Qualified Infectious Disease Product under the Generating Antibiotic Incentives Now provision of the Food and Drug Administration Safety and Innovation Act. Development of ceftazidime/avibactam was fast-tracked by the FDA due to the shortage of drugs for treatment of infections due to antibiotic-resistant bacteria. References External links "Avibactam mixture with ceftazidime". Drug Information Portal. U.S. National Library of Medicine.
Cefotetan
Cefotetan is an injectable antibiotic of the cephamycin type for prophylaxis and treatment of bacterial infections. It is often grouped together with second-generation cephalosporins and has a similar antibacterial spectrum, but with additional anti-anaerobe coverage. Cefotetan was developed by Yamanouchi. It is marketed outside Japan by AstraZeneca with the brand names Apatef and Cefotan. Adverse effects The chemical structure of cefotetan, like that of several other cephalosporins, contains an N-methylthiotetrazole (NMTT or 1-MTT) side chain. As the antibiotic is broken down in the body, it releases free NMTT, which can cause hypoprothrombinemia (likely due to inhibition of the enzyme vitamin K epoxide reductase) and a reaction with ethanol similar to that produced by disulfiram (Antabuse), due to inhibition of aldehyde dehydrogenase. Spectrum of bacterial susceptibility Cefotetan has a broad spectrum of activity and has been used to treat bacterial infections of the bone, skin, urinary tract, and lower respiratory tract. Notable species include Bacteroides, Streptococcus, and Escherichia. The following represents MIC susceptibility data for a few medically significant bacteria. Escherichia coli: 0.06 µg/mL Bacteroides fragilis: ≤0.06 µg/mL - 512 µg/mL Clostridium perfringens: 1 µg/mL - 4 µg/mL References External links Cefotan official web site run by AstraZeneca US Cefotetan entry in RxList
Sodium ferric gluconate complex
Sodium ferric gluconate complex, sold under the brand name Ferrlecit, is an intravenously administered iron medication for the treatment of iron deficiency anemia in adults and in children aged six years and older with chronic kidney disease receiving hemodialysis who are receiving supplemental epoetin therapy. The macromolecule has an apparent molecular weight of 289,000 – 440,000 Dalton.The most common side effects in adults are nausea, vomiting and/or diarrhea, injection site reaction, hypotension, cramps, hypertension, dizziness, dyspnea, chest pain, leg cramps, and pain. In children the most common side effects are hypotension, headache, hypertension, tachycardia and vomiting. References External links "Sodium ferric gluconate complex". Drug Information Portal. U.S. National Library of Medicine.
Hydralazine
Hydralazine, sold under the brand name Apresoline among others, is a medication used to treat high blood pressure and heart failure. This includes high blood pressure in pregnancy and very high blood pressure resulting in symptoms. It has been found to be particularly useful in heart failure, together with isosorbide dinitrate, for treatment of people of African descent. It is given by mouth or by injection into a vein. Effects usually begin around 15 minutes and last up to six hours.Common side effects include headache and fast heart rate. It is not recommended in people with coronary artery disease or in those with rheumatic heart disease that affects the mitral valve. In those with kidney disease a low dose is recommended. Hydralazine is in the vasodilator family of medications, so it is believed to work by causing the dilation of blood vessels.Hydralazine was discovered while scientists at Ciba were looking for a treatment for malaria. It was patented in 1949. It is on the World Health Organizations List of Essential Medicines. In 2019, it was the 99th most commonly prescribed medication in the United States, with more than 6 million prescriptions. Hydralazine has an adverse drug event of inducing drug-induced lupus and this drugs use is declining with more prescribers prescribing calcium channel blockers. Medical use Hydralazine is not used as a primary drug for treating hypertension because it elicits a reflex sympathetic stimulation of the heart (the baroreceptor reflex). The sympathetic stimulation may increase heart rate and cardiac output, and in people with coronary artery disease may cause angina pectoris or myocardial infarction. Hydralazine may also increase plasma renin concentration, resulting in fluid retention. To prevent these undesirable side effects, hydralazine is usually prescribed in combination with a beta blocker (e.g., propranolol) and a diuretic. Beta-blockers licensed to treat heart failure in the UK include bisoprolol, carvedilol, and nebivolol.Hydralazine is used to treat severe hypertension, but is not a first-line therapy for essential hypertension. Hydralazine is often used to treat hypertension in pregnancy, though, with either labetalol and/or methyldopa.Hydralazine is commonly used in combination with isosorbide dinitrate for the treatment of congestive heart failure in self-identified African-American populations. This preparation, isosorbide dinitrate/hydralazine, was the first race-based prescription drug.It should not be used in people who have tachycardia, heart failure, constrictive pericarditis, lupus, a dissecting aortic aneurysm, or porphyria. Adverse effects Prolonged treatment may cause a syndrome similar to lupus, which can become fatal if the symptoms are not noticed and drug treatment stopped. Hydralazine is within the top three drugs that is known to induce systemic lupus and this adverse drug event is dose dependent yet significant. Very common (>10% frequency) side effects include headache, tachycardia, and palpitations.Common (1–10% frequency) side effects include flushing, hypotension, anginal symptoms, aching or swelling joints, muscle aches, positive tests for atrial natriuretic peptide, stomach upset, diarrhea, nausea and vomiting, and swelling (sodium and water retention). Interactions It may potentiate the antihypertensive effects of: Drugs subject to a strong first-pass effect such as beta blockers may increase the bioavailability of hydralazine. Epinephrine (adrenaline), by its heart rate-accelerating effects as increased by hydralazine, may lead to toxicity. Mechanism of action Hydralazine is a drug that conducts the blood pressure lowering effects by vasoconstrictive repression. It is a direct-acting smooth muscle relaxant and acts as a vasodilator primarily in resistance arterioles, also known as the smooth muscle of the arterial bed. The molecular mechanism involves inhibition of inositol trisphosphate-induced Ca2+ release from the sarcoplasmic reticulum in arterial smooth muscle cells. By relaxing vascular smooth muscle, vasodilators act to decrease peripheral resistance, thereby lowering blood pressure and decreasing afterload. Chemistry Hydralazine belongs to the hydrazinophthalazine class of drugs. History The antihypertensive activity of hydralazine was discovered by scientists at Ciba, who were trying to discover drugs to treat malaria; it was initially called C-5968 and 1-hydrazinophthalazine; Cibas patent application was filed in 1945 and issued in 1949, and the first scientific publications of its blood pressure-lowering activities appeared in 1950. It was approved by the FDA in 1953.It was one of the first antihypertensive medications that could be taken by mouth. Research Hydralazine has also been studied as a treatment for myelodysplastic syndrome in its capacity as a DNA methyltransferase inhibitor. See also Arteriolar vasodilator Cadralazine Dihydralazine Endralazine Sodium nitroprusside References External links "Hydralazine". Drug Information Portal. U.S. National Library of Medicine.
Saquinavir
Saquinavir (SQV), sold under the brand names Invirase and Fortovase, is an antiretroviral drug used together with other medications to treat or prevent HIV/AIDS. Typically it is used with ritonavir or lopinavir/ritonavir to increase its effect. It is taken by mouth.Common side effects include nausea, vomiting, diarrhea, and feeling tired. More serious side effects include problems with QT prolongation, heart block, high blood lipids, and liver problems. It appears to be safe in pregnancy. It is in the protease inhibitor class and works by blocking the HIV protease.Saquinavir was patented in 1988 and first sold in 1995. Medical uses Saquinavir is used together with other medications to treat or prevent HIV/AIDS. Typically it is used with ritonavir or lopinavir/ritonavir to increase its effect. Side effects The most frequent adverse events with saquinavir in either formulation are mild gastrointestinal symptoms, including diarrhoea, nausea, loose stools and abdominal discomfort. Invirase is better tolerated than Fortovase. Bioavailability and drug interactions Saquinavir, in the Invirase formulation, has a low and variable oral bioavailability, when given alone. The Fortovase formulation at the standard dosage delivers approximately eightfold more active drug than Invirase, also at the standard dosage.In the clinic, it was found that the oral bioavailability of saquinavir in both formulations significantly increases when patients also receive the PI ritonavir. For patients, this has the major benefit that they can take less saquinavir, while maintaining sufficient saquinavir blood plasma levels to efficiently suppress the replication of HIV.The mechanism behind this welcome observation was not directly known, but later it was determined that ritonavir inhibits the cytochrome P450 3A4 isozyme. Normally, this enzyme metabolizes saquinavir to an inactive form, but with the ritonavir inhibiting this enzyme, the saquinavir blood plasma levels increased considerably. Additionally, ritonavir also inhibits multidrug transporters, although to a much lower extent.Unlike other protease inhibitors, the absorption of saquinavir seems to be improved by omeprazole. Mechanism of action Saquinavir is a protease inhibitor. Proteases are enzymes that cleave protein molecules into smaller fragments. HIV protease is vital for both viral replication within the cell and release of mature viral particles from an infected cell. Saquinavir binds to the active site of the viral protease and prevents cleavage of viral polyproteins, preventing maturation of the virus. Saquinavir inhibits both HIV-1 and HIV-2 proteases. History Saquinavir was developed by the pharmaceutical company Roche. Saquinavir was the sixth antiretroviral and the first protease inhibitor approved by the US Food and Drug Administration (FDA), leading ritonavir and indinavir by a few months. This new class of antiretrovirals played a critical role in the development of highly active antiretroviral therapy (HAART), which helped significantly lower the risk of death from AIDS-related causes, as seen by a reduction of the annual U.S. HIV-associated death rate, from over 50,000 to about 18,000 over a period of two years.Roche requested and received approval of Invirase via the FDAs "Accelerated Approval" program—a process designed to speed drugs to market for the treatment of serious diseases—a decision that was controversial, as AIDS activists disagreed over the benefits of thorough testing versus early access to new drugs. It was approved again on November 7, 1997, as Fortovase, a soft gel capsule reformulated for improved bioavailability. Roche announced in May 2005 that, given reduced demand, Fortovase would cease being marketed early in 2006, in favor of Invirase boosted with ritonavir, owing to the ability of the latter co-formulated drug to inhibit the enzyme that metabolizes the AIDS drugs. Society and culture Economics As of 2015, it is not available as a generic medication. Formulations Two formulations have been marketed: a hard-gel capsule formulation of the mesylate, with trade name Invirase, which requires combination with ritonavir to increase the saquinavir bioavailability; a soft-gel capsule formulation of saquinavir (microemulsion, orally-administered formulation), with trade name Fortovase, which was discontinued worldwide in 2006. References External links "Saquinavir". Drug Information Portal. U.S. National Library of Medicine.
Cilostazol
Cilostazol, sold under the brand name Pletal among others, is a medication used to help the symptoms of intermittent claudication in peripheral vascular disease. If no improvement is seen after 3 months, stopping the medication is reasonable. It may also be used to prevent stroke. It is taken by mouth.Common side effects include headache, diarrhea, dizziness, and cough. Serious side effects may include decreased survival in those with heart failure, low platelets, and low white blood cells. Cilostazol is a phosphodiesterase 3 inhibitor which works by inhibiting platelet aggregation and dilating arteries.Cilostazol was approved for medical use in the United States in 1999. It is available as a generic medication. In 2017, it was the 301st most commonly prescribed medication in the United States, with more than one million prescriptions. Medical uses Cilostazol is approved for the treatment of intermittent claudication in the United States and United Kingdom.Cilostazol is also used for secondary stroke prevention, though to date no regulatory body has approved it specifically for that indication. Heart failure Cilostazol is dangerous for people with severe heart failure. Cilostazol has been studied in people without heart failure, without evidence of harm, but much more data would be needed to determine no risk exists. Although cilostazol would not be approvable for a trivial condition the Cardio-Renal Advisory Committee and FDA concluded that fully informed patients and physicians should be able to choose to use it to treat intermittent claudication. Patient and physician labeling will describe the basis for concern and the incomplete information available. Adverse effects Possible side effects of cilostazol use include headache (the most common), diarrhea, severe heat intolerance, abnormal stools, increased heart rate, and palpitations. Interactions Cilostazol is metabolized by CYP3A4 and CYP2C19, two isoenzymes of the cytochrome P450 system. Drugs that inhibit CYP3A4, such as itraconazole, erythromycin, ketoconazole, and diltiazem, are known to interact with cilostazol. The proton pump inhibitor omeprazole, an inhibitor of CYP2C19, increases exposure to the active metabolite of cilostazol.A single report has been made of grapefruit juice possibly increasing the effects of cilostazol; some drug information sources list this as a possible interaction. The FDA-approved labeling of cilostazol notes that grapefruit juice (which is a CYP3A4 inhibitor) increases the drugs maximum concentration by around 50%. Mechanism Cilostazol is a selective inhibitor of phosphodiesterase type 3 (PDE3) with therapeutic focus on increasing cAMP. An increase in cAMP results in an increase in the active form of protein kinase A (PKA), which is directly related with an inhibition in platelet aggregation. PKA also prevents the activation of an enzyme (myosin light-chain kinase) that is important in the contraction of smooth muscle cells, thereby exerting its vasodilatory effect. References External links "Cilostazol". Drug Information Portal. U.S. National Library of Medicine.
Dutasteride/tamsulosin
Dutasteride/tamsulosin, sold under the brand name Jalyn among others, is a medication produced by GlaxoSmithKline for the treatment of adult male symptomatic benign prostatic hyperplasia (BPH). It is a combination of two previously existing medications: dutasteride, brand name Avodart, and tamsulosin, brand name Flomax. It contains 0.5 mg of dutasteride and 0.4 mg of tamsulosin hydrochloride.Jalyn was the result of the CombAT (Combination of Avodart and Tamsulosin) trial of 2008. It was approved by the U.S. Food and Drug Administration (FDA) on June 14, 2010. In June 2011, the FDA approved a label change warning of "Increased Risk of High-grade Prostate Cancer" from Jalyn. References External links "Dutasteride mixture with tamsulosin". Drug Information Portal. U.S. National Library of Medicine.
Celecoxib
Celecoxib, sold under the brand name Celebrex among others, is a COX-2 inhibitor and nonsteroidal anti-inflammatory drug (NSAID). It is used to treat the pain and inflammation in osteoarthritis, acute pain in adults, rheumatoid arthritis, ankylosing spondylitis, painful menstruation, and juvenile rheumatoid arthritis. It may also be used to decrease the risk of colorectal adenomas in people with familial adenomatous polyposis. It is taken by mouth. Benefits are typically seen within an hour.Common side effects include abdominal pain, nausea, and diarrhea. Serious side effects may include heart attacks, strokes, gastrointestinal perforation, gastrointestinal bleeding, kidney failure, and anaphylaxis. Use is not recommended in people at high risk for heart disease. The risks are similar to other NSAIDs, such as ibuprofen and naproxen. Use in the later part of pregnancy or during breastfeeding is not recommended.Celecoxib was patented in 1993 and came into medical use in 1999. It is available as a generic medication. In 2019, it was the 102nd most commonly prescribed medication in the United States, with more than 6 million prescriptions. Medical uses Celecoxib is indicated for the treatment of osteoarthritis, rheumatoid arthritis, acute pain, musculoskeletal pain, painful menstruation, ankylosing spondylitis, juvenile rheumatoid arthritis, and to reduce the number of colon and rectal polyps in people with familial adenomatous polyposis. It may be used in children with juvenile rheumatoid arthritis who are older than two years of age and weigh more than 10 kg (22 lb).For postoperative pain, it is more or less equal to ibuprofen. For pain relief, it is similar to paracetamol (acetaminophen), which is the first line treatment for osteoarthritis.Evidence of effects are not clear as a number of studies done by the manufacturer have not been released for independent analysis. Familial adenomatous polyposis It has been used to reduce colon and rectal polyps in people with familial adenomatous polyposis, but it is not known if it decreases rates of cancer, so it is not a good choice for this reason. Adverse effects Cardiovascular events: NSAIDs are associated with an increased risk of serious (and potentially fatal) adverse cardiovascular thrombotic events, including myocardial infarction and stroke. Risk may be increased with duration of use or pre-existing cardiovascular risk factors or disease. Individual cardiovascular risk profiles should be evaluated prior to prescribing. New-onset hypertension or exacerbation of hypertension may occur (NSAIDs may impair response to thiazide or loop diuretics), and may contribute to cardiovascular events; monitor blood pressure and use with caution in patients with hypertension. May cause sodium and fluid retention, use with caution in patients with edema or heart failure. Long-term cardiovascular risk in children has not been evaluated. Use the lowest effective dose for the shortest duration of time, consistent with individual patient goals, to reduce risk of cardiovascular events; alternative therapies should be considered for patients at high risk. The increased risk is about 37%. Gastrointestinal events: NSAIDs may increase risk of serious gastrointestinal (GI) ulceration, bleeding, and perforation (may be fatal). These events may occur at any time during therapy and without warning. Use caution with a history of GI disease (bleeding or ulcers), concurrent therapy with aspirin, anticoagulants and/or corticosteroids, smoking, use of alcohol, the elderly or debilitated patients. Use the lowest effective dose for the shortest duration of time, consistent with individual patient goals, to reduce risk of GI adverse events; alternate therapies should be considered for patients at high risk. When used concomitantly with ≤325 mg of aspirin, a substantial increase in the risk of gastrointestinal complications (e.g., ulcer) occurs; concomitant gastroprotective therapy (e.g., proton pump inhibitors) is recommended. The increased risk is about 81%. Hematologic effects: Anemia may occur; monitor hemoglobin or hematocrit in people on long-term treatment. Celecoxib does not usually affect prothrombin time, partial thromboplastin time or platelet counts; it does not inhibit platelet aggregation at approved doses.People with prior history of ulcer disease or GI bleeding require special precaution. Moderate to severe liver impairment or GI toxicity can occur with or without warning symptoms in people treated with NSAIDs. In October 2020, the U.S. Food and Drug Administration (FDA) required the drug label to be updated for all nonsteroidal anti-inflammatory medications to describe the risk of kidney problems in unborn babies that result in low amniotic fluid. They recommend avoiding NSAIDs in pregnant women at 20 weeks or later in pregnancy. Allergy Celecoxib contains a sulfonamide moiety and may cause allergic reactions in those allergic to other sulfonamide-containing drugs. This is in addition to the contraindication in people with severe allergies to other NSAIDs. However, it has a low (reportedly 4%) chance of inducing cutaneous reactions among persons who have a history of such reactions to aspirin or nonselective NSAIDs. NSAIDs may cause serious skin adverse events, including exfoliative dermatitis, Stevens-Johnson syndrome, and toxic epidermal necrolysis; events may occur without warning and in patients without prior known sulfa allergy. Use should be discontinued at first sign of rash (or any other hypersensitivity). Heart attack and stroke A 2013 meta-analysis of hundreds of clinical trials found that coxibs (the class of drugs that includes celecoxib) increase the risk of major cardiovascular problems by about 37% over placebo. In 2016, a randomized trial provided strong evidence that treatment with celecoxib is not more likely to result in poor cardiovascular outcomes than treatment with naproxen or ibuprofen. As a result, in 2018 an FDA advisory panel concluded that celecoxib poses no greater risk for causing heart attacks and strokes than the commonly-used NSAIDs ibuprofen or naproxen and recommended that the FDA consider changing its advice to physicians regarding celecoxibs safety.The COX-2 inhibitor rofecoxib (Vioxx) was removed from the market in 2004 due to its risk. Like all NSAIDs on the US market, celecoxib carries an FDA-mandated "black box warning" for cardiovascular and gastrointestinal risk. In February 2007, the American Heart Association warned that with respect to "patients with a prior history of or at high risk for cardiovascular disease... use of COX-2 inhibitors for pain relief should be limited to patients for whom there are no appropriate alternatives, and then, only in the lowest dose and for the shortest duration necessary."In 2005, a study published in the Annals of Internal Medicine found that cardiovascular effects of COX-2 inhibitors differ, depending on the drug. Other COX-2-selective inhibitors, such as rofecoxib, have significantly higher myocardial infarction rates than celecoxib. In April 2005, after an extensive review of data, the FDA concluded it was likely "that there is a class effect for increased CV risk for all NSAIDs". In a 2006 meta-analysis of randomized control studies, the cerebrovascular events associated with COX-2 inhibitors were examined, but no significant risks were found when compared to nonselective NSAIDs or placebos. Drug interactions Celecoxib is predominantly metabolized by cytochrome P450 2C9. Caution must be exercised with concomitant use of 2C9 inhibitors, such as fluconazole, which can greatly elevate celecoxib serum levels. If used concomitantly with lithium, celecoxib increases lithium plasma levels. If used concomitantly with warfarin, celecoxib may result in increased risk of bleeding complications. The risk of bleeding and gastric ulcers also increase further when SSRIs are used in combination with celecoxib. The drug may increase the risk of kidney failure with angiotensin-converting enzyme-inhibitors, such as lisinopril, and diuretics, such as hydrochlorothiazide. Pregnancy In the US FDAs pregnancy categories, the drug is category C prior to 30 weeks gestation, and category D starting at 30 weeks gestation. Mechanism of action Anti-inflammatory A highly selective reversible inhibitor of the COX-2 isoform of cyclooxygenase, celecoxib inhibits the transformation of arachidonic acid to prostaglandin precursors. Therefore, it has analgesic and anti-inflammatory properties. Nonselective NSAIDs (such as aspirin, naproxen, and ibuprofen) inhibit both COX-1 and COX-2. Inhibition of COX-1 (which celecoxib does not inhibit at therapeutic concentrations) inhibits the production of prostaglandins and the production of thromboxane A2, a platelet activator. COX-1 is traditionally defined as a constitutively expressed "housekeeping" enzyme and plays a role in the protection of the gastrointestinal mucosa, kidney hemodynamics, and platelet thrombogenesis. COX-2, on the contrary, is extensively expressed in cells involved in inflammation and is upregulated by bacterial lipopolysaccharides, cytokines, growth factors, and tumor promoters. Celecoxib is approximately 10-20 times more selective for COX-2 inhibition over COX-1. It binds with its polar sulfonamide side chain to a hydrophilic side pocket region close to the active COX-2 binding site. In theory, this selectivity allows celecoxib and other COX-2 inhibitors to reduce inflammation (and pain) while minimizing gastrointestinal adverse drug reactions (e.g. stomach ulcers) that are common with nonselective NSAIDs. Anti-cancer For its use in reducing colon polyps, celecoxib affects genes and pathways involved in inflammation and malignant transformation in tumors, but not normal tissues.Celecoxib binds to Cadherin-11 (which may explain the reduction in cancer progression). Structure-activity relationship The Searle research group found the two appropriately substituted aromatic rings must reside on adjacent positions about the central ring for adequate COX-2 inhibition. Various modifications can be made to the 1,5-diarylpyrazole moiety to deduce the structure-activity relationship of celecoxib. A para-sulfamoylphenyl at position 1 of the pyrazole was found to have a higher potency for COX-2 selective inhibition than a para-methoxyphenyl (see structures 1 and 2, below). In addition, a 4-(methylsulfonyl)phenyl or 4-sulfamoylphenyl is known to be necessary for COX-2 inhibition. For instance, replacing either of these entities with a –SO2NHCH3 substituent diminishes COX-2 inhibitory activity as noted with a very high inhibitory concentration-50 (see structures 3 – 5). At the 3-position of the pyrazole, a trifluoromethyl or difluoromethyl provides superior selectivity and potency compared to a fluoromethyl or methyl substitution (see structures 6 – 9).Celecoxib is compound 22; the 4-sulfamoylphenyl on the 1-pyrazol substituent is required for COX-2 inhibition and the 4-methyl on the 5-pyrazol system has low steric hindrance to maximize potency, while the 3-trifluoromethyl group provides superior selectivity and potency. To explain the selectivity of celecoxib, it is necessary to analyze the free energy of binding difference between the drug molecule and COX-1 compared to COX-2 enzymes. The structural modifications highlight the importance of binding to residue 523 in the side binding pocket of the cyclooxygenase enzyme, which is an isoleucine in COX-1 and a valine in COX-2. This mutation appears to contribute to COX-2 selectivity by creating steric hindrance between the sulfonamide oxygen and the methyl group of Ile523 that effectively destabilizes the celecoxib-COX-1 complex. History It was initially marketed by Pfizer for arthritis. Celecoxib and other COX-2 selective inhibitors, valdecoxib, parecoxib, and mavacoxib, were discovered by a team at the Searle division of Monsanto led by John Talley.Two lawsuits arose over discovery of celecoxib. Daniel L. Simmons of Brigham Young University (BYU) discovered the COX-2 enzyme in 1988, and in 1991, BYU entered into a collaboration with Monsanto to develop drugs to inhibit it. Monsantos pharmaceutical division was later purchased by Pfizer, and in 2006, BYU sued Pfizer for breach of contract, claiming Pfizer did not properly pay contractual royalties back to BYU. A settlement was reached in April 2012, in which Pfizer agreed to pay $450 million. Other important discoveries in COX-2 were made at University of Rochester, which patented the discoveries. When the patent issued, the university sued Searle (later Pfizer) in a case called, University of Rochester v. G.D. Searle & Co., 358 F.3d 916 (Fed. Cir. 2004). The court ruled in favor of Searle in 2004, holding in essence that the university had claimed a method requiring, yet provided no written description of, a compound that could inhibit COX-2 and therefore the patent was invalid.According to the National Academy of Sciences, Philip Needleman, who was vice president of Monsanto in 1989 and president of Searle in 1993 oversaw research into COX-2 that led to the development of the anti-inflammatory drug celecoxib (Celebrex). He became senior executive vice president and chief scientist of Pharmacia from 2000 to 2003. Celecoxib was discovered and developed by G. D. Searle & Company and was approved by the FDA on 31 December 1998. It was co-promoted by Monsanto Company (parent company of Searle) and Pfizer under the brand name Celebrex. Monsanto merged with Pharmacia, from which the Medical Research Division was acquired by Pfizer, giving Pfizer ownership of Celebrex. The drug was at the core of a major patent dispute that was resolved in Searles favor (later Pfizer) in 2004. In University of Rochester v. G.D. Searle & Co., 358 F.3d 916 (Fed. Cir. 2004), the University of Rochester claimed that United States Pat. No. 6,048,850 (which claimed a method of inhibiting COX-2 in humans using a compound, without actually disclosing what that compound might be) covered drugs such as celecoxib. The court ruled in favor of Searle, holding in essence that the university had claimed a method requiring, yet provided no written description of, a compound that could inhibit COX-2 and therefore the patent was invalid. After the withdrawal of rofecoxib from the market in September 2004, celecoxib enjoyed a robust increase in sales. However, the results of the APC trial in December of that year raised concerns that Celebrex might carry risks similar to those of rofecoxib, and Pfizer announced a moratorium on direct-to-consumer advertising of Celebrex soon afterwards. Sales reached $2 billion in 2006. Prior to its availability in generic form, it was one of Pfizers "best-selling drugs, amounting to more than $2.5 billion in sales [by 2012], and was prescribed to 2.4 million" people in 2011. By 2012, 33 million Americans had taken celecoxib.Pfizer resumed advertising Celebrex in magazines in 2006, and resumed television advertising in April 2007 with an unorthodox, 2+1⁄2-minute advertisement which extensively discussed the adverse effects of Celebrex in comparison with other anti-inflammatory drugs. The ad drew criticism from the consumer advocacy group Public Citizen, which called the ads comparisons misleading. Pfizer responded to Public Citizens concerns with assurances that they are truthfully advertising the risk and benefits of Celebrex as set forth by the FDA. Society and culture Fabricated efficacy studies Pfizer and its partner, Pharmacia presented findings from their study that Celebrex was "better in protecting the stomach from serious complications than other drugs." This became Celebrexs main selling point. However, following federal investigations it was revealed that Pfizer and Pharmacia "only presented the results from the first six months of a year long study rather than the whole thing." These partial results were then published in The Journal of the American Medical Association. In 2001, the US Food and Drug Administration (FDA) released the full results of the Pfizer and Pharmacia study which showed that they had withheld crucial data. By 2012, a federal judge unsealed "thousands of pages of internal documents and depositions" in a "long-running securities fraud case against Pfizer."On 11 March 2009, Scott S. Reuben, former chief of acute pain at Baystate Medical Center, Springfield, Massachusetts, revealed that the data for 21 studies he had authored for the efficacy of the drug (along with others such as Vioxx) had been fabricated. The analgesic effects of the drugs had been exaggerated. Reuben was also a former paid spokesperson for Pfizer. Although from 2002 to 2007 Pfizer underwrote much of Dr. Reubens research and "many of his trials found that Celebrex and Lyrica, Pfizer drugs, were effective against postoperative pain," Pfizer was not aware of the fraudulent data. None of the retracted studies were submitted to either the US Food and Drug Administration or the European Unions regulatory agencies prior to the drugs approval. Although Pfizer issued a public statement declaring, "It is very disappointing to learn about Dr. Scott Reubens alleged actions. When we decided to support Dr. Reubens research, he worked for a credible academic medical center and appeared to be a reputable investigator", the documents unsealed in 2012, revealed that by February 2000, Pharmacia employees had devised a strategy to present the findings. Availability Pfizer markets celecoxib under the brand name Celebrex, and it is available as oral capsules containing 50, 100, 200 or 400 mg of celecoxib.It is legally available in many jurisdictions as a generic under several brand names. In the US, celecoxib was covered by three patents, two of which expired on 30 May 2014, and one of which (US RE44048) was due to expire 2 December 2015. On 13 March 2014, that patent was found to be invalid for double patenting. Upon the patent expiry on 30 May 2014, the FDA approved the first versions of generic celecoxib. Research Psychiatry On the theory that inflammation plays a role in the pathogenesis of major mental disorders, celecoxib has been trialed for a number of psychiatric disorders, including major depression, bipolar disorder, and schizophrenia. Bipolar disorder A meta-analysis considering trials of celecoxib as an adjunctive treatment in bipolar disorder was inconclusive citing low evidence quality. Familial adenomatous polyposis It has been used to reduce colon and rectal polyps in people with familial adenomatous polyposis, but it is not known if it decreases rates of cancer, so it is not a good choice for this reason. Cancer prevention The use of celecoxib to reduce the risk of colorectal cancer has been investigated, but neither celecoxib nor any other drug is indicated for this use. Small-scale clinical trials in very high-risk people (belonging to FAP families) showed celecoxib can prevent polyp growth. Hence, large-scale randomized clinical trials were undertaken. Results show a 33 to 45% polyp recurrence reduction in people treated with celecoxib each day. However, serious cardiovascular events were significantly more frequent in the celecoxib-treated groups. Aspirin shows a similar (and possibly larger) protective effect, has demonstrated cardioprotective effects and is significantly cheaper, but no head-to-head clinical trials have compared the two drugs. Cancer treatment Different from cancer prevention, cancer treatment is focused on the therapy of tumors that have already formed and have established themselves inside the patient. Many studies are going on to determine whether celecoxib might be useful for this latter condition. However, during molecular studies in the laboratory, it became apparent that celecoxib could interact with other intracellular components besides its most famous target, COX-2. The discovery of these additional targets has generated much controversy, and the initial assumption that celecoxib reduces tumor growth primarily by the inhibition of COX-2 became contentious.Certainly, the inhibition of COX-2 is paramount for the anti-inflammatory and analgesic function of celecoxib. However, whether inhibition of COX-2 also plays a dominant role in this drugs anticancer effects is unclear. For example, a recent study with malignant tumor cells showed celecoxib could inhibit the growth of these cells in vitro, but COX-2 played no role in this outcome; even more strikingly, the anticancer effects of celecoxib were also obtained with the use of cancer cell types that do not even contain COX-2. Karen Seibert and colleagues have published research showing antiangiogenic and antitumor activity of celecoxib in animal models.Additional support for the idea that other targets besides COX-2 are important for celecoxibs anticancer effects has come from studies with chemically modified versions of celecoxib. Several dozen analogs of celecoxib were generated with small alterations in their chemical structures. Some of these analogs retained COX-2 inhibitory activity, whereas many others did not. However, when the ability of all these compounds to kill tumor cells in cell culture was investigated, the antitumor potency did not at all depend on whether or not the respective compound could inhibit COX-2, showing the inhibition of COX-2 was not required for the anticancer effects. One of these compounds, 2,5-dimethyl-celecoxib, which entirely lacks the ability to inhibit COX-2, actually displayed stronger anticancer activity than celecoxib. References Further reading Dean L (2016). "Celecoxib Therapy and CYP2C9 Genotype". In Pratt VM, McLeod HL, Rubinstein WS, et al. (eds.). Medical Genetics Summaries. National Center for Biotechnology Information (NCBI). PMID 28520369. Bookshelf ID: NBK379478. Zhang J, Ding EL, Song Y (October 2006). "Adverse effects of cyclooxygenase 2 inhibitors on renal and arrhythmia events: meta-analysis of randomized trials". JAMA. 296 (13): 1619–32. doi:10.1001/jama.296.13.jrv60015. PMID 16968832. External links "Celecoxib". Drug Information Portal. U.S. National Library of Medicine. "COX-2 Selective (includes Bextra, Celebrex, and Vioxx) and Non-Selective Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)". U.S. Food and Drug Administration (FDA). 15 July 2005. "FDA Approves Labeling Supplement for Celebrex (celecoxib)". U.S. Food and Drug Administration (FDA). 28 June 2018.
Talimogene laherparepvec
Talimogene laherparepvec, sold under the brand name Imlygic, is a biopharmaceutical medication used to treat melanoma that cannot be operated on; it is injected directly into a subset of lesions which generates a systemic immune response against the recipients cancer. The final four year analysis from the pivotal phase 3 study upon which TVEC was approved by the FDA showed a 31.5% response rate with a 16.9% complete response (CR) rate. There was also a substantial and statistically significant survival benefit in patients with earlier metastatic disease (stages IIIb-IVM1a) and in patients who hadnt received prior systemic treatment for melanoma. The earlier stage group had a reduction in the risk of death of approximately 50% with one in four patients appearing to have met, or be close to be reaching, the medical definition of cure. Real world use of talimogene laherparepvec have shown response rates of up to 88.5% with CR rates of up to 61.5%.Around half of people treated with talimogene laherparepvec in clinical trials experienced fatigue and chills; around 40% had fever, around 35% had nausea, and around 30% had flu-like symptoms as well as pain at the injection site. The reactions were mild to moderate in severity; 2% of people had severe reactions and these were generally cellulitis.Talimogene laherparepvec is a genetically engineered herpes virus (an oncolytic herpes virus). Two genes were removed – one that shuts down an individual cells defenses, and another that helps the virus evade the immune system – and a gene for human GM-CSF was added. The drug works by replicating in cancer cells, causing them to burst; it was also designed to stimulate an immune response against the patients cancer, which has been demonstrated by multiple pieces of data, including regression of tumors which have not been injected with talimogene laherparepvec.The drug was created and initially developed by BioVex, Inc. and was continued by Amgen, which acquired BioVex in 2011. It was one of the first oncolytic immunotherapy approved globally; it was approved in the US in October 2015 and approved in Europe in December 2015. Medical uses Talimogene laherparepvec is delivered by injecting it directly into tumors, thereby creating a systemic anti-tumor immune response.In the US, talimogene laherparepvec is FDA approved to treat Stage IIIb-IVM1c melanoma patients for whom surgical intervention is not appropriate and with tumors which can be directly injected; the EMA approved population in Europe is for Stage IIIb-IVM1a.Talimogene laherparepvec has been shown to extend survival in patients with Stage IIIb-IVM1a melanoma and patients who have not received prior systemic therapy for melanoma. Adverse effects Around half of people treated with talimogene laherparepvec in clinical trials experienced fatigue and chills; around 40% had fever, around 35% had nausea, and around 30% had flu-like symptoms as well as pain at the injection site. The reactions were mild to moderate in severity; 2% of people had severe reactions and these were generally cellulitis.More than 10% of people had edema, headache, cough, vomiting, diarrhea, constipation, muscle pain, or joint pain. Between 1% and 10% developed cold sores, pain or infection in the lesion, anemia, immune mediated events (like vasculitis, pneumonia, worsening psoriasis, glomerulonephritis and vitiligo ), dehydration, confusion, anxiety, depression, dizziness, insomnia, ear pain, fast heart beating, deep vein thrombosis, high blood pressure, flushing, shortness of breath when exercising, sore throat, symptoms of the common cold, stomach pain, back pain, groin pain, weight loss, or oozing from the injection site. Pharmacology Talimogene laherparepvec is taken up by normal cells and cancer cells like the wild type herpes simplex virus, it is cleared in the same way. Mechanism Talimogene laherparepvec directly destroys the cancer cells it infects, inducing a systemic immune response against the patients cancer.The virus invades both cancerous and healthy cells, but it cannot productively replicate in healthy tissue because it lacks Infected cell protein 34.5 (ICP34.5). When cells are infected with a virus they shut down and die, but ICP34.5 blocks this stress response, allowing the virus to hijack the cells translation machinery to replicate itself. A herpesvirus lacking the gene coding for ICP34.5 cannot replicate in normal tissue. However, in many cancer cells the stress response is already disrupted, so a virus lacking ICP34.5 can still replicate in tumors. After the virus has replicated many times, the cell swells and finally bursts, killing the cell and releasing the copies of the virus, which can then infect nearby cells.While talimogene laherparepvec is using the cells translation machinery to replicate, it also uses it to make the cell create GM-CSF. GM-CSF is secreted or released when the cancer cell bursts, attracting dendritic cells to the site, which pick up the tumor antigens, process them, and then present them on their surface to cytotoxic (killer) T cells which in turn sets off an immune response. Composition Talimogene laherparepvec is a biopharmaceutical drug; it is an oncolytic herpes virus that was created by genetically engineering a strain of herpes simplex virus 1 (HSV-1) taken from a person infected with the virus, rather than a laboratory strain. Both copies of the viral gene coding for ICP34.5 were deleted and replaced with the gene coding for human GM-CSF, and the gene coding for ICP47 was removed. In wild herpes virus, ICP47 suppresses the immune response to the virus; it was removed because the drug was designed with the intention of activating the immune system. History The first oncolytic virus to be approved by a regulatory agency was a genetically modified adenovirus named H101 by Shanghai Sunway Biotech. It gained regulatory approval in 2005 from Chinas State Food and Drug Administration (SFDA) for the treatment of head and neck cancer. Talimogene laherparepvec is the worlds first approved oncolytic immunotherapy, i.e. it was also designed to provide systemic anti-tumor effects through the induction of an anti-tumor immune response. Talimogene laherparepvec was created and initially developed by BioVex, Inc. under the brand OncoVEXGM-CSF. Development was continued by Amgen, which acquired BioVex in 2011. BioVex was founded in 1999, based on research by Robert Coffin at University College London, and moved its headquarters to Woburn, Massachusetts in 2005, leaving about half its employees in the UK.The phase II clinical trial in melanoma was published in 2009 and the phase III trial was published in 2013.Talimogene laherparepvec was approved by the U.S. Food and Drug Administration to treat melanoma in October 2015. It was the first approval of an oncolytic virus and the first approval of a gene therapy in the West. It was approved by the European Medicines Agency in December of that year. Society and culture Economics Amgen estimated that talimogene laherparepvec would be priced at US$65,000 per patient at the time it was approved. International Press The Conversation (website) which has multilingual articles, published in French and Spanish in October 2022 the following article by Arthur Battistoni and Françoise Debierre-Grockiego both of the University of Tours Immunotherapy a parasite of dogs that helps fight incurable skin cancers Research As of 2016, talimogene laherparepvec has been studied in early stage clinical trials in pancreatic cancer, soft-tissue sarcoma, and head and neck squamous-cell carcinoma; it had also been tested in combination with checkpoint inhibitors ipilimumab and pembrolizumab. See also Virotherapy Oncolytic adenovirus Notes References External links "Talimogene laherparepvec". Drug Information Portal. U.S. National Library of Medicine.
Lactic acid/citric acid/potassium bitartrate
Lactic acid/citric acid/potassium bitartrate, sold under the brand name Phexxi, is a non-hormonal combination medication used as a method of birth control. It contains lactic acid, citric acid, and potassium bitartrate. It is a gel inserted into the vagina.The most common adverse reactions include vulvovaginal burning sensation, vulvovaginal pruritus, vulvovaginal mycotic infection, urinary tract infection, vulvovaginal discomfort, bacterial vaginosis, vaginal discharge, genital discomfort, dysuria, and vulvovaginal pain. Medical uses The combination is indicated for the prevention of pregnancy in females of reproductive potential for use as an on-demand method of contraception. History The combination was approved for medical use in the United States in May 2020. References External links "Lactic acid". Drug Information Portal. U.S. National Library of Medicine. "Citric acid". Drug Information Portal. U.S. National Library of Medicine. "Potassium bitartrate". Drug Information Portal. U.S. National Library of Medicine.
Olopatadine/mometasone
Olopatadine/mometasone, sold under the brand name Ryaltris, is a fixed-dose combination medication for the treatment of allergic rhinitis and rhinoconjunctivitis in adults and adolescents twelve years of age and older. It contains olopatadine hydrochloride and mometasone furoate monohydrate. It is sprayed into the nose.Common side effects include an unpleasant taste (dysgeusia).It was approved for medical use in Australia in December 2019, and in the United States in January 2022. References External links "Olopatadine". Drug Information Portal. U.S. National Library of Medicine. "Mometasone furoate". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT02631551 for "Efficacy and Safety of Fixed Dose Combination GSP 301 Nasal Spray (NS) in the Treatment of Seasonal Allergic Rhinitis (SAR) (GSP 301-301)" at ClinicalTrials.gov Clinical trial number NCT02870205 for "Efficacy and Safety of GSP 301 Nasal Spray in the Treatment of Seasonal Allergic Rhinitis (SAR) (GSP 301-304)" at ClinicalTrials.gov
Fosfomycin
Fosfomycin, sold under the brand name Monurol among others, is an antibiotic primarily used to treat lower UTI. It is not indicated for kidney infections. Occasionally it is used for prostate infections. It is generally taken by mouth.Common side effects include diarrhea, nausea, headache, and vaginal yeast infections. Severe side effects may include anaphylaxis and Clostridium difficile-associated diarrhea. While use during pregnancy has not been found to be harmful, such use is not recommended. A single dose when breastfeeding appears safe. Fosfomycin works by interfering with the production of the bacterial cell wall.Fosfomycin was discovered in 1969 and approved for medical use in the United States in 1996. It is on the World Health Organizations List of Essential Medicines. The World Health Organization classifies fosfomycin as critically important for human medicine. It is available as a generic medication. It was originally produced by certain types of Streptomyces, although it is now made chemically. Medical uses Fosfomycin is used to treat bladder infections, where it is usually given as a single dose by mouth.Oral fosfomycin is not recommended for children under 12 years old.Additional uses have been proposed. The global problem of advancing antimicrobial resistance has led to a renewed interest in its use more recently.Fosfomycin can be used as an efficacious treatment for both UTIs and complicated UTIs including acute pyelonephritis. The standard regimen for complicated UTIs is an oral 3 g dose administered once every 48 or 72 hours for a total of 3 doses or a 6 g dose every 8 hours for 7–14 days when fosfomycin is given in IV form. Intravenous fosfomycin is being increasing used for treating infections caused by multidrug-resistant bacteria, mostly as partner drug in order to avoid the occurrence of resistances and to take advantage of its synergistic activity with several other antimicrobials. Daily adult dose usually ranges from 12 to 24 grams. Bacterial sensitivity The fosfomycin molecule has an epoxide or oxirane ring, which is highly strained and thus very reactive. Fosfomycin has broad antibacterial activity against both Gram-positive and Gram-negative pathogens, with useful activity against E. faecalis, E. coli, and various Gram-negatives such as Citrobacter and Proteus. Given a greater activity in a low-pH milieu, and predominant excretion in active form into the urine, fosfomycin has found use for the prophylaxis and treatment of UTIs caused by these uropathogens. Of note, activity against S. saprophyticus, Klebsiella, and Enterobacter is variable and should be confirmed by minimum inhibitory concentration testing. Activity against extended-spectrum β-lactamase-producing pathogens, notably ESBL-producing E. coli, is good to excellent, because the drug is not affected by cross-resistance issues. Existing clinical data support use in uncomplicated UTIs, caused by susceptible organisms. However, susceptibility break-points of 64 mg/L should not be applied for systemic infections. Resistance Development of bacterial resistance under therapy is a frequent occurrence and makes fosfomycin unsuitable for sustained therapy of severe infections. Mutations that inactivate the nonessential glycerophosphate transporter render bacteria resistant to fosfomycin.Prescribing fosfomycin together with at least another active drug reduces the risk of developing bacterial resistance. Fosfomycin acts synergistically with many other antibiotics, including aminoglycosides, carbapenems, cephalosporins, daptomycin and oritavancin. Enzymes conferring resistance to fosfomycin have also been identified and are encoded both chromosomally and on plasmids.Three related fosfomycin resistance enzymes (named FosA, FosB, and FosX) are members of the glyoxalase superfamily. These enzymes function by nucleophilic attack on carbon 1 of fosfomycin, which opens the epoxide ring and renders the drug ineffective. The enzymes differ by the identity of the nucleophile used in the reaction: glutathione for FosA, bacillithiol for FosB, and water for FosX.In general, FosA and FosX enzymes are produced by Gram-negative bacteria, whereas FosB is produced by Gram-positive bacteria.FosC uses ATP and adds a phosphate group to fosfomycin, thus altering its properties and making the drug ineffective. Side effects The drug is well tolerated and has a low incidence of harmful side effects. Mechanism of action Despite its name (ending in -omycin) Fosfomycin is not a macrolide, but a member of a novel class of phosphonic antibiotics. Fosfomycin is bactericidal and inhibits bacterial cell wall biogenesis by inactivating the enzyme UDP-N-acetylglucosamine-3-enolpyruvyltransferase, also known as MurA. This enzyme catalyzes the committed step in peptidoglycan biosynthesis, namely the ligation of phosphoenolpyruvate (PEP) to the 3-hydroxyl group of UDP-N-acetylglucosamine. This pyruvate moiety provides the linker that bridges the glycan and peptide portion of peptidoglycan. Fosfomycin is a PEP analog that inhibits MurA by alkylating an active site cysteine residue (Cys 115 in the Escherichia coli enzyme).Fosfomycin enters the bacterial cell through the glycerophosphate transporter. History Fosfomycin (originally known as phosphonomycin) was discovered in a joint effort of Merck and Co. and Spains Compañía Española de Penicilina y Antibióticos (CEPA). It was first isolated by screening broth cultures of Streptomyces fradiae isolated from soil samples for the ability to cause formation of spheroplasts by growing bacteria. The discovery was described in a series of papers published in 1969. CEPA began producing fosfomycin on an industrial scale in 1971 at its Aranjuez facility. Manufacture The complete fosfomycin biosynthetic gene cluster from Streptomyces fradiae has been cloned and sequenced and the heterologous production of fosfomycin in S. lividans has been achieved by Ryan Woodyer of the Huimin Zhao and Wilfred van der Donk research groups.Large scale production of fosfomycin is achieved by making an epoxide of cis-propenylphosphonic acid to yield racemic mixture fosfomycin. References External links "Fosfomycin". Drug Information Portal. U.S. National Library of Medicine.
Fenoldopam
Fenoldopam mesylate (Corlopam) is a drug and synthetic benzazepine derivative which acts as a selective D1 receptor partial agonist. Fenoldopam is used as an antihypertensive agent. It was approved by the Food and Drug Administration (FDA) in September 1997. Indications Fenoldopam is used as an antihypertensive agent postoperatively, and also intravenously (IV) to treat a hypertensive crisis. Since fenoldopam is an intravenous agent with minimal adrenergic effects that improves renal perfusion, in theory it could be beneficial in hypertensive patients with concomitant chronic kidney disease. It can cause reflex tachycardia, but it is dependent on the infusion of the drug. Pharmacology Fenoldopam causes arterial/arteriolar vasodilation leading to a decrease in blood pressure by activating peripheral D1 receptors. It decreases afterload and also promotes sodium excretion via specific dopamine receptors along the nephron. The renal effect of fenoldopam and dopamine may involve physiological antagonism of the renin-angiotensin system in the kidney. In contrast to dopamine, fenoldopam is a selective D1 receptor agonist with no effect on beta adrenoceptors, although there is evidence that it may have some alpha-1 and alpha-2 adrenoceptor antagonist activity. D1 receptor stimulation activates adenylyl cyclase and raises intracellular cyclic AMP, resulting in vasodilation of most arterial beds, including renal, mesenteric, and coronary arteries. to cause a reduction in systemic vascular resistance. Fenoldopam has a rapid onset of action (4 minutes) and short duration of action (< 10 minutes) and a linear dose–response relationship at usual clinical doses. Side effects Adverse effects include headache, flushing, nausea, hypotension, reflex tachycardia, and increased intraocular pressure. Contraindications, warnings and precautions Fenoldopam mesylate contains sodium metabisulfite, a sulfite that may rarely cause allergic-type reactions including anaphylactic symptoms and asthma in susceptible people. Fenoldopam mesylate administration should be undertaken with caution to patients with glaucoma or raised intraocular pressure as fenoldopam raises intraocular pressure. Concomitant use of fenoldopam with a beta-blocker should be avoided if possible, as unexpected hypotension can result from beta-blocker inhibition of sympathetic-mediated reflex tachycardia in response to fenoldopam. == References ==
Arava
Arava, Aravah or Arabah may refer to: Places Arava, Estonia, a village in Anija Commune, Harju County, Estonia Arava(h) (Hebrew) or Arabah (Arabic), a section of the Great Rift Valley between the Dead Sea and the Gulf of Aqaba in Israel and Jordan Other uses Arava Institute for Environmental Studies, an Israeli study programme Arava Power Company, an Israeli solar energy company Arava Shahaf (born 1990), Israeli footballer Arava spider, a huntsman spider found in the southern Arava Valley of Israel and Jordan Arava, a brand name for the antirheumatic drug leflunomide IAI Arava, a plane manufactured by Israel Aircraft Industries Aravah (Sukkot), a willow branch, one of the Four Species used on the Jewish holiday of Sukkot See also Arraba (disambiguation) Araba (disambiguation)
Dextromethorphan
Dextromethorphan is a medication most often used as a cough suppressant in over-the-counter cold and cough medicines. It is sold in syrup, tablet, spray, and lozenge forms. It is in the morphinan class of medications with sedative, dissociative, and stimulant properties (at lower doses). Dextromethorphan does not have a significant affinity for the mu-opioid receptor activity typical of morphinan compounds and exerts its therapeutic effects through several other receptors. In its pure form, dextromethorphan occurs as a white powder.Dextromethorphan is also used recreationally. When exceeding approved dosages, dextromethorphan acts as a dissociative hallucinogen. It has multiple mechanisms of action, including actions as a nonselective serotonin reuptake inhibitor and a sigma-1 receptor agonist. Dextromethorphan and its major metabolite, dextrorphan, also block the NMDA receptor at high doses, which produces effects similar to other dissociative anesthetics such as ketamine, nitrous oxide, and phencyclidine. It was patented in 1949 and approved for medical use in 1953. Medical uses Cough suppression The primary use of dextromethorphan is as a cough suppressant, for the temporary relief of cough caused by minor throat and bronchial irritation (such as commonly accompanies the flu and common cold), as well as those resulting from inhaled particle irritants. Pseudobulbar affect In 2010, the FDA approved the combination drug dextromethorphan/quinidine for the treatment of pseudobulbar affect (uncontrollable laughing/crying). Dextromethorphan is the actual therapeutic agent in the combination; quinidine merely serves to inhibit the enzymatic degradation of dextromethorphan and thereby increase its circulating concentrations via inhibition of CYP2D6. Treatment-resistant depression The combination medicine dextromethorphan/bupropion is approved for treatment-resistant major depressive disorder due to its action on the NMDA receptor. Available forms Dextromethorphan is available alone in the form of cough syrup and pills as well as in combination with other agents. As a pharmaceutical drug, it is available as dextromethorphan/quinidine (Nuedexta) for the treatment of pseudobulbar affect and as dextromethorphan/bupropion (Auvelity) for treatment-resistant major depressive disorder. Contraindications Because dextromethorphan can trigger a histamine release (allergic reaction), atopic children, who are especially susceptible to allergic reactions, should be administered dextromethorphan only if absolutely necessary, and only under the strict supervision of a healthcare professional. Adverse effects Side effects of dextromethorphan at normal therapeutic doses can include: A rare side effect is respiratory depression. Neurotoxicity Dextromethorphan was once thought to cause Olneys lesions when administered intravenously; however, this was later proven inconclusive, due to lack of research on humans. Tests were performed on rats, giving them 50 mg or more every day for as long as a month. Neurotoxic changes, including vacuolation, have been observed in posterior cingulate and retrosplenial cortices of rats administered other NMDA receptor antagonists such as PCP, but not with dextromethorphan. Dependence and withdrawal In many documented cases, dextromethorphan has produced psychological dependence in people who used it recreationally. It is considered less addictive than other common cough suppressants, such as the weak opiate codeine. Since dextromethorphan also acts as a serotonin reuptake inhibitor, users report that regular recreational use over a long period of time can cause withdrawal symptoms similar to those of antidepressant discontinuation syndrome. Additionally, disturbances have been reported in sleep, senses, movement, mood, and thinking. Overdose Adverse effects of dextromethorphan in overdose at doses 3 to 10 times the recommended therapeutic dose: At doses 11 to 75 times the recommended therapeutic dose: Episodic acute psychosis can occur when high doses of dextromethorphan are taken for recreational use, and an abundance of psychiatric symptoms can result, including dissociation and other PCP-like symptoms. Interactions Serotonin syndrome may result from the combined use of dextromethorphan and serotonergic antidepressants such as selective serotonin reuptake inhibitor (SSRIs) or monoamine oxidase inhibitor (MAOIs). Further research is needed to determine whether doses of dextromethorphan beyond those normally used therapeutically are needed to produce this effect. In any case, dextromethorphan should not be taken with MAOIs due to the possibility of this complication. Serotonin syndrome is a potentially life-threatening condition that can occur rapidly, due to a buildup of an excessive amount of serotonin in the body. Patients who are taking dextromethorphan should exercise caution when drinking grapefruit juice or eating grapefruit, as compounds in grapefruit affect a number of drugs, including dextromethorphan, through the inhibition of the cytochrome P450 system in the liver, and can lead to excessive accumulation of the drug which both increases and prolongs effects. Grapefruit and grapefruit juices (especially white grapefruit juice, but also including other citrus fruits such as bergamot and lime, as well as a number of noncitrus fruits) generally are recommended to be avoided while using dextromethorphan and numerous other medications. Pharmacology Pharmacodynamics Dextromethorphan has been found to possess the following actions (<1 μM) using rat tissues: Uncompetitive antagonist of the NMDA receptor via the MK-801/PCP site SERT and NET blocker (cf. serotonin–norepinephrine reuptake inhibitor) Sigma σ1 receptor agonist Negative allosteric modulator of nicotinic acetylcholine receptors Ligand of the serotonin 5-HT1B/1D, histamine H1, α2-adrenergic, and muscarinic acetylcholine receptorsDextromethorphan is a prodrug of dextrorphan, which is the actual mediator of most of its dissociative effects through acting as a more potent NMDA receptor antagonist than dextromethorphan itself. What role, if any, (+)-3-methoxymorphinan, dextromethorphans other major metabolite, plays in its effects is not entirely clear. Pharmacokinetics Following oral administration, dextromethorphan is rapidly absorbed from the gastrointestinal tract, where it enters the bloodstream and crosses the blood–brain barrier.At therapeutic doses, dextromethorphan acts centrally (meaning that it acts on the brain) as opposed to locally (on the respiratory tract). It elevates the threshold for coughing, without inhibiting ciliary activity. Dextromethorphan is rapidly absorbed from the gastrointestinal tract and converted into the active metabolite dextrorphan in the liver by the cytochrome P450 enzyme CYP2D6. The average dose necessary for effective antitussive therapy is between 10 and 45 mg, depending on the individual. The International Society for the Study of Cough recommends "an adequate first dose of medication is 60 mg in the adult and repeat dosing should be infrequent rather than qds recommended."Dextromethorphan has an elimination half-life of approximately 4 hours in individuals with an extensive metabolizer phenotype; this is increased to approximately 13 hours when dextromethorphan is given in combination with quinidine. The duration of action after oral administration is about three to eight hours for dextromethorphan hydrobromide, and 10 to 12 hours for dextromethorphan polistirex. Around one in 10 of the Caucasian population has little or no CYP2D6 enzyme activity, leading to long-lived high drug levels. Metabolism The first pass through the hepatic portal vein results in some of the drug being metabolized by O-demethylation into an active metabolite of dextromethorphan called dextrorphan, the 3-hydroxy derivative of dextromethorphan. The therapeutic activity of dextromethorphan is believed to be caused by both the drug and this metabolite. Dextromethorphan also undergoes N-demethylation (to 3-methoxymorphinan or MEM), and partial conjugation with glucuronic acid and sulfate ions. Hours after dextromethorphan therapy, (in humans) the metabolites (+)-3-hydroxy-N-methylmorphinan, (+)-3-morphinan, and traces of the unchanged drug are detectable in the urine.A major metabolic catalyst involved is the cytochrome P450 enzyme known as 2D6, or CYP2D6. A significant portion of the population has a functional deficiency in this enzyme and are known as poor CYP2D6 metabolizers. O-demethylation of dextromethorphan to dextrorphan contributes to at least 80% of the dextrorphan formed during dextromethorphan metabolism. As CYP2D6 is a major metabolic pathway in the inactivation of dextromethorphan, the duration of action and effects of dextromethorphan can be increased by as much as three times in such poor metabolizers. In one study on 252 Americans, 84.3% were found to be "fast" (extensive) metabolizers, 6.8% to be "intermediate" metabolizers, and 8.8% were "slow" metabolizers of dextromethorphan. A number of alleles for CYP2D6 are known, including several completely inactive variants. The distribution of alleles is uneven amongst ethnic groups. A large number of medications are potent inhibitors of CYP2D6. Some types of medications known to inhibit CYP2D6 include certain SSRIs and tricyclic antidepressants, some antipsychotics, and the commonly available antihistamine diphenhydramine. Therefore, the potential of interactions exists between dextromethorphan and medications that inhibit this enzyme, particularly in slow metabolizers. Dextromethorphan is also metabolized by CYP3A4. N-demethylation is primarily accomplished by CYP3A4, contributing to at least 90% of the MEM formed as a primary metabolite of dextromethorphan.A number of other CYP enzymes are implicated as minor pathways of dextromethorphan metabolism. CYP2D6 is more effective than CYP3A4 at N-demethylation of dextromethorphan, but since the average individual has a much lower CYP2D6 content in the liver compared to CYP3A4, most N-demethylation of dextromethorphan is catalyzed by CYP3A4. Chemistry Dextromethorphan is the dextrorotatory enantiomer of levomethorphan, which is the methyl ether of levorphanol, both opioid analgesics. It is named according to IUPAC rules as (+)-3-methoxy-17-methyl-9α,13α,14α-morphinan. As its pure form, dextromethorphan occurs as an odorless, opalescent white powder. It is freely soluble in chloroform and insoluble in water; the hydrobromide salt is water-soluble up to 1.5 g/100 mL at 25 °C. Dextromethorphan is commonly available as the monohydrated hydrobromide salt, however some newer extended-release formulations contain dextromethorphan bound to an ion-exchange resin based on polystyrene sulfonic acid. Dextromethorphans specific rotation in water is +27.6° (20 °C, Sodium D-line). Synthesis Several routes exist for the synthesis of Dextromethorphan. Even though many of the syntheses have been known since the middle of the 20th century, researchers are still working today to further develop the synthesis of Dextromethorphan and, for example, to make it more environmentally friendly. This includes the synthesis by means of ionic liquids. Racemate separation Since only one of the stereoisomers has the desired effect, the separation of a racemic mixture of hydroxy N- methyl morphinan using tartaric acid and subsequent methylation of the hydroxyl group is a suitable method. By using (D)-tartrate, the (+)-isomer remains as the product. This synthetic pathway was patented by Roche in 1950. Traditional synthesis The traditional synthetic route uses Raney nickel and has been further improved over time, for example by the use of ibuprofen and AlCl3. Overall, it is a cost-effective method with moderate reaction conditions that is easy to handle and suitable for industrial production. Grewes cyclization Grewes cyclization is easier to handle in terms of the chemicals used, produces higher yields and higher purity of the product. Improved Grewes cyclization Formylation prior to cyclization avoids ether cleavage as a side reaction and yields higher than without N-substitution or N-methylation. In this example, the purification was done by formation of a brucine salt. This process has also been patented by Roche. History The racemic parent compound racemorphan was first described in a Swiss and US patent application from Hoffmann-La Roche in 1946 and 1947, respectively; a patent was granted in 1950. A resolution of the two isomers of racemorphan with tartaric acid was published in 1952, and dextromethorphan was successfully tested in 1954 as part of US Navy and CIA-funded research on nonaddictive substitutes for codeine. Dextromethorphan was approved by the FDA in 1958 as an over-the-counter antitussive. As had been initially hoped, dextromethorphan was a solution for some of the problems associated with the use of codeine phosphate as a cough suppressant, such as sedation and opiate dependence, but like the dissociative anesthetics phencyclidine and ketamine, dextromethorphan later became associated with nonmedical use.During the 1960s and 1970s, dextromethorphan became available in an over-the-counter tablet form by the brand name Romilar. In 1973, Romilar was taken off the shelves after a burst in sales because of frequent misuse. A few years later, products with an unpleasant taste were introduced (such as Robitussin, Vicks-44, and Dextrotussion), but later the same manufacturers began producing products with a better taste. The advent of widespread internet access in the 1990s allowed users to rapidly disseminate information about dextromethorphan, and online discussion groups formed around use and acquisition of the drug. As early as 1996, dextromethorphan hydrobromide powder could be purchased in bulk from online retailers, allowing users to avoid consuming dextromethorphan in syrup preparations.FDA panels considered moving dextromethorphan to prescription status due to its potential for abuse, but voted against the recommendation in September 2010, citing lack of evidence that making it prescription-only would curb abuse. Some states have restricted the sale of dextromethorphan to adults or put other restrictions on its purchase in place, similar to those for pseudoephedrine. As of January 1, 2012, dextromethorphan is prohibited for sale to minors in the State of California and in the State of Oregon as of January 1, 2018, except with a doctors prescription. Several other states have also begun regulating sales of dextromethorphan to minors. In Indonesia, the National Agency of Drug and Food Control (BPOM-RI) prohibited single-component dextromethorphan drug sales with or without prescription. Indonesia is the only country in the world that makes single-component dextromethorphan illegal even by prescription and violators may be prosecuted by law. National Anti-Narcotics Agency (BNN RI) has even threatened to revoke pharmacies and drug stores licenses if they still stock dextromethorphan, and will notify the police for criminal prosecution. As a result of this regulation, 130 medications have been withdrawn from the market, but those containing multicomponent dextromethorphan can still be sold over the counter. Society and culture Marketing It may be used in generic labels and store brands, Benylin DM, Mucinex DM, Camydex-20 tablets, Robitussin, NyQuil, Dimetapp, Vicks, Coricidin, Delsym, TheraFlu, Charcoal D, Cinfatós and others. It has been used in counterfeit medications. Recreational use Over-the-counter preparations containing dextromethorphan have been used in manners inconsistent with their labeling, often as a recreational drug. At doses much higher than medically recommended, dextromethorphan and its major metabolite, dextrorphan, acts as an NMDA receptor antagonist, which produces dissociative hallucinogenic states somewhat similar to ketamine and phencyclidine.It may produce distortions of the visual field – feelings of dissociation, distorted bodily perception, excitement, and a loss of sense of time. Some users report stimulant-like euphoria, particularly in response to music. Dextromethorphan usually provides its recreational effects in a non-linear fashion, so that they are experienced in significantly varied stages. These stages are commonly referred to as "plateaus". These plateaus are numbered from one to four, with the first having the mildest effects to fourth being the most intense. Each plateau is said to come with different related effects and experiences.The first plateau is said to induce music euphoria and mild stimulation, likened to that of MDMA. The second plateau is likened to the state of being drunk and high at the same time, featuring euphoria, sedation and minor hallucinations. The third plateau induces a significant dissociative state which can often cause anxiety in users. Reaching the fourth plateau is said to cause extreme sedation and a significant hallucinatory state as well as complete dissociation from reality. Teens tend to have a higher likelihood to use dextromethorphan-related drugs as they are easier to access, and an easier way to cope with psychiatric disorders. Research The combination drug dextromethorphan/quinidine (AVP-923), traditionally used to treat pseudobulbar affect, is under investigation for the treatment of a variety of other neurological and neuropsychiatric conditions including agitation associated with Alzheimers disease, among others. In 2013, a randomized clinical trial found that dextromethorphan may reduce the overall discomfort and duration of withdrawal symptoms associated with opioid use disorder. When combined with clonidine, dextromethorphan reduced the overall time needed for withdrawal symptoms to peak by 24 hours while reducing severity of symptoms compared to clonidine alone. References External links U.S. National Library of Medicine: Drug Information Portal – Dextromethorphan
Epinephrine (medication)
Epinephrine, also known as adrenaline, is a medication and hormone. As a medication, it is used to treat several conditions, including anaphylaxis, cardiac arrest, asthma, and superficial bleeding. Inhaled epinephrine may be used to improve the symptoms of croup. It may also be used for asthma when other treatments are not effective. It is given intravenously, by injection into a muscle, by inhalation, or by injection just under the skin.Common side effects include shakiness, anxiety, and sweating. A fast heart rate and high blood pressure may occur. Occasionally, it may result in an abnormal heart rhythm. While the safety of its use during pregnancy and breastfeeding is unclear, the benefits to the mother must be taken into account.Epinephrine is normally produced by both the adrenal glands and a small number of neurons in the brain, where it acts as a neurotransmitter. It plays an essential role in the fight-or-flight response by increasing blood flow to muscles, heart output, pupil dilation, and blood sugar. Epinephrine does this through its effects on alpha and beta receptors. It is found in many animals and some single-celled organisms, but the medication is produced synthetically and is not harvested from animals.Jōkichi Takamine first isolated epinephrine in 1901, and it came into medical use in 1905. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2017, it was the 263rd most commonly prescribed medication in the United States, with more than one million prescriptions. Medical uses Epinephrine is used to treat a number of conditions, including cardiac arrest, anaphylaxis, and superficial bleeding. It has been used historically for bronchospasm and low blood sugar, but newer treatments for these that are selective for β2 adrenoceptors, such as salbutamol, are currently preferred. Heart problems While epinephrine is often used to treat cardiac arrest, it has not been shown to improve long-term survival or mental function after recovery. It does, however, improve return of spontaneous circulation. When used intravenously, epinephrine is typically given every three to five minutes.Epinephrine infusions may also be used for symptomatic bradycardia. Anaphylaxis Epinephrine is the drug of choice for treating allergic reaction anaphylaxis. The commonly used epinephrine autoinjector delivers a 0.3 mg epinephrine injection (0.3 mL, 1:1000). It is indicated in the emergency treatment of allergic reactions, including anaphylaxis to stings, contrast agents, medicines, or people with a history of anaphylactic reactions to known triggers. A single dose is recommended for people who weigh 30 kg or more, repeated if necessary. A lower-strength product is available for children.Intramuscular injection can be complicated in that the depth of subcutaneous fat varies and may result in subcutaneous injection, or may be injected intravenously in error, or the wrong strength used. Intramuscular injection gives a faster and higher pharmacokinetic profile compared to subcutaneous injection. Asthma Epinephrine is also used as a bronchodilator for asthma if specific β2 agonists are unavailable or ineffective.When given by the subcutaneous or intramuscular routes for asthma, an appropriate dose is 0.3 to 0.5 mg.Because of the high intrinsic efficacy (receptor binding ability) of epinephrine, high drug concentrations cause adverse side effects when treating asthma. The value of using nebulized epinephrine in acute asthma is unclear. Croup Racemic epinephrine has historically been used for the treatment of croup. Regular epinephrine, however, works equally well. Racemic adrenaline is a 1:1 mixture of the two enantiomers of adrenaline. The L-form is the active component. Racemic adrenaline works by stimulating the alpha-adrenergic receptors in the airway, with resultant mucosal vasoconstriction and decreased subglottic edema, and by stimulating the β adrenergic receptors, with resultant relaxation of the bronchial smooth muscle. Bronchiolitis There is a lack of consensus as to whether inhaled nebulized epinephrine is beneficial in the treatment of bronchiolitis, with most guidelines recommending against its use. Local anesthetics When epinephrine is mixed with local anesthetics, such as bupivacaine or lidocaine, and used for local anesthesia or intrathecal injection, it prolongs the numbing effect and motor block effect of the anesthetic by up to an hour. Epinephrine is frequently combined with local anesthetic and can cause panic attacks.Epinephrine is mixed with cocaine to form Moffetts solution, used in nasal surgery. Upper airway obstruction Upper airway obstruction with edema and stridor can be treated with racemic epinephrine. Adverse effects Adverse reactions to adrenaline include palpitations, tachycardia, arrhythmia, anxiety, panic attack, headache, tremor, hypertension, and acute pulmonary edema. The use of epinephrine based eye-drops, commonly used to treat glaucoma, may also lead to a buildup of adrenochrome pigments in the conjunctiva, iris, lens, and retina. Rarely, exposure to medically administered epinephrine may cause Takotsubo cardiomyopathy.Use is contraindicated in people on nonselective β-blockers because severe hypertension and even cerebral hemorrhage may result. Mechanism of action As a hormone, epinephrine acts on nearly all body tissues. Its actions vary by tissue type and tissue expression of adrenergic receptors. For example, high epinephrine levels cause smooth muscle relaxation in the airways but cause contraction of the smooth muscle that lines most arterioles.Epinephrine acts by binding to a variety of adrenergic receptors. Epinephrine is a nonselective agonist of all adrenergic receptors, including the major subtypes α1, α2, β1, β2, and β3. Epinephrines binding to these receptors triggers several metabolic changes. Binding to α-adrenergic receptors inhibits insulin secretion by the pancreas, stimulates glycogenolysis in the liver and muscle, and stimulates glycolysis and inhibits insulin-mediated glycogenesis in muscle. β adrenergic receptor binding triggers glucagon secretion in the pancreas, increased adrenocorticotropic hormone (ACTH) secretion by the pituitary gland, and increased lipolysis by adipose tissue. Together, these effects increase blood glucose and fatty acids, providing substrates for energy production within cells throughout the body. In the heart, the coronary arteries have a predominance of β2 receptors, which cause vasodilation of the coronary arteries in the presence of epinephrine.Its actions increase peripheral resistance via α1 receptor-dependent vasoconstriction and increase cardiac output via its binding to β1 receptors. The goal of reducing peripheral circulation is to increase coronary and cerebral perfusion pressures and therefore increase oxygen exchange at the cellular level. While epinephrine does increase aortic, cerebral, and carotid circulation pressure, it lowers carotid blood flow and end-tidal CO2 or ETCO2 levels. It appears that epinephrine may improve macrocirculation at the expense of the capillary beds where perfusion takes place. History Extracts of the adrenal gland were first obtained by Polish physiologist Napoleon Cybulski in 1895. These extracts, which he called nadnerczyna, contained adrenaline and other catecholamines. American ophthalmologist William H. Bates discovered adrenalines usage for eye surgeries prior to 20 April 1896. Japanese chemist Jōkichi Takamine and his assistant Keizo Uenaka independently discovered adrenaline in 1900. In 1901, Takamine successfully isolated and purified the hormone from the adrenal glands of sheep and oxen. Adrenaline was first synthesized in the laboratory by Friedrich Stolz and Henry Drysdale Dakin, independently, in 1904. Society and culture Brand names Common brand names include Asthmanefrin, Micronefrin, Nephron, VapoNefrin, and Primatene Mist. Delivery forms Epinephrine is available in an autoinjector delivery system. There is an epinephrine metered-dose inhaler sold over the counter in the United States to relieve bronchial asthma. It was introduced in 1963 by Armstrong Pharmaceuticals.A common concentration for epinephrine is 2.25% w/v epinephrine in solution, which contains 22.5 mg/mL, while a 1% solution is typically used for aerosolization. Adults: 0.5–0.75 ml of a 2.25% solution in 2.0 ml normal saline. Pediatrics: 0.25–0.75 ml of a 2.25% solution in 2.0 ml normal saline. References External links "Epinephrine". Drug Information Portal. U.S. National Library of Medicine.
Ketamine
Ketamine is a dissociative anesthetic used medically for induction and maintenance of anesthesia. It is also used as a recreational drug. It is one of the safest anesthetics, as, in contrast with opiates, ether, and propofol, it suppresses neither respiration nor heart rate. Ketamine is also simple to administer and highly tolerable compared to drugs with similar effects which are flammable, irritating, or even explosive. Ketamine is a novel compound, derived from PCP, created in pursuit of a safer anesthetic with similar characteristics. Ketamine is also used for acute pain management.At anesthetic doses, ketamine induces a state of "dissociative anesthesia", a trance-like state providing pain relief, sedation, and amnesia. The distinguishing features of ketamine anesthesia are preserved breathing and airway reflexes, stimulated heart function with increased blood pressure, and moderate bronchodilation. At lower, sub-anesthetic doses, ketamine is a promising agent for pain and treatment-resistant depression. However, the antidepressant action of a single administration of ketamine wanes with time. The long-term effects of repeated use are largely unknown, and are an area of active investigation.Liver and urinary toxicity have been reported among regular users of high doses of ketamine for recreational purposes. Ketamine is an NMDA receptor antagonist and that accounts for most of its actions except the antidepressive effect, the mechanism of which is a matter of much research and debate. Ketamine was first synthesized in 1962 and approved for use in the United States in 1970. It has been regularly used in veterinary medicine and was extensively used for surgical anaesthesia in the Vietnam War. When used as a recreational drug, it is found both in powder and liquid form, and is often referred to as "Special K" for its hallucinogenic and dissociative effects. Along with other psychotropic drugs, it is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. Medical uses Anesthesia The use of ketamine in anesthesia reflects its characteristics. It is a drug of choice for short-term procedures when muscle relaxation is not required. The effect of ketamine on the respiratory and circulatory systems is different from that of other anesthetics. It suppresses breathing much less than most other available anesthetics. When used at anesthetic doses, ketamine usually stimulates rather than depresses the circulatory system. Protective airway reflexes are preserved and it is sometimes possible to administer ketamine anesthesia without protective measures to the airways. Psychotomimetic effects limit the acceptance of ketamine; however, lamotrigine and nimodipine decrease psychotomimetic effects and can be counteracted also by benzodiazepines administered or propofol.Ketamine is frequently used in severely injured people and appears to be safe in this group. It has been widely used for emergency surgery in field conditions in war zones, for example, during the Vietnam War. A 2011 clinical practice guideline supports the use of ketamine as a sedative in emergency medicine, including during physically painful procedures. It is the drug of choice for people in traumatic shock who are at risk of hypotension. Low blood pressure is dangerous for people with severe head injury and ketamine is unlikely to lower blood pressure — conversely, often raising blood pressure, making it often the best suited for those with severe head injury.Ketamine is an option in children, as the sole anesthetic for minor procedures or as an induction agent followed by neuromuscular blocker and tracheal intubation In particular, children with cyanotic heart disease and neuromuscular disorders are good candidates for ketamine anesthesia.Due to the bronchodilating properties of ketamine, it can be used for anesthesia in people with asthma, chronic obstructive airway disease, and with severe reactive airway disease including active bronchospasm. Pain Ketamine infusions are used for acute pain treatment in emergency departments and in the perioperative period in individuals with refractory pain. The doses are lower than those used for anesthesia; they are usually referred to as sub-anesthetic doses. Adjunctive to morphine or on its own, ketamine reduces morphine use, pain level, nausea, and vomiting after surgery. Ketamine is likely to be most beneficial for surgical patients when severe post-operative pain is expected and for opioid-tolerant patients.Ketamine is especially useful in the prehospital setting, due to its effectiveness and low risk of respiratory depression. Ketamine has similar efficacy to opioids in a hospital emergency department setting for management of acute pain and for control of procedural pain. It may also prevent opioid-induced hyperalgesia and postanesthetic shivering.For chronic pain, ketamine is used as an intravenous analgesic, particularly, if the pain is neuropathic. It has the added benefit of counteracting spinal sensitization or wind-up phenomena experienced with chronic pain. In multiple clinical trials, ketamine infusions delivered short-term pain relief in neuropathic pain diagnoses, pain after traumatic spine injury, fibromyalgia, and complex regional pain syndrome (CRPS). However, the 2018 consensus guidelines on chronic pain concluded that, overall, there is only weak evidence in favor of ketamine use in spinal injury pain, moderate evidence in favor of ketamine for CRPS, and weak or no evidence for ketamine in mixed neuropathic pain, fibromyalgia, and cancer pain. In particular, only for CRPS there is evidence of medium to longer term pain relief. Depression Ketamine is a robust and rapid-acting antidepressant, although its effect is transient. Intravenous ketamine infusion in treatment resistant depression may result in improved mood within 4 hours reaching the peak at 24 hours. A single dose of intravenous ketamine has been shown to result in a response rate greater than 60% as early as 4.5 hours after the dose (with a sustained effect after 24 hours) and greater than 40% after 7 days. Although there are only a few pilot studies studying the optimal dose, increasing evidence suggests that 0.5 mg/kg dose injected over 40 minutes gives an optimal outcome. The antidepressant effect of ketamine is diminished at 7 days, and most people relapse within 10 days, although for a significant minority the improvement may last 30 days and longer. One of the main challenges with ketamine treatment can be the length of time that the antidepressant effects lasts after finishing a course of treatment. A possible option may be maintenance therapy with ketamine which usually runs twice a week to once in two weeks. Ketamine may decrease suicidal thoughts for up to three days after the injection.An enantiomer of ketamine – esketamine commercially sold as Spravato – was approved as an antidepressant by the European Medicines Agency in 2019. Esketamine was approved as a nasal spray for treatment-resistant depression in the United States and elsewhere in 2019 (see Esketamine and Depression). The Canadian Network for Mood and Anxiety Treatments (CANMAT) recommends esketamine as a third-line treatment for depression.A Cochrane review of randomized controlled trials in adults with unipolar major depressive disorder, found that when compared with placebo, people treated with either ketamine or esketamine experienced reduction or remission of symptoms lasting 1 to 7 days. There were 18.7% (4.1 to 40.4%) more people reporting some benefit and 9.6% (0.2 to 39.4%) more who achieved remission within 24-hours of ketamine treatment. Among people receiving esketamine, 2.1% (2.5 to 24.4%) more encountered some relief at 24-hours and 10.3% (4.5 to 18.2%) more had few or no symptoms. These effects did not persist beyond one week, although higher dropout rate in some studies mean that the duration of benefit remains unclear.Ketamine may partially improve depressive symptoms among people with bipolar depression, at 24 hours after treatment, but not 3 or more days. Potentially, 10 more people with bipolar depression per 1000 may experience brief improvement, but not cessation of symptoms, one day following treatment. These estimates are based on limited available research.In February 2022, the US Food and Drug Administration issued an alert to health care professionals concerning compounded nasal spray products containing ketamine intended to treat depression: "There is no FDA-approved ketamine nasal spray product. Compounded drugs are not FDA-approved, which means FDA has not evaluated their safety, effectiveness, or quality prior to marketing." Near-death experience Most people who were able to remember their dreams during ketamine anesthesia report near-death experiences (NDE) when the widest possible definition of an NDE is used. Ketamine can reproduce features that commonly have been associated with NDEs. A 2019 large-scale study found that written reports of ketamine experiences had a high degree of similarity to written reports of NDE in comparison to other written reports of drug experiences. Seizures Ketamine is sometimes used in the treatment of status epilepticus that has failed to adequately respond to standard treatments, although only limited evidence (case studies and no randomized controlled trials) exists in its favor. Contraindications Main contraindications for ketamine: Severe cardiovascular disease such as unstable angina or poorly controlled hypertension Increased intracranial or intraocular pressure. Both of these contraindications are controversial Poorly controlled psychosis Severe liver disease such as cirrhosis Pregnancy Active substance use disorder (for serial ketamine injections) Age less than 3 months Side effects At anesthetic doses, 10–20% of adults (1–2% of children) experience adverse psychiatric reactions that occur during emergence from anesthesia, ranging from dreams and dysphoria to hallucinations and emergence delirium. Psychotomimetic effects decrease adding lamotrigine and nimodipine and can be counteracted by pretreatment with a benzodiazepine or propofol. Ketamine anesthesia commonly causes tonic-clonic movements (greater than 10% of people) and rarely hypertonia. Vomiting can be expected in 5–15% of the patients; pretreatment with propofol mitigates it as well. Laryngospasm occurs only rarely with ketamine. Ketamine, generally, stimulates breathing; however, in the first 2–3 minutes of a high-dose rapid intravenous injection it may cause a transient respiratory depression.At lower sub-anesthetic doses, psychiatric side effects are prominent. Most people feel strange, spacey, woozy, or a sense of floating, or have visual distortions or numbness. Also very frequent (20–50%) are difficulty speaking, confusion, euphoria, drowsiness, and difficulty concentrating. The symptoms of psychosis such as going into a hole, disappearing, feeling as if melting, experiencing colors, and hallucinations are described by 6–10% of people. Dizziness, blurred vision, dry mouth, hypertension, nausea, increased or decreased body temperature, or feeling flushed are the common (>10%) non-psychiatric side effects. All these adverse effects are most pronounced by the end of the injection, dramatically reduced 40 minutes afterward, and completely disappear within 4 hours after the injection. Urinary and liver toxicity Urinary toxicity occurs primarily in people who use large amounts of ketamine routinely, with 20–30% of frequent users having bladder complaints. It includes a range of disorders from cystitis to hydronephrosis to kidney failure. The typical symptoms of ketamine-induced cystitis are frequent urination, dysuria, and urinary urgency sometimes accompanied by pain during urination and blood in urine. The damage to the bladder wall has similarities to both interstitial and eosinophilic cystitis. The wall is thickened and the functional bladder capacity is as low as 10–150 mL.Management of ketamine-induced cystitis involves ketamine cessation as the first step. This is followed by NSAIDs and anticholinergics and, if the response is insufficient, by tramadol. The second line treatments are epithelium-protective agents such as oral pentosan polysulfate or intravesical (intra-bladder) instillation of hyaluronic acid. Intravesical botulinum toxin is also useful.Liver toxicity of ketamine involves higher doses and repeated administration. In a group of chronic high dose ketamine users, the frequency of liver injury was reported to be about 10%. There are case reports of increased liver enzymes involving ketamine treatment of chronic pain. Dependence and tolerance Although the incidence of ketamine dependence is unknown, some people who regularly use ketamine develop ketamine dependence. Animal experiments also confirm the risk of misuse. Additionally, the rapid onset of effects following insufflation may increase potential use as a recreational drug. The short duration of effects promotes bingeing. Ketamine tolerance rapidly develops, even with repeated medical use, prompting the use of higher doses. Some daily users reported withdrawal symptoms, primarily anxiety, shaking, sweating, and palpitations, following the attempts to stop. Cognitive deficits as well as increased dissociation and delusion symptoms were observed in frequent recreational users of ketamine. Interactions Ketamine potentiates the sedative effects of propofol and midazolam. Naltrexone potentiates psychotomimetic effects of a low dose of ketamine, while lamotrigine and nimodipine decrease them. Clonidine reduces the increase of salivation, heart-rate and blood-pressure during ketamine anesthesia and decreases the incidence of nightmares.Clinical observations suggest that benzodiazepines may diminish the antidepressant effects of ketamine. It appears most conventional antidepressants can be safely combined with ketamine. Pharmacology Pharmacodynamics Mechanism of action Antagonism of the NMDA receptor is responsible for the anesthetic, analgesic, and psychotomimetic effects of ketamine. NMDA receptor antagonism results in analgesia by preventing central sensitization in dorsal horn neurons; in other words, ketamines actions interfere with pain transmission in the spinal cord.The mechanism of action of ketamine in alleviating depression is not well understood, and is an area of active investigation. Possible mechanisms include direct action on the NMDA receptor, downstream effects on regulators such as BDNF and mTOR, and effects of ketamines metabolites such as hydroxynorketamine. It is not clear whether NMDA receptor is solely responsible for this action or interactions with other receptors are also necessary. It is not also not clear whether ketamine alone is sufficient for the antidepressive action or its metabolites also are important. In any case, it has been elucidated that acute blockade of NMDA receptors in the brain results in an activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPA receptors), which in turn modulate a variety of downstream signaling pathways to influence neurotransmission in the limbic system and mediate antidepressant effects of NMDA receptor antagonists like ketamine. Such downstream actions of this activation of AMPA receptors include upregulation of brain-derived neurotrophic factor (BDNF) and activation of its signaling receptor tropomyosin receptor kinase B (TrkB), activation of the mammalian target of rapamycin (mTOR) pathway, deactivation of glycogen synthase kinase 3 (GSK-3), and inhibition of the phosphorylation of the eukaryotic elongation factor 2 (eEF2) kinase. In addition to blockade of the NMDA receptor, the active metabolite of ketamine hydroxynorketamine, which does not interact importantly with the NMDA receptor, but nonetheless indirectly activates AMPA receptors similarly, may also or alternatively be involved in the rapid-onset antidepressant effects of ketamine. Recent research has elucidated that an acute inhibition of the lateral habenula, a part of the brain in the limbic system that has been referred to as the "anti-reward center" (projecting to and inhibiting the mesolimbic reward pathway and modulating other limbic areas), may be involved in the antidepressant effects of ketamine.Ketamine is a mixture of equal amounts of two enantiomers: esketamine and arketamine. Esketamine is a more potent NMDA receptor antagonist and dissociative hallucinogen than arketamine. Because of the hypothesis that NMDA receptor antagonism underlies the antidepressant effects of ketamine, esketamine was developed as an antidepressant. However, multiple other NMDA receptor antagonists, including memantine, lanicemine, rislenemdaz, rapastinel, and 4-chlorokynurenine, thus far have failed to demonstrate sufficient effectiveness for depression. Furthermore, animal research indicates that arketamine, the enantiomer with a weaker NMDA receptor antagonism, as well as (2R,6R)-hydroxynorketamine, the metabolite with negligible affinity for the NMDA receptor, but a potent alpha-7 nicotinic receptor antagonist may have antidepressive action. It is now argued that NMDA receptor antagonism may not be primarily responsible for the antidepressant effects of ketamine. Molecular targets Ketamine principally acts as an antagonist of the NMDA receptor, an ionotropic glutamate receptor. The S(+) and R(–) stereoisomers of ketamine bind to the dizocilpine site of the NMDA receptor with different affinities, the former showing approximately 3- to 4- fold greater affinity for the receptor than the latter. As a result, the S isomer is a more potent anesthetic and analgesic than its R counterpart.Ketamine may interact with and inhibit the NMDAR via another allosteric site on the receptor.With a couple of exceptions ketamine actions at other receptors are far weaker than ketamines antagonism of the NMDA receptor (see the activity table to the right).Although ketamine is a very weak ligand of the monoamine transporters (Ki > 60 μM), it has been suggested that it may interact with allosteric sites on the monoamine transporters to produce monoamine reuptake inhibition. However, no functional inhibition (IC50) of the human monoamine transporters has been observed with ketamine or its metabolites at concentrations of up to 10,000 nM. Moreover, animal studies and at least three human case reports have found no interaction between ketamine and the monoamine oxidase inhibitor (MAOI) tranylcypromine, which is of importance as the combination of a monoamine reuptake inhibitor with an MAOI can produce severe toxicity such as serotonin syndrome or hypertensive crisis. Collectively, these findings shed doubt on the involvement of monoamine reuptake inhibition in the effects of ketamine in humans. Ketamine has been found to increase dopaminergic neurotransmission in the brain, but instead of being due to dopamine reuptake inhibition, this may be via indirect/downstream mechanisms, namely through antagonism of the NMDA receptor.Whether ketamine is an agonist of D2 receptors is controversial. Early research by the Philip Seeman group found ketamine to be a D2 partial agonist with the potency similar to that of its NMDA receptor antagonism. However, later studies by different researchers found the affinity of ketamine of >10 μM for the regular human and rat D2 receptors, Moreover, whereas D2 receptor agonists such as bromocriptine are able to rapidly and powerfully suppress prolactin secretion, subanesthetic doses of ketamine have not been found to do this in humans and in fact, have been found to dose-dependently increase prolactin levels. Imaging studies have shown mixed results on inhibition of striatal [11C] raclopride binding by ketamine in humans, with some studies finding a significant decrease and others finding no such effect. However, changes in [11C] raclopride binding may be due to changes in dopamine concentrations induced by ketamine rather than binding of ketamine to the D2 receptor. Relationships between levels and effects Dissociation and psychotomimetic effects are reported in people treated with ketamine at plasma concentrations of approximately 100 to 250 ng/mL (0.42–1.1 μM). The typical intravenous antidepressant dosage of ketamine used to treat depression is low and results in maximal plasma concentrations of 70 to 200 ng/mL (0.29–0.84 μM). At similar plasma concentrations (70 to 160 ng/mL; 0.29–0.67 μM) it also shows analgesic effects. In 1–5 minutes after inducing anesthesia by a rapid intravenous injection of ketamine, its plasma concentration reaches as high as 60–110 μM. When the anesthesia was maintained using nitrous oxide together with continuous injection of ketamine, the ketamine concentration stabilized at approximately 9.3 μM. In an experiment with purely ketamine anesthesia, people began to awaken once the plasma level of ketamine decreased to about 2,600 ng/mL (11 μM) and became oriented in place and time when the level was down to 1,000 ng/mL (4 μM). In a single-case study, the concentration of ketamine in cerebrospinal fluid, a proxy for the brain concentration, during anesthesia varied between 2.8 and 6.5 μM and was approximately 40% lower than in plasma. Pharmacokinetics Ketamine can be absorbed by many different routes due to both its water and lipid solubility. Intravenous ketamine bioavailability is 100% by definition, intramuscular injection bioavailability is slightly lower at 93%, and epidural bioavailability is 77%. Subcutaneous bioavailability has never been measured, but is presumed to be high. Among the less invasive routes, the intranasal route has the highest bioavailability (45–50%) and oral – the lowest (16–20%). Sublingual and rectal bioavailabilities are intermediate at approximately 25–50%.After absorption ketamine is rapidly distributed into the brain and other tissues. The plasma protein binding of ketamine is variable at 23 to 47%. In the body ketamine undergoes extensive metabolism. It is biotransformed by CYP3A4 and CYP2B6 isoenzymes into norketamine, which, in turn, is converted by CYP2A6 and CYP2B6 into hydroxynorketamine and dehydronorketamine. Low oral bioavailability of ketamine is due to the first-pass effect and, possibly, ketamine intestinal metabolism by CYP3A4. As a result, norketamine plasma levels are several-fold higher than ketamine following oral administration, and norketamine may play a role in anesthetic and analgesic action of oral ketamine. This also explains why oral ketamine levels are independent of CYP2B6 activity, unlike subcutaneous ketamine levels.After an intravenous injection of tritium-labelled ketamine, 91% of the radioactivity is recovered from urine and 3% from the feces. The medication is excreted mostly in the form of metabolites, with only 2% remaining unchanged. Conjugated hydroxylated derivatives of ketamine (80%) followed by dehydronorketamine (16%) are the most prevalent metabolites detected in urine. Chemistry Synthesis 2-chlorobenzonitrile is reacted with the Grignard reagent cyclopentylmagnesium bromide to give (2-chlorophenyl)(cyclopentyl)methanone. This is then brominated using bromine to form the corresponding bromoketone, which is then reacted with methylamine in an aqueous solution to form the methylimino derivative, 1-(2-Chloro-N-methylbenzimidoyl)cyclopentanol, with hydrolysis of the tertiary bromine atom. This final intermediate is then heated in decalin or another suitable high-boiling solvent, upon which a ring-expansion rearrangement occurs, forming ketamine. Structure In chemical structure, ketamine is an arylcyclohexylamine derivative. Ketamine is a chiral compound. The more active enantiomer, esketamine (S-ketamine), is also available for medical use under the brand name Ketanest S, while the less active enantiomer, arketamine (R-ketamine), has never been marketed as an enantiopure drug for clinical use. While S-ketamine is more effective as an analgesic and anesthetic through NMDA receptor antagonism, R-ketamine produces longer-lasting effects as an antidepressant. The optical rotation of a given enantiomer of ketamine can vary between its salts and free base form. The free base form of (S)‑ketamine exhibits dextrorotation and is therefore labelled (S)‑(+)‑ketamine. However, its hydrochloride salt shows levorotation and is thus labelled (S)‑(−)‑ketamine hydrochloride. Detection Ketamine may be quantitated in blood or plasma to confirm a diagnosis of poisoning in hospitalized people, provide evidence in an impaired driving arrest, or to assist in a medicolegal death investigation. Blood or plasma ketamine concentrations are usually in a range of 0.5–5.0 mg/L in persons receiving the drug therapeutically (during general anesthesia), 1–2 mg/L in those arrested for impaired driving and 3–20 mg/L in victims of acute fatal overdosage. Urine is often the preferred specimen for routine drug use monitoring purposes. The presence of norketamine, a pharmacologically active metabolite, is useful for confirmation of ketamine ingestion. History Ketamine was first synthesized in 1962 by Calvin L. Stevens, a professor of chemistry at Wayne State University and a Parke-Davis consultant. It was known by the developmental code name CI-581. After promising preclinical research in animals, ketamine was tested in human prisoners in 1964. These investigations demonstrated ketamines short duration of action and reduced behavioral toxicity made it a favorable choice over phencyclidine (PCP) as an anesthetic. The researchers wanted to call the state of ketamine anesthesia "dreaming", but Parke-Davis did not approve of the name. Hearing about this problem and about the "disconnected" appearance of treated people, Mrs. Edward F. Domino, the wife of one of the pharmacologists working on ketamine, suggested "dissociative anesthesia". Following FDA approval in 1970, ketamine anesthesia was first given to American soldiers during the Vietnam War.The discovery of antidepressive action of ketamine in 2000 has been described as the single most important advance in the treatment of depression in more than 50 years. It has sparked interest in NMDA receptor antagonists for depression, and has shifted the direction of antidepressant research and development. Society and culture Legal status While ketamine is marketed legally in many countries worldwide, it is also a controlled substance in many countries. In Australia, ketamine is listed as a schedule 8 controlled drug under the Poisons Standard (October 2015). In Canada, ketamine is classified as a Schedule I narcotic, since 2005. In December 2013, the government of India, in response to rising recreational use and the use of ketamine as a date rape drug, has added it to Schedule X of the Drug and Cosmetics Act requiring a special license for sale and maintenance of records of all sales for two years. In the United Kingdom, it became labeled a Class B drug on 12 February 2014. The increase in recreational use prompted ketamine to be placed in Schedule III of the United States Controlled Substance Act in August 1999. Recreational use At sub-anesthetic doses ketamine produces a dissociative state, characterised by a sense of detachment from ones physical body and the external world that is known as depersonalization and derealization. At sufficiently high doses, users may experience what is called the "K-hole", a state of dissociation with visual and auditory hallucination. John C. Lilly, Marcia Moore, D. M. Turner, and David Woodard (amongst others) have written extensively about their own entheogenic and psychonautic experiences with ketamine. Turner died prematurely due to drowning during presumed unsupervised ketamine use. In
Ketamine
2006 the Russian edition of Adam Parfreys Apocalypse Culture II was banned and destroyed by authorities owing to its inclusion of an essay by Woodard about the entheogenic use of, and psychonautic experiences with, ketamine.: 288–295  Recreational ketamine use has been implicated in deaths globally, with more than 90 deaths in England and Wales in the years of 2005–2013. They include accidental poisonings, drownings, traffic accidents, and suicides. The majority of deaths were among young people. Because of its ability to cause confusion and amnesia, ketamine has been used for date rape. Research Ketamine is under investigation for its potential in treating treatment-resistant depression.. Ketamine is a known psychoplastogen, which refers to a compound capable of promoting rapid and sustained neuroplasticity.A phase 2 clinical study showed that ketamine can safely and effectively reduce levodopa-induced dyskinesia in patients with Parkinson’s disease. A phase II clinical trial is underway to test the use of ketamine as an antidepressant for patients with Parkinson’s disease. Veterinary medicine In veterinary anaesthesia, ketamine is often used for its anaesthetic and analgesic effects on cats, dogs, rabbits, rats, and other small animals. It is frequently used in induction and anaesthetic maintenance in horses. It is an important part of the "rodent cocktail", a mixture of drugs used for anaesthetising rodents. Veterinarians often use ketamine with sedative drugs to produce balanced anaesthesia and analgesia, and as a constant-rate infusion to help prevent pain wind-up. Ketamine is also used to manage pain among large animals. It is the primary intravenous anaesthetic agent used in equine surgery, often in conjunction with detomidine and thiopental, or sometimes guaifenesin.Ketamine appears not to produce sedation or anaesthesia in snails. Instead, it appears to have an excitatory effect. References External links Ketamine — from the U.S. National Library of Medicine (NLM) Drug Information Portal Ketamine hydrochloride — from the U.S. National Library of Medicine (NLM)Drug Information Portal Ketamine fact sheet — from the United States DEA, via Archive.org
Naloxone
Naloxone, sold under the brand names Narcan (4 mg) and Kloxxado (8 mg) among others, is a medication used to reverse the effects of opioids. It is commonly used to counter decreased breathing in opioid overdose. Effects begin within two minutes when given intravenously, and within five minutes when injected into a muscle. The medicine can also be administered by spraying it into a persons nose. Naloxone commonly blocks the effects of opioids for 30 to 90 minutes. Multiple doses may be required, as the duration of action of some opioids is greater than that of naloxone.Administration to opioid-dependent individuals may cause symptoms of opioid withdrawal, including restlessness, agitation, nausea, vomiting, a fast heart rate, and sweating. To prevent this, small doses every few minutes can be given until the desired effect is reached. In those with previous heart disease or taking medications that negatively affect the heart, further heart problems have occurred. It appears to be safe in pregnancy, after having been given to a limited number of women. Naloxone is a non-selective and competitive opioid receptor antagonist. It works by reversing the depression of the central nervous system and respiratory system caused by opioids. Naloxone generally has no effect on those not using opioids, has no abuse potential, and is recommended by the World Health Organization for distribution to anyone likely to encounter a fatal opioid overdose, including emergency personnel and friends and family members of those using opioids. Naloxone was patented in 1961 and approved for opioid overdose in the United States in 1971. It is on the World Health Organizations List of Essential Medicines. Naloxone is available as a generic medication. In April 2021, the U.S. Food and Drug Administration (FDA) approved a higher dose naloxone hydrochloride nasal spray product (Kloxxado) intended to treat opioid overdose from fentanyl and its analogues, which are many times stronger than heroin. Medical uses Opioid overdose Naloxone is useful in treating both acute opioid overdose and respiratory or mental depression due to opioids. Whether it is useful in those in cardiac arrest due to an opioid overdose is unclear.It is included as a part of emergency overdose response kits distributed to heroin and other opioid drug users, and to emergency responders. This has been shown to reduce rates of deaths due to overdose. A prescription for naloxone is recommended if a person is on a high dose of opioid (>100 mg of morphine equivalence/day), is prescribed any dose of opioid accompanied by a benzodiazepine, or is suspected or known to use opioids nonmedically. Prescribing naloxone should be accompanied by standard education that includes preventing, identifying, and responding to an overdose; rescue breathing; and calling emergency services.Distribution of naloxone to individuals likely to encounter people who overdose is part of the harm reduction initiatives that have spread throughout the US and the world. This approach to dealing with substance use disorder is to treat it as a medical problem and focusing efforts on reducing the harm produced directly (e.g., overdose) and indirectly (exposure to infectious disease). Clonidine overdose Naloxone can also be used as an antidote in overdose of clonidine, a medication that lowers blood pressure. Clonidine overdoses are of special relevance for children, in whom even small doses can cause significant harm. However, there is controversy regarding naloxones efficacy in treating the symptoms of clonidine overdose, namely slow heart rate, low blood pressure, and confusion/somnolence. Case reports that used doses of 0.1 mg/kg (maximum of 2 mg/dose) repeated every 1–2 minutes (10 mg total dose) have shown inconsistent benefit. As the doses used throughout the literature vary, it is difficult to form a conclusion regarding the benefit of naloxone in this setting. The mechanism for naloxones proposed benefit in clonidine overdose is unclear, but it has been suggested that endogenous opioid receptors mediate the sympathetic nervous system in the brain and elsewhere in the body. Some poison control centers recommend naloxone in the setting of clonidine overdose, including intravenous bolus doses of up to 10 mg naloxone. Preventing recreational opioid use Naloxone is poorly absorbed when taken by mouth, so it is commonly combined with a number of oral opioid preparations, including buprenorphine and pentazocine, so that when taken by mouth, only the opioid has an effect. However, if the opioid and naloxone combination is injected, the naloxone blocks the effect of the opioid. This combination is used in an effort to prevent non-medical use. Other uses Naloxone can be used to treat opioid induced itchiness and constipation.A 2003 meta-analysis of existing research showed naloxone to improve blood flow in patients with shock, including septic, cardiogenic, hemorrhagic, or spinal shock, but could not determine if this reduced patient deaths.Naloxone has been used experimentally in the treatment of congenital insensitivity to pain with anhidrosis. Special populations Pregnancy and breastfeeding Naloxone is pregnancy category B or C in the United States. Studies in rodents given a daily maximum dose of 10 mg naloxone showed no harmful effects to the fetus, although human studies are lacking and the drug does cross the placenta, which may lead to the precipitation of withdrawal in the fetus. In this setting, further research is needed before safety can be assured, so naloxone should be used during pregnancy only if it is a medical necessity.Whether naloxone is excreted in breast milk is unknown, however, it is not orally bioavailable and therefore is unlikely to affect a breastfeeding infant. Children Naloxone can be used on infants who were exposed to intrauterine opiates administered to mothers during delivery. However, there is insufficient evidence for the use of naloxone to lower cardiorespiratory and neurological depression in these infants. Infants exposed to high concentrations of opiates during pregnancy may have CNS damage in the setting of perinatal asphyxia. Naloxone has been studied to improve outcomes in this population, however the evidence is currently weak.Intravenous, intramuscular, or subcutaneous administration of naloxone can be given to children and neonates to reverse opiate effects. The American Academy of Pediatrics recommends only intravenous administration as the other two forms can cause unpredictable absorption. After a dose is given, the child should be monitored for at least 24 hours. For children with low blood pressure due to septic shock, naloxone safety and effectiveness are not established. Geriatric use For patients 65 years and older, it is unclear if there is a difference in response. However, older people often have decreased liver and kidney function that may lead to an increased level of naloxone in their body. Side effects Naloxone has little to no effect if opioids are not present. In people with opioids in their system, it may cause increased sweating, nausea, restlessness, trembling, vomiting, flushing, and headache, and has in rare cases been associated with heart rhythm changes, seizures, and pulmonary edema.Besides the side effects listed above, naloxone also has other adverse events, such as other cardiovascular effects (hypertension, hypotension, tachycardia, ventricular fibrillation, ventricular tachycardia) and central nervous system effects, such as agitation, body pain, brain disease, and coma. In addition to these adverse effects, naloxone is also contraindicated in people with hypersensitivity to naloxone or any of its formulation components.Naloxone has been shown to block the action of pain-lowering endorphins the body produces naturally. These endorphins likely operate on the same opioid receptors that naloxone blocks. It is capable of blocking a placebo pain-lowering response, if the placebo is administered together with a hidden or blind injection of naloxone. Other studies have found that placebo alone can activate the bodys μ-opioid endorphin system, delivering pain relief by the same receptor mechanism as morphine.Naloxone should be used with caution in people with cardiovascular disease as well as those that are currently taking medications that could have adverse effects on the cardiovascular system such as causing low blood pressure, fluid accumulation in the lungs (pulmonary edema), and abnormal heart rhythms. There have been reports of abrupt reversals with opioid antagonists leading to pulmonary edema and ventricular fibrillation. Hypersensitivities Naloxone preparations may contain methylparaben and propylparaben and are inappropriate for use by people with a paraben hypersensitivity. If a person is sensitive to nalmefene or naltrexone, naloxone should be used with caution as these three medications are structurally similar. Cross-sensitivity among these drugs is unknown. Preservative-free preparations are available for those with paraben hypersensitivities. Pharmacology Pharmacodynamics Naloxone is a lipophilic compound that acts as a non-selective and competitive opioid receptor antagonist. The pharmacologically active isomer of naloxone is (−)-naloxone. Naloxones binding affinity is highest for the μ-opioid receptor (MOR), then the δ-opioid receptor (DOR), and lowest for the κ-opioid receptor (KOR); naloxone has negligible affinity for the nociceptin receptor.If naloxone is administered in the absence of concomitant opioid use, no functional pharmacological activity occurs, except the inability of the body to combat pain naturally. In contrast to direct opiate agonists, which elicit opiate withdrawal symptoms when discontinued in opiate-tolerant people, no evidence indicates the development of tolerance or dependence on naloxone. The mechanism of action is not completely understood, but studies suggest it functions to produce withdrawal symptoms by competing for opioid receptors within the brain (a competitive antagonist, not a direct agonist), thereby preventing the action of both endogenous and xenobiotic opioids on these receptors without directly producing any effects itself.A single administration of naloxone at a relatively high dose of 2 mg by intravenous injection has been found to produce brain MOR blockade of 80% at 5 minutes, 47% at 2 hours, 44% at 4 hours, and 8% at 8 hours. A low dose (2 μg/kg) produced brain MOR blockade of 42% at 5 minutes, 6% at 2 hours, 33% at 4 hours, and 10% at 8 hours. Intranasal administration of naloxone via nasal spray has likewise been found to rapidly occupy brain MORs, with peak occupancy occurring at 20 minutes, peak occupancies of 67% at a dose of 2 mg and 85% with 4 mg, and an estimated half-life of occupancy disappearance of approximately 100 minutes (1.67 hours). Pharmacokinetics When administered parenterally (non-orally or non-rectally, e.g., intravenously or by injection), as is most common, naloxone has a rapid distribution throughout the body. The mean serum half-life has been shown to range from 30 to 81 minutes, shorter than the average half-life of some opiates, necessitating repeat dosing if opioid receptors must be stopped from triggering for an extended period. Naloxone is primarily metabolized by the liver. Its major metabolite is naloxone-3-glucuronide, which is excreted in the urine. For people with liver diseases such as alcoholic liver disease or hepatitis, naloxone usage has not been shown to increase serum liver enzyme levels.Naloxone has low systemic bioavailability when taken by mouth due to hepatic first-pass metabolism, but it does block opioid receptors that are located in the intestine. Chemistry Naloxone, also known as N-allylnoroxymorphone or as 17-allyl-4,5α-epoxy-3,14-dihydroxymorphinan-6-one, is a synthetic morphinan derivative and was derived from oxymorphone (14-hydroxydihydromorphinone), an opioid analgesic. Oxymorphone, in turn, was derived from morphine, an opioid analgesic and naturally occurring constituent of the opium poppy. Naloxone is a racemic mixture of two enantiomers, (–)-naloxone (levonaloxone) and (+)-naloxone (dextronaloxone), only the former of which is active at opioid receptors. The drug is highly lipophilic, allowing it to rapidly penetrate the brain and to achieve a far greater brain to serum ratio than that of morphine. Opioid antagonists related to naloxone include cyprodime, nalmefene, nalodeine, naloxol, and naltrexone.The chemical half-life of naloxone is such that injection and nasal forms have been marketed with 24-month and 18-month shelf-lives, respectively. A 2018 study noted that the nasal and injection forms presented as chemically stable to 36- and 28-months, respectively, which prompted an as yet incomplete five-year stability study to be initiated. This suggests that expired caches of material in community and healthcare settings may still be efficacious substantially beyond their labeled expiration dates. History Naloxone was patented in 1961 by Mozes J. Lewenstein, Jack Fishman, and the company Sankyo. It was approved for opioid use disorder treatment in the United States in 1971, with opioid overdose prevention kits being distributed by many states to medically untrained people beginning in 1996. From the period of 1996 to 2014, the CDC estimates over 26,000 cases of opioid overdose have been reversed using the kits.Naloxone (Nyxoid) was approved for use in the European Union in September 2017. Society and culture Names Naloxone is the generic name of the medication and its INN, BAN, DCF, DCIT, and JAN, while naloxone hydrochloride is its USAN and BANM.The patent has expired and it is available as a generic medication. Several of the newer formulations use patented dispensers (spray mechanisms or autoinjectors), and patent disputes over generic forms of the nasal spray were litigated between 2016 and 2020, when a judge ruled in favor of Teva, the generic manufacturer. Teva announced entry of the first generic nasal spray formulation in December 2021. Brand names of naloxone include Narcan, Kloxxado, Nalone, Evzio, Prenoxad Injection, Narcanti, Narcotan, and Zimhi, among others. Identification The CAS number of naloxone is 465-65-6; the anhydrous hydrochloride salt has CAS 357-08-4 and the hydrochloride salt with 2 molecules of water, hydrochloride dihydrate, has CAS 51481-60-8 Routes of administration Intravenous In hospital settings, naloxone is commonly injected intravenously, with an onset of 1–2 minutes and a duration of up to 45 minutes. While the onset is achieved fastest through IV than through other routes of administration, it may be difficult to obtain venous access in patients who use IV drugs chronically. This may be an issue under emergency conditions. Intramuscular or subcutaneous Naloxone can also be administered via intramuscular or subcutaneous injection. The onset of naloxone provided through this route is 2 to 5 minutes with a duration of around 30-120min. Naloxone administered intramuscularly are provided through pre-filled syringes, vials, and auto-injector. Evzio is the only auto-injector on the market and can be used both intramuscularly and subcutaneously. It is pocket-sized and can be used in non-medical settings such as in the home. It is designed for use by laypersons, including family members and caregivers of opioid users at-risk for an opioid emergency, such as an overdose. According to the FDAs National Drug Code Directory, a generic version of the auto-injector began to be marketed at the end of 2019. Intranasal Administration of naloxone intranasally is recommended for people who are unconscious or unresponsive. While the onset of action is slightly delayed in this method of administration, the ease of use and portability are what make naloxone nasal sprays useful.Narcan Nasal Spray was approved in 2015 and was the first FDA-approved nasal spray for emergency treatment or suspected overdose. Narcan Nasal Spray is prepackaged, requires no assembly, and delivers a consistent 4 mg dose of naloxone. It was developed in a partnership between LightLake Therapeutics and the National Institute on Drug Abuse. The approval process was fast-tracked. A generic version of the nasal spray was approved in the United States in 2019, though did not come to market until 2021.In 2021, the FDA approved Kloxxado, a 8 mg dose of intranasal naloxone developed by Hikma Pharmaceuticals. Citing the frequent need for multiple 4 mg doses of Narcan to successfully reverse overdose, packs of Kloxxado Nasal Spray contain two pre-packaged nasal spray devices, each containing 8 mg of naloxone. However, a wedge device (nasal atomizer) can also be attached to a syringe that may also be used to create a mist to deliver the drug to the nasal mucosa. This is useful near facilities where many overdoses occur that already stock injectors. Storage Naloxone should be stored at room temperature and protected from light. For the auto-injector, naloxone should be stored in the outer case provided. If the product is cloudy, discolored, or contains particulate matter, use is not recommended. Legal status and availability to law enforcement and emergency personnel In the United States, naloxone is ostensibly available without a prescription in every state with the exception of Hawaii. In reality, not all pharmacies stock or dispense naloxone. Depending on the pharmacy, a pharmacist may have to write a prescription or not be able to give naloxone to comply with accounting rules, as naloxone is still considered a prescription-only medication under FDA rules. As of mid-2019, officials in 29 states had issued standing orders to enable licensed pharmacists to provide naloxone to patients without the individual first visiting a prescriber. Prescribers working with harm reduction or low threshold treatment programs have also issued standing orders to enable these organizations to distribute naloxone to their clients. A standing order, also referred to as a "non-patient specific prescription" is written by a physician, nurse or other prescriber to authorize medicine distribution outside the doctor-patient relationship. In the case of naloxone, these orders are meant to facilitate naloxone distribution to people using opioids, family members and friends. Over 200 naloxone distribution programs utilize licensed prescribers to distribute the drug through such orders, or through the authority of pharmacists (as with Californias legal proision, AB1535).Laws and policies in many US jurisdictions have been changed in recent years to allow wider distribution of naloxone. In addition to laws or regulations permitting distribution of medicine to at risk individuals and families, some 36 states have passed laws that provide naloxone prescribers with immunity against both civil and criminal liabilities. While paramedics in the US have carried naloxone for decades, law enforcement officers in many states throughout the country carry naloxone to reverse the effects of heroin overdoses when reaching the location before paramedics. As of July 12, 2015, law enforcement departments in 28 US states are allowed to or required to carry naloxone to quickly respond to opioid overdoses. Programs training fire personnel in opioid overdose response using naloxone have also shown promise in the US, and efforts to integrate opioid fatality prevention into emergency response have grown due to the US overdose crisis.Following the use of the nasal spray device by police officers on Staten Island in New York, an additional 20,000 police officers will begin carrying naloxone in mid-2014. The states Office of the Attorney General will provide US$1.2 million to supply nearly 20,000 kits. Police Commissioner William Bratton said: "Naloxone gives individuals a second chance to get help". Emergency Medical Service Providers (EMS) routinely administer naloxone, except where basic Emergency Medical Technicians are prohibited by policy or by state law. In efforts to encourage citizens to seek help for possible opioid overdoses, many states have adopted Good Samaritan laws that provide immunity against certain criminal liabilities for anybody who, in good faith, seeks emergency medical care for either themselves or someone around them who may be experiencing an opioid overdose.States including Vermont and Virginia have developed programs that mandate the prescription of naloxone when a prescription has exceeded a certain level of morphine milliequivalents per day as preventative measures against overdose. Healthcare institution-based naloxone prescription programs have also helped reduce rates of opioid overdose in North Carolina, and have been replicated in the US military.In Canada, naloxone single-use syringe kits are distributed and available at various clinics and emergency rooms. Alberta Health Services is increasing the distribution points for naloxone kits at all emergency rooms, and various pharmacies and clinics province-wide. All Edmonton Police Service and Calgary Police Service patrol cars carry an emergency single-use naloxone syringe kit. Some Royal Canadian Mounted Police patrol vehicles also carry the drug, occasionally in excess to help distribute naloxone among users and concerned family/friends. Nurses, paramedics, medical technicians, and emergency medical responders can also prescribe and distribute the drug. As of February 2016, pharmacies across Alberta and some other Canadian jurisdictions are allowed to distribute single-use take-home naloxone kits or prescribe the drug to people using opioids.Following Alberta Health Services, Health Canada reviewed the prescription-only status of naloxone, resulting in plans to remove it in 2016, making naloxone more accessible. Due to the rising number of drug deaths across the country, Health Canada proposed a change to make naloxone more widely available to Canadians in support of efforts to address the growing number of opioid overdoses. In March 2016, Health Canada did change the prescription status of naloxone, as "pharmacies are now able to proactively give out naloxone to those who might experience or witness an opioid overdose." Community access Schools, government agencies, and nonprofit organizations hold training programs to educate laypeople on the proper use of naloxone and to send them home with medicine. It is estimated that programs like these have helped to reverse more than 26,000 overdoses in the US. Harm reduction organizations providing needle and syringes to those injecting drugs have been particularly involved in naloxone distribution, purchasing medicine at discounted rates through a Buyers Club and distributing more than 3 million vials to those at high risk or likely to be with those at high risk between 2017 and 2020 alone. In a survey of US laypersons in December 2021, most people believed the scientifically-supported idea that trained bystanders can reverse overdoses with naloxone.A survey of US naloxone prescription programs in 2010 revealed that 21 out of 48 programs reported challenges in obtaining naloxone in the months leading up to the survey, due mainly to either cost increases that outstripped allocated funding or the suppliers inability to fill orders. The approximate cost of a 1 ml ampoule of naloxone in the US is estimated to be significantly higher than in most other countries.Take-home naloxone programs for people who use opioids is under way in many North American cities. CDC estimates that the US programs for drug users and their caregivers prescribing take-home doses of naloxone and training on its use prevented 10,000 opioid overdose deaths by 2014.In Australia, as of February 1, 2016, some forms of naloxone are available "over the counter" in pharmacies without a prescription. It comes in single-use filled syringe similar to law enforcement kits. A single dose costs AU$20; for those with a prescription, five doses can bought for AU$40, amounting to a rate of eight dollars per dose (2019).In Alberta, in addition to pharmacy distribution, take-home naloxone kits are available and commonly distributed in most drug treatment or rehabilitation centres.In Europe, take home naloxone pilots were launched in the Channel Islands and in Berlin in the late 1990s. In 2008 the Welsh Assembly government announced its intention to establish demonstration sites for take-home naloxone, and in 2010 Scotland instituted a national naloxone program. Inspired by North American and European efforts, non-governmental organizations running programs to train drug users as overdose responders and supply them with naloxone are now operational in Russia, Ukraine, Georgia, Kazakhstan, Tajikistan, Afghanistan, China, Vietnam, and Thailand. Noting the high risk of overdose among people with HIV who inject drugs, international HIV donors including the Presidents Emergency Plan for AIDS Relief, the Global Fund to Fight AIDS, Tuberculosis and Malaria, and the Open Society Foundations, have supported the purchase and distribution of naloxone to those at risk in low- and middle income countries.In 2017, Next Harm Reduction in New York State began distributing naloxone and other harm reduction supplies by mail to those in the US unable to get them locally.In 2018, a maker of naloxone announced it would provide a free kit including two doses of the nasal spray, as well as educational materials, to each of the 16,568 public libraries and 2,700 YMCAs in the U.S. Media The 2013 documentary film Reach for Me: Fighting to End the American Drug Overdose Epidemic interviews people involved in naloxone programs aiming to make naloxone available to opioid users and people with chronic pain. Criticism Some political commentators, law enforcement workers, and addiction specialists have argued naloxone enables opioid addiction and worsens the crisis. Some police officers report reviving the same addict multiple times and that the availability of naloxone have allowed some addicts to push their use over the edge. Conservative radio host Lars Larson noted that naloxone only works for an hour, and if a person does not receive stabilizing medical help in that time, the addict just overdoses again. Other critics have noted Narcan nasal sprays American manufacturer views colleges, schools, libraries, and community centers as "untapped markets" and a "growth opportunity." Narcans manufacturer also charges $150 for the nasal spray and aggressively sues competitors looking to market a cheaper unauthorized generic version of the drug. The public relations effort to raise awareness of naloxone and promote policies such as bulk purchases by police departments obviously increases sales. See also Buprenorphine/naloxone Oxycodone/naloxone Naloxazone, the hydrazone analog References Further reading Naloxone, Flumazenil and Dantrolene as Antidotes. IPCS/CEC Evaluation of Antidotes Series. Vol. 1. Cambridge University Press. 1993. ISBN 0-521-45459-X. EUR 14797 EN. External links "Naloxone". Drug Information Portal. U.S. National Library of Medicine. "Naloxone hydrochloride". Drug Information Portal. U.S. National Library of Medicine. "Naloxone Nasal Spray". MedlinePlus. "Naloxone". Substance Abuse and Mental Health Services Administration (SAMHSA). "FDA recommends health care professionals discuss naloxone with all patients when prescribing opioid pain relievers or medicines to treat opioid use disorder". U.S. Food and Drug Administration (FDA). 23 July 2020.</ref>
Burosumab
Burosumab, sold under the brand name Crysvita, is a human monoclonal antibody medication for the treatment of X-linked hypophosphatemia and tumor-induced osteomalacia. Burosumab was approved by the FDA for its intended purpose, in patients aged one year and older, in April 2018. The FDA approval fell under both the breakthrough therapy and orphan drug designations. It was approved for use in the European Union in February 2018.The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication. Medical uses In the United States, burosumab is indicated for the treatment of adults and children ages one year and older with x-linked hypophosphatemia (XLH), a rare, inherited form of rickets, and for the treatment of people age two and older with tumor-induced osteomalacia (TIO), a rare disease that is characterized by the development of tumors that cause weakened and softened bones. The tumors associated with TIO release a peptide hormone-like substance known as fibroblast growth factor 23 (FGF23) that lowers phosphate levels.In the European Union, burosumab is indicated for the treatment of X-linked hypophosphataemia with radiographic evidence of bone disease in children one year of age and older and adolescents with growing skeletons.XLH is genetic disorder affecting phosphate metabolism within the body, which results in hypophosphatemia. The disease is characterized by overproduction of the FGF23 hormone in bone cells. The FGF23 hormone is responsible for blocking phosphate re-absorption by the kidney and the suppression of the vitamin D dependent phosphate absorption by the intestine. Due to the excess activity of FGF23, phosphate levels in the blood are abnormally low, which affects the constitution of bone. Thus, burosumab is designed to bind to the FGF23 receptor and inhibit the excess activity of the FGF23 hormone within the body.While burosumab is effective for the treatment of X-linked hypophosphatemia, the National Institute for Health and Care Excellence in England and Wales initially raised concerns regarding the incremental cost-effectiveness of the new treatment but the drug is available through a simple discount scheme. History This drug was developed by Ultragenyx and is in a collaborative license agreement with Kyowa Hakko Kirin. References External links "Burosumab". Drug Information Portal. U.S. National Library of Medicine.
Isavuconazonium
Isavuconazonium sulfate, sold under the brand name Cresemba, is a systemic antifungal medication of the triazole class which is used to treat invasive aspergillosis and mucormycosis.The most common side effects include abnormal liver tests, nausea, vomiting, difficulty breathing, abdominal pain, diarrhea, injection site reactions, headache, low blood potassium and skin rash.Isavuconazonium is a prodrug of isavuconazole. Medical uses Isavuconazonium is used to treat invasive aspergillosis and invasive mucormycosis in adults aged eighteen years old and older. It is available in a capsule for administration by mouth and as a powder for administration via infusion. Contraindications Isavuconazonium is contraindicated in people taking strong CYP3A4 inhibitors, strong CYP3A4 inducers, or moderate CYP3A4 or CYP3A5 inducers. It is contraindicated in people with familial short QT syndrome. Side effects Common adverse effects (occurring in between 1 and 10% of people) include low potassium, decreased appetite, delirium, headache, sleepiness, vein inflammation, difficulty breathing, acute respiratory failure, vomiting, diarrhea, nausea, stomach pain, elevated results in liver function tests, rash, itchy skin, kidney failure, chest pain, and fatigue. There are several uncommon side effects as well.In preclinical studies, isavuconazonium caused birth defects in animals; it has not been tested in pregnant women. Interactions Isavuconazonium is converted into isavuconazole inside the body, and isavuconazole is a substrate for CYP3A4 or CYP3A5. Many other medications inhibit or induce those two enzymes, and isavuconazonium should not be administered with them. Inducers result in levels of isavuconazole that are too low and wont work, and inhibitors can cause high levels of isavuconazole which will in turn cause increased adverse events and toxicity. Likewise isavuconazonium can interfere with appropriate dosing of other drugs that are substrates for those enzymes.In addition, isavuconazole induces CYP2B6 and can decrease the amount of drugs that are metabolized by the enzyme. Isavuconazole inhibits P-glycoprotein (P-gp), BCRP, SLC22A2, and uridine diphosphate-glucuronosyltransferases, each of which remove drugs from circulation; isavuconazonium will increase the amount of drugs that are affected by those proteins and may increase their toxicities. Pharmacology After oral or intravenous (IV) administration, isavuconazonium is rapidly hydrolysed by esterases in blood or the gastrointestinal tract to the active form, isavuconazole.Isavuconazole works by inhibition of lanosterol 14α-demethylase, the enzyme responsible for converting lanosterol to ergosterol by demethylation. The resulting depletion of ergosterol and buildup of lanosterol compromise the structure of the fungal cell membrane. Mammalian cells are resistant to demethylation inhibition by azoles, making the drug effects specific to fungi. Chemistry Isavuconazonium comprises an N-(3-acetoxypropyl)-N-methylamino-carboxymethyl group linked through an ester moiety to the triazole nitrogen in isavuconazole. History Isavuconazole and isavuconazonium were discovered in Japan by researchers at Roches research center in Kamakura. Basilea Pharmaceutica, which had been spun out of Roche to develop antimicrobial assets, developed isavuconazonium through Phase II clinical trials. In February 2010, Basilea partnered with Astellas Pharma to complete Phase III trials, obtain regulatory approvals, and market the drug. In 2013 and 2014, the partners won orphan drug designation in the US for isavuconazonium for treating invasive aspergillosis, mucormycosis, and invasive candidiasis.In 2014, Basilea and Astellas amended the agreement to give Astellas sole marketing authority in North America, and Basilea the rights to market in the rest of the world.The U.S. Food and Drug Administration (FDA) granted approval in March 2015, and the European Medicines Agency (EMA) approved it in October 2015.In 2017, Basilea licensed rights to Pfizer to market isavuconazole in Europe and other regions. References External links "Isavuconazonium". Drug Information Portal. U.S. National Library of Medicine. "Isavuconazonium sulfate". Drug Information Portal. U.S. National Library of Medicine. "Isavuconazole". Drug Information Portal. U.S. National Library of Medicine.
Nelarabine
Nelarabine, sold under the brand names Arranon (US) and Atriance (EU), is a chemotherapy medication used for the treatment of T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL). Nelarabine is a prodrug of arabinosylguanine nucleotide triphosphate (araGTP), a type of purine nucleoside analog, which causes inhibition of DNA synthesis and cytotoxicity. Pre-clinical studies suggest that T-cells are particularly sensitive to nelarabine. In October 2005, it was approved by the FDA for acute lymphoblastic leukemia and T-cell lymphoblastic lymphoma that has not responded to or has relapsed following treatment with at least two chemotherapy regimens. It was later approved in the European Union in October 2005. Complete responses have been achieved with this medication. References External links "Nelarabine". Drug Information Portal. U.S. National Library of Medicine. "Nelarabine". NCI Dictionary of Cancer Terms. National Cancer Institute. "Nelarabine". National Cancer Institute.
Emicizumab
Emicizumab (trade name Hemlibra) is a humanized bispecific antibody for the treatment of haemophilia A, developed by Genentech and Chugai (a subsidiary of Roche). A Phase I clinical trial found that it was well tolerated by healthy subjects.In November 2017, it was approved in the United States for treatment of haemophilia A in those who had developed resistance to other treatments. It was subsequently approved by the US FDA in April 2018 under the breakthrough therapy designation for treatment of haemophila A in those who have not developed resistance to other treatments. The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication. Mechanism of action Emicizumab binds to both the activated coagulation factor IX and to factor X, mediating the activation of the latter. This is normally the function of coagulation factor VIII, which is missing in haemophilia A patients. References External links "Emicizumab". Drug Information Portal. U.S. National Library of Medicine.
Haloperidol decanoate
Haloperidol decanoate, sold under the brand name Haldol Decanoate among others, is a typical antipsychotic which is used in the treatment of schizophrenia. It is administered by injection into muscle at a dose of 100 to 200 mg once every 4 weeks or monthly. The dorsogluteal site is recommended. A 3.75-cm (1.5-inch), 21-gauge needle is generally used, but obese individuals may require a 6.5-cm (2.5-inch) needle to ensure that the drug is indeed injected intramuscularly and not subcutaneously. Haloperidol decanoate is provided in the form of 50 or 100 mg/mL oil solution of sesame oil and benzyl alcohol in ampoules or pre-filled syringes. Its elimination half-life after multiple doses is 21 days. The medication is marketed in many countries throughout the world. See also List of antipsychotics § Antipsychotic esters == References ==
Selinexor
Selinexor sold under the brand name Xpovio among others, is a selective inhibitor of nuclear export used as an anti-cancer medication. It works by blocking the action of exportin 1 and thus blocking the transport of several proteins involved in cancer-cell growth from the cell nucleus to the cytoplasm, which ultimately arrests the cell cycle and leads to apoptosis. It is the first drug with this mechanism of action.The most common side effects include nausea (feeling sick), vomiting, decreased appetite, weight loss, diarrhea, tiredness, thrombocytopenia (low blood-platelet counts), anaemia (low red-blood cell counts), low levels of white blood cells and hyponatraemia (low blood sodium levels).Selinexor was granted accelerated approval by the U.S. Food and Drug Administration (FDA) in July 2019, for use in combination with the corticosteroid dexamethasone for the treatment of adults with relapsed refractory multiple myeloma (RRMM) who have received at least four prior therapies and whose disease is resistant to several other forms of treatment, including at least two proteasome inhibitors, at least two immunomodulatory agents, and an anti-CD38 monoclonal antibody. In December 2020, selinexor was approved by the FDA in combination with bortezomib and dexamethasone for the treatment of adults with multiple myeloma who have received at least one prior therapy. In clinical trials, it was associated with a high incidence of severe side effects, including low platelet counts and low blood sodium levels.The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication. Selinexor was approved for medical use in the European Union in March 2021. Medical uses Selinexor is approved in combination with bortezomib and dexamethasone for the treatment of adults with multiple myeloma who have received at least one prior therapy. Selinexor is also approved for use in combination with the steroid dexamethasone in people with relapsed or refractory multiple myeloma who have received at least four prior therapies and whose disease is refractory to at least two proteosome inhibitors, at least two immunomodulatory agents, and an anti-CD38 monoclonal antibody (so-called "quad-refractory" or "penta-refractory" myeloma), for whom no other treatment options are available. It is the first drug to be approved for this indication.In June 2020, the U.S. Food and Drug Administration (FDA) approved an additional indication for selinexor to treat adults with relapsed or refractory diffuse large B-cell lymphoma (DLBCL), not otherwise specified, including DLBCL arising from follicular lymphoma, after at least two lines of systemic therapy.In the European Union, selinexor is indicated in combination with dexamethasone for the treatment of multiple myeloma in adults who have received at least four prior therapies and whose disease is refractory to at least two proteasome inhibitors, two immunomodulatory agents and an anti-CD38 monoclonal antibody, and who have demonstrated disease progression on the last therapy. Adverse effects In the clinical study (the BOSTON study) used to support FDA approval in patients with multiple myeloma after at least one prior therapy (once-weekly selinexor in combination with once-weekly bortezomib and dexamethasone),the most common adverse reactions were cytopenias, along with gastrointestinal and constitutional symptoms and were consistent with those previously reported from other selinexor studies. Most adverse reactions were manageable with dose modifications and/or standard supportive care. The most common non-hematologic adverse reactions were fatigue (59%), nausea (50%), decreased appetite (35%), and diarrhea (32%) and were mostly Grade 1 and 2 events. The most common Grade 3 and 4 adverse reactions were thrombocytopenia (43%), lymphopenia (38%), fatigue (28%) and anemia (17%).The most common adverse reactions (incidence ≥20%) in people with diffuse large B-cell lymphoma (DLBCL), excluding laboratory abnormalities, were fatigue, nausea, diarrhea, appetite decrease, weight decrease, constipation, vomiting, and pyrexia. Grade 3-4 laboratory abnormalities in ≥15% were thrombocytopenia, lymphopenia, neutropenia, anemia, and hyponatremia. Serious adverse reactions occurred in 46% of people, most often from infection. Thrombocytopenia was the leading cause of dose modifications. Gastrointestinal toxicity developed in 80% of people and any grade hyponatremia developed in 61%. Central neurological adverse reactions occurred in 25% of people, including dizziness and mental status changes.The prescribing information provides warnings and precautions for thrombocytopenia, neutropenia, gastrointestinal toxicity, hyponatremia, serious infection, neurological toxicity, and embryo-fetal toxicity. Mechanism of action Like other selective inhibitors of nuclear export (SINEs), selinexor works by binding to exportin 1 (also known as XPO1 or CRM1). XPO1 is a karyopherin which performs nuclear transport of several proteins, including tumor suppressors, oncogenes, and proteins involved in governing cell growth, from the cell nucleus to the cytoplasm; it is often overexpressed and its function misregulated in several types of cancer. By inhibiting the XPO1 protein, SINEs lead to a buildup of tumor suppressors in the nucleus of malignant cells and reduce levels of oncogene products which drive cell proliferation. This ultimately leads to cell cycle arrest and death of cancer cells by apoptosis. In vitro, this effect appeared to spare normal (non-malignant) cells.Inhibiting XPO1 affects many different cells in the body which may explain the incidence of adverse reactions to selinexor. Thrombocytopenia, for example, is a mechanistic and dose-dependent effect, occurring because selinexor causes a buildup of the transcription factor STAT3 in the nucleus of hematopoietic stem cells, preventing their differentiation into mature megakaryocytes (platelet-producing cells) and thus slowing production of new platelets. Chemistry Selinexor is a fully synthetic small-molecule compound, developed by means of a structure-based drug design process known as induced-fit docking. It binds to a cysteine residue in the nuclear export signal groove of exportin 1. Although this bond is covalent, it is slowly reversible. History Selinexor was developed by Karyopharm Therapeutics, a pharmaceutical company focused on the development of drugs that target nuclear transport. It was approved in the United States in July 2019, on the basis of a single-arm Phase IIb clinical trial. The FDA decided to grant accelerated approval despite a previous recommendation from an FDA Advisory Committee Panel which had voted 8–5 to delay approving the drug until the results from an ongoing Phase III study were known.Selinexor in combination with dexamethasone was granted accelerated approval and was granted orphan drug designation. The FDA granted the approval of Xpovio to Karyopharm Therapeutics.In June 2020, the U.S. Food and Drug Administration (FDA) approved an additional indication for selinexor to treat adults with relapsed or refractory diffuse large B-cell lymphoma (DLBCL), not otherwise specified, including DLBCL arising from follicular lymphoma, after at least two lines of systemic therapy.Approval was based on SADAL (KCP-330-009; NCT02227251), a multicenter, single-arm, open-label trial in participants with DLBCL after two to five systemic regimens. Participants received selinexor 60 mg orally on days one and three of each week.In December 2020, the FDA expanded selinexors approved indication to include its combination with bortezomib and dexamethasone for the treatment of adults with multiple myeloma who have received at least one prior therapy. Society and culture Legal status On 28 January 2021, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a conditional marketing authorization for the medicinal product Nexpovio intended for the treatment of relapsed and refractory multiple myeloma. The applicant for this medicinal product is Karyopharm Europe GmbH. Selinexor was approved for medical use in the European Union in March 2021. Research Under the codename KPT-330, selinexor was tested in several preclinical animal models of cancer, including pancreatic cancer, breast cancer, non-small-cell lung cancer, lymphomas, and acute and chronic leukemias. In humans, early clinical trials (phase I) have been conducted in non-Hodgkin lymphoma, blast crisis, and a wide range of advanced or refractory solid tumors, including colon cancer, head and neck cancer, melanoma, ovarian cancer, and prostate cancer. Compassionate use in patients with acute myeloid leukemia has also been reported.The pivotal clinical trial which served to support approval of selinexor for people with relapsed/refractory multiple myeloma was an open-label study of 122 patients known as the STORM trial. In all of the enrolled patients, patients had been treated with a median of seven prior treatment regimens including conventional chemotherapy, targeted therapy with bortezomib, carfilzomib, lenalidomide, pomalidomide, and a monoclonal antibody (daratumumab or isatuximab); nearly all had also undergone hematopoietic stem cell transplantation but had disease that continued to progress. The overall response rate was 26%, including two stringent complete responses; 39% of patients had a minimal response or better. The median duration of response was 4.4 months, median progression-free survival was 3.7 months, and median overall survival was 8.6 months.As of 2019, phase I/II and III trials are ongoing, including the use of selinexor in other cancers and in combinations with other drugs used for multiple myeloma.In November 2020, results from the multi-center, Phase III, randomized study (NCT03110562) which evaluated 402 participants with relapsed or refractory multiple myeloma who had received one to three prior lines of therapy were published in The Lancet. The study was designed to compare the efficacy, safety and certain health-related quality of life parameters of once-weekly selinexor in combination with once-weekly Velcade® (bortezomib) plus low-dose dexamethasone (SVd) versus twice-weekly Velcade® plus low-dose dexamethasone (Vd). The primary endpoint of the study was progression-free survival (PFS) and key secondary endpoints included overall response rate (ORR), rate of peripheral neuropathy, and others. Additionally, the BOSTON study allowed for patients on the Vd control arm to crossover to the SVd arm following objective (quantitative) progression of disease verified by an Independent Review Committee (IRC). The BOSTON study was conducted at over 150 clinical sites internationally. Although the study had one of the highest proportions of patients with high-risk cytogenetics (~50%) as compared with other Velcade-based studies in previously treated myeloma, the median PFS in the SVd arm was 13.93 months compared to 9.46 months in the Vd arm, representing a 4.47 month (47%) increase in median PFS (hazard ratio[HR]=0.70; p=0.0075). The SVd group also demonstrated a significantly greater ORR compared to the Vd group (76.4% vs. 62.3%, p=0.0012). Patients who had received only one prior line of therapy also demonstrated a higher ORR on the SVd arm as compared to the Vd arm (80.8% vs. 65.7%, p=0.0082). Importantly, SVd therapy compared to Vd therapy showed consistent PFS benefit and higher ORR across several important subgroups.In 2020, selinexor underwent a clinical trial for treatment of COVID-19. In this phase 2 randomized placebo-controlled single-blind trial named XPORT-CoV-1001 with a total of 190 participants with severe COVID-19, treatment with selinexor resulted in higher mortality (16% vs. 9%) and more serious adverse events (23% vs. 16%) than placebo. References External links "Selinexor". Drug Information Portal. U.S. National Library of Medicine.
Terconazole
Terconazole is an antifungal drug used to treat vaginal yeast infection. It comes as a lotion or a suppository and disrupts the biosynthesis of fats in a yeast cell. It has a relatively broad spectrum compared to azole compounds but not triazole compounds. Testing shows that it is a suitable compound for prophylaxis for those that suffer from chronic vulvovaginal candidiasis. Medical uses Terconazole is approved to treat vulvovaginal candidiasis (vaginal thrush). It works as a broad spectrum antifungal and has shown to be an effective first-line treatment against other Candida species. It also shows effectiveness against dermatomycoses in animal models.A review found that short-term rates for intravaginally administered azole treatments shows cure in 80% of cases in a short term follow-up and 66% over long term follow-up. In a double-blind study by Slavin in 1992, terconazole showed a 75% mycological cure over a short-term period (7–14 days) and 100% mycological cure over a long-term period (28–34 days). This study focused on the drug as an 80 mg vaginal suppository, taken three times overnight by 10 women. In another placebo-controlled, double blind study by Schmidt et al., the efficacy of different concentrations of terconazole creams were tested. Cream was applied for three days to 24 women between the ages of 18–60. The results showed 0.8% terconazole mycologic cure rates were 83.3% within 1–3 days of starting treatment, 83.3% within 8–11 days of treatment and 58.3% within 30–35 days of treatment. The suppository is more effective after a long-term follow-up than terconazole as a cream or other intravaginal treatments. Side effects The most common side effects of terconazole include headaches, vulvar/vaginal irritation, rash, itching, burning or discomfort. Other side effects may include abdominal pain or cramps, dysmenorrhea, chills, fever and allergic reactions. Flu-like symptoms have been recorded in those that take suppositories greater than 160 mg. May cause birth defects if used in the first trimester.Terconazole is not considered hazardous when handled under normal conditions. It is generally non-flammable and non-carcinogenic. Generally is non-toxic, however, can emit toxic fumes when dust is set alight. Can cause respiratory distress as dust. Can be absorbed by embryo within the first trimester of pregnancy and cause birth defects. Cross inhibition shows that there may be some toxicity. Interactions Terconazole may interact with the spermicide nonoxynol-9. A precipitate is formed upon combination of both drugs. Terconazole may weaken latex-based condoms. Chemistry Terconazole is a triazole ketal with broad-spectrum antifungal/antimycotic tendencies. Terconazole synthesis synologous with ketoconazole except for the fact that triazole and not imidazole heterocyclic ring is used, and that isopropyl group instead of acetamide. Terconazole has the chemical formula C26H31Cl2N5O3. The chemical name for terconazole is 1-{[(2S,4S)-2-(2,4-dichlorophenyl)-4-{[p-(4-isopropyl-1-piperazinyl)phenoxy]methyl}-1,3-dioxolan-2-yl]methyl}-1H-1,2,4-triazole. Terconazole has a melting point of 126.3 °C (259.34 °F). The molecular weight of terconazole is 532.462 g/mol. Terconazole is synthesized using two chemical compounds: cis-[2(bromomethyl)-2-(2,4-dichlorophenyl)-1,3-dioxolan-4-yl] methyl benzoate and the sodium salt of triazole, created by mixing triazole with sodium hydride. These are put in a solution and catalyzed using dimethyl sulfate at 1300 °C (2372 °F) to give many different types of triazole derivatives. These are purified using alcohol and chromatography. Terconazole is non-reactive except when exposed to strong oxidizing agents or strong bases due to the nitrogen attached to the triazole ring. It has been found to be photosensitive. Mechanism of action Terconazole binds to the heme iron component on the cytochrome P450 enzyme lanosterol of fungi, also known as CYP3A4. The gene ERG11 controls lanosterol creation. Lanosterol is found within the yeast plasma membrane. It is a class of methylsterol. Within a normal yeast cell, lanosterol is demethylated using 14α-demethylation. This process creates zymosterol: a major constituent in the ergosterol biosynthesis pathway for the creation of cell membrane constituents in yeast. This structure provides the membrane with fluidity. This occurs by transforming lanosterol into 4,4-dimethyl cholesta-8,14,24-triene-3-β-ol. This stops respiration by prohibiting reduction of NADH to NAD. This stops biosynthesis of cell membrane products as well as transport and catabolism. Eventually, membrane fluidity and activity of membrane bound enzymes become depleted. It has also been shown to inhibit morphologic change of yeast as well as cell adherence and is directly toxic to yeast. Terconazole targets fungi specifically since humans do not use lanosterol in this pathway. This process does not affect all fungi such as Pneumocystis jirovecii, which lacks lanosterol. Metabolism Absorption of terconazole is 5–8% in patients that have had a hysterectomy and 12–16% in other patients. In those that administered 0.8% terconazole, plasma concentrations of the drug remained quite low with the peak plasma concentration being 0.006 mcg at 6.6 hours. Those metabolism rates show similar results in pregnant vulvovaginal candidiasis, non-pregnant vulvovaginal candidiasis and healthy women. The half-life of terconazole in blood is recorded to be around 6.9 hours over a range of 4–11.3 hours). Radioactivity of plasma terconazole is low compared to terconazole at 0.6%. Excretion of radioactivity is via two routes, renal (32–53%) and fecal (47–52%). Metabolism is extensive and is highly protein bound (94.9%) with the degree of binding being independent of drug concentration. History In 1940, the first commercial antifungal drug, called amphotericin B, was available on the market, replacing rare and expensive treatments. It was effective in its function but was very toxic and only used for serious infections. The drug was infused into the bloodstream and could cause kidney damage and other side effects. The first azole compounds to replace this treatment were synthesized in the late 1960s and early 1970s and administered to humans under strict care. These compounds were imidazoles, a molecule containing two non-adjacent nitrogen atoms in a 5 membered ring. The first oral antimycotic imidazole, called ketoconazole, was available on the market in 1981. Triazole based drugs came shortly after and quickly gained popularity due to its broader spectrum of antifungal activity and less toxicity. Terconazole was the first triazole-based antifungal drug synthesized for human use. Janssen Pharmaceutica developed it in 1983. Previously, all triazole based drugs targeted fungal infections related to plants from Candida species. Since creation, terconazole has been superseded by second-generation triazoles due to their even broader spectrum and higher activity levels against resistant pathogens like Aspergillus spp. It is still used as a treatment in cases of resistance to other drugs. Available forms Terconazole is a white, odourless powder. It can be purchased commercially in the following forms: Terconazole 0.4% cream 5 g applied intravaginally once a day for 7 days; Terconazole 0.8% cream 5 g applied intravaginally once a day for 3 days; Terconazole 80 mg vaginal suppository used once daily for 3 days. References External link Information about terconazole from the United States Government
Tafenoquine
Tafenoquine, sold under the brand name Krintafel among others, is a medication used to prevent and to treat malaria. With respect to acute malaria, it is used together with other medications to prevent relapse by Plasmodium vivax. It may be used to prevent all types of malaria. It is taken by mouth.Common side effects include vomiting, headache, and dizziness. Other side effects may include methemoglobinemia, trouble sleeping, and anaphylaxis. In people with G6PD deficiency, red blood cell breakdown may occur. Use in pregnancy is not recommended. Tafenoquine is in the 8-aminoquinoline family of medications. How it works is unclear but it is effective both in the liver and bloodstream. A possible mechanism of action and other novel perspectives have been published.Tafenoquine was approved for medical use in Australia and in the United States in 2018. Tafenoquine is related to primaquine. Medical use Prevention Tafenoquine may be used to prevent all types of malaria. For this use 200 mg 3 days before travel then 200 mg per week until one week after travel is recommended. Treatment Tafenoquine is used for eliminating the hypnozoite stage of Plasmodium vivax and Plasmodium ovale that is responsible for relapse of these malarial infections, even when the blood stages are successfully cleared. Primaquine for 14 days can also be used for this. The advantage of tafenoquine is that it has a long half-life (2–3 weeks) and therefore a single treatment is sufficient. For this use, a single dose of 300 mg is recommended. It is used with another medication, such as chloroquine, that kills the parasites in the bloodstream.There is a need to determine whether or not tafenoquine kills the numerous, non-circulating asexual P. vivax parasites that are now known to occur in the spleen, bone marrow, and possibly elsewhere in chronic infections. Chemistry Tafenoquine contains a stereocenter and consists of two enantiomers. This is a mixture of (R) - and the (S) - Form: History Tafenoquine was approved for medical use in Australia and in the United States in 2018. Tafenoquine was given an orphan drug designation and was granted breakthrough therapy status in 2013 in the United States. Society and culture One version is made by GlaxoSmithKline. While another is made by 60 Degrees Pharmaceutical. Names Etaquine was a generic name proposed by WRAIR, and subsequently rejected by CDER.Trade names Kozenis (Australia) Kodatef (Australia) Arakoda (USA), Krintafel (USA) References External links "Tafenoquine". Drug Information Portal. U.S. National Library of Medicine.
Desloratadine
Desloratadine (trade names Clarinex and Aerius) is a tricyclic H1 inverse agonist that is used to treat allergies. It is an active metabolite of loratadine. It was patented in 1984 and came into medical use in 2001. Medical uses Desloratadine is used to treat allergic rhinitis, nasal congestion and chronic idiopathic urticaria (hives). It is the major metabolite of loratadine and the two drugs are similar in safety and effectiveness. Desloratadine is available in many dosage forms and under many trade names worldwide.An emerging indication for desloratadine is in the treatment of acne, as an inexpensive adjuvant to isotretinoin and possibly as maintenance therapy or monotherapy. Side effects The most common side-effects are fatigue (1.2%), dry mouth (3%), and headache (0.6%). Interactions Co-administration with erythromycin, ketoconazole, azithromycin, fluoxetine or cimetidine resulted in elevated blood plasma concentrations of desloratadine and its metabolite 3-hydroxydesloratadine in studies. However, no clinically relevant changes were observed. Pharmacology Pharmacodynamics Desloratadine is a selective H1-antihistamine which functions as an inverse agonist at the histamine H1 receptor.At very high doses, is also an antagonist at various subtypes of the muscarinic acetylcholine receptors. This effect is not relevant for the drugs action at therapeutic doses. Pharmacokinetics Desloratadine is well absorbed from the gut and reaches highest blood plasma concentrations after about three hours. In the bloodstream, 83 to 87% of the substance are bound to plasma proteins.Desloratadine is metabolized to 3-hydroxydesloratadine in a three-step sequence in normal metabolizers. First, n-glucuronidation of desloratadine by UGT2B10; then, 3-hydroxylation of desloratadine N-glucuronide by CYP2C8; and finally, a non-enzymatic deconjugation of 3-hydroxydesloratadine N-glucuronide. Both desloratadine and 3-hydroxydesloratadine are eliminated via urine and feces with a half-life of 27 hours in normal metabolizers. It exhibits only peripheral activity since it does not readily cross the blood-brain barrier; hence, it does not normally cause drowsiness because it does not readily enter the central nervous system.Desloratadine does not have a strong effect on a number of tested enzymes in the cytochrome P450 system. It was found to weakly inhibit CYP2B6, CYP2D6, and CYP3A4/CYP3A5, and not to inhibit CYP1A2, CYP2C8, CYP2C9, or CYP2C19. Desloratadine was found to be a potent and relatively selective inhibitor of UGT2B10, a weak to moderate inhibitor of UGT2B17, UGT1A10, and UGT2B4, and not to inhibit UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9, UGT2B7, UGT2B15, UGT1A7, and UGT1A8. Pharmacogenomics 2% of Caucasian people and 18% of people from African descent are desloratadine poor metabolizers. In these people, the drug reaches threefold highest plasma concentrations six to seven hours after intake, and has a half-life of about 89 hours. However, the safety profile for these subjects is not worse than for extensive (normal) metabolizers. See also Benzocycloheptenes Azatadine References External links "Desloratadine". Drug Information Portal. U.S. National Library of Medicine.
Tropicamide
Tropicamide, sold under the brand name Mydriacyl among others, is a medication used to dilate the pupil and help with examination of the eye. Specifically it is used to help examine the back of the eye. It is applied as eye drops. Effects occur within 40 minutes and last for up to a day.Common side effects include blurry vision, increased intraocular pressure, and sensitivity to light. Another rare but severe side effect is psychosis, particularly in children. It is unclear if use during pregnancy is safe for the fetus. Tropicamide is in the antimuscarinic part of the anticholinergic family of medications. It works by making the muscles within the eye unable to respond to nerve signals.Tropicamide was approved for medical use in the United States in 1960. It is on the World Health Organizations List of Essential Medicines. Medical use Tropicamide is an antimuscarinic drug that produces short acting mydriasis (dilation of the pupil) and cycloplegia when applied as eye drops. It is used to allow better examination of the lens, vitreous humor, and retina. Due to its relatively short duration of effect (4–8 hours), it is typically used during eye examinations such as the dilated fundus examination, but it may also be used before or after eye surgery. Cycloplegic drops are often also used to treat anterior uveitis, decreasing risk of posterior synechiae and decreasing inflammation in the anterior chamber of the eye. Tropicamide is occasionally administered in combination with p-hydroxyamphetamine (brand name Paremyd), which is a sympathomimetic. The use of the sympathomimetic drug causes the iris dilator muscle to be directly stimulated, causing increased dilation. In the United States, the sympathomimetic drop most commonly used along with tropicamide, is 2.5% phenylephrine hydrochloride (brand name AK-Dilate). Side effects Tropicamide induces transient stinging and a slight and transient rise in intraocular pressure in the majority of patients. It may cause redness or conjunctivitis (inflammation) and also blurs near vision for a short while after instillation (care must be taken, and the patient must only drive when vision returns to normal). Tropicamide may, in very rare cases, cause an attack of acute angle-closure glaucoma. This tends to be in patients with narrow anterior chamber angles, and closure risk must be assessed by the practitioner prior to instillation. Tropicamide is often preferred to atropine because atropine has a longer half-life, causing prolonged dilation and blurry vision for up to a week. Atropine has less sting effect, but can be toxic or fatal if ingested in large quantities by children or adults. With eye drops, systemic effects are minimal to nonexistent due to very low absorption into the bloodstream. Illicit use According to the researchers of the European Commission-funded ReDNet Project, in Russia tropicamide is currently abused (injected intravenously) as an inexpensive recreational deliriant drug. Stereochemistry Tropicamide has a chiral center and two enantiomers. Medications are racemates. References External links "Tropicamide". Drug Information Portal. U.S. National Library of Medicine.
Guanfacine
Guanfacine, sold under the brand name Tenex among others, is an oral medication used to treat attention deficit hyperactivity disorder (ADHD) and high blood pressure. Guanfacine is FDA-approved for monotherapy treatment of ADHD as well as being used for augmentation of other treatments, such as stimulants. Guanfacine is also used off-label to treat tic disorders, anxiety disorders and PTSD.Common side effects include sleepiness, constipation, and dry mouth. Other side effects may include low blood pressure and urinary problems. The FDA has categorized Guanfacine as "Category B" in pregnancy which means animal-reproduction studies have not demonstrated a fetal risk or an adverse effect during pregnancy or breastfeeding. It appears to work by activating the α2A receptors in the brain thereby decreasing sympathetic nervous system activity.Guanfacine was approved for medical use in the United States in 1986. It is available as a generic medication. In 2019, it was the 140th most commonly prescribed medication in the United States, with more than 4 million prescriptions. Medical uses Guanfacine is FDA approved as monotherapy or augmentation with stimulants to treat attention deficit hyperactivity disorder. It is also FDA approved to treat high blood pressure. It is FDA approved as monotherapy treatment for ADHD, and it is also FDA approved to be used in augmentation with stimulant medications when stimulants medications are not fully effective (stimulants include medications such as amphetamines and methylphenidate). Guanfacine can offer a synergistic enhancement of stimulant treatment for ADHD, and in many cases can also help control the side effect profile of stimulant medications. Guanfacine is also used off-label to treat Tic Disorders, Anxiety Disorders and PTSD.An off-label use of guanfacine is for treatment of anxiety, such as generalized anxiety disorder and post-traumatic stress disorder symptoms. Guanfacine and other α2A agonists have anxiolytic-like action, thereby reducing the emotional responses of the amygdala, and strengthening prefrontal cortical regulation of emotion, action and thought. These actions arise from both inhibition of stress-induced catecholamine release, and from prominent, post-synaptic actions in prefrontal cortex. Due to its prolonged half-life, it also has been seen to improve sleep interrupted by nightmares in PTSD patients. All of these actions likely contribute to the relief of the hyperarousal, re-experiencing of memory, and impulsivity associated with PTSD. Guanfacine appears to be especially helpful in treating children who have been traumatized or abused. Adverse effects Side effects of guanfacine are dose-dependent.Very common (>10% incidence) adverse effects include sleepiness, tiredness, headache, and stomach ache.Common (1-10% incidence) adverse effects include decreased appetite, nausea, dry mouth, urinary incontinence, and rashes.Typical side effects such as fatigue, irritability and stomach upset can take a week or two to subside. Increases in dosage can have the same adjustment period. Interactions Guanfacine availability is significantly affected by the CYP3A4 and CYP3A5 enzymes. Medications that inhibit or induce those enzymes change the amount of guanfacine in circulation and thus its efficacy and rate of adverse effects. Because of its impact on the heart, it should be used with caution with other cardioactive drugs. Similar concern is appropriate when it is used with sedating medications.Guanfacine is known to lower the users tolerance for alcohol, heightening its effect, and alcohol use may prolong the effects of the medication. Pharmacology Guanfacine is a highly selective agonist of the α2A adrenergic receptor, with low affinity for other receptors. However it may also be a potent 5-HT2B receptor agonist, which can be associated with valvulopathy, although not all 5-HT2B agonists have this effect. Mechanism of action Guanfacine works by activating α2A adrenoceptors within the central nervous system. This leads to reduced peripheral sympathetic outflow and thus a reduction in peripheral sympathetic tone, which lowers both systolic and diastolic blood pressure.In ADHD, guanfacine works by strengthening regulation of attention and behavior by the prefrontal cortex. These enhancing effects on prefrontal cortical functions are believed to be due to drug stimulation of post-synaptic α2A adrenoceptors on dendritic spines. cAMP-mediated opening of HCN and KCNQ channels is inhibited, which enhances prefrontal cortical synaptic connectivity and neuronal firing. The use of guanfacine for treating prefrontal disorders was developed by the Arnsten Lab at Yale University. Pharmacokinetics Guanfacine has an oral bioavailability of 80%. There is no clear evidence of any first-pass metabolism. Elimination half-life is 17 hours with the major elimination route being renal. The principal metabolite is the 3-hydroxy-derivative, with evidence of moderate biotransformation, and the key intermediate is an epoxide. Elimination is not impacted with impaired renal function. As such, metabolism by liver is the assumption for those with impaired renal function, as supported by increased frequency of known side effects of orthostatic hypotension and sedation. History In 1986, guanfacine was approved by the FDA for the treatment of hypertension under the brand name Tenex (Drugs@FDA). In 2010, guanfacine was approved by the FDA for the treatment of attention deficit hyperactivity disorder for people 6–17 years old. It was approved for ADHD by the European Medicines Agency under the name Intuniv in 2015. It was added to the Australian Pharmaceutical Benefits Scheme for the treatment of ADHD in 2018. Brand names Brand names include Tenex, Afken, Estulic, and Intuniv (an extended release formulation). Research Guanfacine has been studied as a treatment for post-traumatic stress disorder (PTSD). Evidence of efficacy in adults is limited, but one study found positive results in children with comorbid ADHD. It may be also useful in adult PTSD patients who do not respond to SSRIs.Results of studies using guanfacine to treat Tourettes have been mixed.Guanfacine has been investigated for treatment of withdrawal for opioids, ethanol, and nicotine. Guanfacine has been shown to help reduce stress-induced craving of nicotine in smokers trying to quit, which may involve strengthening of prefrontal cortex meditated self-control. References External links "Guanfacine". Drug Information Portal. U.S. National Library of Medicine.
Pegvisomant
Pegvisomant, sold under the brand name Somavert, is a growth hormone receptor antagonist used in the treatment of acromegaly. It is primarily used if the pituitary gland tumor causing the acromegaly cannot be controlled with surgery or radiation, and the use of somatostatin analogues is unsuccessful, but is also effective as a monotherapy. It is delivered as a powder that is mixed with water and injected under the skin. Medical uses Pegvisomant is indicated for the treatment of adults with acromegaly. Side effects Side effects of pegvisomant include reactions at the injection site, swelling of the limbs, chest pain, hypoglycemia, nausea and hepatitis. Discovery Pegvisomant was discovered at Ohio University in 1987 by Distinguished Professor John Kopchick and graduate student Wen Chen at the Edison Biotechnology Institute. After completing clinical trials, it was approved for the treatment of acromegaly by the FDA in 2003 and marketed by Pfizer. Structure Pegvisomant is a protein containing 191 amino acid residues to which several polyethylene glycol polymers have been covalently bound in order to slow clearance from the blood. The protein is a modified version of human growth hormone designed to bind to and block the growth hormone receptor. It is manufactured using genetically modified E. coli bacteria. Mechanism of action Pegvisomant blocks the action of growth hormone on the growth hormone receptor to reduce the production of IGF-1. IGF-1 is responsible for most of the symptoms of acromegaly, and the normalization of its levels can control the symptoms.Long-term treatment studies with pegvisomant as a monotherapy have shown it to be safe, and effective. Research Some studies show the potential of using pegvisomant as an anti-tumor treatment for certain types of cancers. References External links "Pegvisomant". Drug Information Portal. U.S. National Library of Medicine.
Pioglitazone/glimepiride
Pioglitazone/glimepiride, sold under the brand name Duetact among others, is a fixed-dose combination anti-diabetic medication for the treatment of type 2 diabetes. It contains the thiazolidinedione pioglitazone and the sulfonylurea glimepiride. It is taken by mouth.The most common side effects include upper respiratory tract infections (such as colds), hypoesthesia (reduced sense of touch), bone fractures, weight gain, dizziness, flatulence (gas) and edema (swelling).Pioglitazone makes cells (fat, muscle and liver) more sensitive to insulin, which means that the body makes better use of the insulin it produces. Glimepiride is a sulphonylurea: it stimulates the pancreas to produce more insulin. Pioglitazone/glimepiride was approved for medical use in the United States in July 2006, and in the European Union in January 2007. Medical uses In the United States pioglitazone/glimepiride is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus who are already treated with a thiazolidinedione and sulfonylurea or who have inadequate glycemic control on a thiazolidinedione alone or a sulfonylurea alone.In the European Union pioglitazone/glimepiride is indicated for the treatment of people with type 2 diabetes mellitus who show intolerance to metformin or for whom metformin is contraindicated and who are already treated with a combination of pioglitazone and glimepiride. References External links "Glimepiride mixture with pioglitazone hydrochloride". Drug Information Portal. U.S. National Library of Medicine. "Glimepiride mixture with pioglitazone". Drug Information Portal. U.S. National Library of Medicine.
Succimer
Succimer, sold under the brand name Chemet among others, is a medication used to treat lead, mercury, and arsenic poisoning. When radiolabeled with technetium-99m, it is used in a number of types of diagnostic testing. A full course is 19 days of medications by mouth. More than two weeks should pass before a second course is given.Common side effects include vomiting, diarrhea, rash, and low blood neutrophil levels. Liver problems and allergic reactions may also occur with use. Whether use during pregnancy is safe for the baby is unclear. Dimercaptosuccinic acid is in the chelating agent family of medications. It works by binding with lead and a number of other heavy metals, allowing them to leave the body in the urine.Dimercaptosuccinic acid has been used medically since the 1950s. It is on the World Health Organizations List of Essential Medicines. In the United States, no generic version was available as of 2015. Medical uses Dimercaptosuccinic acid is indicated for the treatment of lead poisoning in children with blood level measured above 45 µg/dl. The use of dimercaptosuccinic acid is not approved for prevention of lead poisoning in anticipation of exposure in known lead-contaminated environments. Dimercaptosuccinic acid can cross the blood–brain barrier of mice, but it is not known if this is also the case in humans. Even if dimercaptosuccinic acid cannot reverse the damages done to the central nervous system, it might prevent further deterioration.Dimercaptosuccinic acid facilitates urinary excretion of lead, and with sufficiently aggressive treatment, can reduce lead content in the brain. It also increases urinary excretion of copper and zinc. Dimercaptosuccinic acid improved cognitive function in rats that had been exposed to lead, but reduced cognitive function in rats that had not been exposed to lead.7,8-dihydroxyflavone can reverse long-term effects of chronic Lead exposure in the brain. Chemistry It is the organosulfur compound with the formula HO2CCH(SH)CH(SH)CO2H. This colorless solid contains two carboxylic acid and two thiol groups, the latter being responsible for its mildly unpleasant odour. It occurs in two diastereomers, meso and the chiral dl forms. The 2,3-dimercaptosuccinic acid molecule has two stereocentres (two asymmetric carbon atoms), and can exist as three different stereoisomers. The 2S,3S and 2R,3R isomers are a pair of enantiomers, whereas the 2R,3S isomer is a meso compound and thus optically inactive. Preparation and reactivity Dimercaptosuccinic acid may be prepared by reacting acetylenedicarboxylic acid with sodium thiosulfate or thioacetic acid followed by hydrolysis. The dimethyl ester is also known.Meso 2,3-dimercaptosuccinic acid binds to "soft" heavy metals such as Hg2+ and Pb2+, mobilizing these ions for excretion. It binds to metal cations through the thiol groups, which ionize upon complexation. History Dimercaptosuccinic acid was first synthesized by V. Nirenburg in the Urals Polytechnic Institute, commissioned by one of the electrical enterprises of Sverdlovsk, which consumed many tons of mercury and was looking for a medicine to prevent poisoning of personnel. In 1957, Chinese scientists found that dimercaptosuccinic acid can effectively treat antimony poisoning due to overdose of tartar emetic. Pronounced protective effect in animal poisoning with arsenic and mercury was first shown by I. Okonishnikova in 1962. In 1984, the now-defunct Bock Pharmaceutical Company requested the FDA grant approval for orphan drug status under the brand name Chemet and the FDA approved of this in 1991, providing exclusivity until 1998 which was conveyed to the successor Sanofi in 1996. References Further reading Aposhian, H.V.; Aposhian, M.M. (1990). "Meso-2,3-dimercaptosuccinic acid: Chemical, pharmacological and toxicological properties of an orally effective metal chelating agent". Annual Review of Pharmacology and Toxicology. 30 (1): 279–306. doi:10.1146/annurev.pa.30.040190.001431. PMID 2160791. External links "Succimer". Drug Information Portal. U.S. National Library of Medicine.
Ruxolitinib
Ruxolitinib, sold under the brand names Jakafi and Jakavi, is a medication approved in the US in 2011 for the treatment of intermediate or high-risk myelofibrosis, a type of myeloproliferative disorder that affects the bone marrow; polycythemia vera (PCV), when there has been an inadequate response to or intolerance of hydroxyurea; and steroid-refractory acute graft-versus-host disease. Ruxolitinib is a janus kinase inhibitor.It was developed and marketed by Incyte Corp in the US under the brand name Jakafi, and by Novartis elsewhere in the world, under the brand name Jakavi. Medical uses In the United States and the European Union, ruxolitinib is indicated for the treatment of disease-related splenomegaly or symptoms in adults with primary myelofibrosis (also known as chronic idiopathic myelofibrosis), post-polycythaemia-vera myelofibrosis, or post-essential thrombocythaemia myelofibrosis. It is also indicated for the treatment of adults with polycythaemia vera who are resistant to or intolerant of hydroxyurea. Ruxolitinib is also indicated for the treatment of steroid-refractory acute graft-versus-host disease in people who are twelve years of age and older, and for the treatment of chronic graft-versus-host disease (cGVHD) after failure of one or two lines of systemic therapy in people twelve years of age and older.In the United States, ruxolitinib cream is indicated for the topical treatment of mild to moderate atopic dermatitis and vitiligo. Side effects In myelofibrosis, the most common side effects include thrombocytopenia (low blood platelet counts), anaemia (low red blood cell counts), neutropenia (low levels of neutrophils), urinary tract infections (infection of the structures that carry urine), bleeding, bruising, weight gain, hypercholesterolaemia (high blood cholesterol levels), dizziness, headache and raised liver enzyme levels.In polycythaemia vera, the most common side effects include anemia (low red blood cell counts) and thrombocytopenia (low blood platelet count), bleeding, bruising, hypercholesterolaemia (high blood cholesterol levels), hypertriglyceridemia (high blood fat levels), dizziness, raised liver enzyme levels and high blood pressure.In acute graft-versus-host disease, the most common hematologic adverse reactions include anemia, thrombocytopenia, and neutropenia. The most common nonhematologic adverse reactions include infections and edema.Immunologic side effects have included herpes zoster (shingles) and case reports of opportunistic infections. Metabolic side effects have included weight gain. Laboratory abnormalities have included alanine transaminase (ALT) abnormalities, aspartate transaminase (AST) abnormalities, and mildly elevated cholesterol levels. Mechanism of action Ruxolitinib is a janus kinase inhibitor (JAK inhibitor) with selectivity for subtypes JAK1 and JAK2. Ruxolitinib inhibits dysregulated JAK signaling associated with myelofibrosis. JAK1 and JAK2 recruit signal transducers and activators of transcription (STATs) to cytokine receptors leading to modulation of gene expression. History In March 2012 the phase III Controlled Myelofibrosis Study with Oral JAK Inhibitor-I (COMFORT-I) and COMFORT-II trials showed significant benefits by reducing spleen size and relieving debilitating symptoms.In September 2021, ruxolitinib cream (sold under the brand name Opzelura) was approved for medical use in the United States for the treatment of mild to moderate atopic dermatitis (AD). It is the first topical janus kinase inhibitor approved in the United States.In July 2022, ruxolitinib cream (sold under the brand name Opzelura) was approved for medical use in the United States for the treatment of vitiligo. Society and culture Legal status In November 2011, ruxolitinib was approved by the U.S. Food and Drug Administration (FDA) for the treatment of intermediate or high-risk myelofibrosis based on results of the COMFORT-I and COMFORT-II Trials.In 2014, it was approved in polycythemia vera (PCV) when there has been an inadequate response to or intolerance of hydroxyurea, based on the RESPONSE trial. Research It is being investigated for plaque psoriasis, alopecia areata, relapsed diffuse large B-cell lymphoma, and peripheral T-cell lymphoma.In February 2016, a phase III trial for pancreatic cancer was terminated due to insufficient efficacy.Eight weeks-treatment with ruxolitinib blunted senescent cell-mediated inhibition of adipogenesis and increased insulin sensitivity in 22-month-old mice.As of September 2019, a clinical trial is in progress to evaluate "Treatment Free Remission After Combination Therapy With Ruxolitinib Plus Tyrosine Kinase Inhibitors". References External links "Ruxolitinib". Drug Information Portal. U.S. National Library of Medicine. "Ruxolitinib phosphate". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT03112603 for "A Study of Ruxolitinib vs Best Available Therapy (BAT) in Patients With Steroid-refractory Chronic Graft vs. Host Disease (GvHD) After Bone Marrow (REACH3)" at ClinicalTrials.gov Clinical trial number NCT03745638 for "TRuE AD1 - An Efficacy and Safety Study of Ruxolitinib Cream in Adolescents and Adults With Atopic Dermatitis" at ClinicalTrials.gov Clinical trial number NCT03745651 for "TRuE AD2 - An Efficacy and Safety Study of Ruxolitinib Cream in Adolescents and Adults With Atopic Dermatitis" at ClinicalTrials.gov
Prochlorperazine
Prochlorperazine, formerly sold under the brand name Compazine among others, is a medication used to treat nausea, migraines and anxiety. It is a less preferred medication for anxiety. It may be taken by mouth, rectally, injection into a vein, or injection into a muscle.Common side effects include sleepiness, blurry vision, low blood pressure, and dizziness. Serious side effects may include movement disorders including tardive dyskinesia and neuroleptic malignant syndrome. Use in pregnancy and breastfeeding is generally not recommended. It is a typical antipsychotic which is believed to work by reducing the action of dopamine in the brain.Prochlorperazine was approved for medical use in the United States in 1956. It is available as a generic medication. In 2019, it was the 313th most commonly prescribed medication in the United States, with more than 1 million prescriptions. Medical uses Vomiting Prochlorperazine is used to prevent vomiting caused by chemotherapy, radiation therapy and in the pre- and postoperative setting. A 2015 Cochrane review found no differences in efficacy among drugs commonly used for this purpose in emergency rooms. Migraine Prochlorperazine, generally by intravenous, is used to treat migraine. Such use is recommended by The American Headache Society. A 2019 systematic review found prochlorperazine was nearly three times as likely as metoclopramide to relieve headache within 60 minutes of administration. Labyrinthitis In the UK prochlorperazine maleate has been used for labyrinthitis, which include not only nausea and vertigo, but spatial and temporal jerking and distortion. Side effects Sedation is very common, and extrapyramidal side effects are common and include restlessness, dystonic reactions, pseudoparkinsonism, and akathisia; the extrapyramidal symptoms can affect 2% of people at low doses, whereas higher doses may affect as many as 40% of people.Prochlorperazine can also cause a life-threatening condition called neuroleptic malignant syndrome (NMS). Some symptoms of NMS include high fever, stiff muscles, neck muscle spasm, confusion, irregular pulse or blood pressure, fast heart rate (tachycardia), sweating, abnormal heart rhythms (arrhythmias). Research from the Veterans Administration and United States Food and Drug Administration show injection site reactions. Adverse effects are similar in children. Warning The FDA approved label for prochlorperazine includes a warning for increased risk of mortality in elderly patients with dementia related psychosis. Discontinuation The British National Formulary recommends a gradual withdrawal when discontinuing antipsychotics to avoid acute withdrawal syndrome or rapid relapse. Symptoms of withdrawal commonly include nausea, vomiting, and loss of appetite. Other symptoms may include restlessness, increased sweating, and trouble sleeping. Less commonly there may be a feeling of the world spinning, numbness, or muscle pains. Symptoms generally resolve after a short period of time.There is tentative evidence that discontinuation of antipsychotics can result in psychosis. It may also result in reoccurrence of the condition that is being treated. Rarely tardive dyskinesia can occur when the medication is stopped. Pharmacology Prochlorperazine is thought to exert its antipsychotic effects by blocking dopamine receptors.Prochlorperazine is analogous to chlorpromazine; both of these agents antagonize dopaminergic D2 receptors in various pathways of the central nervous system. This D2 blockade results in antipsychotic, antiemetic and other effects. Hyperprolactinemia is a side effect of dopamine antagonists as blockade of D2 receptors within the tuberoinfundibular pathway results in increased plasma levels of prolactin due to increased secretion by lactotrophs in the anterior pituitary. Following intramuscular injection, the antiemetic action is evident within 5 to 10 minutes and lasts for 3 to 4 hours. Rapid action is also noted after buccal treatment. With oral dosing, the start of action is delayed but the duration somewhat longer (approximately 6 hours). Society and culture In the UK, prochlorperazine is available for the treatment of nausea caused by migraine as a tablet dissolved in the mouth, and in Australia as a tablet swallowed whole. It is sold as a "pharmacy medicine", meaning it does not require a prescription but is only available after talking with a pharmacist. Marketing Prochlorperazine is available as tablets, suppositories, and in an injectable form.As of September 2017 it was marketed under the trade names Ametil, Antinaus, Buccastem, Bukatel, Chlormeprazine, Chloropernazine, Compazine, Compro, Daolin, Dhaperazine, Emedrotec, Emetiral, Eminorm, Lotamin, Mitil, Mormal, Nautisol, Novamin, Novomit, Proazine, Procalm, Prochlorperazin, Prochlorperazine, Prochlorpérazine, Prochlorperazinum, Prochlozine, Proclorperazina, Promat, Promin, Promtil, Roumin, Scripto-metic, Seratil, Stemetil, Steremal, Vergon, Vestil, and Volimin.It was also marketed at that time as a combination drug for humans with paracetamol as Vestil-A, as a combination drug for veterinary use, with isopropamide as Darbazine. Research Alexza Pharmaceuticals studied an inhaled form of prochlorperazine for the treatment of migraine through Phase II trials under the development name AT-001; development was discontinued in 2011. References External links "Prochlorperazine". Drug Information Portal. U.S. National Library of Medicine.
Quinidine
Quinidine is a class IA antiarrhythmic agent used to treat heart rhythm disturbances. It is a stereoisomer of antimalarial agent quinine, originally derived from the bark of the cinchona tree. The drug causes increased action potential duration, as well as a prolonged QT interval. As of 2019 its IV formulation is no longer being manufactured for use in the United States. Medical uses Quinidine is occasionally used as a class I antiarrhythmic agent to prevent ventricular arrhythmias, particularly in Brugada Syndrome, although its safety in this indication is uncertain.It reduces the recurrence of atrial fibrillation after patients undergo cardioversion, but it has proarrhythmic effects and trials suggest that it may lead to an overall increased mortality in these patients.Quinidine is also used to treat short QT syndrome.Eli Lilly has discontinued manufacture of parenteral quinidine gluconate in the US, and its future availability in many countries is uncertain. Other uses There is one study supporting the use of a novel combination of dextromethorphan and low dose quinidine in alleviating symptoms of easy laughing and crying (pseudobulbar affect); these are a type rather severe uncontrollable behaviors which can be present in various neurological pathologies such as amyotrophic lateral sclerosis and multiple sclerosis. The dose of quinidine (10mg two times daily) is about 1/40th of a relatively low antiarrhythmic dose (400mg, twice or 3 times daily, as an example; antiarrhythmic doses can sometimes exceed 1500mg/day). The authors did not observe significant safety risks using the low quinidine dose, but urged caution and also pointed out that quinidine interacts with a large number of other medications in dangerous or unpredictable ways. Interestingly, a meta analysis was published referencing only that one study.Although intravenous quinidine is sometimes used to treat Plasmodium falciparum malaria, the future availability of this agent is uncertain. Side effects Quinidine is also an inhibitor of the cytochrome P450 enzyme 2D6, and can lead to increased blood levels of lidocaine, beta blockers, opioids, and some antidepressants. Quinidine also inhibits the transport protein P-glycoprotein and so can cause some peripherally acting drugs such as loperamide to have central nervous system side effects, such as respiratory depression, if the two drugs are coadministered.Quinidine can cause thrombocytopenia, granulomatous hepatitis, myasthenia gravis, and torsades de pointes (dangerous heart rhythm), so is not used much today. Torsades can occur after the first dose. Quinidine-induced thrombocytopenia (low platelet count) is mediated by the immune system, and may lead to thrombocytic purpura. Quinidine intoxication can lead to a collection of symptoms collectively known as cinchonism, with tinnitus (ringing in the ears) being among the most characteristic and common symptoms of this toxicity syndrome. Pharmacology Pharmacodynamics Quinidine acts as a blocker of voltage-gated sodium channels. Inhibition of the Nav1.5 channel is specifically involved in its antiarrhythmic effects as a class I antiarrhythmic agent. Quinidine also blocks certain voltage-gated potassium channels (e.g., Kv1.4, Kv4.2, hERG, among others), acts as an antimuscarinic and alpha-1 blocker, and is an antimalarial. Mechanism of action Like all other class I antiarrhythmic agents, quinidine primarily works by blocking the fast inward sodium current (INa). Quinidines effect on INa is known as a use dependent block. This means at higher heart rates, the block increases, while at lower heart rates, the block decreases. The effect of blocking the fast inward sodium current causes the phase 0 depolarization of the cardiac action potential to decrease (decreased Vmax). It seems still efficacious as an IV antimalarial against Plasmodium falciparum. This electrolyte dependent agent also increases action potentials and prolongs the QT interval. Quinidine also blocks the slowly inactivating, tetrodotoxin-sensitive Na current, the slow inward calcium current (ICa), the rapid (IKr) and slow (IKs) components of the delayed potassium rectifier current, the inward potassium rectifier current (IKI), the ATP-sensitive potassium channel (IKATP) and Ito. At micromolar concentrations, quinidine inhibits Na+/K+-ATPase by binding to the same receptor sites as the digitalis glycosides such as ouabain. The effect of quinidine on the ion channels is to prolong the cardiac action potential, thereby prolonging the QT interval on the surface ECG. Other ECG effects include a wide notched P wave, wide QRS complex, depressed ST segment, and U waves. These are the results of both slowed depolarization and repolarization. Pharmacokinetics Elimination The elimination half-life of oral quinidine is 6 to 8 hours, and it is eliminated by the cytochrome P450 system in the liver. About 20% is excreted unchanged via the kidneys. History The effects of cinchona bark (the botanical source from which quinidine is extracted) had been commented on long before the understanding of cardiac physiology arose. Jean-Baptiste de Sénac, in his 1749 work on the anatomy, function, and diseases of the heart, had this to say: "Long and rebellious palpitations have ceded to this febrifuge". "Of all the stomachic remedies, the one whose effects have appeared to me the most constant and the most prompt in many cases is quinquina [Peruvian bark] mixed with a little rhubarb." Sénac subsequently became physician to Louis XV of France, a counselor of the state, and superintendent of the mineral waters and medicinals in France. As a result of his influence, throughout the 19th century, quinine was used to augment digitalis therapy. It was described as das Opium des Herzens (the opium of the heart). However, the use of quinidine to treat arrhythmia really only came into its own because a physician listened to the astute observation of one of his patients. In 1912, Karel Frederik Wenckebach saw a man with atrial fibrillation. He was a Dutch merchant, used to good order in his affairs. He would like to have good order in his heart business, also, and asked, "why there were heart specialists if they could not abolish this very disagreeable phenomenon ... he knew himself how to get rid of his attacks. As I did not believe him, he promised to come back next morning with a regular pulse, and he did." The man had found by chance that when he took one gram of quinine during an attack, it reliably halted it in 25 minutes; otherwise it would last for two to 14 days. Wenckebach often tried quinine again, but he succeeded in only one other patient.He made passing mention of it in his book on cardiac arrhythmias published in 1914. Four years later, Walter von Frey of Berlin reported in a leading Viennese medical journal that quinidine was the most effective of the four principal cinchona alkaloids in controlling atrial arrhythmias. Chemistry Quinidine-based ligands are used in AD-mix-β for sharpless asymmetric dihydroxylation. Veterinary use Quinidine sulfate is used in the treatment of atrial fibrillation in horses. References External links MedlinePlus Poisons Information Monograph
Letermovir
Letermovir (INN; trade name Prevymis) is an antiviral drug for the treatment of cytomegalovirus (CMV) infections. It has been tested in CMV infected patients with allogeneic stem cell transplants and may also be useful for other patients with a compromised immune system such as those with organ transplants or HIV infections. The drug was initially developed by the anti-infective division at Bayer, which became AiCuris Anti-infective Cures AG through a spin-out and progressed the development to end of Phase 2 before the project was sold to Merck & Co for Phase 3 development and approval.The drug was granted fast track status by the US Food and Drug Administration (FDA) and orphan drug status by the European Medicines Agency. It is now approved for prevention of CMV infection and disease in recipients of an allogeneic stem cell transplant.The FDA considers it to be a first-in-class medication. Medical use In the US as well as in the EU, letermovir is used for the prevention of cytomegalovirus infection and disease in adult CMV-seropositive recipients of an allogeneic stem cell transplant. The therapy is started shortly after the transplantation and typically lasts for 100 days. Although letermovir is a relatively new antiviral, CMV resistance has been documented in stem cell transplantation recipients; although rare, breakthrough infections of prophylactic treatment with letermovir underscores the ongoing selective pressure on CMVs viral evolution and its continued ability to evade therapeutic suppression through mutations in critical gene regions such as within the UL56 amplicon. Contraindications Combining the drug with pimozide or ergot alkaloids (such as ergotamine or methylergometrine) is contraindicated because these drugs are metabolized by the liver enzyme CYP3A4, and letermovir inhibits this enzyme. In people who also take ciclosporin, which increases letermovir concentrations in the body, combination with the cholesterol lowering drugs simvastatin and pitavastatin is also contraindicated. In Canada, this also applies to bosentan, lovastatin and rosuvastatin; and in the EU, to dabigatran, atorvastatin, and rosuvastatin. Adverse effects Side effects from the use of letermovir are uncommon, but gastrointestinal symptoms such as gastritis and nausea may occur, as can dyspnea (difficulties breathing) and hepatitis. In general, side effects of the drug are comparable to those under placebo treatment. Overdose In studies, giving the threefold therapeutic dose for 14 days resulted in no additional adverse effects. It is unknown whether the substance can be removed from the system by hemodialysis. Pharmacology Mechanism of action Letermovir is a viral terminase inhibitor. It specifically inhibits the CMV viral terminase complex which is encoded by the CMV genes UL56, UL51 and UL89. This inhibition has the effect of preventing cleavage of CMV DNA concatamers, resulting in long uncleaved DNA and noninfectious viral particles. Letermovir is only active against CMV and has no effect on other herpesviruses. Pharmacokinetics Letermovir is quickly absorbed from the gut, reaching its highest concentrations in the blood plasma after 1.5 to 3 hours. Its bioavailability is estimated to be 37%. Ciclosporin increases this bioavailability to about 85%. When in the bloodstream, the substance is almost completely (98.2%) bound to plasma proteins. It is mostly (96.6%) circulating in its original form; only a small proportion is metabolized by the liver enzymes UGT1A1 and UGT1A3, resulting in a glucuronide.The drug is mainly excreted via the faeces (93.3%). Less than 2% is found in the urine. Chemistry Letermovir is used as the free acid. It is a white to off-white, amorphous powder that is slightly hygroscopic, very slightly soluble in water, and very soluble in acetonitrile, acetone, dimethylacetamide, ethanol, and 2-propanol.The molecule has one asymmetric carbon atom, which is in S configuration. References External links "Letermovir". Drug Information Portal. U.S. National Library of Medicine. "Letermovir Injection". MedlinePlus.
Doxepin
Doxepin is a medication used to treat major depressive disorder, anxiety disorders, chronic hives, and insomnia. For hives it is a less preferred alternative to antihistamines. It has a mild to moderate benefit for sleeping problems. It is used as a cream for itchiness due to atopic dermatitis or lichen simplex chronicus.Common side effects include sleepiness, dry mouth, constipation, nausea, and blurry vision. Serious side effects may include increased risk of suicide in those under the age of 25, mania, and urinary retention. A withdrawal syndrome may occur if the dose is rapidly decreased. Use during pregnancy and breastfeeding is not generally recommended. Doxepin is a tricyclic antidepressant (TCA). Although how it works for treating depression remains an area of active inquiry, it may involve increasing the levels of norepinephrine, along with blocking histamine, acetylcholine, and serotonin.Doxepin was approved for medical use in the United States in 1969. It is available as a generic medication. In 2017, it was the 240th most commonly prescribed medication in the United States, with more than two million prescriptions. Medical uses Doxepin is used as a pill to treat major depressive disorder, anxiety disorders, and chronic hives, and for short-term help with trouble remaining asleep after going to bed (a form of insomnia). As a cream it is used for short-term treatment of itchiness caused by atopic dermatitis or lichen simplex chronicus. Insomnia Doxepin is used in the treatment of insomnia. In 2016, the American College of Physicians advised that insomnia be treated first by treating comorbid conditions, then with cognitive behavioral therapy and behavioral changes, and then with drugs; doxepin was among those recommended for short-term help maintaining sleep, on the basis of weak evidence. The 2017 American Academy of Sleep Medicine recommendations focused on treatment with drugs were similar. A 2015 Agency for Healthcare Research and Quality review of treatments for insomnia had similar findings.A major systematic review and network meta-analysis of medications for the treatment of insomnia published in 2022 found that doxepin had an effect size (standardized mean difference (SMD)) against placebo for treatment of insomnia at 4 weeks of 0.30 (95% CI –0.05 to 0.64). The certainty of evidence was rated as very low, and no data were available for longer-term treatment (3 months). For comparison, the other sedating antihistamines assessed, trimipramine and doxylamine, had effect sizes (SMD) at 4 weeks of 0.55 (95% CI –0.11 to 1.21) (very low certainty evidence) and 0.47 (95% CI 0.06 to 0.89) (moderate certainty evidence), respectively. Benzodiazepines and Z-drugs generally showed larger effect sizes (e.g., SMDs of 0.45 to 0.83) than doxepin, whereas the effect sizes of orexin receptor antagonists, such as suvorexant, were more similar (SMDs of 0.23 to 0.44).Doses of doxepin used for sleep normally range from 3 to 6 mg, but high doses of up to 25 to 50 mg may be used as well. Other uses A 2010 review found that topical doxepin is useful to treat itchiness.A 2010 review of treatments for chronic hives found that doxepin had been superseded by better drugs but was still sometimes useful as a second-line treatment. Contraindications Known contraindications include: Hypersensitivities to doxepin, other TCAs, or any of the excipients inside the product used Glaucoma A predisposition to developing urinary retention such as in benign prostatic hyperplasia Use of monoamine oxidase inhibitors in last 14 days Pregnancy and lactation Its use in pregnant and lactating women is advised against, although the available evidence suggests it is unlikely to cause negative effects on fetal development. The lack of evidence from human studies, however, means it is currently impossible to rule out any risk to the fetus and it is known to cross the placenta. Doxepin is secreted in breast milk and neonatal cases of respiratory depression in association with maternal doxepin use have been reported. Side effects Doxepins side effects profile may differ from the list below in some countries where it is licensed to be used in much smaller doses (viz., 3 mg and 6 mg). Central nervous system: fatigue, dizziness, drowsiness, lightheadedness, confusion, nightmares, agitation, increased anxiety, difficulty sleeping, seizures (infrequently), temporary confusion (delirium), rarely induction of hypomania and schizophrenia (stop medication immediately), extrapyramidal side effects (rarely), abuse in patients with polytoxicomania (rarely), ringing in the ears (tinnitus) Anticholinergic: dry mouth, constipation, even ileus (rarely), difficulties in urinating, sweating, precipitation of glaucoma Antiadrenergic: Low blood pressure, (if patient arises too fast from the lying/sitting position to standing—known as orthostatic hypotension), abnormal heart rhythms (e.g., sinus tachycardia, bradycardia, and atrioventricular block) Allergic/toxic: skin rash, photosensitivity, liver damage of the cholestatic type (rarely), hepatitis (extremely rare), leuko- or thrombocytopenia (rarely), agranulocytosis (very rarely), hypoplastic anemia (rarely) Others: frequently increased appetite and weight gain, rarely nausea, rarely high blood pressure. May increase or decrease liver function in some people.The side effects of low-dose doxepin for insomnia in long-term clinical trials (28 to 85 days) in adults and elderly people were as follows: Overdose Like other TCAs, doxepin is highly toxic in cases of overdose. Mild symptoms include drowsiness, stupor, blurred vision, and excessive dryness of mouth. More serious adverse effects include respiratory depression, hypotension, coma, convulsions, cardiac arrhythmia, and tachycardia. Urinary retention, decreased gastrointestinal motility (paralytic ileus), hyperthermia (or hypothermia), hypertension, dilated pupils, and hyperactive reflexes are other possible symptoms of doxepin overdose. Management of overdose is mostly supportive and symptomatic, and can include the administration of a gastric lavage so as to reduce absorption of the doxepin. Supportive measures to prevent respiratory aspiration is also advisable. Antiarrhythmic agents may be an appropriate measure to treat cardiac arrhythmias resulting from doxepin overdose. Slow intravenous administration of physostigmine may reverse some of the toxic effects of overdose such as anticholinergic effects. Haemodialysis is not recommended due to the high degree of protein binding with doxepin. ECG monitoring is recommended for several days after doxepin overdose due to the potential for cardiac conduction abnormalities. Interactions Doxepin should not be used within 14 days of using a monoamine oxidase inhibitor (MAOI) such as phenelzine due to the potential for hypertensive crisis or serotonin syndrome to develop. Its use in those taking potent CYP2D6 inhibitors such as fluoxetine, paroxetine, sertraline, duloxetine, bupropion, and quinidine is recommended against owing to the potential for its accumulation in the absence of full CYP2D6 catalytic activity. Hepatic enzyme inducers such as carbamazepine, phenytoin, and barbiturates are advised against in patients receiving TCAs like doxepin owing to the potential for problematically rapid metabolism of doxepin to occur in these individuals. Sympathomimetic agents may have their effects potentiated by TCAs like doxepin. Doxepin also may potentiate the adverse effects of anticholinergic agents such as benztropine, atropine and hyoscine (scopolamine). Tolazamide, when used in conjunction with doxepin has been associated with a case of severe hypoglycaemia in a type II diabetic individual. Cimetidine may influence the absorption of doxepin. Alcohol may potentiate some of the CNS depressant effects of doxepin. Antihypertensive agents may have their effects mitigated by doxepin. Cotreatment with CNS depressants such as the benzodiazepines can cause additive CNS depression. Co-treatment with thyroid hormones may also increase the potential for adverse reactions. Pharmacology Doxepin is a tricyclic antidepressant (TCA). It acts as a serotonin–norepinephrine reuptake inhibitor (SNRI) (a reuptake inhibitor of serotonin and norepinephrine), with additional antiadrenergic, antihistamine, antiserotonergic, and anticholinergic activities. Pharmacodynamics Doxepin is a reuptake inhibitor of serotonin and norepinephrine, or a serotonin–norepinephrine reuptake inhibitor (SNRI), and has additional antiadrenergic, antihistamine, antiserotonergic, and anticholinergic activities. It is specifically an antagonist of the histamine H1 and H2 receptors, the serotonin 5-HT2A and 5-HT2C receptors, the α1-adrenergic receptor, and the muscarinic acetylcholine receptors (M1–M5). Similarly to other tricyclic antidepressants, doxepin is often prescribed as an effective alternative to SSRI medications. Doxepin is also a potent blocker of voltage-gated sodium channels, and this action is thought to be involved in both its lethality in overdose and its effectiveness as an analgesic (including in the treatment of neuropathic pain, and as a local anesthetic). The potencies of doxepin in terms of its receptor antagonism specifically are as follows: Extremely strong: Histamine H1 receptor Strong: α1-adrenergic receptor, 5-HT2A and muscarinic acetylcholine receptors Moderate: 5-HT2C and 5-HT1A receptors Weak: α2-adrenergic and D2 receptorsBased on its IC50 values for monoamine reuptake inhibition, doxepin is relatively selective for the inhibition of norepinephrine reuptake, with a much weaker effect on the serotonin transporter. Although there is a significant effect that takes place at one of the specific serotonergic binding sites, the 5-HT2A serotonin receptor subtype. There is negligible influence on dopamine reuptake.The major metabolite of doxepin, nordoxepin (desmethyldoxepin), is pharmacologically active similarly, but relative to doxepin, is much more selective as a norepinephrine reuptake inhibitor. In general, the demethylated variants of tertiary amine TCAs like nordoxepin are much more potent inhibitors of norepinephrine reuptake, less potent inhibitors of serotonin reuptake, and less potent in their antiadrenergic, antihistamine, and anticholinergic activities.Antidepressant doses of doxepin are defined as 25 to 300 mg/day, although are typically above 75 mg/day. Antihistamine doses, including for dermatological uses and as a sedative/hypnotic for insomnia, are considered to be 3 to 25 mg, although higher doses between 25 and 50 mg and in some cases even up to 150 mg have been used to treat insomnia. At low doses, below 25 mg, doxepin is a pure antihistamine and has more of a sedative effect. At antidepressant doses of above 75 mg, doxepin is more stimulating with antiadrenergic, antiserotonergic, and anticholinergic effects, and these activities contribute to its side effects.Doxepin is a mixture of (E) and (Z) stereoisomers with an approximate ratio of 85:15. When doxepin was developed, no effort was made to separate or balance the mixture following its synthesis, resulting in the asymmetric ratio. (Z)-Doxepin is more active as an inhibitor of serotonin and norepinephrine reuptake than (E)-doxepin. The selectivity of doxepin for inhibition of norepinephrine reuptake over that of serotonin is likely due to the 85% presence of (E)-doxepin in the mixture. Most other tertiary amine TCAs like amitriptyline and imipramine do not exhibit E-Z isomerism or such mixture asymmetry and are comparatively more balanced inhibitors of serotonin and norepinephrine reuptake. As a hypnotic Doxepin is a highly potent antihistamine, with this being its strongest activity. In fact, doxepin has been said to be the most or one of the most potent H1 receptor antagonists available, with one study finding an in vitro Ki of 0.17 nM. It is the most potent and selective H1 receptor antagonist of the TCAs (although the tetracyclic antidepressant (TeCA) mirtazapine is slightly more potent), and other sedating antihistamines, for instance the over-the-counter diphenhydramine (Ki = 16 nM) and doxylamine (Ki = 42 nM), show far lower affinities for this receptor in comparison. The affinity of doxepin for the H1 receptor is far greater than its affinity for other sites, and 10- to 100-fold higher doses are needed for antidepressant effects. In accordance, although it is often described as a "dirty drug" due to its highly promiscuous binding profile, doxepin acts as a highly selective antagonist of the H1 receptor at very low doses (less than 10 mg; typically 3 to 6 mg). At these doses, it notably has no clinically relevant anticholinergic effects such as dry mouth or cognitive/memory impairment, unlike most other sedating antihistamines, and similarly has no effect on other receptors such as adrenergic and serotonin receptors.The H1 receptor antagonism of doxepin is responsible for its hypnotic effects and its effectiveness in the treatment of insomnia at low doses. The incidence of side effects with doxepin and its safety at these doses was similar to that of placebo in clinical trials; the most frequent side effects were headache and somnolence/sedation, both with an incidence of less than 5%. Other side effects sometimes associated with antihistamines, including daytime sedation, increased appetite, and weight gain, all were not observed. Clinical evidence of H1 receptor antagonists and TCAs for the treatment insomnia shows mixed effectiveness and is limited in its quality due to weaknesses like small sample sizes and poor generalizability. However, doxepin is a unique and notable exception; it has been well-studied in the treatment of insomnia and shows consistent benefits with excellent tolerability and safety. Aside from diphenhydramine and doxylamine, which have historical approval as hypnotics, doxepin is the only H1 receptor antagonist that is specifically approved for the treatment of insomnia in the United States.The effect sizes of very low-dose doxepin in the treatment of insomnia range from small to medium. These include subjective and objective measures of sleep maintenance, sleep duration, and sleep efficiency. Conversely, very low-dose doxepin shows relatively weak effects on sleep initiation and does not significantly separate from placebo on this measure. This is in contrast to benzodiazepines and nonbenzodiazepine (Z-drug) hypnotics, which are additionally effective in improving sleep onset latency. However, it is also in contrast to higher doses of doxepin (50 to 300 mg/day), which have been found to significantly reduce latency to sleep onset. A positive dose–response relationship on sleep measures was observed for doses of doxepin between 1 and 6 mg in clinical studies, whereas the incidence of adverse effects remained constant across this dose range in both young and older adults. However, the incidence of adverse effects appeared to increase with longer treatment duration. A dose of doxepin as low as 1 mg/day was found to significantly improve most of the assessed sleep measures, but unlike the 3 and 6 mg/day doses, was not able to improve wake time during sleep. This, along with greater effect sizes with the higher doses, was likely the basis for the approval of the 3 and 6 mg doses of doxepin for insomnia and not the 1 mg dose.At very low doses, doxepin has not shown discontinuation or withdrawal effects nor rebound insomnia. Sustained effectiveness without apparent tolerance was demonstrated in clinical studies of up to 12 weeks duration. This appears to be in contrast to over-the-counter antihistamines like diphenhydramine and doxylamine and all other first-generation antihistamines, which are associated with rapid development of tolerance and dependence (by day 3 or 4 of continuous dosing) and loss of hypnotic effectiveness. It is for this reason that, unlike doxepin, they are not recommended for the chronic management of insomnia and are advised for only short-term treatment (i.e., 1 week). It is not entirely clear why doxepin and first-generation antihistamines are different in this regard, but it has been suggested that it may have to do with the lack of selectivity for the H1 receptor of the latter or may have to do with the use of optimal doses. Unlike very-low-dose doxepin, most first-generation antihistamines also have marked anticholinergic activity as well as associated side effects such as dry mouth, constipation, urinary retention, and confusion. This is particularly true in older people, and antihistamines with concomitant anticholinergic effects are not recommended in adults over the age of 65. Anticholinergic activity notably may interfere with the sleep-promoting effects of H1 receptor blockade.Antagonism of the H1, 5-HT2A, 5-HT2C, and α1-adrenergic receptors is thought to have sleep-promoting effects and to be responsible for the sedative effects of TCAs including those of doxepin. Although doxepin is selective for the H1 receptor at doses lower than 25 mg, blockade of serotonin and adrenergic receptors may also be involved in the hypnotic effects of doxepin at higher doses. However, in contrast to very low doses of doxepin, rebound insomnia and daytime sedation are significantly more frequent than placebo with moderate doses (25 to 50 mg/day) of the drug. In addition, one study found that although such doses of doxepin improved sleep measures initially, most of the benefits were lost with chronic treatment (by 4 weeks). Due to limited data however, more research on potential tolerance and withdrawal effects of moderate doses of doxepin is needed. At these doses of doxepin, dry mouth, an anticholinergic effect, was common (71%), and other side effects such as headache (25%), increased appetite (21%), and dizziness (21%) were also frequently observed, although these adverse effects were notably not significantly more frequent than with placebo in the study in question. In any case, taken together, higher doses of doxepin than very low doses are associated with an increased rate of side effects as well as apparent loss of hypnotic effectiveness with chronic treatment.Doxepin at a dose of 25 mg/day for 3 weeks has been found to decrease cortisol levels by 16% in adults with chronic insomnia and to increase melatonin production by 26% in healthy volunteers. In individuals with neuroendocrine dysregulation in the form of nocturnal melatonin deficiency presumably due to chronic insomnia, very-low-dose doxepin was found to restore melatonin levels to near-normal values after 3 weeks of treatment. These findings suggest that normalization of the hypothalamic–pituitary–adrenal axis and the circadian sleep–wake cycle may be involved in the beneficial effects of doxepin on sleep and insomnia. CYP2D6 inhibition Doxepin has been identified as an inhibitor of CYP2D6 in vivo in a study of human patients being treated with 75 to 250 mg/day for depression. While it significantly altered metabolic ratios for sparteine and its metabolites, doxepin did not convert any of the patients to a different metabolizer phenotype (e.g., extensive to intermediate or poor). Nonetheless, inhibition of CYP2D6 by doxepin could be of clinical importance. Pharmacokinetics Absorption Doxepin is well-absorbed from the gastrointestinal tract but between 55 and 87% undergoes first-pass metabolism in the liver, resulting in a mean oral bioavailability of approximately 29%. Following a single very low dose of 6 mg, peak plasma levels of doxepin are 0.854 ng/mL (3.06 nmol/L) at 3 hours without food and 0.951 ng/mL (3.40 nmol/L) at 6 hours with food. Plasma concentrations of doxepin with antidepressant doses are far greater, ranging between 50 and 250 ng/mL (180 to 900 nmol/L). Area-under-curve levels of the drug are increased significantly when it is taken with food. Distribution Doxepin is widely distributed throughout the body and is approximately 80% plasma protein-bound, specifically to albumin and α1-acid glycoprotein. Metabolism Doxepin is extensively metabolized by the liver via oxidation and N-demethylation. Its metabolism is highly stereoselective. Based on in vitro research, the major enzymes involved in the metabolism of doxepin are the cytochrome P450 enzymes CYP2D6 and CYP2C19, with CYP1A2, CYP2C9, and CYP3A4 also involved to a lesser extent. The major active metabolite of doxepin, nordoxepin, is formed mainly by CYP2C19 (>50% contribution), while CYP1A2 and CYP2C9 are involved to a lesser extent, and CYP2D6 and CYP3A4 are not involved. Both doxepin and nordoxepin are hydroxylated mainly by CYP2D6, and both doxepin and nordoxepin are also transformed into glucuronide conjugates. The elimination half-life of doxepin is about 15–18 hours, whereas that of nordoxepin is around 28–31 hours. Up to 10% of Caucasian individuals show substantially reduced metabolism of doxepin that can result in up to 8-fold elevated plasma concentrations of the drug compared to normal.Nordoxepin is a mixture of (E) and (Z) stereoisomers similarly to doxepin. Whereas pharmaceutical doxepin is supplied in an approximate 85:15 ratio mixture of (E)- and (Z)-stereoisomers and plasma concentrations of doxepin remain roughly the same as this ratio with treatment, plasma levels of the (E)- and (Z)-stereoisomers of nordoxepin, due to stereoselective metabolism of doxepin by cytochrome P450 enzymes, are approximately 1:1. Elimination Doxepin is eliminated primarily in the urine and predominantly in the form of glucuronide conjugates, with less than 3% of a dose excreted unchanged as doxepin or nordoxepin. Pharmacogenetics Since doxepin is mainly metabolized by CYP2D6, CYP2C9, and CYP2C19, genetic variations within the genes coding for these enzymes can affect its metabolism, leading to changes in the concentrations of the drug in the body. Increased concentrations of doxepin may increase the risk for side effects, including anticholinergic and nervous system adverse effects, while decreased concentrations may reduce the drugs efficacy. Individuals can be categorized into different types of cytochrome P450 metabolizers depending on which genetic variations they carry. These metabolizer types include poor, intermediate, extensive, and ultrarapid metabolizers. Most people are extensive metabolizers, and have "normal" metabolism of doxepin. Poor and intermediate metabolizers have reduced metabolism of the drug as compared to extensive metabolizers; patients with these metabolizer types may have an increased probability of experiencing side effects. Ultrarapid metabolizers break down doxepin much faster than extensive metabolizers; patients with this metabolizer type may have a greater chance of experiencing pharmacological failure. A study assessed the metabolism of a single 75 mg oral dose of doxepin in healthy volunteers with genetic polymorphisms in CYP2D6, CYP2C9, and CYP2C19 enzymes. In CYP2D6 extensive, intermediate, and poor metabolizers, the mean clearance rates of (E)-doxepin were 406, 247, and 127 L/hour, respectively (~3-fold difference between extensive and poor). In addition, the bioavailability of (E)-doxepin was about 2-fold lower in extensive relative to poor CYP2D6 metabolizers, indicating a significant role of CYP2D6 in the first-pass metabolism of (E)-doxepin. The clearance of (E)-doxepin in CYP2C9 slow metabolizers was also significantly reduced at 238 L/hour. CYP2C19 was involved in the metabolism of (Z)-doxepin, with clearance rates of 191 L/hour in CYP2C19 extensive metabolizers and 73 L/hour in poor metabolizers (~2.5-fold difference). Area-under-the-curve (0–48 hour) levels of nordoxepin were dependent on the genotype of CYP2D6 with median values of 1.28, 1.35, and 5.28 nM•L/hour in CYP2D6 extensive, intermediate, and poor metabolizers, respectively (~4-fold difference between extensive and poor). Taken together, doxepin metabolism appears to be highly stereoselective, and CYP2D6 genotype has a major influence on the pharmacokinetics of (E)-doxepin. Moreover, CYP2D6 poor metabolizers, as well as patients taking potent CYP2D6 inhibitors (which can potentially convert a CYP2D6 extensive metabolizer into a poor metabolizer), may be at an increased risk for adverse effects of doxepin due to their slower clearance of the drug.Another study assessed doxepin and nordoxepin metabolism in CYP2D6 ultra-rapid, extensive, and poor metabolizers following a single 75 mg oral dose. They found up to more than 10-fold variation in total exposure to doxepin and nordoxepin between the different groups. The researchers suggested that in order to achieve equivalent exposure, based on an average dose of 100%, the dosage of doxepin might be adjusted to 250% in ultra-rapid metabolizers, 150% in extensive metabolizers, 50% in intermediate metabolizers, and 30% in poor metabolizers. Chemistry Doxepin is a tricyclic compound, specifically a dibenzoxepin, and possesses three rings fused together with a side chain attached in its chemical structure. It is the only TCA with a dibenzoxepin ring system to have been marketed. Doxepin is a tertiary amine TCA, with its side chain-demethylated metabolite nordoxepin being a secondary
Doxepin
amine. Other tertiary amine TCAs include amitriptyline, imipramine, clomipramine, dosulepin (dothiepin), and trimipramine. Doxepin is a mixture of (E) and (Z) stereoisomers (the latter being known as cidoxepin or cis-doxepin) and is used commercially in a ratio of approximately 85:15. The chemical name of doxepin is (E/Z)-3-(dibenzo[b,e]oxepin-11(6H)-ylidene)-N,N-dimethylpropan-1-amine and its free base form has a chemical formula of C19H21NO with a molecular weight of 279.376 g/mol. The drug is used commercially almost exclusively as the hydrochloride salt; the free base has been used rarely. The CAS Registry Number of the free base is 1668-19-5 and of the hydrochloride is 1229-29-4. History Doxepin was discovered in Germany in 1963 and was introduced in the United States as an antidepressant in 1969. It was subsequently approved at very low doses in the United States for the treatment of insomnia in 2010. Society and culture Generic names Doxepin is the generic name of the drug in English and German and its INN and BAN, while doxepin hydrochloride is its USAN, USP, BANM, and JAN. Its generic name in Spanish and Italian and its DCIT are doxepina, in French and its DCF are doxépine, and in Latin is doxepinum.The cis or (Z) stereoisomer of doxepin is known as cidoxepin, and this is its INN while cidoxepin hydrochloride is its USAN. Brand names It was introduced under the brand names Quitaxon and Aponal by Boehringer and as Sinequan by Pfizer.Doxepin is marketed under many brand names worldwide, including: Adnor, Anten, Antidoxe, Colian, Deptran, Dofu, Doneurin, Dospin, Doxal, Doxepini, Doxesom, Doxiderm, Flake, Gilex, Ichderm, Li Ke Ning, Mareen, Noctaderm, Oxpin, Patoderm, Prudoxin, Qualiquan, Quitaxon, Sagalon, Silenor, Sinepin, Sinequan, Sinquan, and Zonalon. It is also marketed as a combination drug with levomenthol under the brand name Doxure. Approvals The oral formulations of doxepin are FDA-approved for the treatment of depression and sleep-maintenance insomnia, and its topical formulations are FDA-approved the short-term management for some itchy skin conditions. In Australia and the United Kingdom, the only licensed indications are in the treatment of major depression and pruritus in eczema. Research Antihistamine Cidoxepin is under development by Elorac, Inc. for the treatment of chronic urticaria (hives). As of 2017, it is in phase II clinical trials for this indication. The drug was also under investigation for the treatment of allergic rhinitis, atopic dermatitis, and contact dermatitis, but development for these indications was discontinued. Headache Doxepin was under development by Winston Pharmaceuticals in an intranasal formulation for the treatment of headache. As of August 2015, it was in phase II clinical trials for this indication. Oxetorone is an antimigraine agent. Neuropathic pain As of 2017, there was no good evidence that topical doxepin was useful to treat localized neuropathic pain. References External links Media related to Doxepin at Wikimedia Commons "Doxepin". Drug Information Portal. U.S. National Library of Medicine. "Doxepin hydrochloride". Drug Information Portal. U.S. National Library of Medicine.
Elapegademase
Elapegademase, sold under the brand name Revcovi, is a medication for the treatment of the rare disease adenosine deaminase deficiency-SCID in children and adults.It is a recombinant enzyme that is administered weekly by intramuscular injection.Elapegademase may interact with PEGylated drugs.Elapegademase-lvlr was approved by the U.S. Food and Drug Administration (FDA) in 2018. Leadiant Biosciences was awarded a priority review voucher for its development under the pediatric rare diseases program. References External links "Elapegademase". Drug Information Portal. U.S. National Library of Medicine.
Metronidazole
Metronidazole, sold under the brand name Flagyl among others, is an antibiotic and antiprotozoal medication. It is used either alone or with other antibiotics to treat pelvic inflammatory disease, endocarditis, and bacterial vaginosis. It is effective for dracunculiasis, giardiasis, trichomoniasis, and amebiasis. It is an option for a first episode of mild-to-moderate Clostridium difficile colitis if vancomycin or fidaxomicin is unavailable. Metronidazole is available by mouth, as a cream, and by injection into a vein.Common side effects include nausea, a metallic taste, loss of appetite, and headaches. Occasionally seizures or allergies to the medication may occur. Some state that metronidazole should not be used in early pregnancy, while others state doses for trichomoniasis are safe. Metronidazole is generally considered compatible with breastfeeding.Metronidazole began to be commercially used in 1960 in France. It is on the World Health Organizations List of Essential Medicines. It is available in most areas of the world. In 2019, it was the 138th most commonly prescribed medication in the United States, with more than 4 million prescriptions. Medical uses Metronidazole is primarily used to treat: bacterial vaginosis, pelvic inflammatory disease (along with other antibacterials like ceftriaxone), pseudomembranous colitis, aspiration pneumonia, rosacea (topical), fungating wounds (topical), intra-abdominal infections, lung abscess, periodontitis, amoebiasis, oral infections, giardiasis, trichomoniasis, and infections caused by susceptible anaerobic organisms such as Bacteroides, Fusobacterium, Clostridium, Peptostreptococcus, and Prevotella species. It is also often used to eradicate Helicobacter pylori along with other drugs and to prevent infection in people recovering from surgery.Metronidazole is bitter and so the liquid suspension contains metronidazole benzoate. This may require hydrolysis in the gastrointestinal tract and some sources speculate that it may be unsuitable in people with diarrhea or feeding-tubes in the duodenum or jejunum. Bacterial vaginosis Drugs of choice for the treatment of bacterial vaginosis include metronidazole and clindamycin. The treatment of choice for bacterial vaginosis in nonpregnant women include metronidazole oral twice daily for seven days, or metronidazole gel intravaginally once daily for five days, or clindamycin intravaginally at bedtime for seven days. For pregnant women, the treatment of choice is metronidazole oral three times a day for seven days. Data does not report routine treatment of male sexual partners. Trichomoniasis The 5-nitroimidazole drugs (metronidazole and tinidazole) are the mainstay of treatment for infection with Trichomonas vaginalis. Treatment for both the infected patient and the patients sexual partner is recommended, even if asymptomatic. Therapy other than 5-nitroimidazole drugs is also an option, but cure rates are much lower. Giardiasis Oral metronidazole is a treatment option for giardiasis, however, the increasing incidence of nitroimidazole resistance is leading to the increased use of other compound classes. Dracunculus In the case of Dracunculus medinensis (Guinea worm), metronidazole just eases worm extraction rather than killing the worm. C. difficile colitis Initial antibiotic therapy for less-severe Clostridioides difficile infection colitis (pseudomembranous colitis) consists of metronidazole, vancomycin, or fidaxomicin by mouth. In 2017, the IDSA generally recommended vancomycin and fidaxomicin over metronidazole. Vancomycin by mouth has been shown to be more effective in treating people with severe C. difficile colitis. E. histolytica Entamoeba histolytica invasive amebiasis is treated with metronidazole for eradication, in combination with diloxanide to prevent recurrence. Although it is generally a standard treatment it is associated with some side effects. Preterm births Metronidazole has also been used in women to prevent preterm birth associated with bacterial vaginosis, amongst other risk factors including the presence of cervicovaginal fetal fibronectin (fFN). Metronidazole was ineffective in preventing preterm delivery in high-risk pregnant women (selected by history and a positive fFN test) and, conversely, the incidence of preterm delivery was found to be higher in women treated with metronidazole. Hypoxic radiosensitizer In addition to its anti-biotic properties, attempts were also made to use a possible radiation-sensitizing effect of metronidazole in the context of radiation therapy against hypoxic tumors. However, the neurotoxic side effects occurring at the required dosages have prevented the widespread use of metronidazole as an adjuvant agent in radiation therapy. However, other nitroimidazoles derived from metronidazole such as nimorazole with reduced electron affinity showed less serious neuronal side effects and have found their way into radio-onological practice for head and neck tumors in some countries. Perioral dermatitis Canadian Family Physician has recommended topical metronidazole as a third-line treatment for the perioral dermatitis either along with or without oral tetracycline or oral erythromycin as first and second line treatment respectively. Adverse effects Common adverse drug reactions (≥1% of those treated with the drug) associated with systemic metronidazole therapy include: nausea, diarrhea, weight loss, abdominal pain, vomiting, headache, dizziness, and metallic taste in the mouth. Intravenous administration is commonly associated with thrombophlebitis. Infrequent adverse effects include: hypersensitivity reactions (rash, itch, flushing, fever), headache, dizziness, vomiting, glossitis, stomatitis, dark urine, and paraesthesia. High doses and long-term systemic treatment with metronidazole are associated with the development of leucopenia, neutropenia, increased risk of peripheral neuropathy, and central nervous system toxicity. Common adverse drug reaction associated with topical metronidazole therapy include local redness, dryness and skin irritation; and eye watering (if applied near eyes). Metronidazole has been associated with cancer in animal studies. In rare cases, it can also cause temporary hearing loss that reverses after cessation of the treatment.Some evidence from studies in rats indicates the possibility it may contribute to serotonin syndrome, although no case reports documenting this have been published to date. Mutagenesis and carcinogenesis In 2016 metronidazole was listed by the U.S. National Toxicology Program (NTP) as reasonably anticipated to be a human carcinogen. Although some of the testing methods have been questioned, oral exposure has been shown to cause cancer in experimental animals and has also demonstrated some mutagenic effects in bacterial cultures. The relationship between exposure to metronidazole and human cancer is unclear. One study found an excess in lung cancer among women (even after adjusting for smoking), while other studies found either no increased risk, or a statistically insignificant risk. Metronidazole is listed as a possible carcinogen according to the World Health Organization (WHO) International Agency for Research on Cancer (IARC). A study in those with Crohns disease also found chromosomal abnormalities in circulating lymphocytes in people treated with metronidazole. Stevens–Johnson syndrome Metronidazole alone rarely causes Stevens–Johnson syndrome, but is reported to occur at high rates when combined with mebendazole. Drug interactions Alcohol Consuming alcohol while taking metronidazole has been suspected in case reports to cause a disulfiram-like reaction with effects that can include nausea, vomiting, flushing of the skin, tachycardia, and shortness of breath. People are often advised not to drink alcohol during systemic metronidazole therapy and for at least 48 hours after completion of treatment. However, some studies call into question the mechanism of the interaction of alcohol and metronidazole, and a possible central toxic serotonin reaction for the alcohol intolerance is suggested. Metronidazole is also generally thought to inhibit the liver metabolism of propylene glycol (found in some foods, medicines, and in many electronic cigarette e-liquids), thus propylene glycol may potentially have similar interaction effects with metronidazole. Other drug interactions Metronidazole is a moderate CYP2C9 inhibitor. CYP2C9 is an enzyme of cytochrome P450 family. Therefore, metronidazole may interact with medications metabolized by this enzyme. Examples of such medications are lomitapide, warfarin, etc. Pharmacology Mechanism of action Metronidazole is of the nitroimidazole class. It inhibits nucleic acid synthesis by forming nitroso radicals, which disrupt the DNA of microbial cells. This function only occurs when metronidazole is partially reduced, and because this reduction usually happens only in anaerobic bacteria and protozoans, it has relatively little effect upon human cells or aerobic bacteria. Pharmacokinetics Oral metronidazole is approximately 80% bioavailable via the gut and peak blood plasma concentrations occur after one to two hours. Food may slow down absorption but does not diminish it. Of the circulating substance, about 20% is bound to plasma proteins. It penetrates well into tissues, the cerebrospinal fluid, the amniotic fluid and breast milk, as well as into abscess cavities.About 60% of the metronidazole is metabolized by oxidation to the main metabolite hydroxymetronidazole and a carboxylic acid derivative, and by glucuronidation. The metabolites show antibiotic and antiprotozoal activity in vitro. Metronidazole and its metabolites are mainly excreted via the kidneys (77%) and to a lesser extent via the faeces (14%). The biological half-life of metronidazole in healthy adults is eight hours, in infants during the first two months of their lives about 23 hours, and in premature babies up to 100 hours.The biological activity of hydroxymetronidazole is 30% to 65%, and the elimination half-life is longer than that of the parent compound. The serum half-life of hydroxymetronidazole after suppository was 10 hours, 19 hours after intravenous infusion, and 11 hours after a tablet. History The drug was initially developed by Rhône-Poulenc in the 1950s and licensed to G.D. Searle. Searle was acquired by Pfizer in 2003. The original patent expired in 1982, but evergreening reformulation occurred thereafter. Brand name In India, it is sold under the brand name Metrogyl and Flagyl. In Bangladesh, it is available as Amodis, Amotrex, Dirozyl, Filmet, Flagyl, Flamyd, Metra, Metrodol, Metryl, etc. In Pakistan, it is sold under the brand name of Flagyl and Metrozine. Synthesis 2-Methylimidazole (1) may be prepared via the Debus-Radziszewski imidazole synthesis, or from ethylenediamine and acetic acid, followed by treatment with lime, then Raney nickel. 2-Methylimidazole is nitrated to give 2-methyl-4(5)-nitroimidazole (2), which is in turn alkylated with ethylene oxide or 2-chloroethanol to give metronidazole (3): Veterinary use Metronidazole is used to treat infections of Giardia in dogs, cats, and other companion animals, although it does not reliably clear infection with this organism and is being supplanted by fenbendazole for this purpose in dogs and cats. It is also used for the management of chronic inflammatory bowel disease in cats and dogs. Another common usage is the treatment of systemic and/or gastrointestinal clostridial infections in horses. Metronidazole is used in the aquarium hobby to treat ornamental fish and as a broad-spectrum treatment for bacterial and protozoan infections in reptiles and amphibians. In general, the veterinary community may use metronidazole for any potentially susceptible anaerobic infection. The U.S. Food and Drug Administration (FDA) suggests it only be used when necessary because it has been shown to be carcinogenic in mice and rats, as well as to prevent antimicrobial resistance. References External links "Metronidazole". Drug Information Portal. U.S. National Library of Medicine. "Metronidazole and Tinidazole". Merck manuals.
Macimorelin
Macimorelin (INN) – or Macrilen (trade name) – is a drug that was developed by Æterna Zentaris for use in the diagnosis of adult growth hormone deficiency. Macimorelin acetate, the salt formulation, is a synthetic growth hormone secretagogue receptor agonist. It is a growth hormone secretagogue receptor (ghrelin receptor) agonist causing release of growth hormone from the pituitary gland.Macimorelin acetate is described chemically as D-Tryptophanamide, 2-methylalanyl-N-[(1R)-1-(formylamino)-2-(1H-indol-3-yl)ethyl]-acetate. Macimorelin (Macrilen™) was invented and first synthesized by the research group of Professor Martinez at University of Montpellier, Centre National de la Recherche Scientitifique (CNRS), France. This transpired from a long-lasting research collaboration with Aeterna Zentaris. Aeterna Zentaris later in-licensed macimorelin as a development candidate from the CNRS and proceeded with the pre-clinical and clinical development of the compound. As of January 2014, it was in Phase III clinical trials. The phase III trial for growth hormone deficiency is expected to be complete in December 2016.As of December 2017, it became FDA-approved as a method to diagnose growth hormone deficiency. Traditionally, growth hormone deficiency was diagnosed via means of insulin tolerance test (IST) or glucagon stimulation test (GST). These two means are done parenterally, whereas Macrilen boasts an oral formulation for ease of administration for patients and providers. The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication. See also List of growth hormone secretagogues References External links "Macimorelin". Drug Information Portal. U.S. National Library of Medicine. "Macimorelin acetate". Drug Information Portal. U.S. National Library of Medicine.
Metoclopramide
Metoclopramide is a medication used for stomach and esophageal problems. It is commonly used to treat and prevent nausea and vomiting, to help with emptying of the stomach in people with delayed stomach emptying, and to help with gastroesophageal reflux disease. It is also used to treat migraine headaches.Common side effects include: feeling tired, diarrhea, and feeling restless. More serious side effects include: movement disorder like tardive dyskinesia, a condition called neuroleptic malignant syndrome, and depression. It is thus rarely recommended that people take the medication for longer than twelve weeks. No evidence of harm has been found after being taken by many pregnant women. It belongs to the group of medications known as dopamine-receptor antagonists and works as a prokinetic.In 2012, metoclopramide was one of the top 100 most prescribed medications in the United States. It is available as a generic medication. It is on the World Health Organizations List of Essential Medicines. In 2017, it was the 253rd most commonly prescribed medication in the United States, with more than one million prescriptions. Medical uses Nausea Metoclopramide is commonly used to treat nausea and vomiting associated with conditions such as uremia, radiation sickness, cancer and the effects of chemotherapy, labor, infection, and emetogenic drugs. As a perioperative anti-emetic, the effective dose is usually 25 to 50 mg (compared to the usual 10 mg dose). It is also used in pregnancy as a second choice for treatment of hyperemesis gravidarum (severe nausea and vomiting of pregnancy).It is also used preventatively by some EMS providers when transporting people who are conscious and spinally immobilized. Migraine In migraine headaches, metoclopramide may be used in combination with paracetamol (acetaminophen) or in combination with aspirin. Gastroparesis Evidence also supports its use for gastroparesis, a condition that causes the stomach to empty poorly, and as of 2010 it was the only drug approved by the FDA for that condition.It is also used in gastroesophageal reflux disease. Lactation While metoclopramide is used to try to increase breast milk production, evidence for its effectiveness for this is poor. Its safety for this use is also unclear. Procedures Intravenous metoclopramide is used in small-bowel follow-through, small-bowel enema, and radionuclide gastric-emptying studies to reduce the time taken for barium to go through the intestines, thus reducing the total time needed for the procedures. Metoclopramide also prevents vomiting after oral ingestion of barium. Contraindications Metoclopramide is contraindicated in pheochromocytoma. It should be used with caution in Parkinsons disease since, as a dopamine antagonist, it may worsen symptoms. Long-term use should be avoided in people with clinical depression, as it may worsen ones mental state. It is contraindicated for people with a suspected bowel obstruction, in epilepsy, if a stomach operation has been performed in the previous three or four days, if the person has ever had bleeding, perforation or blockage of the stomach, and in newborn babies.The safety of the drug was reviewed by the European Medicines Agency in 2011, which determined that it should not be prescribed in high doses, for periods of more than five days, or given to children below 1 year of age. They suggested its use in older children should be restricted to treating post-chemotherapy or post-surgery nausea and vomiting, and even then only for patients where other treatments have failed. For adults, they recommended its use be restricted to treating migraines and post-chemotherapy or post-surgery patients. Pregnancy Metoclopramide has long been used in all stages of pregnancy with no evidence of harm to the mother or foetus. A large cohort study of babies born to Israeli women exposed to metoclopramide during pregnancy found no evidence that the drug increases the risk of congenital malformations, low birth weight, preterm birth, or perinatal mortality. A large cohort study in Denmark found, in addition, no association between metoclopramide exposure and miscarriage. Metoclopramide is excreted into milk. Infants A systematic review found a wide range of reported outcomes for treatment of gastroesophageal reflux disease (GERD) in infants and concluded a "poor" rating of evidence and "inconclusive" rating of safety and efficacy for the treatment of GERD in infants. Side effects Common adverse drug reactions (ADRs) associated with metoclopramide therapy include restlessness (akathisia), and focal dystonia. Infrequent ADRs include hypertension, hypotension, hyperprolactinaemia leading to galactorrhea, headache, and extrapyramidal effects such as oculogyric crisis.Metoclopramide may be the most common cause of drug-induced movement disorders. The risk of extrapyramidal effects is increased in people under 20 years of age, and with high-dose or prolonged therapy. Tardive dyskinesia may be persistent and irreversible in some people. The majority of reports of tardive dyskinesia occur in people who have used metoclopramide for more than three months. Consequently, the US Food and Drug Administration (FDA) recommends that metoclopramide be used for short-term treatment, preferably less than 12 weeks. In 2009, the FDA required all manufacturers of metoclopramide to issue a black box warning regarding the risk of tardive dyskinesia with chronic or high-dose use of the drug.Dystonic reactions may be treated with benzatropine, diphenhydramine, trihexyphenidyl, or procyclidine. Symptoms usually subside with diphenhydramine injected intramuscularly. Agents in the benzodiazepine class of drugs may be helpful, but benefits are usually modest and side effects of sedation and weakness can be problematic.In some cases, the akathisia effects of metoclopramide are directly related to the infusion rate when the drug is administered intravenously. Side effects were usually seen in the first 15 min after the dose of metoclopramide. Rare side effects Diabetes, age, and female gender are risk factors that increase the likelihood of experiencing a neuropsychiatric side effect of metoclopramide. Panic disorder Major depressive disorder Agoraphobia Agranulocytosis, supraventricular tachycardia, hyperaldosteronism, neuroleptic malignant syndrome, akathisia and tardive dyskinesia. Methaemoglobinaemia* Pharmacology Pharmacodynamics Metoclopramide appears to bind to dopamine D2 receptors with nanomolar affinity (Ki = 28.8 nM), where it is a receptor antagonist, and is also a mixed 5-HT3 receptor antagonist/5-HT4 receptor agonist. Mechanism of action The antiemetic action of metoclopramide is due to its antagonist activity at D2 receptors in the chemoreceptor trigger zone in the central nervous system — this action prevents nausea and vomiting triggered by most stimuli. At higher doses, 5-HT3 antagonist activity may also contribute to the antiemetic effect.The gastroprokinetic activity of metoclopramide is mediated by muscarinic activity, D2 receptor antagonist activity, and 5-HT4 receptor agonist activity. The gastroprokinetic effect itself may also contribute to the antiemetic effect. Metoclopramide also increases the tone of the lower esophageal sphincter.Metoclopramide might influence on mood because of its blockade action on 5-HT4 and 5-HT3. Chemistry Metoclopramide is a substituted benzamide; cisapride and mosapride are structurally related. History Metoclopramide was first described by Louis Justin-Besançon and Charles Laville in 1964, while working to improve the anti-dysrhythmic properties of procainamide. That research project also produced the product sulpiride. The first clinical trials were published by Tourneu et al. in 1964 and by Boisson and Albot in 1966. Justin-Besançon and Laville worked for Laboratoires Delagrange and that company introduced the drug as Primperan in 1964. Laboratoires Delagrange was acquired by Synthelabo in 1991 which eventually became part of Sanofi.A.H. Robins introduced the drug in the US under the brand name Reglan in 1979 as an injectable and an oral form was approved in 1980. in 1989 A.H. Robins was acquired by American Home Products, which changed its name to Wyeth in 2002.The drugs were initially used to control nausea for people with severe headaches or migraines, and later uses for nausea caused by radiation therapy and chemotherapy, and later yet for treating nausea caused by anesthesia. In the US the injectable form was labelled for chemotherapy-induced nausea and the oral form was eventually labelled for gastroesophageal reflux disease.It became widely used in the 1980s, becoming the most commonly used drug to treat anesthesia-induced nausea and for treating gastritis in emergency rooms.The first generics were introduced in 1985.In the early 1980s signs began to emerge in pharmacovigilance studies from Sweden that the drug was causing tardive dyskinesia in some patients. The FDA required a warning about tardive dyskinesia to be added to the drug label in 1985 stating that: "tardive dyskinesia . . . may develop in patients treated with metoclopramide,” and warned against use longer than 12 weeks, as that was how long the drug has been tested. In 2009 the FDA required that a black box warning be added to the label.The emergence of this severe side effect led to a wave of product liability litigation against generic manufacturers as well as Wyeth. The litigation was complicated since there was a lack of clarity in jurisdiction between state laws, where product liability is determined, and federal law, which determines how drugs are labelled, as well as between generics companies, which had no control over labelling, and the originator company, which did. The litigation yielded at least two important cases. In Conte v. Wyeth in the California state courts, the claims of the plaintiff against the generic companies Pliva, Teva, and Purepac that had sold the drugs that the plaintiff actually took, and the claims against Wyeth, whose product the plaintiff never took, were all dismissed by the trial court, but the case was appealed, and in 2008 the appellate court upheld the dismissal of the cases against the generic companies, but reversed on Wyeth, allowing the case against Wyeth to proceed. This established an "innovator liability" or "pioneer liability" for pharmaceutical companies. The precedent was not widely followed in California nor in other states. Litigation over the same issues related to metoclopramide also reached the US Supreme Court in PLIVA, Inc. v. Mensing, in which the court held in 2011 that generic companies cannot be held liable for information, or the lack of information, on the originators label. As of August 2015 there were about 5000 suits pending across the US and efforts to consolidate them into a class action had failed.Shortly following the Pliva decision, the FDA proposed a rule change that would allow generics manufacturers to update the label if the originating drug had been withdrawn from the market for reasons other than safety. As of May 2016 the rule, which turned out to be controversial since it would open generic companies to product liability suits, was still not finalized, and the FDA had stated the final rule would be issued in April 2017. The FDA issued a draft guidance for generic companies to update labels in July 2016. Society and culture Brand names Veterinary use Metoclopramide is commonly used to prevent vomiting in cats and dogs. It is also used as a gut stimulant in rabbits. References External links "Metoclopramide". Drug Information Portal. U.S. National Library of Medicine. "Metoclopramide Injection". MedlinePlus.
Anastrozole
Anastrozole, sold under the brand name Arimidex among others, is a medication used in addition to other treatments for breast cancer. Specifically it is used for hormone receptor-positive breast cancer. It has also been used to prevent breast cancer in those at high risk. It is taken by mouth.Common side effects of anastrozole include hot flashes, altered mood, joint pain, and nausea. Severe side effects include an increased risk of heart disease and osteoporosis. Use during pregnancy may harm the baby. Anastrozole is in the aromatase-inhibiting family of medications. It works by blocking the production of estrogens in the body, and hence has antiestrogenic effects.Anastrozole was patented in 1987 and was approved for medical use in 1995. It is on the World Health Organizations List of Essential Medicines. Anastrozole is available as a generic medication. In 2019, it was the 176th most commonly prescribed medication in the United States, with more than 3 million prescriptions. Medical uses Breast cancer Anastrozole is used in the treatment and prevention of breast cancer in women. The Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial was of localized breast cancer and women received either anastrozole, the selective estrogen receptor modulator tamoxifen, or both for five years, followed by five years of follow-up. After more than 5 years the group that received anastrozole had better results than the tamoxifen group. The trial suggested that anastrozole is the preferred medical therapy for postmenopausal women with localized estrogen receptor-positive breast cancer. Early puberty Anastrozole is used at a dosage of 0.5 to 1 mg/day in combination with the antiandrogen bicalutamide in the treatment of peripheral precocious puberty, for instance due to familial male-limited precocious puberty (testotoxicosis) and McCune–Albright syndrome, in boys. Available forms Anastrozole is available in the form of 1 mg oral tablets. No alternative forms or routes are available. Contraindications Contraindications of anastrozole include hypersensitivity to anastrozole or any other component of anastrozole formulations, pregnancy, and breastfeeding. Hypersensitivity reactions to anastrozole including anaphylaxis, angioedema, and urticaria have been observed. Side effects Common side effects of anastrozole (≥10% incidence) include hot flashes, asthenia, arthritis, pain, arthralgia, hypertension, depression, nausea and vomiting, rash, osteoporosis, bone fractures, back pain, insomnia, headache, bone pain, peripheral edema, coughing, dyspnea, pharyngitis, and lymphedema. Serious but rare adverse effects (<0.1% incidence) include skin reactions such as lesions, ulcers, or blisters; allergic reactions with swelling of the face, lips, tongue, and/or throat that may cause difficulty swallowing or breathing; and abnormal liver function tests as well as hepatitis. Interactions Anastrozole is thought to have clinically negligible inhibitory effects on the cytochrome P450 enzymes CYP1A2, CYP2A6, CYP2D6, CYP2C8, CYP2C9, and CYP2C19. As a result, it is thought that drug interactions of anastrozole with cytochrome P450 substrates are unlikely. No clinically significant drug interactions have been reported with anastrozole as of 2003.Anastrozole does not affect circulating levels of tamoxifen or its major metabolite N-desmethyltamoxifen. However, tamoxifen has been found to decrease steady-state area-under-the-curve levels of anastrozole by 27%. But estradiol levels were not significantly different in the group that received both anastrozole and tamoxifen compared to the anastrozole alone group, so the decrease in anastrozole levels is not thought to be clinically important. Pharmacology Pharmacodynamics Anastrozole works by reversibly binding to the aromatase enzyme, and through competitive inhibition blocks the conversion of androgens to estrogens in peripheral (extragonadal) tissues. The medication has been found to achieve 96.7% to 97.3% inhibition of aromatase at a dosage of 1 mg/day and 98.1% inhibition of aromatase at a dosage of 10 mg/day in humans. As such, 1 mg/day is considered to be the minimal dosage required to achieve maximal suppression of aromatase with anastrozole. This decrease in aromatase activity results in an at least 85% decrease in estradiol levels in postmenopausal women. Levels of corticosteroids and other adrenal steroids are unaffected by anastrozole. Pharmacokinetics The bioavailability of anastrozole in humans is unknown, but it was found to be well-absorbed in animals. Absorption of anastrozole is linear over a dosage range of 1 to 20 mg/day in humans and does not change with repeated administration. Food does not significantly influence the extent of absorption of anastrozole. Peak levels of anastrozole occur a median 3 hours after administration, but with a wide range of 2 to 12 hours. Steady-state levels of anastrozole are achieved within 7 to 10 days of continuous administration, with 3.5-fold accumulation. However, maximal suppression of estradiol levels occurs within 3 or 4 days of therapy.Active efflux of anastrozole by P-glycoprotein at the blood–brain barrier has been found to limit the central nervous system penetration of anastrozole in rodents, whereas this was not the case with letrozole and vorozole. As such, anastrozole may have peripheral selectivity in humans, although this has yet to be confirmed. In any case, estradiol is synthesized peripherally and readily crosses the blood–brain barrier, so anastrozole would still expected to reduce estradiol levels in the central nervous system to a certain degree. The plasma protein binding of anastrozole is 40%.The metabolism of anastrozole is by N-dealkylation, hydroxylation, and glucuronidation. Inhibition of aromatase is due to anastrozole itself rather than to metabolites, with the major circulating metabolite being inactive. The elimination half-life of anastrozole is 40 to 50 hours (1.7 to 2.1 days). This allows for convenient once-daily administration. The medication is eliminated predominantly by metabolism in the liver (83 to 85%) but also by residual excretion by the kidneys unchanged (11%). Anastrozole is excreted primarily in urine but also to a lesser extent in feces. Chemistry Anastrozole is a nonsteroidal benzyltriazole. It is also known as α,α,α,α-tetramethyl-5-(1H-1,2,4-triazol-1-ylmethyl)-m-benzenediacetonitrile. Anastrozole is structurally related to letrozole, fadrozole, and vorozole, with all being classified as azoles. History Anastrozole was patented by Imperial Chemical Industries (ICI) in 1987 and was approved for medical use, specifically the treatment of breast cancer, in 1995. Society and culture Generic names Anastrozole is the generic name of the drug and its INN, USAN, BAN, and JAN. Brand names Anastrozole is primarily sold under the brand name Arimidex. However, it is also marketed under a variety of other brand names throughout the world. Availability Anastrozole is available widely throughout the world. Research Anastrozole is surprisingly ineffective at treating gynecomastia, in contrast to selective estrogen receptor modulators like tamoxifen.Anastrozole was under development for the treatment of female infertility but did not complete development and hence was never approved for this indication.An anastrozole and levonorgestrel vaginal ring (developmental code name BAY 98–7196) was under development for use as a hormonal contraceptive and treatment for endometriosis, but development was discontinued in November 2018 and the formulation was never marketed.Anastrozole increases testosterone levels in males and has been studied as an alternative method of androgen replacement therapy in men with hypogonadism. However, there are concerns about its long-term influence on bone mineral density in this patient population, as well as other adverse effects. References External links "Anastrozole". Drug Information Portal. U.S. National Library of Medicine.
Asciminib
Asciminib, sold under the brand name Scemblix, is a medication used to treat Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML). Asciminib is a protein kinase inhibitor.The most common adverse reactions include upper respiratory tract infections, musculoskeletal pain, fatigue, nausea, rash, and diarrhea.Asciminib was approved for medical use in the United States in October 2021, and in the European Union in August 2022.The U.S. Food and Drug Administration (FDA) granted the application for asciminib priority review, fast track, orphan drug, and breakthrough therapy designations. Mechanism of action Asciminib is described as a "STAMP inhibitor," which means "specifically targeting the ABL myristoyl pocket." The wild-type ABL has a myristoylated N-terminus, which binds to an allosteric site, but the ABL fusion protein does not have the myristoylated domain. In the wild-type protein, when myristoylated N-terminus binds to the allosteric site, the kinase has reduced activity. Since the mutant fusion protein does not have the myristoylated N-terminus domain, it is not subject to this form of regulation, and thus the fusion protein is constitutively active. Asciminib binds to the allosteric site, resulting in an inhibition of bcr-abl activity.Unlike other bcr-abl inhibitors, such as imatinib, asciminib does not bind to the ATP-binding site on the active site of the enzyme. Asciminib and active site bcr-abl inhibitors have non-overlapping resistance mutations. The mutations A337V and P223S overcome the inhibitory activity of asciminib, but asciminib is not affected by the notorious T315I mutation that affects most ATP-competitive active site inhibitors, except ponatinib. Adverse effects Common side effects of Asciminib are symptoms of a cold, muscle pain, joint pain, bone pain, fatigue, nausea, diarrhea, rash as well as the patient displaying abnormal blood tests. Serious side effects of the medication include high blood pressure, low blood cell count, problems with the pancreas, and heart issues. Side effects of the medication on the pancreas may be observed via changes in serum lipase and amylase levels. Pharmacodynamics Asciminib is a substrate of the CYP3A4 enzyme. Asciminib is an inhibitor of CYP3A4, CYP2C9, and P-glycoprotein. Asciminib reaches steady state in 3 days. The volume of distribution of Asciminib is 151 L. Society and culture Legal status On 23 June 2022, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Scemblix, intended for the treatment of adults with Philadelphia chromosome‑positive chronic myeloid leukemia in chronic phase who have previously been treated with two or more tyrosine kinase inhibitors. The applicant for this medicinal product is Novartis Europharm Limited. Asciminib was approved for medical use in the European Union in August 2022. References External links "Asciminib". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT02081378 for "A Phase I Study of Oral ABL001 in Patients With CML or Ph+ ALL" at ClinicalTrials.gov Clinical trial number NCT03106779 for "Study of Efficacy of CML-CP Patients Treated With ABL001 Versus Bosutinib, Previously Treated With 2 or More TKIs" at ClinicalTrials.gov
Carbamazepine
Carbamazepine (CBZ), sold under the trade name Tegretol among others, is an anticonvulsant medication used primarily in the treatment of epilepsy and neuropathic pain. It is used as an adjunctive treatment in schizophrenia along with other medications and as a second-line agent in bipolar disorder. Carbamazepine appears to work as well as phenytoin and valproate for focal and generalized seizures. It is not effective for absence or myoclonic seizures.Carbamazepine was discovered in 1953 by Swiss chemist Walter Schindler. It was first marketed in 1962. It is available as a generic medication. It is on the World Health Organizations List of Essential Medicines. In 2018, it was the 204th most commonly prescribed medication in the United States, with more than 2 million prescriptions. The newer but structurally related drugs, Oxcarbazepine and eslicarbazepine acetate, both show similar interactions, adverse events, and mechanism of action profiles. Medical uses Carbamazepine is typically used for the treatment of seizure disorders and neuropathic pain. It is used off-label as a second-line treatment for bipolar disorder and in combination with an antipsychotic in some cases of schizophrenia when treatment with a conventional antipsychotic alone has failed. However, evidence does not support this usage. It is not effective for absence seizures or myoclonic seizures. Although carbamazepine may have a similar effectiveness (as measured by people continuing to use a medication) and efficacy (as measured by the medicine reducing seizure recurrence and improving remission) when compared to phenytoin and valproate, choice of medication should be evaluated on an individual basis as further research is needed to determine which medication is most helpful for people with newly-onset seizures.In the United States, the FDA-approved medical uses are epilepsy (including partial seizures, generalized tonic-clonic seizures and mixed seizures), trigeminal neuralgia, and manic and mixed episodes of bipolar I disorder. Carbamazepine is the only FDA approved drug for the use of trigeminal neuralgia.The drug is also claimed to be effective for ADHD.As of 2014, a controlled release formulation was available for which there is tentative evidence showing fewer side effects and unclear evidence with regard to whether there is a difference in efficacy. Adverse effects In the US, the label for carbamazepine contains warnings concerning: effects on the bodys production of red blood cells, white blood cells, and platelets: rarely, there are major effects of aplastic anemia and agranulocytosis reported and more commonly, there are minor changes such as decreased white blood cell or platelet counts, but these do not progress to more serious problems. increased risks of suicide increased risks of hyponatremia and SIADH risk of seizures, if the person stops taking the drug abruptly risks to the fetus in women who are pregnant, specifically congenital malformations like spina bifida, and developmental disorders.Common adverse effects may include drowsiness, dizziness, headaches and migraines, motor coordination impairment, nausea, vomiting, and/or constipation. Alcohol use while taking carbamazepine may lead to enhanced depression of the central nervous system. Less common side effects may include increased risk of seizures in people with mixed seizure disorders, abnormal heart rhythms, blurry or double vision. Also, rare case reports of an auditory side effect have been made, whereby patients perceive sounds about a semitone lower than previously; this unusual side effect is usually not noticed by most people, and disappears after the person stops taking carbamazepine. Pharmacogenetics Serious skin reactions such as Stevens–Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) due to carbamazepine therapy are more common in people with a particular human leukocyte antigen gene-variant (allele), HLA-B*1502. Odds ratios for the development of SJS or TEN in people who carry the allele can be in the double, triple or even quadruple digits, depending on the population studied. HLA-B*1502 occurs almost exclusively in people with ancestry across broad areas of Asia, but has a very low or absent frequency in European, Japanese, Korean and African populations. However, the HLA-A*31:01 allele has been shown to be a strong predictor of both mild and severe adverse reactions, such as the DRESS form of severe cutaneous reactions, to carbamazepine among Japanese, Chinese, Korean, and Europeans. It is suggested that carbamazepine acts as a potent antigen that binds to the antigen-presenting area of HLA-B*1502 alike, triggering an everlasting activation signal on immature CD8-T cells, thus resulting in widespread cytotoxic reactions like SJS/TEN. Interactions Carbamazepine has a potential for drug interactions. Drugs that decrease breaking down of carbamazepine or otherwise increase its levels include erythromycin, cimetidine, propoxyphene, and calcium channel blockers. Grapefruit juice raises the bioavailability of carbamazepine by inhibiting the enzyme CYP3A4 in the gut wall and in the liver. Lower levels of carbamazepine are seen when administrated with phenobarbital, phenytoin, or primidone, which can result in breakthrough seizure activity.Valproic acid and valnoctamide both inhibit microsomal epoxide hydrolase (mEH), the enzyme responsible for the breakdown of the active metabolite carbamazepine-10,11-epoxide into inactive metabolites. By inhibiting mEH, valproic acid and valnoctamide cause a build-up of the active metabolite, prolonging the effects of carbamazepine and delaying its excretion. Carbamazepine, as an inducer of cytochrome P450 enzymes, may increase clearance of many drugs, decreasing their concentration in the blood to subtherapeutic levels and reducing their desired effects. Drugs that are more rapidly metabolized with carbamazepine include warfarin, lamotrigine, phenytoin, theophylline, valproic acid, many benzodiazepines, and methadone. Carbamazepine also increases the metabolism of the hormones in birth control pills and can reduce their effectiveness, potentially leading to unexpected pregnancies. Pharmacology Mechanism of action Carbamazepine is a sodium channel blocker. It binds preferentially to voltage-gated sodium channels in their inactive conformation, which prevents repetitive and sustained firing of an action potential. Carbamazepine has effects on serotonin systems but the relevance to its antiseizure effects is uncertain. There is evidence that it is a serotonin releasing agent and possibly even a serotonin reuptake inhibitor. It has been suggested that carbamazepine can also block voltage-gated calcium channels, which will reduce neurotransmitter release. Pharmacokinetics Carbamazepine is relatively slowly but practically completely absorbed after administration by mouth. Highest concentrations in the blood plasma are reached after 4 to 24 hours depending on the dosage form. Slow release tablets result in about 15% lower absorption and 25% lower peak plasma concentrations than ordinary tablets, as well as in less fluctuation of the concentration, but not in significantly lower minimum concentrations.20 to 30% of the substance are circulating in form of carbamazepine itself, the rest are metabolites. 70 to 80% are bound to plasma proteins. Concentrations in the breast milk are 25 to 60% of those in the blood plasma.Carbamazepine itself is not pharmacologically active. It is activated, mainly by CYP3A4, to carbamazepine-10,11-epoxide, which is solely responsible for the drugs anticonvulsant effects. The epoxide is then inactivated by microsomal epoxide hydrolase (mEH) to carbamazepine-trans-10,11-diol and further to its glucuronides. Other metabolites include various hydroxyl derivatives and carbamazepine-N-glucuronide.The plasma half-life is about 35 to 40 hours when carbamazepine is given as single dose, but it is a strong inducer of liver enzymes, and the plasma half-life shortens to about 12 to 17 hours when it is given repeatedly. The half-life can be further shortened to 9–10 hours by other enzyme inducers such as phenytoin or phenobarbital. About 70% are excreted via the urine, almost exclusively in form of its metabolites, and 30% via the faeces. History Carbamazepine was discovered by chemist Walter Schindler at J.R. Geigy AG (now part of Novartis) in Basel, Switzerland, in 1953. It was first marketed as a drug to treat epilepsy in Switzerland in 1963 under the brand name "Tegretol"; its use for trigeminal neuralgia (formerly known as tic douloureux) was introduced at the same time. It has been used as an anticonvulsant and antiepileptic in the UK since 1965, and has been approved in the US since 1968.In 1971, Drs. Takezaki and Hanaoka first used carbamazepine to control mania in patients refractory to antipsychotics (lithium was not available in Japan at that time). Dr. Okuma, working independently, did the same thing with success. As they were also epileptologists, they had some familiarity with the antiaggression effects of this drug. Carbamazepine was studied for bipolar disorder throughout the 1970s. Society and culture Environmental impact Carbamazepine and its bio-transformation products have been detected in wastewater treatment plant effluent: 224  and in streams receiving treated wastewater. Field and laboratory studies have been conducted to understand the accumulation of carbamazepine in food plants grown in soil treated with sludge, which vary with respect to the concentrations of carbamazepine present in sludge and in the concentrations of sludge in the soil. Taking into account only studies that used concentrations commonly found in the environment, a 2014 review concluded that "the accumulation of carbamazepine into plants grown in soil amended with biosolids poses a de minimis risk to human health according to the approach.": 227 Brand names Carbamazepine is available worldwide under many brand names including Tegretol. See also Oxcarbazepine References Further reading External links "Carbamazepine". Drug Information Portal. U.S. National Library of Medicine. "Carbamazepine". National Health Service.
Amitriptyline
Amitriptyline, sold under the brand name Elavil among others, is a tricyclic antidepressant primarily used to treat cyclic vomiting syndrome (CVS), major depressive disorder and a variety of pain syndromes from neuropathic pain to fibromyalgia to migraine and tension headaches. Due to the frequency and prominence of side effects, amitriptyline is generally considered a second-line therapy for these indications.The most common side effects are dry mouth, drowsiness, dizziness, constipation, and weight gain. Of note is sexual dysfunction, observed primarily in males. Glaucoma, liver toxicity and abnormal heart rhythms are rare but serious side effects. Blood levels of amitriptyline vary significantly from one person to another, and amitriptyline interacts with many other medications potentially aggravating its side effects. Amitriptyline was discovered in the late 1950s by scientists at Merck and approved by the US Food and Drug Administration (FDA) in 1961. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2019, it was the 94th most commonly prescribed medication in the United States, with more than 8 million prescriptions. Medical uses Amitriptyline is indicated for the treatment of major depressive disorder and neuropathic pain and for the prevention of migraine and chronic tension headache. It can be used for the treatment of nocturnal enuresis in children older than 6 after other treatments have failed. Depression Amitriptyline is effective for depression, but it is rarely used as a first-line antidepressant due to its higher toxicity in overdose and generally poorer tolerability. It can be tried for depression as a second-line therapy, after the failure of other treatments. For treatment-resistant adolescent depression or for cancer-related depression amitriptyline is no better than placebo. It is sometimes used for the treatment of depression in Parkinsons disease, but supporting evidence for that is lacking. Pain Amitriptyline alleviates painful diabetic neuropathy. It is recommended by a variety of guidelines as a first or second line treatment. It is as effective for this indication as gabapentin or pregabalin but less well tolerated.Low doses of amitriptyline moderately improve sleep disturbances and reduce pain and fatigue associated with fibromyalgia. It is recommended for fibromyalgia accompanied by depression by Association of the Scientific Medical Societies in Germany and as a second-line option for fibromyalgia, with exercise being the first line option, by European League Against Rheumatism. Combinations of amitriptyline and fluoxetine or melatonin may reduce fibromyalgia pain better than either medication alone.There is some (low-quality) evidence that amitriptyline may reduce pain in cancer patients. It is recommended only as a second line therapy for non-chemotherapy-induced neuropathic or mixed neuropathic pain, if opioids did not provide the desired effect.Moderate evidence exists in favor of amitriptyline use for atypical facial pain. Amitriptyline is ineffective for HIV-associated neuropathy. Headache Amitriptyline is probably effective for the prevention of periodic migraine in adults. Amitriptyline is similar in efficacy to venlafaxine and topiramate but carries a higher burden of adverse effects than topiramate. For many patients, even very small doses of amitriptyline are helpful, which may allow for minimization of side effects. Amitriptyline is not significantly different from placebo when used for the prevention of migraine in children.Amitriptyline may reduce the frequency and duration of chronic tension headache, but it is associated with worse adverse effects than mirtazapine. Overall, amitriptyline is recommended for tension headache prophylaxis, along with lifestyle advice, which should include avoidance of analgesia and caffeine. Other indications Amitriptyline is effective for the treatment of irritable bowel syndrome; however, because of its side effects, it should be reserved for select patients for whom other agents do not work. There is insufficient evidence to support its use for abdominal pain in children with functional gastrointestinal disorders.Tricyclic antidepressants decrease the frequency, severity, and duration of cyclic vomiting syndrome episodes. Amitriptyline, as the most commonly used of them, is recommended as a first-line agent for its therapy.Amitriptyline may improve pain and urgency intensity associated with bladder pain syndrome and can be used in the management of this syndrome. Amitriptyline can be used in the treatment of nocturnal enuresis in children. However, its effect is not sustained after the treatment ends. Alarm therapy gives better short- and long-term results.In the US, amitriptyline is commonly used in children with ADHD as an adjunct to stimulant medications without any evidence or guideline supporting this practice. Many physicians in the UK (and the US also) commonly prescribe amitriptyline for insomnia; however, Cochrane reviewers were not able to find any randomized controlled studies that would support or refute this practice. Contraindications and precautions The known contraindications of amitriptyline are: Amitriptyline should be used with caution in patients with epilepsy, impaired liver function, pheochromocytoma, urinary retention, prostate enlargement, hyperthyroidism, and pyloric stenosis.In patients with the rare condition of shallow anterior chamber of eyeball and narrow anterior chamber angle, amitriptyline may provoke attacks of acute glaucoma due to dilation of the pupil. It may aggravate psychosis, if used for depression with schizophrenia, or precipitate the switch to mania in those with bipolar disorder.CYP2D6 poor metabolizers should avoid amitriptyline due to increased side effects. If it is necessary to use it, half dose is recommended. Amitriptyline can be used during pregnancy and lactation, in the cases when SSRI do not work. Side effects The most frequent side effects, occurring in 20% or more of users, are dry mouth, drowsiness, dizziness, constipation, and weight gain (on average 1.8 kg). Other common side effects (in 10% or more) are vision problems (amblyopia, blurred vision), tachycardia, increased appetite, tremor, fatigue/asthenia/feeling slowed down, and dyspepsia.A literature review about abnormal movements and amitriptyline found that this drug is associated with various movement disorders, particularly dyskinesia, dystonia, and myoclonus. Stuttering and restless legs syndrome are some of the less common associations.A less common side effect of amitriptyline is urination problems (8.7%).Amitriptyline-associated sexual dysfunction (occurring at a frequency of 6.9%) seems to be mostly confined to males with depression and is expressed predominantly as erectile dysfunction and low libido disorder, with lesser frequency of ejaculatory and orgasmic problems. The rate of sexual dysfunction in males treated for indications other than depression and in females is not significantly different from placebo.Liver tests abnormalities occur in 10-12% of patients on amitriptyline, but are usually mild, asymptomatic and transient, with consistently elevated alanine transaminase in 3% of all patients. The increases of the enzymes above the 3-fold threshold of liver toxicity are uncommon, and cases of clinically apparent liver toxicity are rare; nevertheless, amitriptyline is placed in the group of antidepressants with greater risks of hepatic toxicity.Amitriptyline prolongs the QT interval. This prolongation is relatively small at therapeutic doses but becomes severe in overdose. Overdose The symptoms and the treatment of an overdose are largely the same as for the other TCAs, including the presentation of serotonin syndrome and adverse cardiac effects. The British National Formulary notes that amitriptyline can be particularly dangerous in overdose, thus it and other TCAs are no longer recommended as first-line therapy for depression. The treatment of overdose is mostly supportive as no specific antidote for amitriptyline overdose is available. Activated charcoal may reduce absorption if given within 1–2 hours of ingestion. If the affected person is unconscious or has an impaired gag reflex, a nasogastric tube may be used to deliver the activated charcoal into the stomach. ECG monitoring for cardiac conduction abnormalities is essential and if one is found close monitoring of cardiac function is advised. Body temperature should be regulated with measures such as heating blankets if necessary. Cardiac monitoring is advised for at least five days after the overdose. Benzodiazepines are recommended to control seizures. Dialysis is of no use due to the high degree of protein binding with amitriptyline. Interactions Since amitriptyline and its active metabolite nortriptyline are primarily metabolized by cytochromes CYP2D6 and CYP2C19 (see Amitriptyline#Pharmacology), the inhibitors of these enzymes are expected to exhibit pharmacokinetic interactions with amitriptyline. According to the prescribing information, the interaction with CYP2D6 inhibitors may increase the plasma level of amitriptyline. However, the results in the other literature are inconsistent: the co-administration of amitriptyline with a potent CYP2D6 inhibitor paroxetine does increase the plasma levels of amitriptyline two-fold and of the main active metabolite nortriptyline 1.5-fold, but combination with less potent CYP2D6 inhibitors thioridazine or levomepromazine does not affect the levels of amitriptyline and increases nortriptyline by about 1.5-fold; a moderate CYP2D6 inhibitor fluoxetine does not seem to have a significant effect on the levels of amitriptyline or nortriptyline. A case of clinically significant interaction with potent CYP2D6 inhibitor terbinafine has been reported.A potent inhibitor of CYP2C19 and other cytochromes fluvoxamine increases the level of amitriptyline two-fold while slightly decreasing the level of nortriptyline. Similar changes occur with a moderate inhibitor of CYP2C19 and other cytochromes cimetidine: amitriptyline level increases by about 70%, while nortriptyline decreases by 50%. CYP3A4 inhibitor ketoconazole elevates amitriptyline level by about a quarter. On the other hand, cytochrome P450 inducers such as carbamazepine and St. Johns Wort decrease the levels of both amitriptyline and nortriptylineOral contraceptives may increase the blood level of amitriptyline by as high as 90%. Valproate moderately increases the levels of amitriptyline and nortriptyline through an unclear mechanism.The prescribing information warns that the combination of amitriptyline with monoamine oxidase inhibitors may cause potentially lethal serotonin syndrome; however, this has been disputed. The prescribing information cautions that some patients may experience a large increase in amitriptyline concentration in the presence of topiramate. However, other literature states that there is little or no interaction: in a pharmacokinetic study topiramate only increased the level of amitriptyline by 20% and nortriptyline by 33%.Amitriptiline counteracts the antihypertensive action of guanethidine. When given with amitriptyline, other anticholinergic agents may result in hyperpyrexia or paralytic ileus. Co-administration of amitriptyline and disulfiram is not recommended due to the potential for the development of toxic delirium. Amitriptyline causes an unusual type of interaction with the anticoagulant phenprocoumon during which great fluctuations of the prothrombin time have been observed. Pharmacology Pharmacodynamics Amitriptyline inhibits serotonin transporter (SERT) and norepinephrine transporter (NET). It is metabolized to nortriptyline, a stronger norepinephrine reuptake inhibitor, further augmenting amitriptylines effects on norepinephrine reuptake (see the Table on the right). Amitriptyline additionally acts as a potent inhibitor of the serotonin 5-HT2A, 5-HT2C, the α1A-adrenergic, the histamine H1 and the M1-M5 muscarinic acetylcholine receptors (see the Table on the right). Amitriptyline is a non-selective blocker of multiple ion channels, in particular, voltage-gated sodium channels Nav1.3, Nav1.5, Nav1.6, Nav1.7, and Nav1.8, voltage-gated potassium channels Kv7.2/ Kv7.3, Kv7.1, Kv7.1/KCNE1, and hERG. Mechanism of action Inhibition of serotonin and norepinephrine transporters by amitriptyline results in interference with neuronal reuptake of serotonin and norepinephrine. Since the reuptake process is important physiologically in terminating transmitting activity, this action may potentiate or prolong activity of serotonergic and adrenergic neurons and is believed to underlie the antidepressant activity of amitriptyline.Inhibition of norepinephrine reuptake leading to increased concentration of norepinephrine in the posterior grey column of the spinal cord appears to be mostly responsible for the analgesic action of amitriptyline. Increased level of norepinephrine increases the basal activity of alpha-2 adrenergic receptors, which mediate an analgesic effect by increasing gamma-aminobutyric acid transmission among spinal interneurons. The blocking effect of amitriptyline on sodium channels may also contribute to its efficacy in pain conditions. Pharmacokinetics Amitriptyline is readily absorbed from the gastrointestinal tract (90–95%). Absorption is gradual with the peak concentration in blood plasma reached after about 4 hours. Extensive metabolism on the first pass through the liver leads to average bioavailability of about 50% (45%-53%). Amitriptyline is metabolized mostly by CYP2C19 into nortriptyline and by CYP2D6 leading to a variety of hydroxylated metabolites, with the principal one among them being (E)-10-hydroxynortriptyline (see metabolism scheme), and to a lesser degree, by CYP3A4. Nortriptyline, the main active metabolite of amitriptyline, is an antidepressant on its own right. Nortriptyline reaches 10% higher level in the blood plasma than the parent drug amitriptyline and 40% greater area under the curve, and its action is an important part of the overall action of amitriptyline.Another active metabolite is (E)-10-hydroxynortriptyline, which is a norepinephrine uptake inhibitor four times weaker than nortriptyline. (E)-10-hydroxynortiptyline blood level is comparable to that of nortriptyline, but its cerebrospinal fluid level, which is a close proxy of the brain concentration of a drug, is twice higher than nortriptylines. Based on this, (E)-10-hydroxynortriptyline was suggested to significantly contribute to antidepressant effects of amitriptyline.Blood levels of amitriptyline and nortriptyline and pharmacokinetics of amitriptyline in general, with clearance difference of up to 10-fold, vary widely between individuals. Variability of the area under the curve in steady state is also high, which makes a slow upward titration of the dose necessary.In the blood, amitriptyline is 96% bound to plasma proteins; nortriptyline is 93–95% bound, and (E)-10-hydroxynortiptyline is about 60% bound. Amitriptyline has an elimination half life of 21 hours, nortriptyline - 23–31 hours, and (E)-10-hydroxynortiptyline - 8–10 hours. Within 48 hours, 12-80% of amitriptyline is eliminated in the urine, mostly as metabolites. 2% of the unchanged drug is excreted in the urine. Elimination in the feces, apparently, have not been studied. Therapeutic levels of amitriptyline range from 75 to 175 ng/mL (270–631 nM), or 80–250 ng/mL of both amitriptyline and its metabolite nortriptyline. Pharmacogenetics Since amitriptyline is primarily metabolized by CYP2D6 and CYP2C19, genetic variations within the genes coding for these enzymes can affect its metabolism, leading to changes in the concentrations of the drug in the body. Increased concentrations of amitriptyline may increase the risk for side effects, including anticholinergic and nervous system adverse effects, while decreased concentrations may reduce the drugs efficacy.Individuals can be categorized into different types of CYP2D6 or CYP2C19 metabolizers depending on which genetic variations they carry. These metabolizer types include poor, intermediate, extensive, and ultrarapid metabolizers. Most individuals (about 77–92%) are extensive metabolizers, and have "normal" metabolism of amitriptyline. Poor and intermediate metabolizers have reduced metabolism of the drug as compared to extensive metabolizers; patients with these metabolizer types may have an increased probability of experiencing side effects. Ultrarapid metabolizers use amitriptyline much faster than extensive metabolizers; patients with this metabolizer type may have a greater chance of experiencing pharmacological failure.The Clinical Pharmacogenetics Implementation Consortium recommends avoiding amitriptyline in patients who are CYP2D6 ultrarapid or poor metabolizers, due to the risk for a lack of efficacy and side effects, respectively. The consortium also recommends considering an alternative drug not metabolized by CYP2C19 in patients who are CYP2C19 ultrarapid metabolizers. A reduction in starting dose is recommended for patients who are CYP2D6 intermediate metabolizers and CYP2C19 poor metabolizers. If use of amitriptyline is warranted, therapeutic drug monitoring is recommended to guide dose adjustments. The Dutch Pharmacogenetics Working Group also recommends selecting an alternative drug or monitoring plasma concentrations of amitriptyline in patients who are CYP2D6 poor or ultrarapid metabolizers, and selecting an alternative drug or reducing initial dose in patients who are CYP2D6 intermediate metabolizers. Chemistry Amitriptyline is a highly lipophilic molecule having an octanol-water partition coefficient (pH 7.4) of 3.0, while the log P of the free base was reported as 4.92. Solubility of the free base amitriptyline in water is 14 mg/L. Amitriptyline is prepared by reacting dibenzosuberone with 3-(dimethylamino)propylmagnesium chloride and then heating the resulting intermediate product with hydrochloric acid to eliminate water. History Amitriptyline was first developed by the American pharmaceutical company Merck in the late 1950s. In 1958, Merck approached a number of clinical investigators proposing to conduct clinical trials of amitriptyline for schizophrenia. One of these researchers, Frank Ayd, instead, suggested using amitriptyline for depression. Ayd treated 130 patients and, in 1960, reported that amitriptyline had antidepressant properties similar to another, and the only known at the time, tricyclic antidepressant imipramine. Following this, the US Food and Drug Administration approved amitriptyline for depression in 1961.In Europe, due to a quirk of the patent law at the time allowing patents only on the chemical synthesis but not on the drug itself, Roche and Lundbeck were able to independently develop and market amitriptyline in the early 1960s.According to research by the historian of psychopharmacology David Healy, amitriptyline became a much bigger selling drug than its precursor imipramine because of two factors. First, amitriptyline has much stronger anxiolytic effect. Second, Merck conducted a marketing campaign raising clinicians awareness of depression as a clinical entity. Society and culture English folk singer Nick Drake died from an overdose of Tryptizol in 1974.Senteni Masango, wife of Swaziland King Mswati, died on 6 April 2018 after committing suicide by overdosing on amytriptyline capsules.In the 2021 film The Many Saints of Newark, amitriptyline (referred to by the brand name Elavil) is part of the plot line of the movie. Generic names Amitriptyline is the English and French generic name of the drug and its INN, BAN, and DCF, while amitriptyline hydrochloride is its USAN, USP, BANM, and JAN. Its generic name in Spanish and Italian and its DCIT are amitriptilina, in German is Amitriptylin, and in Latin is amitriptylinum. The embonate salt is known as amitriptyline embonate, which is its BANM, or as amitriptyline pamoate unofficially. Research The few randomized controlled trials investigating amitriptyline efficacy in eating disorder have been discouraging. References Further reading Dean L (March 2017). "Amitriptyline Therapy and CYP2D6 and CYP2C19 Genotype". In Pratt VM, McLeod HL, Rubinstein WS, et al. (eds.). Medical Genetics Summaries. National Center for Biotechnology Information (NCBI). PMID 28520380. External links "Amitriptyline". Drug Information Portal. U.S. National Library of Medicine.
Naftifine
Naftifine hydrochloride (brand names include Exoderil and Naftin) is an allylamine antifungal drug for the topical treatment of tinea pedis, tinea cruris, and tinea corporis (topical fungal infections). Naftifine has triple action: antifungal, antibacterial, and anti-inflammatory. Its fungistatic activity is believed to be based on inhibition of the squalene-2,3-epoxidase enzyme, which in turn results in the shortage of ergosterol required for the formation of fungal cell membranes. With some fungal species, there is also fungicidal activity from a resulting accumulation of squalenes, leading to damage of the fungal cell membranes, including at the endoplasmatic reticulum. The half-life is approximately 2–3 days. The metabolites are excreted in the urine and feces.Naftifine was invented at the Sandoz Research Institute in Vienna, Austria. It was the first succesful antifungal medication of the allylamine class. Naftifine shows mostly fungicidal activity toward dematophytes and molds, and mostly fungistatic activity toward yeasts. It is also effective as an antibacterial agent in treating pyoderma. Naftifine is almost completely metabolized in the human body, with a half-life of 2–3 days. Its metabolytes do not have antifungal activity, and they are excreted with urine and bile. == References ==
Conjugated estrogens
Conjugated estrogens (CEs), or conjugated equine estrogens (CEEs), sold under the brand name Premarin among others, is an estrogen medication which is used in menopausal hormone therapy and for various other indications. It is a mixture of the sodium salts of estrogen conjugates found in horses, such as estrone sulfate and equilin sulfate. CEEs are available in the form of both natural preparations manufactured from the urine of pregnant mares and fully synthetic replications of the natural preparations. They are formulated both alone and in combination with progestins such as medroxyprogesterone acetate. CEEs are usually taken by mouth, but can also be given by application to the skin or vagina as a cream or by injection into a blood vessel or muscle.Side effects of CEEs include breast tenderness and enlargement, headache, fluid retention, and nausea among others. It may increase the risk of endometrial hyperplasia and endometrial cancer in women with an intact uterus if it is not taken together with a progestogen like progesterone. The medication may also increase the risk of blood clots, cardiovascular disease, and, when combined with most progestogens, breast cancer. CEEs are estrogens, or agonists of the estrogen receptor, the biological target of estrogens like estradiol. Compared to estradiol, certain estrogens in CEEs are more resistant to metabolism, and the medication shows relatively increased effects in certain parts of the body like the liver. This results in an increased risk of blood clots and cardiovascular problems with CEEs relative to estradiol.Premarin, the major brand of CEEs in use, is manufactured by Pfizer and was first marketed in 1941 in Canada and in 1942 in the United States. It is the most commonly used form of estrogen in menopausal hormone therapy in the United States. However, it has begun to fall out of favor relative to bioidentical estradiol, which is the most widely used form of estrogen in Europe for menopausal hormone therapy. CEEs are available widely throughout the world. An estrogen preparation very similar to CEEs but differing in source and composition is esterified estrogens. In 2017, it was the 206th most commonly prescribed medication in the United States, with more than two million prescriptions. Medical uses CEEs are a form of hormone therapy used in women. It is used most commonly in postmenopausal women who have had a hysterectomy to treat hot flashes, and burning, itching, and dryness of the vagina and surrounding areas. It must be used in combination with a progestogen in women who have not had a hysterectomy. For women already taking the medication, it can be used to treat osteoporosis, although it is not recommended solely for this use. Some lesser known uses are as a means of high-dose estrogen therapy in the treatment of breast cancer in both women and men and in the treatment of prostate cancer in men. It has been used at a dosage of 2.5 mg three times per day (7.5 mg/day total) for prostate cancer.CEEs are specifically approved in countries such as the United States and Canada for the treatment of moderate to severe vasomotor symptoms (hot flashes) and vulvovaginal atrophy (atrophic vaginitis, atrophic urethritis) associated with menopause, hypoestrogenism due to hypogonadism, ovariectomy, or primary ovarian failure, abnormal uterine bleeding, the palliative treatment of metastatic breast cancer in women, the palliative treatment of advanced androgen-dependent prostate cancer in men, and the prevention of postmenopausal osteoporosis. The intravenous formulation of CEEs is specifically used to rapidly limit bleeding in women with hemorrhage due to dysfunctional uterine bleeding.: 318 : 60 Available forms Natural CEEs, as Premarin, are available in the form of oral tablets (0.3 mg, 0.625 mg, 0.9 mg, 1.25 mg, or 2.5 mg), creams for topical or vaginal administration (0.625 mg/g), and vials for intravenous or intramuscular injection (25 mg/vial). Synthetic CEEs, such as Cenestin (Synthetic A), Enjuvia (Synthetic B), and generic formulations, are available in the form of oral tablets (0.3 mg, 0.45 mg, 0.625 mg, 0.9 mg, or 1.25 mg) and creams for topical or vaginal administration (0.625 mg/g). Contraindications Contraindications of CEEs include breast cancer and a history of venous thromboembolism, among others. Side effects The most common side effects associated with CEEs are vaginal yeast infections, vaginal spotting or bleeding, painful menses, and cramping of the legs. While there are some contradictory data, estrogen alone does not appear to increase the risk of coronary heart disease or breast cancer, unlike the case of estrogen in combination with certain progestins such as levonorgestrel or medroxyprogesterone acetate. Only a few clinical studies have assessed differences between oral CEEs and oral estradiol in terms of health parameters. Oral CEEs have been found to possess a significantly greater risk of thromboembolic and cardiovascular complications than oral estradiol (OR = 2.08) and oral esterified estrogens (OR = 1.78). However, in another study, the increase in venous thromboembolism risk with oral CEEs plus medroxyprogesterone acetate and oral estradiol plus norethisterone acetate was found to be equivalent (RR = 4.0 and 3.9, respectively). As of present, there are no randomized controlled trials that would allow for unambiguous conclusions. Overdose Estrogens, including CEEs, are relatively safe in acute overdose. Interactions Inhibitors and inducers of cytochrome P450 enzymes may interact with CEEs. Pharmacology Pharmacodynamics CEEs are a combination of estrogens, or agonists of the estrogen receptors. The major estrogen in CEEs, sodium estrone sulfate, itself is inactive, and rather serves as a prodrug of estrone and then of estradiol. The transformation of estrone sulfate to estrone is catalyzed by steroid sulfatase, and of estrone into estradiol by 17β-hydroxysteroid dehydrogenase. CEEs (as Premarin) and estrone have been found to be equivalent in potency in an animal model of estrogenic activity. On the other hand, the active forms of the equine estrogens in CEEs, such as equilin and 17β-dihydroequilin, have greater potency in the liver relative to bioidentical estradiol, similarly to synthetic estrogens like ethinylestradiol and diethylstilbestrol. This results in disproportionate effects on liver protein production compared to estradiol, although to a lesser extent than ethinylestradiol and diethylstilbestrol. In addition, 17β-dihydroequilenin has shown a selective estrogen receptor modulator (SERM)-like profile of estrogenic activity in studies with monkeys, in which beneficial effects on bone and the cardiovascular system were observed but proliferative responses in breast or endometrium were not seen, although the clinical significance of this is unknown.CEEs consists of the sodium salts of the sulfate esters of equine estrogens in a specific and consistent composition (see the table). The major estrogens in CEEs are sodium estrone sulfate and sodium equilin sulfate, which together account for approximately 71.5 to 92.0% of the total content of CEEs. CEEs are prodrugs of the active forms of the estrogens. Sodium estrone sulfate is a prodrug of estrone, which in turn is a prodrug of estradiol, while sodium equilin sulfate is a prodrug of equilin and then of 17β-dihydroequilin. As such, the major active estrogens with CEEs are estradiol and 17β-dihydroequilin, which have potent estrogenic activity and account for most of the effects of CEEs. The 17α-estrogens in CEEs such as 17α-estradiol and 17α-dihydroequilin have low estrogenicity and are thought to contribute minimally to its effects. There are many different steroids in natural CEE products like Premarin, as many as 230 compounds and including even androgens and progestogens, but only the estrogens are present in sufficient amounts to produce clinically-relevant effects.A dosage of 0.625 mg/day oral CEEs has been found to increase SHBG levels by 100%. For comparison, 1 mg/day oral estradiol increased SHBG levels by 45%, while 50 µg/day transdermal estradiol increased SHBG levels by 12%. Ethinylestradiol is more potent in its effects on liver protein synthesis than either CEEs or estradiol, with 10 µg/day oral ethinylestradiol having been found to be approximately equivalent to 1.25 mg/day CEEs. Antigonadotropic effects A preliminary study of ovulation inhibition in women found that oral CEEs was 33% effective at 1.25 mg/day and 94% at 3.75 mg/day. A dosage of oral CEEs of 2.5 mg three times daily (7.5 mg/day total) has been found to suppress total testosterone levels in men to an equivalent extent as 3 mg/day oral diethylstilbestrol, which is the minimum dosage of diethylstilbestrol required to consistently suppress total testosterone levels into the castrate range (<50 ng/dL). Pharmacokinetics CEEs are hydrolyzed in the intestines during first-pass metabolism upon oral administration. Following their absorption, they are resulfated mainly in the liver also during the first pass. Following this, they serve as a circulating reservoir and are slowly rehydrolyzed into their unconjugated active forms.Oral CEEs, at a daily dosage of 0.625 mg, achieve estrone and estradiol levels of 150 pg/mL and 30–50 pg/mL, respectively, while a daily oral dosage of 1.25 mg achieves levels of 120–200 pg/mL and 40–60 pg/mL of estrone and estradiol, respectively. The oral ingestion of 10 mg CEEs, which contains about 4.5 mg sodium estrone sulfate and 2.5 mg sodium equilin sulfate, produces maximal plasma concentrations of estrone and equilin of 1,400 pg/mL and 560 pg/mL within 3 and 5 hours, respectively. By 24 hours post-dose of 10 mg, the levels of estrone and equilin fall to 280 pg/mL and 125 pg/mL, respectively. Oral CEEs 1.25 mg/daily and oral micronized estradiol 1 mg/daily result in similar plasma concentrations of estrone and estradiol (150–300 pg/mL and 30–50 pg/mL for micronized estradiol, respectively) (oral estradiol is extensively metabolized into estrone during hepatic first-pass metabolism), although this does not account for equilin and other equine estrogens involved in the effects of CEEs, which may be significantly more potent in comparison to estrone. The pharmacokinetics of vaginal CEEs and of intravenous CEEs have been studied as well.Eoncentrations of equilin that are very high relative to those of other estrogens are produced by typical clinical doses of CEEs. With a dosage of 1.25 mg oral CEEs, equilin levels of 1,082 to 2,465 pg/mL have been observed. The clinical significance of these levels of equilin is unknown.The active forms are metabolized primarily in the liver. There is some enterohepatic recirculation of CEEs. Following a single oral dose of 0.625 CEEs, the biological half-life of estrone was 26.7 hours, of baseline-adjusted estrone was 14.8 hours, and of equilin was 11.4 hours. Chemistry CEEs are naturally occurring estrane steroids. They are in conjugate form, as the sodium salts of the C17β sulfate esters. The estrogens in CEEs, in their unconjugated active forms, include bioidentical human estrogens like estradiol and estrone as well as equine-specific estrogens such as equilin and 17β-dihydroequilin. The equine estrogens differ from human estrogens in that they have additional double bonds in the B ring of the steroid nucleus. CEEs contain both 17β-estrogens like estradiol and 17β-dihydroequilin and the C17α epimers like 17α-estradiol and 17α-dihydroequilin. History Conjugated estriol, an extract of the urine of pregnant women and sold under the brand names Progynon and Emmenin in the 1930s, was the predecessor of Premarin. Both of these products contained conjugated estrogens similarly to Premarin, but the estrogens were human estrogens as opposed to equine estrogens and the composition differed. The major active ingredient in Progynon and Emmenin was estriol glucuronide. Estrone sulfate was first isolated from the urine of pregnant mares in the late 1930s by researchers in the Department of Biochemistry at University of Toronto. Premarin was first introduced in 1941 by Wyeth Ayerst as a treatment for hot flashes and other symptoms of menopause; at that time, Wyeth Ayerst only had to prove its safety, and not its efficacy. In response to the 1962 Kefauver Harris Amendment the FDA had its efficacy reviewed, and in 1972 found it effective for menopausal symptoms and probably effective for osteoporosis. The review also determined that two estrogens – estrone sulfate and equilin sulfate – were primarily responsible for the activity of Premarin, and it laid the groundwork for Abbreviated New Drug Application (ANDA) submissions of generic versions. In 1984 an NIH consensus panel found that estrogens were effective for preventing osteoporosis and 1986 the FDA announced in the Federal Register that Premarin was effective for preventing osteoporosis. This announcement led to a rapid growth in sales, and interest from generic manufacturers to introduce generic versions.Conjugated estrogens was introduced for medical use under the brand name Premarin in Canada in 1941, in the United States in 1942, and in the United Kingdom in 1956. Society and culture Names Estrogens, conjugated is the generic name of the drug and its USP and JAN. It is also known as conjugated estrogens or as conjugated equine estrogens. The brand name Premarin is a contraction of "pregnant mares urine".CEEs are marketed under a large number of brand names throughout the world. The major brand name of the natural form of CEEs manufactured from the urine of pregnant mares is Premarin. Major brand names of fully synthetic versions of CEEs include Cenestin and Enjuvia in the United States and C.E.S. and Congest in Canada. CEEs are also formulated in combination with progestins. Major brand names of CEEs in combination with medroxyprogesterone acetate include Prempro and Premphase in the United States, Premplus in Canada, Premique in the United Kingdom and Ireland, Premia in Australia and New Zealand, and Premelle in South Africa. Prempak-C is a combination of CEEs and norgestrel which is used in the United Kingdom and Ireland, and Prempak N is a combination of CEEs and medrogestone which is used in South Africa. Many of the aforementioned brand names are also used in other, non-English-speaking countries. Availability CEEs are marketed and available widely throughout the world. This includes in all English-speaking countries, throughout Europe, Latin America, Asia, and elsewhere in the world. Usage Besides ethinylestradiol used in birth control pills, CEEs were the second most used estrogen in the U.S. in 2016, with 4.2 million total prescriptions filled. The first most used estrogen was estradiol, with 13.4 million total prescriptions filled. CEEs were the 206th most commonly prescribed medication in the U.S. that year. Health effects Research starting in 1975 showed substantially increased risk of endometrial cancer. Since 1976 the drug has carried a label warning about the risk. As part of the Womens Health Initiative sponsored by the National Institutes of Health, a large-scale clinical trial of menopausal HRT showed that long-term use of estrogen and a progestin may increase the risk of strokes, heart attacks, blood clots, and breast cancer. Following these results, Wyeth experienced a significant decline in its sales of Premarin, Prempro (CEEs and medroxyprogesterone acetate), and related products, from over $2 billion in 2002 to just over $1 billion in 2006. Litigation This drug has been the subject of litigation; more than 13,000 people have sued Wyeth between 2002 and 2009. Wyeth and Pharmacia & Upjohn prevailed in the vast majority of hormone therapy cases previously set for trial through a combination of rulings by judges, verdicts by juries, and dismissals by plaintiffs themselves. Of the companys losses, two of the jury verdicts were reversed post-trial and others are being challenged on appeal. Wyeth also won five summary judgments on Prempro cases and had 15 cases voluntarily dismissed by plaintiffs. The company won dismissals in another 3,000 cases. In 2006, Mary Daniel, in a trial in Philadelphia, was awarded $1.5 million in compensatory damages as well as undisclosed punitive damages. As of 2010, Wyeth had won the last four of five cases, most recently in Virginia, finding that they were not responsible for the breast cancer of plaintiff Georgia Torkie-Tork. Wyeth has been quoted as saying "many risk factors associated with breast cancer have been identified, but science cannot establish what role any particular risk factor or combination play in any individual womans breast cancer." Wyeths counsel in the case also noted that in the WHI trial, 99.62% of women took the drug and "did not get breast cancer." Animal welfare Animal welfare groups claim that animal husbandry and urine collection methods used in the production of CEEs cause undue stress and suffering to the mares involved. Animal activists have made claims of abuses ranging from inadequate stall size, long periods of confinement, cumbersome urine collection, and continuous breeding cycles. After reaching advanced age, many of the mares are adopted for recreation use, while some are sent to feed lots for slaughter. Despite the controversy, the USDA called the CEEs HRT industry a model of self-regulation. See also Conjugated estrogens/medroxyprogesterone acetate Conjugated estrogens/norgestrel Conjugated estrogens/methyltestosterone Bazedoxifene/conjugated estrogens Estrogenic substances Conjugated estriol List of combined sex-hormonal preparations Notes References Further reading Bhavnani, Bhagu R. (1988). "The Saga of the Ring B Unsaturated Equine Estrogens*". Endocrine Reviews. 9 (4): 396–416. doi:10.1210/edrv-9-4-396. ISSN 0163-769X. PMID 3065072. Ansbacher R (April 1993). "Bioequivalence of conjugated estrogen products". Clin Pharmacokinet. 24 (4): 271–4. doi:10.2165/00003088-199324040-00001. PMID 8387902. S2CID 7681617. OConnell MB (September 1995). "Pharmacokinetic and pharmacologic variation between different estrogen products". J Clin Pharmacol. 35 (9 Suppl): 18S–24S. doi:10.1002/j.1552-4604.1995.tb04143.x. PMID 8530713. S2CID 10159196. Egarter C, Geurts P, Boschitsch E, Speiser P, Huber J (April 1996). "The effects of estradiol valerate plus medroxyprogesterone acetate and conjugated estrogens plus medrogestone on climacteric symptoms and metabolic variables in perimenopausal women". Acta Obstet Gynecol Scand. 75 (4): 386–93. doi:10.3109/00016349609033337. PMID 8638462. S2CID 44498140. Bhavnani BR (January 1998). "Pharmacokinetics and pharmacodynamics of conjugated equine estrogens: chemistry and metabolism". Proc. Soc. Exp. Biol. Med. 217 (1): 6–16. doi:10.3181/00379727-217-44199. PMID 9421201. S2CID 45177839. Gruber DM, Huber JC (December 1999). "Conjugated estrogens--the natural SERMs". Gynecol. Endocrinol. 13 Suppl 6: 9–12. PMID 10862263. Campagnoli C, Ambroggio S, Biglia N, Sismondi P (December 1999). "Conjugated estrogens and breast cancer risk". Gynecol. Endocrinol. 13 Suppl 6: 13–9. PMID 10862264. Bhavnani BR (June 2003). "Estrogens and menopause: pharmacology of conjugated equine estrogens and their potential role in the prevention of neurodegenerative diseases such as Alzheimers". J. Steroid Biochem. Mol. Biol. 85 (2–5): 473–82. doi:10.1016/S0960-0760(03)00220-6. PMID 12943738. S2CID 45552896. Ortmann J, Traupe T, Vetter W, Barton M (May 2004). "[Postmenopausal hormone replacement therapy and cardiovascular risk: role of conjugated equine estrogens and medroxyprogesterone acetate]". Praxis (in German). 93 (21): 904–14. doi:10.1024/0369-8394.93.21.904. PMID 15216975. Kuhl H (2005). "Pharmacology of estrogens and progestogens: influence of different routes of administration" (PDF). Climacteric. 8 Suppl 1: 3–63. doi:10.1080/13697130500148875. PMID 16112947. S2CID 24616324. Kurabayashi T (November 2007). "[New evidence of conjugated estrogen and 17beta-estradiol for treatment and prevention of osteoporosis]". Nippon Rinsho (in Japanese). 65 Suppl 9: 369–73. PMID 18161134. Lamba G, Kaur H, Adapa S, Shah D, Malhotra BK, Rafiyath SM, Thakar K, Fernandez AC (June 2013). "Use of conjugated estrogens in life-threatening gastrointestinal bleeding in hemodialysis patients--a review". Clin. Appl. Thromb. Hemost. 19 (3): 334–7. doi:10.1177/1076029612437575. PMID 22411999. S2CID 30468265. Mirkin S, Komm BS, Pickar JH (January 2014). "Conjugated estrogens for the treatment of menopausal symptoms: a review of safety data". Expert Opin Drug Saf. 13 (1): 45–56. doi:10.1517/14740338.2013.824965. PMID 23919270. S2CID 24379298. Bhavnani BR, Stanczyk FZ (July 2014). "Pharmacology of conjugated equine estrogens: efficacy, safety and mechanism of action". J. Steroid Biochem. Mol. Biol. 142: 16–29. doi:10.1016/j.jsbmb.2013.10.011. PMID 24176763. S2CID 1360563. Mattison DR, Karyakina N, Goodman M, LaKind JS (2014). "Pharmaco- and toxicokinetics of selected exogenous and endogenous estrogens: a review of the data and identification of knowledge gaps". Crit. Rev. Toxicol. 44 (8): 696–724. doi:10.3109/10408444.2014.930813. PMID 25099693. S2CID 11212469. External links "Estrogens, conjugated". Drug Information Portal. U.S. National Library of Medicine. "Steroidal estrogens". Drug Information Portal. U.S. National Library of Medicine. WHI Follow-up Study Confirms Health Risks of Long-Term Combination Hormone Therapy Outweigh Benefits for Postmenopausal Women NIH press release, March 4, 2008
Lodoxamide
Lodoxamide is an antiallergic pharmaceutical drug. It is marketed under the tradename Alomide in the UK. Like cromoglicic acid it acts as a mast cell stabilizer. In 2014 lodoxamide and bufrolin were found to be potent agonists at the G protein-coupled receptor 35, an orphan receptor believed to play a role in inflammatory processes, pain and the development of stomach cancer. See also Nedocromil Zaprinast Amlexanox Pemirolast Pamoic acid Kynurenic acid CXCL17 == References ==
Docusate
Docusate is the common chemical and pharmaceutical name of the anion bis(2-ethylhexyl) sulfosuccinate, also commonly called dioctyl sulfosuccinate (DOSS). It is on the World Health Organizations List of Essential Medicines.Salts of this anion, especially docusate sodium, are widely used in medicine as laxatives and as stool softeners, by mouth or rectally. In 2019, it was the 187th most commonly prescribed medication in the United States, with more than 3 million prescriptions. Some studies claim that docusate is not more effective than a placebo for improving constipation. Other docusate salts with medical use include those of calcium and potassium.Docusate salts are also used as food additives, emulsifiers, dispersants, and wetting agents, among other uses. History Sodium docusate was patented in 1937 by Coleman R. Caryl and Alphons O. Jaeger for American Cyanamid, which commercialized it for many years as a detergent under the brand name Aerosol OT. Its use for the treatment of constipation was first proposed in 1955 by James L. Wilson and David G. Dickinson, and quickly popularized under the name Doxinate. Medical use Constipation The main medical use of docusate sodium is to treat constipation, acting as a laxative and stool softener. In painful anorectal conditions such as hemorrhoid and anal fissures, it can help avoid pain caused by straining during bowel movements. When administered by mouth, a bowel movement often occurs in 1 to 3 days, while rectal use may be effective within 20 minutes.Sodium docusate is recommended as a stool softener for children.However, its effectiveness for constipation is poorly supported by evidence. Multiple studies have found docusate to be no more effective than a placebo for improving constipation. Others have found it to be less useful for the treatment of chronic constipation than psyllium.The medication may be given to people who are receiving opioid medication, although prolonged use may cause irritation of the gastrointestinal tract. Other medical uses Docusate sodium, when used with ear syringing, may help with earwax removal, particularly in the case of impaction.Sodium docusate is also used as a lubricant in the production of tablets and as an emulsifier in topical preparations and other suspensions. Precautions and contraindications Docusate sodium is approved and recommended as safe during pregnancy and breastfeeding.Docusate is not recommended in people with appendicitis, acute abdomen, or ileus.When taken by mouth it should be ingested with plenty of water. Side effects Side effects are uncommon and typically mild, and may include stomach pain, abdominal cramps or diarrhea, Efficacy decreases with long-term use, and may cause poor bowel function.Serious allergic reactions may occur with the drug. The most severe side effect of docusate, although very rare, is rectal bleeding. Interactions Docusate might increase resorption of other drugs, for example, dantron (1,8-dihydroxyanthraquinone). Mechanism of action Docusate is an anionic surfactant, which works by reducing the surface tension of the stool, allowing more intestinal water and fat to combine with the stool. This decreases the strain and discomfort associated with constipation.It does not stay in the gastrointestinal tract, but is absorbed into the bloodstream and excreted via the gallbladder after undergoing extensive metabolism. The effect of docusate may not necessarily be all due to its surfactant properties. Perfusion studies suggest that docusate inhibits fluid absorption or stimulates secretion in the portion of the small intestine known as the jejunum. Pharmaceutical brand names In the U.S., docusate sodium for pharmaceutical use is available under multiple brand names: Aqualax, Calube, Colace, Colace Micro-Enema, Correctol Softgel Extra Gentle, DC-240, Dialose, Diocto, Dioctocal, Dioctosoftez, Dioctyn, Dionex, Doc-Q-Lace, Docu Soft, Docucal, Doculax, Docusoft S, DOK, DOS, Doss-Relief, DSS, Dulcolax - Stool Softener (not to be confused with another drug marketed under the Dulcolax brand, bisacodyl, which is a stimulant laxative), Ex-Lax Stool Softener, Fleet Sof-Lax, Genasoft, Kasof, Laxa-basic, Modane Soft, Octycine-100, Pedia-Lax, Preferred Plus Pharmacy Stool Softener, Regulax SS, Sulfalax Calcium, Sur-Q-Lax, Surfak Stool Softener, and Therevac-SB. Generic preparations are also available. In the UK, dioctyl sodium sulfosuccinate is sold under the brand name Docusol (Typharm Ltd) and DulcoEase (Boehringer Ingelheim). In Australia, dioctyl sodium sulfosuccinate is sold as Coloxyl and Coloxyl with senna. In India, preparations include Laxatin by Alembic, Doslax by Raptakos Laboratories, Cellubril by AstraZeneca, and Laxicon by Stadmed. Other uses Dioctyl sodium sulfosuccinate is used as a surfactant in a wide range of applications, often under the name Aerosol-OT. It is unusual in that it is able to form microemulsions without the use of co-surfactants, and it has a rich variety of aqueous-phase behavior including multiple liquid crystalline phases. Food additive Dioctyl sodium sulfosuccinate has been approved by the US FDA as a "generally recognized as safe" (GRAS) additive. It is used in a variety of food products, as a surface active agent, stabilizer, thickener, wetting agent, processing aid, solubilizing agent, emulsifier, and dispersant. The highest amount found in food products is 0.5% by weight, which include pasteurized cheese spreads, cream cheeses and salad dressings. The FDA also approved its use as a wetting agent or solubilizer for flavoring agents in carbonated and non-carbonated drinks at levels up to 10 parts per million. Microencapsulation Sodium docusate is the most widely used surfactant in reverse micelle encapsulation studies. Non-medical brand names As a surfactant, docusate sodium is or has been commercialized under many brand names, including DSSj Aerosol OT, Alphasol OT, Colace, Complemix, Coprol, Dioctylal, Dioctyl-Medo Forte, Diotilan, Diovac, Disonate, Doxinate, Doxol, Dulsivac, Molatoc, Molofac, Nevax, Norval, Regutol, Softili, Solusol, Sulfimel DOS, Vatsol OT, Velmol, and Waxsol Chemistry Structure and properties The structural formula of the docusate anion is R−O−C(=O)−CH(SO−3)−CH2−C(=O)−O−R, where R is the 2-ethylhexyl group H3C−(CH2)3−C(−CH2−CH3)H−CH2−. The conjugate acid can be described as the twofold carboxylate ester of sulfosuccinic acid with 2-ethylhexanol. The compound is a white, wax-like, plastic solid, with an odor suggestive of octyl alcohol. It starts to decompose at about 220 °C.Solubility of dioctyl sodium sulfosuccinate in water is 14 g/L at 25 °C, increasing to 55 g/L at 70 °C. Solubility is better in less polar solvents: 1:30 in ethanol, 1:1 in chloroform and diethylether, and practically unlimited in petroleum ether (25 °C). It also is highly soluble in glycerol, although this is a rather polar solvent. It is also highly soluble in xylene, oleic acid, acetone, diacetone alcohol, methanol, isopropanol, 2-butanol, methyl acetate, ethyl acetate, furfurol, and vegetable oils.The ester groups are easily cleaved under basic conditions, but are stable against acids. Synthesis Sodium dioctyl sulfosuccinate can be obtained by treating dioctyl maleate with sodium bisulfite. The bisulfite anion adds to the double bond: −CH=CH− + HSO−3 → −CH(−SO−3)−CH2− Toxicity Ingestion may cause the side effects described above, such as diarrhea, intestinal bloating, and occasionally cramping pains. Dioctyl sodium sulfosuccinate is not known to be carcinogenic, mutagenic, or teratogenic. Marine species Dioctyl sodium sulfosuccinate is of low toxicity for crustaceans such as the hermit crab Clibanarius erythropus and the shrimp Crangon crangon. Toxicity for molluscs varies widely, with 48-hour LD50 found between 5 mg/L for the common limpet and 100 mg/L for the common periwinkle. Various species of phytoplankton have an LD50 around 8 mg/L. In a 2010 study, dioctyl sodium sulfosuccinate exhibited higher toxicity against bacteria (Vibrio fischeri, Anabaena sp.) and algae (Pseudokirchneriella subcapitata) than did a number of fluorinated surfactants (PFOS, PFOA, or PFBS). Measuring bioluminescence inhibition of the bacteria and growth inhibition of the algae, the LD50 were in the range of 43–75 mg/L. Combinations of the fluorinated compounds with dioctyl sodium sulfosuccinate showed mid to highly synergistic effects in most settings, meaning that such combinations are significantly more toxic than the individual substances. Freshwater species The substance is highly toxic for rainbow trout with a median lethal concentration (LC50) of 0.56 mg/L after 48 hours for the pure substance. It is only slightly to moderately toxic for rainbow trout fingerlings, and slightly toxic for harlequin rasboras (LC50 27 mg/L of a 60% formulation after 48 hours). References External links "Docusate". Drug Information Portal. U.S. National Library of Medicine. "Docusate sodium". Drug Information Portal. U.S. National Library of Medicine. Stool Softeners at the N.I.H. PubMed Health resource.
Crofelemer
Crofelemer (USAN, trade name Mytesi) is an antidiarrheal indicated for the symptomatic relief of non-infectious diarrhea in adult patients with HIV/AIDS on antiretroviral therapy. Other possible uses include diarrhea in children, acute infectious diarrhea, and diarrhea in patients with irritable bowel syndrome. It is a purified oligomeric proanthocyanidin from "dragons blood", the sap of the South American tree Croton lechleri.Crofelemer treats the symptoms of disease, but it is not used to treat infectious diarrhea (diarrhea caused by infection of the digestive system by a bacterium, virus or parasite). It was initially developed by Napo Pharmaceuticals, which is a wholly owned subsidiary of Jaguar Health, Inc. A Phase III clinical trial for diarrhea in HIV patients was completed in 2012, and the drug was approved by the US Food and Drug Administration (FDA) on 31 December 2012. Mechanism of action The drug is taken by orally and works by modulating cystic fibrosis transmembrane conductance regulator (CFTR) and the calcium-activated chloride channel (CaCC), two chloride ion channels from the luminal side of the gastrointestinal tract. This is a first-in-class antisecretory antidiarrheal mechanism of action and it does not affect gastrointestinal motility, unlike the traditional antimotility drugs. As a result of the channel regulation, fewer chloride ions are secreted into the gut, which decreases the associated secretion of sodium ions and accompanying water, thus improving stool consistency and reducing the frequency of watery stools and duration of the diarrhea. The mechanism is selective for the CFTR and CaCC, as other channels involved in intestinal fluid secretion, namely sodium and potassium channels, are not affected by crofelemer, nor is cAMP or calcium signaling.Crofelemer is minimally, if at all, absorbed from the gut into the bloodstream, and is mostly excreted in the stools. Adverse effects and interactions Crofelemer is well tolerated; and the only adverse effects found in clinical studies were mild gastrointestinal effects at the same level as under placebo. The most common adverse reactions (≥ 3%) are: upper respiratory tract infection, bronchitis, cough, flatulence and increased bilirubin. Origin and chemistry Crofelemer is an oligomeric proanthocyanidin mixture primarily composed of (+)–catechin, (–)–epicatechin, (+)–gallocatechin, and (–)–epigallocatechin monomer units linked in random sequence, as represented below. The average degree of polymerization for the oligomers ranges between 5 and 7.5, as determined by phloroglucinol degradation. The substance is a purified oligomeric proanthocyanidin from the sap, or more correctly the latex, of the South American tree Croton lechleri (locally called Sangre de Grado or Sangre de Drago). This is one of several plants producing bright red latex or resin called "dragons blood". Crofelemer is a complex mixture of procyanidins and prodelphinidins with up to 30 (epi)catechin or (epi)gallocatechin units per molecule, resulting in a molecular mass of up to 9 kDa. History of Crude Plant Latex (Dragons Blood) and Crofelemer The crude plant latex of C. lechleri is traditionally used in South American medicine for the treatment of diarrhea, wounds, inflammations, tumors, insect bites, and other conditions. A number of chemicals were isolated in the late 1980s and 1990s and tested in cellular and animal models, for example identifying taspine as a cicatrizant (wound healing promoter). Immunomodulatory, antioxidative, antiproliferative and mutagenic effects of dragons blood and its components also received some attention from the scientific community. The purified oligomeric proanthocyanidin fraction was first described in 1994 under the name SP-303 as an antiviral drug, but a study testing it for the treatment of herpes simplex did not show any benefit. In 1999, crofelemer was reported to improve the symptoms of cholera toxin induced diarrhea in mice. Crofelemer demonstrated reduction of duration of diarrhea and frequency of watery stools in patients with travelers diarrhea and patients with HIV/AIDS. Crofelemer has also shown benefit in adult patients with acute infectious diarrhea from E. coli and salmonella, and in patients with moderate to severe watery diarrhea from vibrio cholerae. Crofelemer has also been shown to improve abdominal pain and discomfort in patients with diarrhea-predominate irritable bowel syndrome.SP-303 was eventually named crofelemer and patented by Napo Pharmaceuticals, which licensed it to Glenmark Pharmaceuticals in 2005, for exclusive development and marketing rights in 140 emerging markets including India, and to Salix Pharmaceuticals for exclusive development and marketing rights in North America, the European Union and Japan, in 2008. Subsequently, Napo sued Salix and terminated the agreements with Salix and Glenmark in 2011, alleging that they were stalling the drugs development. In 2012, crofelemer completed a Phase III trial, and it was approved in December 2012 by the FDA for the indication "symptomatic relief of non-infectious diarrhea in patients with HIV/AIDS on anti-retroviral therapy".The drug substance is manufactured by Glenmark Pharmaceuticals, and is manufactured as 125 mg delayed-release tablets by Patheon Pharmaceuticals Inc. for Napo Pharmaceuticals. References External links "Crofelemer". Drug Information Portal. U.S. National Library of Medicine.
Bupropion
Bupropion, sold under the brand names Wellbutrin and Zyban among others, is an atypical antidepressant primarily used to treat major depressive disorder and to support smoking cessation. It is also popular as an add-on medication in the cases of "incomplete response" to the first-line selective serotonin reuptake inhibitor (SSRI) antidepressant. Bupropion has several features that distinguish it from other antidepressants: it does not usually cause sexual dysfunction; it is not associated with weight gain and sleepiness, and it is more effective than SSRIs at improving symptoms of hypersomnia and fatigue. Bupropion does, however, carry a much higher risk of seizure than many other antidepressants and extreme caution must be taken in patients with a history of seizure disorder. Common adverse effects of bupropion with the greatest difference from placebo are dry mouth, nausea, constipation, insomnia, anxiety, tremor, and excessive sweating. Raised blood pressure is notable. Rare but serious side effects include seizure, liver toxicity, psychosis, and risk of overdose. Bupropion use during pregnancy may be associated with increased odds of congenital heart defects.Bupropion acts as a norepinephrine–dopamine reuptake inhibitor and a nicotinic receptor antagonist. However, its effects on dopamine are weak. Chemically, bupropion is an aminoketone that belongs to the class of substituted cathinones and more generally that of substituted amphetamines and substituted phenethylamines.Bupropion was invented by Nariman Mehta, who worked at Burroughs Wellcome, in 1969. It was first approved for medical use in the United States in 1985. Bupropion was originally called by the generic name amfebutamone, before being renamed in 2000. In 2020, it was the eighteenth most commonly prescribed medication in the United States, with more than 28 million prescriptions. It is on the World Health Organizations List of Essential Medicines. Medical uses Depression The evidence overall supports the efficacy of bupropion over placebo for the treatment of depression. However, the quality of evidence is low. Most meta-analyses report that bupropion has an at-most small effect size for depression. On the other hand, one meta-analysis reported a large effect size. However, there were methodological limitations with this meta-analysis, including using a subset of only five trials for the effect size calculation, substantial variability in effect sizes between the selected trials—which led the authors to state that their findings in this area should be interpreted with "extreme caution"—and general lack of inclusion of unpublished trials in the meta-analysis. Unpublished trials are more likely to be negative in findings, and other meta-analyses have included unpublished trials. Evidence suggests that the efficacy of bupropion for depression is similar to that of other antidepressants.Over the fall and winter months, bupropion prevents development of depression in those who have recurring seasonal affective disorder: 15% of participants on bupropion experienced a major depressive episode vs. 27% of those on placebo. Bupropion also improves depression in bipolar disorder, with the efficacy and risk of affective switch being similar to other antidepressants.Bupropion has several features that distinguish it from other antidepressants: for instance, unlike the majority of antidepressants, it does not usually cause sexual dysfunction, and the occurrence of sexual side effects is not different from placebo. Bupropion treatment is not associated with weight gain; on the contrary, the majority of studies observed significant weight loss in bupropion-treated participants. Bupropion treatment also is not associated with the sleepiness that may be produced by other antidepressants. Bupropion is more effective than selective serotonin reuptake inhibitors (SSRIs) at improving symptoms of hypersomnia and fatigue in depressed patients. There appears to be a modest advantage for the SSRIs compared to bupropion in the treatment of depression with high anxiety; they are equivalent for depression with moderate or low anxiety.The addition of bupropion to a prescribed SSRI is a common strategy when people do not respond to the SSRI, and it is supported by clinical trials; however, it appears to be inferior to the addition of atypical antipsychotic aripiprazole. Smoking cessation Prescribed as an aid for smoking cessation bupropion reduces the severity of craving for tobacco and withdrawal symptoms such as depressed mood, irritability, difficulty concentrating, and increased appetite. Initially, bupropion slows the weight gain that often occurs in the first weeks after quitting smoking. With time, however, this effect becomes negligible.The bupropion treatment course lasts for seven to twelve weeks, with the patient halting the use of tobacco about ten days into the course. After the course, the effectiveness of bupropion for maintaining abstinence from smoking declines over time, from 37% of tobacco abstinence at 3 months to 20% at one year. It is unclear whether extending bupropion treatment helps to prevent relapse of smoking.Overall, six months after the therapy, bupropion increases the likelihood of quitting smoking by approximately 1.6 fold as compared to placebo. In this respect, bupropion is as effective as nicotine replacement therapy but inferior to varenicline. Combining bupropion and nicotine replacement therapy does not improve the quitting rate.In children and adolescents, the use of bupropion for smoking cessation does not appear to offer any significant benefits. The evidence for its use to aid smoking cessation in pregnant women is insufficient. Attention deficit hyperactivity disorder The treatment of attention deficit hyperactivity disorder (ADHD) is not an approved indication of bupropion, and it is not mentioned in the current (2019) guideline on the ADHD treatment from the American Academy of Pediatrics. Systematic reviews of bupropion for the treatment of ADHD in both adults and children note that bupropion may be effective for ADHD but warn that this conclusion has to be interpreted with caution, because clinical trials were of low quality due to small sizes and risk of bias. Similarly to atomoxetine, bupropion has a delayed onset of action for ADHD, and several weeks of treatment are required for therapeutic effects. This is in contrast to stimulants, such as amphetamine and methylphenidate, which have an immediate onset of effect in the condition. Sexual dysfunction Bupropion is less likely than other antidepressants to cause sexual dysfunction. A range of studies indicate that bupropion not only produces fewer sexual side effects than other antidepressants but can actually help to alleviate sexual dysfunction including sexual dysfunction induced by SSRI antidepressants. There have also been small studies suggesting that bupropion or a bupropion/trazodone combination may improve some measures of sexual function in women who have hypoactive sexual desire disorder (HSDD) and are not depressed. According to an expert consensus recommendation from the International Society for the Study of Womens Sexual Health, bupropion can be considered as an off-label treatment for HSDD despite limited safety and efficacy data. Likewise, a 2022 systematic review and meta-analysis of bupropion for sexual desire disorder in women reported that although data were limited, bupropion appeared to be dose-dependently effective for the condition. Obesity Bupropion, when used for treating obesity over a period of 6 to 12 months, results in an average weight loss of 2.7 kg (5.9 lbs) over placebo. This is not much different from the weight loss produced by several other weight-loss medications such as sibutramine or orlistat. The combination drug naltrexone/bupropion has been approved by the U.S. Food and Drug Administration (FDA) for the treatment of obesity. Other uses Bupropion is not effective in the treatment of cocaine dependence, but it is showing promise in reducing drug use in light methamphetamine users. Based on studies indicating that bupropion lowers the level of the inflammatory mediator TNF-alpha, there have been suggestions that it might be useful in treating inflammatory bowel disease, psoriasis, and other autoimmune conditions, but very little clinical evidence is available. Bupropion is not effective in treating chronic low back pain. Available forms Bupropion is available as an oral tablet in a number of different formulations. It is formulated mostly as the hydrochloride salt but also to a lesser extent as the hydrobromide salt. The available forms of bupropion hydrochloride include IR (instant-release) tablets (50, 75, 100 mg), SR (sustained-release) tablets (50, 100, 150, 200 mg), and XL (extended-release) tablets (150, 300, 450 mg). The only marketed form of bupropion hydrobromide is Aplenzin, an extended-release oral tablet (174, 348, 522 mg). In addition to single-drug formulations, bupropion is formulated in combinations including naltrexone/bupropion (Contrave; 8 mg/90 mg extended-release tablets) and dextromethorphan/bupropion (Auvelity; 45 mg/105 mg tablets). Contraindications The drug label advises that bupropion should not be prescribed to individuals with epilepsy or other conditions that lower the seizure threshold, such as anorexia nervosa, bulimia nervosa, benzodiazepine or alcohol withdrawal. It should be avoided in individuals who are taking monoamine oxidase inhibitors (MAOIs). When switching from MAOIs to bupropion, it is important to include a washout period of about two weeks between the medications. The label recommends that caution should be exercised when treating people with liver damage, severe kidney disease, and severe hypertension, and in children, adolescents and young adults due to the increased risk of suicidal ideation. Side effects The common adverse effects of bupropion with the greatest difference from placebo are dry mouth, nausea, constipation, insomnia, anxiety, tremor, and excessive sweating. Bupropion has the highest incidence of insomnia of all second-generation antidepressants, apart from desvenlafaxine. It is also associated with about 20% increased risk of headache.Bupropion raises blood pressure in some people. One study showed an average rise of 6 mm Hg in sysolic blood pressure in 10% of patients. The prescribing information notes that hypertension, sometimes severe, is observed in some people taking bupropion, both with and without pre-existing hypertension. Safety of bupropion in people with cardiovascular conditions and its general cardiovascular safety profile remain unclear due to the lack of data.Seizure is a rare but serious adverse effect of bupropion. It is strongly dose-dependent: for the immediate release preparation, the seizure incidence is 0.4% at the dose 300–450 mg per day; the incidence climbs almost ten-fold for the higher than recommended dose of 600 mg. For comparison, the incidence of unprovoked seizure in the general population is 0.07 to 0.09%, and the risk of seizure for a variety of other antidepressants is generally between 0 and 0.5% at the recommended doses.Cases of liver toxicity leading to death or liver transplantation have been reported for bupropion. It is considered to be one of several antidepressants with greater risk of hepatotoxicity.The prescribing information warns about bupropion triggering an angle-closure glaucoma attack. On the other hand, bupropion may decrease the risk of development of open angle glaucoma.Bupropion use by mothers in the first trimester of pregnancy is associated with 23% increase of the odds in congenital heart defects in their children.Bupropion has rarely been associated with instances of Stevens–Johnson syndrome. Psychiatric The FDA requires all antidepressants, including bupropion, to carry a boxed warning stating that antidepressants may increase the risk of suicide in people younger than 25. This warning is based on a statistical analysis conducted by the FDA which found a 2-fold increase in suicidal thought and behavior in children and adolescents, and 1.5-fold increase in the 18–24 age group. For this analysis the FDA combined the results of 295 trials of 11 antidepressants in order to obtain statistically significant results. Considered in isolation, bupropion was not statistically different from placebo.Bupropion prescribed for smoking cessation results in 25% increase of the risk of psychiatric side effects, in particular, anxiety (about 40% increase) and insomnia (about 80% increase). The evidence is insufficient to determine whether bupropion is associated with suicides or suicidal behavior.In rare cases, bupropion-induced psychosis may develop. It is associated with higher doses of bupropion; many cases described are at higher than recommended doses. Concurrent antipsychotic medication appears to be protective. In most cases the psychotic symptoms are eliminated by reducing the dose, ceasing treatment or adding antipsychotic medication.Although studies are lacking, a handful of case reports suggest that abrupt discontinuation of bupropion may cause antidepressant discontinuation syndrome. Overdose Bupropion is considered moderately dangerous in overdose. According to an analysis of US National Poison Data System, adjusted for the number of prescriptions, bupropion and venlafaxine are the two new generation antidepressants (that is excluding tricyclic antidepressants) that result in the highest mortality and morbidity. For significant overdoses, seizures have been reported in about a third of all cases; other serious effects include hallucinations, loss of consciousness, and abnormal heart rhythms. When bupropion was one of several kinds of pills taken in an overdose, fever, muscle rigidity, muscle damage, hypertension or hypotension, stupor, coma, and respiratory failure have been reported. While most people recover, some people have died, having had multiple uncontrolled seizures and myocardial infarction. Interactions Since bupropion is metabolized to hydroxybupropion by the enzyme CYP2B6, drug interactions with CYP2B6 inhibitors are possible: this includes such medications as paroxetine, sertraline, norfluoxetine (active metabolite of fluoxetine), diazepam, clopidogrel, and orphenadrine. The expected result is the increase of bupropion and decrease of hydroxybupropion blood concentration. The reverse effect (decrease of bupropion and increase of hydroxybupropion) can be expected with CYP2B6 inducers such as carbamazepine, clotrimazole, rifampicin, ritonavir, St Johns wort, and phenobarbital. Indeed, carbamazepine decreases exposure to bupropion by 90% and increases exposure to hydroxybupropion by 94%. Ritonavir, lopinavir/ritonavir, and efavirenz have been shown to decrease levels of bupropion and/or its metabolites. Ticlopidine and clopidogrel, both potent CYP2B6 inhibitors, have been found to considerably increase bupropion levels as well as decrease levels of its metabolite hydroxybupropion.Bupropion and its metabolites are inhibitors of CYP2D6, with hydroxybupropion responsible for most of the inhibition. Additionally, bupropion and its metabolites may decrease expression of CYP2D6 in the liver. The end effect is a significant slowing of the clearance of other drugs metabolized by this enzyme. For instance, bupropion has been found to increase area-under-the-curve of desipramine, a CYP2D6 substrate, by 5-fold. Bupropion has also been found to increase levels of atomoxetine by 5.1-fold, while decreasing the exposure to its main metabolite by 1.5-fold. As another example, the ratio of dextromethorphan (a drug that is mainly metabolized by CYP2D6) to its major metabolite dextrorphan increased approximately 35-fold when it was administered to people being treated with 300 mg/day bupropion. When people on bupropion are given MDMA, about 30% increase of exposure to both drugs is observed, with enhanced mood but decreased heart rate effects of MDMA. Interactions with other CYP2D6 substrates, such as metoprolol, imipramine, nortriptyline, venlafaxine, and nebivolol have also been reported. However, in a notable exception, bupropion does not seem to affect the concentrations of CYP2D6 substrates fluoxetine and paroxetine.Bupropion lowers the seizure threshold, and therefore can potentially interact with other medications that also lower it, such as antipsychotics, tricyclic antidepressants, theophylline, and systemic corticosteroids. The prescribing information recommends minimizing the use of alcohol, since in rare cases bupropion reduces alcohol tolerance.Caution should be observed when combining bupropion with a monoamine oxidase inhibitor (MAOI), as it may result in hypertensive crisis. Pharmacology Pharmacodynamics The mechanism of action of bupropion in the treatment of depression and for other indications is unclear. However, it is thought to be related to the fact that bupropion is a norepinephrine–dopamine reuptake inhibitor (NDRI) and antagonist of several nicotinic acetylcholine receptors. It is uncertain whether bupropion is a norepinephrine–dopamine releasing agent. Pharmacological actions of bupropion, to a substantial degree, are due to its active metabolites hydroxybupropion, threo-hydrobupropion, and erythro-hydrobupropion that are present in the blood plasma at comparable or much higher levels. In fact, bupropion could accurately be conceptualized as a prodrug of these metabolites. Overall action of these metabolites, and particularly one enantiomer S,S-hydroxybupropion, is also characterized by inhibition of norepinephrine and dopamine reuptake and nicotinic antagonism (see the chart on the right). Bupropion has no meaningful direct activity at a variety of receptors, including α- and β-adrenergic, dopamine, serotonin, histamine, and muscarinic acetylcholine receptors.The occupancy of dopamine transporter (DAT) by bupropion (300 mg/day) and its metabolites in the human brain as measured by several positron emission tomography (PET) studies is approximately 20%, with a mean occupancy range of about 14 to 26%. For comparison, the NDRI methylphenidate at therapeutic doses is thought to occupy greater than 50% of DAT sites. In accordance with its low DAT occupancy, no measurable dopamine release in the human brain was detected with bupropion (one 150 mg dose) in a PET study. These findings raise questions about the role of dopamine reuptake inhibition in the pharmacology of bupropion, and suggest that other actions may be responsible for its therapeutic effects. More research is needed in this area. No data are available on occupancy of the norepinephrine transporter (NET) by bupropion and its metabolites. However, due to the increased exposure of hydroxybupropion over bupropion itself, which has higher affinity for the NET than the DAT, bupropions overall pharmacological profile in humans may end up making it effectively more of a norepinephrine reuptake inhibitor than a dopamine reuptake inhibitor. Accordingly, the clinical effects of bupropion are more consistent with noradrenergic activity than with dopaminergic actions. Pharmacokinetics After oral administration, bupropion is rapidly and completely absorbed reaching the peak blood plasma concentration after 1.5 hours (tmax). Sustained release (SR) and extended release (XL) formulations have been designed to slow down absorption resulting in tmax of 3 hours and 5 hours, respectively. Absolute bioavailability of bupropion is unknown but is presumed to be low, at 5–20%, due to the first-pass metabolism. As for the relative biovailability of the formulations, XL formulation has lower bioavailability (68%) compared to SR formulation and immediate release bupropion.Bupropion is metabolized in the body by a variety of pathways. The oxidative pathways are by cytochrome P450 isoenzymes CYP2B6 leading to R,R- and S,S-hydroxybupropion and, to a lesser degree, CYP2C19 leading to 4-hydroxybupropion. The reductive pathways are by 11β-hydroxysteroid dehydrogenase type 1 in the liver and AKR7A2/AKR7A3 in the intestine leading to threo-hydrobupropion and by yet unknown enzyme leading to erythro-hydrobupropion.The metabolism of bupropion is highly variable: the effective doses of bupropion received by persons who ingest the same amount of the drug may differ by as much as 5.5 times (with a half-life of 12–30 hours), while the effective doses of hydroxybupropion may differ by as much as 7.5 times (with a half-life of 15–25 hours). Based on this, some researchers have advocated monitoring of the blood level of bupropion and hydroxybupropion. Chemistry Bupropion is an aminoketone that belongs to the class of substituted cathinones and the more general class of substituted phenethylamines. The clinically used bupropion is racemic, that is a mixture of two enantiomers: S-bupropion and R-bupropion. Although the optical isomers on bupropion can be separated, they rapidly racemize under physiological conditions.There have been reported cases of false-positive urine amphetamine tests in persons taking bupropion. Synthesis It is synthesized in two chemical steps starting from 3-chloro-propiophenone. The alpha position adjacent to the ketone is first brominated followed by nucleophilic displacement of the resulting alpha-bromoketone with t-butylamine and treated with hydrochloric acid to give bupropion as the hydrochloride salt in 75–85% overall yield. History Bupropion was invented by Nariman Mehta of Burroughs Wellcome (now GlaxoSmithKline) in 1969, and the US patent for it was granted in 1974. It was approved by the U.S. Food and Drug Administration (FDA) as an antidepressant on 30 December 1985, and marketed under the name Wellbutrin. However, a significant incidence of seizures at the originally recommended dosage (400–600 mg/day) caused the withdrawal of the drug in 1986. Subsequently, the risk of seizures was found to be highly dose-dependent, and bupropion was re-introduced to the market in 1989 with a lower maximum recommended daily dose of 450 mg/day.In 1996, the FDA approved a sustained-release formulation of alcohol-resistant bupropion called Wellbutrin SR, intended to be taken twice a day (as compared with three times a day for immediate-release Wellbutrin). In 2003, the FDA approved another sustained-release formulation called Wellbutrin XL, intended for once-daily dosing. Wellbutrin SR and XL are available in generic form in the United States and Canada. In 1997, bupropion was approved by the FDA for use as a smoking cessation aid under the name Zyban. In 2006, Wellbutrin XL was similarly approved as a treatment for seasonal affective disorder.In France, marketing authorization was granted for Zyban on 3 August 2001, with a maximum daily dose of 300 mg; only sustained-release bupropion is available, and only as a smoking cessation aid.On 11 October 2007, two providers of consumer information on nutritional products and supplements, ConsumerLab.com and The Peoples Pharmacy, released the results of comparative tests of different brands of bupropion. The Peoples Pharmacy received multiple reports of increased side effects and decreased efficacy of generic bupropion, which prompted it to ask ConsumerLab.com to test the products in question. The tests showed that "one of a few generic versions of Wellbutrin XL 300 mg, sold as Budeprion XL 300 mg, didnt perform the same as the brand-name pill in the lab." The FDA investigated these complaints and concluded that Budeprion XL is equivalent to Wellbutrin XL in regard to bioavailability of bupropion and its main active metabolite hydroxybupropion. The FDA also said that coincidental natural mood variation is the most likely explanation for the apparent worsening of depression after the switch from Wellbutrin XL to Budeprion XL. On 3 October 2012, however, the FDA reversed this opinion, announcing that "Budeprion XL 300 mg fails to demonstrate therapeutic equivalence to Wellbutrin XL 300 mg." The FDA did not test the bioequivalence of any of the other generic versions of Wellbutrin XL 300 mg, but requested that the four manufacturers submit data on this question to the FDA by March 2013. As of October 2013 the FDA has made determinations on the formulations from some manufacturers not being bioequivalent.In April 2008, the FDA approved a formulation of bupropion as a hydrobromide salt instead of a hydrochloride salt, to be sold under the name Aplenzin by Sanofi-Aventis.In 2009, the FDA issued a health advisory warning that the prescription of bupropion for smoking cessation has been associated with reports about unusual behavior changes, agitation and hostility. Some people, according to the advisory, have become depressed or have had their depression worsen, have had thoughts about suicide or dying, or have attempted suicide. This advisory was based on a review of anti-smoking products that identified 75 reports of "suicidal adverse events" for bupropion over ten years. Based on the results of follow-up trials this warning was removed in 2016.In 2012, the U.S. Justice Department announced that GlaxoSmithKline had agreed to plead guilty and pay a $3-billion fine, in part for promoting the unapproved use of Wellbutrin for weight loss and sexual dysfunction.In 2017, the European Medicines Agency recommended suspending a number of nationally approved medicines due to misrepresentation of bioequivalence study data by Micro Therapeutic Research Labs in India. The products recommended for suspension included several 300 mg modified-release bupropion tablets. Society and culture Recreational use While bupropion demonstrates some potential for misuse, this potential is less than of other commonly used stimulants, being limited by features of its pharmacology. Bupropion misuse is uncommon. There have been a number of anecdotal and case-study reports of bupropion abuse, but the bulk of evidence indicates that the subjective effects of bupropion when taken orally are markedly different from those of addictive stimulants such as cocaine or amphetamine. However, bupropion, by non-conventional routes of administration like injection or insufflation has been reported to be misused in the United States and Canada, notably in prisons. Legal status In Russia bupropion is banned as a narcotic drug, yet not per se but rather as a derivative of methcathinone. In Australia and the UK, smoking cessation is the only licensed use of bupropion. References External links "Bupropion". Drug Information Portal. U.S. National Library of Medicine. "Bupropion hydrochloride". Drug Information Portal. U.S. National Library of Medicine. "Bupropion hydrobromide". Drug Information Portal. U.S. National Library of Medicine.
Lorazepam
Lorazepam, sold under the brand name Ativan among others, is a benzodiazepine medication. It is used to treat anxiety disorders, trouble sleeping, severe agitation, active seizures including status epilepticus, alcohol withdrawal, and chemotherapy-induced nausea and vomiting. It is also used during surgery to interfere with memory formation and to sedate those who are being mechanically ventilated. It is also used, along with other treatments, for acute coronary syndrome due to cocaine use. It can be given by mouth or as an injection into a muscle or vein. When given by injection onset of effects is between one and thirty minutes and effects last for up to a day.Common side effects include weakness, sleepiness, low blood pressure, and a decreased effort to breathe. When given intravenously the person should be closely monitored. Among those who are depressed there may be an increased risk of suicide. With long-term use, larger doses may be required for the same effect. Physical dependence and psychological dependence may also occur. If stopped suddenly after long-term use, benzodiazepine withdrawal syndrome may occur. Older people more often develop adverse effects. In this age group lorazepam is associated with falls and hip fractures. Due to these concerns, lorazepam use is generally only recommended for up to two to four weeks.Lorazepam was initially patented in 1963 and went on sale in the United States in 1977. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2019, it was the 69th most commonly prescribed medication in the United States, with more than 10 million prescriptions. Medical uses Anxiety Lorazepam is used in the short-term management of severe anxiety. In the US, the FDA advises against use of benzodiazepines such as lorazepam for longer than four weeks. It is fast acting, and useful in treating fast onset panic anxiety.Lorazepam can effectively reduce agitation and induce sleep, and the duration of effects from a single dose makes it an appropriate choice for the short-term treatment of insomnia, especially in the presence of severe anxiety or night terrors. It has a fairly short duration of action.Withdrawal symptoms, including rebound insomnia and rebound anxiety, may occur after seven days use of lorazepam. Seizures Intravenous diazepam or lorazepam are first-line treatments for convulsive status epilepticus. Lorazepam is more effective than diazepam and intravenous phenytoin in the treatment of status epilepticus and has a lower risk of continuing seizures that might require additional medication. However, phenobarbital has a superior success rate compared to lorazepam and other drugs, at least in the elderly.Lorazepams anticonvulsant properties and pharmacokinetic profile make intravenous use reliable for terminating acute seizures, but induce prolonged sedation. Oral benzodiazepines, including lorazepam, are occasionally used as long-term prophylactic treatment of resistant absence seizures; because of gradual tolerance to their anti-seizure effects, benzodiazepines such as lorazepam are not considered first-line therapies.Lorazepams anticonvulsant and CNS depressant properties are useful for the treatment and prevention of alcohol withdrawal syndrome. In this setting, impaired liver function is not a hazard with lorazepam, since lorazepam does not require oxidation, in the liver or otherwise, for its metabolism. Sedation Lorazepam is sometimes used for individuals receiving mechanical ventilation. However, in critically ill people, propofol has been found to be superior to lorazepam both in effectiveness and overall cost; as a result, the use of propofol for this indication is now encouraged, whereas the use of lorazepam is discouraged.Its relative effectiveness in preventing new memory formation, along with its ability to reduce agitation and anxiety, makes lorazepam useful as premedication. It is given before a general anesthetic to reduce the amount of anesthetic required, or before unpleasant awake procedures, such as in dentistry or endoscopies, to reduce anxiety, to increase compliance, and to induce amnesia for the procedure. Lorazepam by mouth is given 90 to 120 minutes before procedures, and intravenous lorazepam as late as 10 minutes before procedures. Lorazepam is sometimes used as an alternative to midazolam in palliative sedation. In intensive care units lorazepam is sometimes used to produce anxiolysis, hypnosis, and amnesia. Agitation Lorazepam is sometimes used as an alternative to haloperidol when there is the need for rapid sedation of violent or agitated individuals, but haloperidol plus promethazine is preferred due to better effectiveness and due to lorazepams adverse effects on respiratory function. However, adverse effects such as behavioral disinhibition may make benzodiazepines inappropriate for some people who are acutely psychotic. Acute delirium is sometimes treated with lorazepam, but as it can cause paradoxical effects, it is preferably given together with haloperidol. Lorazepam is absorbed relatively slowly if given intramuscularly, a common route in restraint situations. Other Catatonia with inability to speak is responsive to lorazepam. Symptoms may recur and treatment for some days may be necessary. Catatonia due to abrupt or overly rapid withdrawal from benzodiazepines, as part of the benzodiazepine withdrawal syndrome, should also respond to lorazepam treatment. As lorazepam can have paradoxical effects, haloperidol is sometimes given at the same time.It is sometimes used in chemotherapy in addition to medications used to treat nausea and vomiting, i.e. nausea and vomiting caused or worsened by psychological sensitization to the thought of being sick. Adverse effects Many beneficial effects of lorazepam (e.g., sedative, muscle relaxant, anti-anxiety, and amnesic effects) may become adverse effects when unwanted. Adverse effects can include sedation and low blood pressure; the effects of lorazepam are increased in combination with other CNS depressant drugs. Other adverse effects include confusion, ataxia, inhibiting the formation of new memories, pupil constriction and hangover effects. With long-term benzodiazepine use it is unclear whether cognitive impairments fully return to normal after stopping lorazepam use; cognitive deficits persist for at least six months after withdrawal, but longer than six months may be required for recovery of cognitive function. Lorazepam appears to have more profound adverse effects on memory than other benzodiazepines; it impairs both explicit and implicit memory. In the elderly, falls may occur as a result of benzodiazepines. Adverse effects are more common in the elderly, and they appear at lower doses than in younger people. Benzodiazepines can cause or worsen depression. Paradoxical effects can also occur, such as worsening of seizures, or paradoxical excitement; paradoxical excitement is more likely to occur in the elderly, children, those with a history of alcohol abuse, and in people with a history of aggression or anger problems. Lorazepams effects are dose-dependent, meaning the higher the dose, the stronger the effects (and side effects) will be. Using the smallest dose needed to achieve desired effects lessens the risk of adverse effects. Sedative drugs and sleeping pills, including lorazepam, have been associated with an increased risk of death.Sedation is the side effect people taking lorazepam most frequently report. In a group of around 3,500 people treated for anxiety, the most common side effects complained of from lorazepam were sedation (15.9%), dizziness (6.9%), weakness (4.2%), and unsteadiness (3.4%). Side effects such as sedation and unsteadiness increased with age. Cognitive impairment, behavioural disinhibition and respiratory depression as well as hypotension may also occur. Paradoxical effects: In some cases, paradoxical effects can occur with benzodiazepines, such as increased hostility, aggression, angry outbursts, and psychomotor agitation. These effects are seen more commonly with lorazepam than with other benzodiazepines. Paradoxical effects are more likely to occur with higher doses, in people with pre-existing personality disorders and those with a psychiatric illness. Frustrating stimuli may trigger such reactions, though the drug may have been prescribed to help the person cope with such stress and frustration in the first place. As paradoxical effects appear to be dose-related, they usually subside on dose reduction or on complete withdrawal of lorazepam. Suicidality: Benzodiazepines are associated with increased risk of suicide, possibly due to disinhibition. Higher dosages appear to confer greater risk. Amnesic effects: Among benzodiazepines, lorazepam has relatively strong amnesic effects, but people soon develop tolerance to this with regular use. To avoid amnesia (or excess sedation) being a problem, the initial total daily lorazepam dose should not exceed 2 mg. This also applies to use for night sedation. Five participants in a sleep study were prescribed lorazepam 4 mg at night, and the next evening, three subjects unexpectedly volunteered memory gaps for parts of that day, an effect that subsided completely after two to three days use. Amnesic effects cannot be estimated from the degree of sedation present, since the two effects are unrelated. High-dose or prolonged parenterally administered lorazepam with its associated solvent can cause propylene glycol intoxication and poisoning.In September 2020, the U.S. Food and Drug Administration (FDA) required the boxed warning be updated for all benzodiazepine medicines to describe the risks of abuse, misuse, addiction, physical dependence, and withdrawal reactions consistently across all the medicines in the class. Contraindications Lorazepam should be avoided in people with: Allergy or hypersensitivity – Past hypersensitivity or allergy to lorazepam, to any benzodiazepine, or to any of the ingredients in lorazepam tablets or injections Respiratory failure – Benzodiazepines, including lorazepam, may depress central nervous system respiratory drive and are contraindicated in severe respiratory failure. An example would be the inappropriate use to relieve anxiety associated with acute severe asthma. The anxiolytic effects may also be detrimental to a persons willingness and ability to fight for breath. However, if mechanical ventilation becomes necessary, lorazepam may be used to facilitate deep sedation. Acute intoxication – Lorazepam may interact synergistically with the effects of alcohol, narcotics, or other psychoactive substances. It should, therefore, not be administered to a drunk or intoxicated person. Ataxia – This is a neurological clinical sign, consisting of unsteady and clumsy motion of the limbs and torso, due to the failure of gross muscle movement coordination, most evident on standing and walking. It is the classic way in which acute alcohol intoxication may affect a person. Benzodiazepines should not be administered to people already-ataxic. Acute narrow-angle glaucoma – Lorazepam has pupil-dilating effects, which may further interfere with the drainage of aqueous humor from the anterior chamber of the eye, thus worsening narrow-angle glaucoma. Sleep apnea – Sleep apnea may be worsened by lorazepams central nervous system depressant effects. It may further reduce the persons ability to protect his or her airway during sleep. Myasthenia gravis – This condition is characterized by muscle weakness, so a muscle relaxant such as lorazepam may exacerbate symptoms. Pregnancy and breastfeeding – Lorazepam belongs to the Food and Drug Administration (FDA) pregnancy category D, which means it is likely to cause harm to the developing baby if taken during the first trimester of pregnancy. The evidence is inconclusive whether lorazepam if taken early in pregnancy results in reduced intelligence, neurodevelopmental problems, physical malformations in cardiac or facial structure, or other malformations in some newborns. Lorazepam given to pregnant women antenatally may cause floppy infant syndrome in the neonate, or respiratory depression necessitating ventilation. Regular lorazepam use during late pregnancy (the third trimester), carries a definite risk of benzodiazepine withdrawal syndrome in the neonate. Neonatal benzodiazepine withdrawal may include hypotonia, reluctance to suck, apneic spells, cyanosis, and impaired metabolic responses to cold stress. Symptoms of floppy infant syndrome and the neonatal benzodiazepine withdrawal syndrome have been reported to persist from hours to months after birth. Lorazepam may also inhibit fetal liver bilirubin glucuronidation, leading to neonatal jaundice. Lorazepam is present in breast milk, so caution must be exercised about breastfeeding. Specific groups Children and the elderly – The safety and effectiveness of lorazepam is not well determined in children under 18 years of age, but it is used to treat acute seizures. Dose requirements have to be individualized, especially in people who are elderly and debilitated in whom the risk of oversedation is greater. Long-term therapy may lead to cognitive deficits, especially in the elderly, which may only be partially reversible. The elderly metabolize benzodiazepines more slowly than younger people and are more sensitive to the adverse effects of benzodiazepines compared to younger individuals even at similar plasma levels. Additionally, the elderly tend to take more drugs which may interact or enhance the effects of benzodiazepines. Benzodiazepines, including lorazepam, have been found to increase the risk of falls and fractures in the elderly. As a result, dosage recommendations for the elderly are about half of those used in younger individuals and used for no longer than two weeks. Lorazepam may also be slower to clear in the elderly, leading potentially to accumulation and enhanced effects. Lorazepam, similar to other benzodiazepines and nonbenzodiazepines, causes impairments in body balance and standing steadiness in individuals who wake up at night or the next morning. Falls and hip fractures are frequently reported. The combination with alcohol increases these impairments. Partial, but incomplete, tolerance develops to these impairments. Liver or kidney failure – Lorazepam may be safer than most benzodiazepines in people with impaired liver function. Like oxazepam, it does not require liver oxidation, but only liver glucuronidation into lorazepam-glucuronide. Therefore, impaired liver function is unlikely to result in lorazepam accumulation to an extent causing adverse reactions. Similarly kidney disease has minimal effects on lorazepam levels. Surgical premedication – Informed consent given only after receiving lorazepam premedication could have its validity challenged later. Staff must use chaperones to guard against allegations of abuse during treatment. Such allegations may arise because of incomplete amnesia, disinhibition, and impaired ability to process cues. Because of its relatively long duration of residual effects (sedation, ataxia, hypotension, and amnesia), lorazepam premedication is best suited for hospital inpatient use. People should not be discharged from the hospital within 24 hours of receiving lorazepam premedication unless accompanied by a caregiver. They should also not drive, operate machinery, or use alcohol within this period. Drug and alcohol dependence – The risk of abuse of lorazepam is increased in dependent people. Comorbid psychiatric disorders also increase the risk of dependence and paradoxical adverse effects. Tolerance and dependence Dependence typified by a withdrawal syndrome occurs in about one-third of individuals who are treated for longer than four weeks with a benzodiazepine. Higher doses and longer periods of use increase the risk of developing a benzodiazepine dependence. Potent benzodiazepines with a relatively short half life, such as lorazepam, alprazolam, and triazolam, have the highest risk of causing a dependence. Tolerance to benzodiazepine effects develops with regular use. This is desirable with amnesic and sedative effects but undesirable with anxiolytic, hypnotic, and anticonvulsant effects. People initially experience drastic relief from anxiety and sleeplessness, but symptoms gradually return, relatively soon in the case of insomnia, but more slowly in the case of anxiety symptoms. After four to six months of regular benzodiazepine use, evidence of continued efficacy declines.If regular treatment is continued for longer than four to six months, dose increases may be necessary to maintain effects, but treatment-resistant symptoms may in fact be benzodiazepine withdrawal symptoms. Due to the development of tolerance to the anticonvulsant effects, benzodiazepines are generally not recommended for long-term use for the management of epilepsy. Increasing the dose may overcome tolerance, but tolerance may then develop to the higher dose and adverse effects may persist and worsen. The mechanism of tolerance to benzodiazepines is complex and involves GABAA receptor downregulation, alterations to subunit configuration of GABAA receptors, uncoupling and internalisation of the benzodiazepine binding site from the GABAA receptor complex as well as changes in gene expression.The likelihood of dependence is relatively high with lorazepam compared to other benzodiazepines. Lorazepams relatively short serum half-life, its confinement mainly to blood, and its inactive metabolite can result in interdose withdrawal phenomena and next-dose cravings, that may reinforce psychological dependence. Because of its high potency, the smallest lorazepam tablet strength of 0.5 mg is also a significant dose. To minimise the risk of physical/psychological dependence, lorazepam is best used only short-term, at the smallest effective dose. If any benzodiazepine has been used long-term, the recommendation is a gradual dose taper over a period of weeks, months or longer, according to dose and duration of use, the degree of dependence and the individual. Coming off long-term lorazepam use may be more realistically achieved by a gradual switch to an equivalent dose of diazepam and a period of stabilization on this, and only then initiating dose reductions. The advantage of switching to diazepam is that dose reductions are felt less acutely, because of the longer half-lives (20–200 hours) of diazepam and its active metabolites. Withdrawal On abrupt or overly rapid discontinuation of lorazepam, anxiety, and signs of physical withdrawal have been observed, similar to those seen on withdrawal from alcohol and barbiturates. Lorazepam, as with other benzodiazepine drugs, can cause physical dependence, addiction, and benzodiazepine withdrawal syndrome. The higher the dose and the longer the drug is taken, the greater the risk of experiencing unpleasant withdrawal symptoms. Withdrawal symptoms can, however, occur from standard dosages and also after short-term use. Benzodiazepine treatment should be discontinued as soon as possible via a slow and gradual dose reduction regimen. Rebound effects often resemble the condition being treated, but typically at a more intense level and may be difficult to diagnose. Withdrawal symptoms can range from mild anxiety and insomnia to more severe symptoms such as seizures and psychosis. The risk and severity of withdrawal are increased with long-term use, use of high doses, abrupt or over-rapid reduction, among other factors. Short-acting benzodiazepines such as lorazepam are more likely to cause a more severe withdrawal syndrome compared to longer-acting benzodiazepines.Withdrawal symptoms can occur after taking therapeutic doses of lorazepam for as little as one week. Withdrawal symptoms include headaches, anxiety, tension, depression, insomnia, restlessness, confusion, irritability, sweating, dysphoria, dizziness, derealization, depersonalization, numbness/tingling of extremities, hypersensitivity to light, sound, and smell, perceptual distortions, nausea, vomiting, diarrhea, appetite loss, hallucinations, delirium, seizures, tremor, stomach cramps, myalgia, agitation, palpitations, tachycardia, panic attacks, short-term memory loss, and hyperthermia. It takes about 18–36 hours for the benzodiazepine to be removed from the body. The ease of physical dependence to lorazepam, (Ativan brand was particularly cited), and its withdrawal were brought to the attention of the British public during the early 1980s in Esther Rantzens BBC TV series Thats Life!, in a feature on the drug over a number of episodes. Interactions Lorazepam is not usually fatal in overdose, but may cause respiratory depression if taken in overdose with alcohol. The combination also causes greater enhancement of the disinhibitory and amnesic effects of both drugs, with potentially embarrassing or criminal consequences. Some experts advise that people should be warned against drinking alcohol while on lorazepam treatment, but such clear warnings are not universal.Greater adverse effects may also occur when lorazepam is used with other drugs, such as opioids or other hypnotics. Lorazepam may also interact with rifabutin. Valproate inhibits the metabolism of lorazepam, whereas carbamazepine, lamotrigine, phenobarbital, phenytoin, and rifampin increase its rate of metabolism. Some antidepressants, antiepileptic drugs such as phenobarbital, phenytoin and carbamazepine, sedative antihistamines, opiates, antipsychotics and alcohol, when taken with lorazepam may result in enhanced sedative effects. Overdose In cases of a suspected lorazepam overdose, it is important to establish whether the person is a regular user of lorazepam or other benzodiazepines since regular use causes tolerance to develop. Also, one must ascertain whether other substances were also ingested. Signs of overdose range through mental confusion, dysarthria, paradoxical reactions, drowsiness, hypotonia, ataxia, hypotension, hypnotic state, coma, cardiovascular depression, respiratory depression, and death. However, fatal overdoses on benzodiazepines alone are rare and less common than with barbiturates. Such a difference is largely due to benzodiazepine activity as a neuroreceptor modulator, and not as an activator per se. Lorazepam and similar medication do however act in synergy with alcohol, which increases the risk of overdose. Early management of people under alert includes emetics, gastric lavage, and activated charcoal. Otherwise, management is by observation, including of vital signs, support and, only if necessary, considering the hazards of doing so, giving intravenous flumazenil. People are ideally nursed in a kind, frustration-free environment, since, when given or taken in high doses, benzodiazepines are more likely to cause paradoxical reactions. If shown sympathy, even quite crudely feigned, people may respond solicitously, but they may respond with disproportionate aggression to frustrating cues. Opportunistic counseling has limited value here, as the person is unlikely to recall this later, owing to drug-induced anterograde amnesia. Detection in body fluids Lorazepam may be quantitated in blood or plasma to confirm poisoning in hospitalized people, provide evidence of an impaired driving arrest or to assist in a medicolegal death investigation. Blood or plasma concentrations are usually in a range of 10–300 μg/L in persons either receiving the drug therapeutically or in those arrested for impaired driving. Approximately 300–1000 μg/L is found in people after acute overdosage. Lorazepam may not be detected by commonly used urine drug screenings for benzodiazepines. Pharmacology Lorazepam has anxiolytic, sedative, hypnotic, amnesic, anticonvulsant, and muscle relaxant properties. It is a high-potency and an intermediate-acting benzodiazepine, and its uniqueness, advantages, and disadvantages are largely explained by its pharmacokinetic properties (poor water and lipid solubility, high protein binding and anoxidative metabolism to a pharmacologically inactive glucuronide form) and by its high relative potency (lorazepam 1 mg is equal in effect to diazepam 10 mg). The biological half-life of lorazepam is 10–20 hours. Pharmacokinetics Lorazepam is highly protein bound and is extensively metabolized into pharmacologically inactive metabolites. Due to its poor lipid solubility, lorazepam is absorbed relatively slowly by mouth and is unsuitable for rectal administration. However, its poor lipid solubility and high degree of protein binding (85–90%) mean its volume of distribution is mainly the vascular compartment, causing relatively prolonged peak effects. This contrasts with the highly lipid-soluble diazepam, which, although rapidly absorbed orally or rectally, soon redistributes from the serum to other parts of the body, in particular, body fat. This explains why one lorazepam dose, despite its shorter serum half-life, has more prolonged peak effects than an equivalent diazepam dose. Lorazepam is rapidly conjugated at its 3-hydroxy group into lorazepam glucuronide which is then excreted in the urine. Lorazepam glucuronide has no demonstrable CNS activity in animals. The plasma levels of lorazepam are proportional to the dose given. There is no evidence of accumulation of lorazepam on administration up to six months. On regular administration, diazepam will accumulate, since it has a longer half-life and active metabolites, these metabolites also have long half-lives. Clinical example: Diazepam has long been a drug of choice for status epilepticus; its high lipid solubility means it gets absorbed with equal speed whether given orally, or rectally (nonintravenous routes are convenient in outside hospital settings), but diazepams high lipid solubility also means it does not remain in the vascular space, but soon redistributes into other body tissues. So, it may be necessary to repeat diazepam doses to maintain peak anticonvulsant effects, resulting in excess body accumulation. Lorazepam is a different case; its low lipid solubility makes it relatively slowly absorbed by any route other than intravenously, but once injected, it will not get significantly redistributed beyond the vascular space. Therefore, lorazepams anticonvulsant effects are more durable, thus reducing the need for repeated doses. If a person is known to usually stop convulsing after only one or two diazepam doses, it may be preferable because sedative after effects will be less than if a single dose of lorazepam is given (diazepam anticonvulsant/sedative effects wear off after 15–30 minutes, but lorazepam effects last 12–24 hours). The prolonged sedation from lorazepam may, however, be an acceptable trade-off for its reliable duration of effects, particularly if the person needs to be transferred to another facility. Although lorazepam is not necessarily better than diazepam at initially terminating seizures, lorazepam is, nevertheless, replacing diazepam as the intravenous agent of choice in status epilepticus.Lorazepam serum levels are proportional to the dose administered. Giving 2 mg oral lorazepam will result in a peak total serum level of around 20 ng/mL around two hours later, half of which is lorazepam, half its inactive metabolite, lorazepam-glucuronide. A similar lorazepam dose given intravenously will result in an earlier and higher peak serum level, with a higher relative proportion of unmetabolised (active) lorazepam. On regular administration, maximum serum levels are attained after three days. Longer-term use, up to six months, does not result in further accumulation. On discontinuation, lorazepam serum levels become negligible after three days and undetectable after about a week. Lorazepam is metabolized in the liver by conjugation into inactive lorazepam-glucuronide. This metabolism does not involve liver oxidation, so is relatively unaffected by reduced liver function. Lorazepam-glucuronide is more water-soluble than its precursor, so gets more widely distributed in the body, leading to a longer half-life than lorazepam. Lorazepam-glucuronide is eventually excreted by the kidneys, and, because of its tissue accumulation, it remains detectable, particularly in the urine, for substantially longer than lorazepam. Pharmacodynamics Relative to other benzodiazepines, lorazepam is thought to have high affinity for GABA receptors, which may also explain its marked amnesic effects. Its
Lorazepam
main pharmacological effects are the enhancement of the effects of the neurotransmitter GABA at the GABAA receptor. Benzodiazepines, such as lorazepam, enhance the effects of GABA at the GABAA receptor via increasing the frequency of opening of the chloride ion channel on the GABAA receptors; which results in the therapeutic actions of benzodiazepines. They, however, do not on their own activate the GABAA receptors, but require the neurotransmitter GABA to be present. Thus, the effect of benzodiazepines is to enhance the effects of the neurotransmitter GABA.The magnitude and duration of lorazepam effects are dose-related, meaning larger doses have stronger and longer-lasting effects, because the brain has spare benzodiazepine drug receptor capacity, with single, clinical doses leading only to an occupancy of some 3% of the available receptors.The anticonvulsant properties of lorazepam and other benzodiazepines may be, in part or entirely, due to binding to voltage-dependent sodium channels rather than benzodiazepine receptors. Sustained repetitive firing seems to get limited, by the benzodiazepine effect of slowing recovery of sodium channels from inactivation to deactivation in mouse spinal cord cell cultures, hence prolonging the refractory period. Physical properties and formulations Pure lorazepam is an almost white powder that is nearly insoluble in water and oil. In medicinal form, it is mainly available as tablets and a solution for injection, but, in some locations, it is also available as a skin patch, an oral solution, and a sublingual tablet. Lorazepam tablets and syrups are administered by mouth only. Lorazepam tablets of the Ativan brand also contain lactose, microcrystalline cellulose, polacrilin, magnesium stearate, and coloring agents (indigo carmine in blue tablets and tartrazine in yellow tablets). Lorazepam for injection formulated with polyethylene glycol 400 in propylene glycol with 2.0% benzyl alcohol as preservative. Lorazepam injectable solution is administered either by deep intramuscular injection or by intravenous injection. The injectable solution comes in 1 mL ampoules containing 2 or 4 mg of lorazepam. The solvents used are polyethylene glycol 400 and propylene glycol. As a preservative, the injectable solution contains benzyl alcohol. Toxicity from propylene glycol has been reported in the case of a person receiving a continuous lorazepam infusion. Intravenous injections should be given slowly and they should be closely monitored for side effects, such as respiratory depression, hypotension, or loss of airway control. Peak effects roughly coincide with peak serum levels, which occur 10 minutes after intravenous injection, up to 60 minutes after intramuscular injection, and 90 to 120 minutes after oral administration, but initial effects will be noted before this. A clinically relevant lorazepam dose will normally be effective for six to 12 hours, making it unsuitable for regular once-daily administration, so it is usually prescribed as two to four daily doses when taken regularly, but this may be extended to five or six, especially in the case of elderly people who could not handle large doses at once. Topical formulations of lorazepam, while used as treatment for nausea especially in people in hospice, ought not be used in this form and for this purpose as they have not been proven effective. History Historically, lorazepam is one of the "classical" benzodiazepines. Others include diazepam, clonazepam, oxazepam, nitrazepam, flurazepam, bromazepam, and clorazepate. Lorazepam was first introduced by Wyeth Pharmaceuticals in 1977 under the brand names Ativan and Temesta. The drug was developed by D.J. Richards, president of research. Wyeths original patent on lorazepam is expired in the United States. Society and culture Recreational use Lorazepam is also used for other purposes, such as recreational use, wherein the drug is taken to achieve a high, or when the drug is continued long-term against medical advice.A large-scale, nationwide, U.S. government study of pharmaceutical-related emergency department visits by SAMHSA found sedative-hypnotics are the pharmaceuticals most frequently used outside of their prescribed medical purpose in the United States, with 35% of drug-related emergency department visits involving sedative-hypnotics. In this category, benzodiazepines are most commonly used. Males and females use benzodiazepines for nonmedical purposes equally. Of drugs used in attempted suicide, benzodiazepines are the most commonly used pharmaceutical drugs, with 26% of attempted suicides involving them. Lorazepam was the third-most-common benzodiazepine used outside of prescription in these ER visit statistics. Legal status Lorazepam is a Schedule IV drug under the Controlled Substances Act in the U.S. and internationally under the United Nations Convention on Psychotropic Substances. It is a Schedule IV drug under the Controlled Drugs and Substances Act in Canada. In the United Kingdom, it is a Class C, Schedule 4 Controlled Drug under the Misuse of Drugs Regulations 2001. Pricing In 2000, the U.S. drug company Mylan agreed to pay $147 million to settle accusations by the FTC that they had raised the price of generic lorazepam by 2600% and generic clorazepate by 3200% in 1998 after having obtained exclusive licensing agreements for certain ingredients. References External links inchem.org – Lorazepam data sheet benzo.org.uk – Ashton H. Benzodiazepines: How They Work And How to Withdraw. August 2002 (The "Ashton Manual"). "Lorazepam". Drug Information Portal. U.S. National Library of Medicine.
Dorzolamide/timolol
Dorzolamide/timolol, sold under the brand name Cosopt among others, is a medication used to treat high pressure inside the eye including glaucoma. It is a combination of dorzolamide hydrochloride and timolol maleate. It may be used when a beta blocker, like timolol, is not sufficient alone. It is used as an eye drop.Common side effects include eye discomfort, eye redness, taste changes, and blurry vision. Serious side effects may include allergic reactions and heart failure. Use is not recommended in those with asthma, a sulfonamide allergy, or a slow heart rate. Dorzolamide is a carbonic anhydrase inhibitor and timolol is a beta blocker. Both work by decreasing the amount of aqueous humor made by the eye.The combination was approved for medical use in the United States in 1998. It is available as a generic medication. In 2019, it was the 207th most commonly prescribed medication in the United States, with more than 2 million prescriptions. Adverse effects Common adverse effects include temporarily blurred vision, cloudy vision, double vision, temporary burning/stinging/itching of the eye, watery eyes, feeling as if something is in the eye, drooping eyelid, sensitivity to light, cough, flu symptoms, nausea, and stomach pain.More serious adverse effects include dizziness, slow or irregular heartbeat, muscle weakness, mental/mood changes, and coldness/numbness/pain in the hands or feet. Pharmacology Dorzolamide is a human carboanydrase II inhibitor. Inhibition of carboanhydrase in the ciliary processes of the eye decreases aqueous humor secretion supposedly by decreasing the formation rate of bicarbonate ions. This results in reduction in both sodium and fluid transport. Timolol is a non-selective beta-adrenergic antagonist. Comparison to other products Despite each of the active ingredients being availed in their own respective formulations, combination formulations are typically more convenient for the patient without sacrificing any quality in therapy. In the case of Cosopt, the combination formulation dosed twice daily provides equivalent treatment to both dorzolamide 2% dosed two times daily and timolol 0.5% dosed three times daily. Specifically, the mean reduction in intraocular pressure was 27.4% for the combination product, 15.5% for dorzolamide 2%, and 22.2% for timolol 0.5%. Compared to other products such as latanoprost, both are equally efficacious with regard to lowering intraocular pressure and getting patients to reach their target intraocular pressure. Cosopt, though, is typically less well tolerated than other treatments due to a well documented feeling of ocular burning upon administration. History Cosopt gained Food and Drug Administration (FDA) approval in April 1998 and was supplied initially by Merck. In 2016, Merck & Co. had $95.3 billion in total assets, $40.3 billion in total equity, $24.3 billion in long term debt, and $13.4 billion in working capital. This same year Merck & Co spent $20 billion total split virtually evenly between research and development (R&D) and marketing efforts. Cosopt had annual sales of $342 million during the 12 months before June 2008. In September 2013, Merck & Co. sold the U.S. rights to their ophthalmic product line (including Cosopt) to Akorn Inc. for $52.8 million cash.Upon the original patent expiration, Hi-Tech Pharma was the first of many generic competitors to submit an abbreviated new drug application (ANDA) for dorzolamide hydrochloride/timolol maleate eye drops. Hi-Tech Pharmas ANDA was approved on 28 October 2008. At the time, controversy surrounded the approval of this first ANDA. Hi-Tech sued the FDA for their right to 180 market exclusivity as laid out in the Hatch-Waxman Act. Apotex, another firm seeking an ANDA approval for generic Cosopt, argued that Hi-Tech "forfeited its rights to market exclusivity because it has failed to market the drug within 30 months of its ANDA submission or within 75 days after Merck withdrew its patent information." The FDA upheld their previous exclusivity decisions on acarbose and granisetron, allowing both Hi-Tech and Apotex to make a generic version of Cosopt. Soon after, ANDAs from Sandoz, Bausch & Laumb, TEVA and others were also approved.Just over a year before Merck sold their ophthalmic line to Akorn, Akorn developed a new formulation of dorzolamide hydrochloride/timolol maleate called Cosopt PF, which is simply a preservative free formulation of Cosopt. It gained FDA approval in July 2012 and is currently protected by market exclusivity. Society and culture Legality In the United States, Cosopt, as well as its generics, is only available to patients with a valid prescription. Cost The brand name Cosopt currently costs upwards of $200 after discounts while the generic formulation costs around $70 cash. The more recent preservative free formulation can be purchased for less than the original brand name formulation at around $160 References External links Drug information from the NIH
Drospirenone
Drospirenone is a progestin medication which is used in birth control pills to prevent pregnancy and in menopausal hormone therapy, among other uses. It is available both alone under the brand name Slynd and in combination with an estrogen under the brand name Yasmin among others. The medication is taken by mouth.Common side effects include acne, headache, breast tenderness, weight increase, and menstrual changes. Rare side effects may include high potassium levels and blood clots, among others. Drospirenone is a progestin, or a synthetic progestogen, and hence is an agonist of the progesterone receptor, the biological target of progestogens like progesterone. It has additional antimineralocorticoid and antiandrogenic activity and no other important hormonal activity. Because of its antimineralocorticoid activity and lack of undesirable off-target activity, drospirenone is said to more closely resemble bioidentical progesterone than other progestins.Drospirenone was patented in 1976 and introduced for medical use in 2000. It is available widely throughout the world. The medication is sometimes referred to as a "fourth-generation" progestin. It is available as a generic medication. In 2018, a formulation of drospirenone with ethinylestradiol was the 167th most commonly prescribed medication in the United States, with more than 3 million prescriptions. Medical uses Drospirenone (DRSP) is used by itself as a progestogen-only birth control pill, in combination with the estrogens ethinylestradiol (EE) or estetrol (E4), with or without supplemental folic acid (vitamin B9), as a combined birth control pill, and in combination with the estrogen estradiol (E2) for use in menopausal hormone therapy. A birth control pill with low-dose ethinylestradiol is also indicated for the treatment of moderate acne, premenstrual syndrome (PMS), premenstrual dysphoric disorder (PMDD), and dysmenorrhea (painful menstruation). For use in menopausal hormone therapy, E2/DRSP is specifically approved to treat moderate to severe vasomotor symptoms (hot flashes), vaginal atrophy, and postmenopausal osteoporosis. The drospirenone component in this formulation is included specifically to prevent estrogen-induced endometrial hyperplasia. Drospirenone has also been used in combination with an estrogen as a component of hormone therapy for transgender women.Studies have found that EE/DRSP is superior to placebo in reducing premenstrual emotional and physical symptoms while also improving quality of life. E2/DRSP has been found to increase bone mineral density and to reduce the occurrence of bone fractures in postmenopausal women. In addition, E2/DRSP has a favorable influence on cholesterol and triglyceride levels and decreases blood pressure in women with high blood pressure. Due to its antimineralocorticoid activity, drospirenone opposes estrogen-induced salt and water retention and maintains or slightly reduces body weight. Available forms Drospirenone is available in the following formulations, brand names, and indications: Drospirenone 4 mg (Slynd) – progestogen-only birth control pill Drospirenone 3 mg and estetrol 14.2 mg (Nextstellis (US)) – combined birth control pill Ethinylestradiol 30 μg and drospirenone 3 mg (Ocella, Syeda, Yasmin, Zarah, Zumandimine) – combined birth control pill Ethinylestradiol 20 μg and drospirenone 3 mg (Gianvi, Jasmiel, Loryna, Lo-Zumandimine, Nikki, Vestura, Yaz) – combined birth control pill, acne, PMS, PMDD, dysmenorrhea Ethinylestradiol 30 μg, drospirenone 3 mg, and levomefolate calcium 0.451 mg (Beyaz, Tydemy) – combined birth control pill with vitamin B9 supplementation, acne, PMS Estetrol 15 mg and drospirenone 3 mg (Nextstellis (CA)) – combined birth control pill Estradiol 0.5 or 1 mg and drospirenone 0.25 or 0.5 mg (Angeliq) – menopausal hormone therapy (menopausal syndrome, postmenopausal osteoporosis) Contraindications Contraindications of drospirenone include renal impairment or chronic kidney disease, adrenal insufficiency, presence or history of cervical cancer or other progestogen-sensitive cancers, benign or malignant liver tumors or hepatic impairment, undiagnosed abnormal uterine bleeding, and hyperkalemia (high potassium levels). Renal impairment, hepatic impairment, and adrenal insufficiency are contraindicated because they increase exposure to drospirenone and/or increase the risk of hyperkalemia with drospirenone. Side effects Adverse effects of drospirenone alone occurring in more than 1% of women may include unscheduled menstrual bleeding (breakthrough or intracyclic) (40.3–64.4%), acne (3.8%), metrorrhagia (2.8%), headache (2.7%), breast pain (2.2%), weight gain (1.9%), dysmenorrhea (1.9%), nausea (1.8%), vaginal hemorrhage (1.7%), decreased libido (1.3%), breast tenderness (1.2%), and irregular menstruation (1.2%). High potassium levels Drospirenone is an antimineralocorticoid with potassium-sparing properties, though in most cases no increase of potassium levels is to be expected. In women with mild or moderate chronic kidney disease, or in combination with chronic daily use of other potassium-sparing medications (ACE inhibitors, angiotensin II receptor antagonists, potassium-sparing diuretics, heparin, antimineralocorticoids, or nonsteroidal anti-inflammatory drugs), a potassium level should be checked after two weeks of use to test for hyperkalemia. Persistent hyperkalemia that required discontinuation occurred in 2 out of around 1,000 women (0.2%) with 4 mg/day drospirenone alone in clinical trials. Blood clots Birth control pills containing ethinylestradiol and a progestin are associated with an increased risk of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE). The incidence is about 4-fold higher on average than in women not taking a birth control pill. The absolute risk of VTE with ethinylestradiol-containing birth control pills is small, in the area of 3 to 10 out of 10,000 women per year, relative to 1 to 5 out of 10,000 women per year not taking a birth control pill. The risk of VTE during pregnancy is 5 to 20 in 10,000 women per year and during the postpartum period is 40 to 65 per 10,000 women per year. The higher risk of VTE with combined birth control pills is thought to be due to the ethinylestradiol component, as ethinylestradiol has estrogenic effects on liver synthesis of coagulation factors which result in a procoagulatory state. In contrast to ethinylestradiol-containing birth control pills, neither progestogen-only birth control nor the combination of transdermal estradiol and an oral progestin in menopausal hormone therapy is associated with an increased risk of VTE.Different progestins in ethinylestradiol-containing birth control pills have been associated with different risks of VTE. Birth control pills containing progestins such as desogestrel, gestodene, drospirenone, and cyproterone acetate have been found to have 2- to 3-fold the risk of VTE of birth control pills containing levonorgestrel in retrospective cohort and nested case–control observational studies. However, this area of research is controversial, and confounding factors may have been present in these studies. Other observational studies, specifically prospective cohort and case control studies, have found no differences in risk between different progestins, including between birth control pills containing drospirenone and birth control pills containing levonorgestrel. These kinds of observational studies have certain advantages over the aforementioned types of studies, like better ability to control for confounding factors. Systematic reviews and meta-analyses of all of the data in the mid-to-late 2010s found that birth control pills containing cyproterone acetate, desogestrel, drospirenone, or gestodene overall were associated with a risk of VTE of about 1.3- to 2.0-fold compared to that of levonorgestrel-containing birth control pills.Androgenic progestins have been found to antagonize to some degree the effects of ethinylestradiol on coagulation. As a result, more androgenic progestins, like levonorgestrel and norethisterone, may oppose the procoagulatory effects of ethinylestradiol and result in a lower increase in risk of VTE. Conversely, this would be the case less or not at all with progestins that are less androgenic, like desogestrel and gestodene, as well as with progestins that are antiandrogenic, like drospirenone and cyproterone acetate.In the early 2010s, the FDA updated the label for birth control pills containing drospirenone and other progestins to include warnings for stopping use prior to and after surgery, and to warn that such birth control pills may have a higher risk of blood clots. Breast cancer Drospirenone has been found to stimulate the proliferation and migration of breast cancer cells in preclinical research, similarly to certain other progestins. However, some evidence suggests that drospirenone may do this more weakly than certain other progestins, like medroxyprogesterone acetate. The combination of estradiol and drospirenone has been found to increase breast density, an established risk factor for breast cancer, in postmenopausal women.Data on risk of breast cancer in women with newer progestins like drospirenone are lacking at present. Progestogen-only birth control is not generally associated with a higher risk of breast cancer. Conversely, combined birth control and menopausal hormone therapy with an estrogen and a progestogen are associated with higher risks of breast cancer. Overdose These have been no reports of serious adverse effects with overdose of drospirenone. Symptoms that may occur in the event of an overdose may include nausea, vomiting, and vaginal bleeding. There is no antidote for overdose of drospirenone and treatment of overdose should be based on symptoms. Since drospirenone has antimineralocorticoid activity, levels of potassium and sodium should be measured and signs of metabolic acidosis should be monitored. Interactions Inhibitors and inducers of the cytochrome P450 enzyme CYP3A4 may influence the levels and efficacy of drospirenone. Treatment for 10 days with 200 mg twice daily ketoconazole, a strong CYP3A4 inhibitor among other actions, has been found to result in a moderate 2.0- to 2.7-fold increase in exposure to drospirenone. Drospirenone does not appear to influence the metabolism of omeprazole (metabolized via CYP2C19), simvastatin (metabolized via CYP3A4), or midazolam (metabolized via CYP3A4), and likely does not influence the metabolism of other medications that are metabolized via these pathways. Drospirenone may interact with potassium-sparing medications such as ACE inhibitors, angiotensin II receptor antagonists, potassium-sparing diuretics, potassium supplements, heparin, antimineralocorticoids, and nonsteroidal anti-inflammatory drugs to further increase potassium levels. This may increase the risk of hyperkalemia (high potassium levels). Pharmacology Pharmacodynamics Drospirenone binds with high affinity to the progesterone receptor (PR) and mineralocorticoid receptor (MR), with lower affinity to the androgen receptor (AR), and with very low affinity to the glucocorticoid receptor (GR). It is an agonist of the PR and an antagonist of the MR and AR, and hence is a progestogen, antimineralocorticoid, and antiandrogen. Drospirenone has no estrogenic activity and no appreciable glucocorticoid or antiglucocorticoid activity. Progestogenic activity Drospirenone is an agonist of the PR, the biological target of progestogens like progesterone. It has about 35% of the affinity of promegestone for the PR and about 19 to 70% of the affinity of progesterone for the PR. Drospirenone has antigonadotropic and functional antiestrogenic effects as a result of PR activation. The ovulation-inhibiting dosage of drospirenone is 2 to 3 mg/day. Inhibition of ovulation occurred in about 90% of women at a dose of 0.5 to 2 mg/day and in 100% of women at a dose of 3 mg/day. The total endometrial transformation dose of drospirenone is about 50 mg per cycle, whereas its daily dose is 2 mg for partial transformation and 4 to 6 mg for full transformation. The medication acts as a contraceptive by activating the PR, which suppresses the secretion of luteinizing hormone, inhibits ovulation, and alters the cervical membrane and endometrium.Due to its antigonadotropic effects, drospirenone inhibits the secretion of the gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and suppresses gonadal sex hormone production, including of estradiol, progesterone, and testosterone. Drospirenone alone at 4 mg/day has been found to suppress estradiol levels in premenopausal women to about 40 to 80 pg/mL depending on the time of the cycle. No studies of the antigonadotropic effects of drospirenone or its influence on hormone levels appear to have been conducted in men. In male cynomolgus monkeys however, 4 mg/kg/day oral drospirenone strongly suppressed testosterone levels. Antimineralocorticoid activity Drospirenone is an antagonist of the MR, the biological target of mineralocorticoids like aldosterone, and hence is an antimineralocorticoid. It has about 100 to 500% of the affinity of aldosterone for the MR and about 50 to 230% of the affinity of progesterone for the MR. Drospirenone is about 5.5 to 11 times more potent as an antimineralocorticoid than spironolactone in animals. Accordingly, 3 to 4 mg drospirenone is said to be equivalent to about 20 to 25 mg spironolactone in terms of antimineralocorticoid activity. It has been said that the pharmacological profile of drospirenone more closely resembles that of progesterone than other progestins due to its antimineralocorticoid activity. Drospirenone is the only clinically used progestogen with prominent antimineralocorticoid activity besides progesterone. For comparison to progesterone, a 200 mg dose of oral progesterone is considered to be approximately equivalent in antimineralocorticoid effect to a 25 to 50 mg dose of spironolactone. Both drospirenone and progesterone are actually weak partial agonists of the MR in the absence of mineralocorticoids.Due to its antimineralocorticoid activity, drospirenone increases natriuresis, decreases water retention and blood pressure, and produces compensatory increases in plasma renin activity as well as circulating levels and urinary excretion of aldosterone. This has been shown to occur at doses of 2 to 4 mg/day. Similar effects occur during the luteal phase of the menstrual cycle due to increased progesterone levels and the resulting antagonism of the MR. Estrogens, particularly ethinylestradiol, activate liver production of angiotensinogen and increase levels of angiotensinogen and angiotensin II, thereby activating the renin–angiotensin–aldosterone system. As a result, they can produce undesirable side effects including increased sodium excretion, water retention, weight gain, and increased blood pressure. Progesterone and drospirenone counteract these undesirable effects via their antimineralocorticoid activity. Accumulating research indicates that antimineralocorticoids like drospirenone and spironolactone may also have positive effects on adipose tissue and metabolic health. Antiandrogenic activity Drospirenone is an antagonist of the AR, the biological target of androgens like testosterone and dihydrotestosterone (DHT). It has about 1 to 65% of the affinity of the synthetic anabolic steroid metribolone for the AR. The medication is more potent as an antiandrogen than spironolactone, but is less potent than cyproterone acetate, with about 30% of its antiandrogenic activity in animals. Progesterone displays antiandrogenic activity in some assays similarly to drospirenone, although this issue is controversial and many researchers regard progesterone as having no significant antiandrogenic activity.Drospirenone shows antiandrogenic effects on the serum lipid profile, including higher HDL cholesterol and triglyceride levels and lower LDL cholesterol levels, at a dose of 3 mg/day in women. The medication does not inhibit the effects of ethinylestradiol on sex hormone-binding globulin (SHBG) and serum lipids, in contrast to androgenic progestins like levonorgestrel but similarly to other antiandrogenic progestins like cyproterone acetate. SHBG levels are significantly higher with ethinylestradiol and cyproterone acetate than with ethinylestradiol and drospirenone, owing to the more potent antiandrogenic activity of cyproterone acetate relative to drospirenone. Androgenic progestins like levonorgestrel have been found to inhibit the procoagulatory effects of estrogens like ethinylestradiol on hepatic synthesis of coagulation factors, whereas this may occur less or not at all with weakly androgenic progestins like desogestrel and antiandrogenic progestins like drospirenone. Other activity Drospirenone stimulates the proliferation of MCF-7 breast cancer cells in vitro, an action that is independent of the classical PRs and is instead mediated via the progesterone receptor membrane component-1 (PGRMC1). Certain other progestins act similarly in this assay, whereas progesterone acts neutrally. It is unclear if these findings may explain the different risks of breast cancer observed with progesterone and progestins in clinical studies. Pharmacokinetics Absorption The oral bioavailability of drospirenone is between 66 and 85%. Peak levels occur 1 to 6 hours after an oral dose. Levels are about 27 ng/mL after a single 4 mg dose. There is 1.5- to 2-fold accumulation in drospirenone levels with continuous administration, with steady-state levels of drospirenone achieved after 7 to 10 days of administration. Peak levels of drospirenone at steady state with 4 mg/day drospirenone are about 41 ng/mL. With the combination of 30 μg/day ethinylestradiol and 3 mg/day drospirenone, peak levels of drospirenone after a single dose are 35 ng/mL, and levels at steady state are 60 to 87 ng/mL at peak and 20 to 25 ng/mL at trough. The pharmacokinetics of oral drospirenone are linear with a single dose across a dose range of 1 to 10 mg. Intake of drospirenone with food does not influence the absorption of drospirenone. Distribution The distribution half-life of drospirenone is about 1.6 to 2 hours. The apparent volume of distribution of drospirenone is approximately 4 L/kg. The plasma protein binding of drospirenone is 95 to 97%. It is bound to albumin and 3 to 5% circulates freely or unbound. Drospirenone has no affinity for sex hormone-binding globulin (SHBG) or corticosteroid-binding globulin (CBG), and hence is not bound by these plasma proteins in the circulation. Metabolism The metabolism of drospirenone is extensive. It is metabolized into the acid form of drospirenone by opening of its lactone ring. The medication is also metabolized by reduction of its double bond between the C4 and C5 positions and subsequent sulfation. The two major metabolites of drospirenone are drospirenone acid and 4,5-dihydrodrospirenone 3-sulfate, and are both formed independently of the cytochrome P450 system. Neither of these metabolites are known to be pharmacologically active. Drospirenone also undergoes oxidative metabolism by CYP3A4. Elimination Drospirenone is excreted in urine and feces, with slightly more excreted in feces than in urine. Only trace amounts of unchanged drospirenone can be found in urine and feces. At least 20 different metabolites can be identified in urine and feces. Drospirenone and its metabolites are excreted in urine about 38% as glucuronide conjugates, 47% as sulfate conjugates, and less than 10% in unconjugated form. In feces, excretion is about 17% glucuronide conjugates, 20% sulfate conjugates, and 33% unconjugated.The elimination half-life of drospirenone is between 25 and 33 hours. The half-life of drospirenone is unchanged with repeated administration. Elimination of drospirenone is virtually complete 10 days after the last dose. Chemistry Drospirenone, also known as 1,2-dihydrospirorenone or as 17β-hydroxy-6β,7β:15β,16β-dimethylene-3-oxo-17α-pregn-4-ene-21-carboxylic acid, γ-lactone, is a synthetic steroidal 17α-spirolactone, or more simply a spirolactone. It is an analogue of other spirolactones like spironolactone, canrenone, and spirorenone. Drospirenone differs structurally from spironolactone only in that the C7α acetylthio substitution of spironolactone has been removed and two methylene groups have been substituted in at the C6β–7β and C15β–16β positions.Spirolactones like drospirenone and spironolactone are derivatives of progesterone, which likewise has progestogenic and antimineralocorticoid activity. The loss of the C7α acetylthio group of spironolactone, a compound with negligible progestogenic activity, appears to be involved in the restoration of progestogenic activity in drospirenone, as SC-5233, the analogue of spironolactone without a C7α substitution, has potent progestogenic activity similarly to drospirenone. History Drospirenone was patented in 1976 and introduced for medical use in 2000. Schering AG of Germany has been granted several patents on the production of drospirenone, including WIPO and US patents, granted in 1998 and 2000, respectively. It was introduced for medical use in combination with ethinylestradiol as a combined birth control pill in 2000. Drospirenone is sometimes described as a "fourth-generation" progestin based on its time of introduction. The medication was approved for use in menopausal hormone therapy in combination with estradiol in 2005. Drospirenone was introduced for use as a progestogen-only birth control pill in 2019. A combined birth control pill containing estetrol and drospirenone was approved in 2021. Society and culture Generic names Drospirenone is the generic name of the drug and its INN, USAN, BAN, and JAN, while drospirénone is its DCF. Its name is a shortened form of the name 1,2-dihydrospirorenone or dihydrospirenone. Drospirenone is also known by its developmental code names SH-470 and ZK-30595 (alone), BAY 86-5300, BAY 98-7071, and SH-T-00186D (in combination with ethinylestradiol), BAY 86-4891 (in combination with estradiol), and FSN-013 (in combination with estetrol). Brand names Drospirenone is marketed in combination with an estrogen under a variety of brand names throughout the world. Among others, it is marketed in combination with ethinylestradiol under the brand names Yasmin and Yaz, in combination with estetrol under the brand name Nextstellis, and in combination with estradiol under the brand name Angeliq. Availability Drospirenone is marketed widely throughout the world. Generation Drospirenone has been categorized as a "fourth-generation" progestin. Litigation Many lawsuits have been filed against Bayer, the manufacturer of drospirenone, due to the higher risk of venous thromboembolism (VTE) that has been observed with combined birth control pills containing drospirenone and certain other progestins relative to the risk with levonorgestrel-containing combined birth control pills.In July 2012, Bayer notified its stockholders that there were more than 12,000 such lawsuits against the company involving Yaz, Yasmin, and other birth control pills with drospirenone. They also noted that the company by then had settled 1,977 cases for US$402.6 million, for an average of US$212,000 per case, while setting aside US$610.5 million to settle the others.As of July 17, 2015, there have been at least 4,000 lawsuits and claims still pending regarding VTE related to drospirenone. This is in addition to around 10,000 claims that Bayer has already settled without admitting liability. These claims of VTE have amounted to US$1.97 billion. Bayer also reached a settlement for arterial thromboembolic events, including stroke and heart attacks, for US$56.9 million. Research A combination of ethinylestradiol, drospirenone, and prasterone is under development by Pantarhei Bioscience as a combined birth control pill for prevention of pregnancy in women. It includes prasterone (dehydroepiandrosterone; DHEA), an oral androgen prohormone, to replace testosterone and avoid testosterone deficiency caused by suppression of testosterone by ethinylestradiol and drospirenone. As of August 2018, the formulation is in phase II/III clinical trials.Drospirenone has been suggested for potential use as a progestin in male hormonal contraception.Drospirenone has been studied in forms for parenteral administration. References Further reading
Drospirenone
Archer DF (February 2007). "Drospirenone and estradiol: a new option for the postmenopausal woman". Climacteric. 10 Suppl 1: 3–10. doi:10.1080/13697130601114859. PMID 17364592. S2CID 9221524. Archer DF (February 2007). "Drospirenone-containing hormone therapy for postmenopausal women. Perspective on current data". J Reprod Med. 52 (2 Suppl): 159–64. PMID 17477110. Archer DF (2007). "Drospirenone, a progestin with added value for hypertensive postmenopausal women". Menopause. 14 (3 Pt 1): 352–4. doi:10.1097/gme.0b013e31804d440b. PMID 17414576. Batur P, Casey PM (February 2017). "Drospirenone Litigation: Does the Punishment Fit the Crime?". J Womens Health (Larchmt). 26 (2): 99–102. doi:10.1089/jwh.2016.6092. PMID 27854556. Bitzer J, Paoletti AM (2009). "Added benefits and user satisfaction with a low-dose oral contraceptive containing drospirenone: results of three multicentre trials". Clin Drug Investig. 29 (2): 73–8. doi:10.2165/0044011-200929020-00001. PMID 19133702. S2CID 10356578. Carranza-Lira S (2009). "Safety, efficacy and patient acceptability of drospirenone and estradiol in the treatment of menopausal vasomotor symptoms: a review". Clin Interv Aging. 4: 59–62. doi:10.2147/CIA.S4117. PMC 2685225. PMID 19503766. Christiansen C (October 2005). "Effects of drospirenone/estrogen combinations on bone metabolism". Climacteric. 8 Suppl 3: 35–41. doi:10.1080/13697130500330283. PMID 16203654. S2CID 42803561. Dickerson V (November 2002). "Quality of life issues. Potential role for an oral contraceptive containing ethinyl estradiol and drospirenone". J Reprod Med. 47 (11 Suppl): 985–93. PMID 12497673. Fenton C, Wellington K, Moen MD, Robinson DM (2007). "Drospirenone/ethinylestradiol 3mg/20microg (24/4 day regimen): a review of its use in contraception, premenstrual dysphoric disorder and moderate acne vulgaris". Drugs. 67 (12): 1749–65. doi:10.2165/00003495-200767120-00007. PMID 17683173. S2CID 46976925. Foidart JM (October 2005). "Added benefits of drospirenone for compliance". Climacteric. 8 Suppl 3: 28–34. doi:10.1080/13697130500330309. PMID 16203653. S2CID 31883491. Foidart JM, Faustmann T (December 2007). "Advances in hormone replacement therapy: weight benefits of drospirenone, a 17alpha-spirolactone-derived progestogen". Gynecol. Endocrinol. 23 (12): 692–9. doi:10.1080/09513590701582323. PMID 18075844. S2CID 12572825. Genazzani AR, Mannella P, Simoncini T (February 2007). "Drospirenone and its antialdosterone properties". Climacteric. 10 Suppl 1: 11–8. doi:10.1080/13697130601114891. PMID 17364593. S2CID 24872884. Han L, Jensen JT (October 2014). "Expert opinion on a flexible extended regimen of drospirenone/ethinyl estradiol contraceptive". Expert Opin Pharmacother. 15 (14): 2071–9. doi:10.1517/14656566.2014.949237. PMID 25186109. S2CID 25338932. Heinemann LA, Dinger J (2004). "Safety of a new oral contraceptive containing drospirenone". Drug Saf. 27 (13): 1001–18. doi:10.2165/00002018-200427130-00003. PMID 15471507. S2CID 1773936. Idota N, Kobayashi M, Miyamori D, Kakiuchi Y, Ikegaya H (March 2015). "Drospirenone detected in postmortem blood of a young woman with pulmonary thromboembolism: A case report and review of the literature". Leg Med (Tokyo). 17 (2): 109–15. doi:10.1016/j.legalmed.2014.10.001. PMID 25454533. Keam SJ, Wagstaff AJ (2003). "Ethinylestradiol/drospirenone: a review of its use as an oral contraceptive". Treat Endocrinol. 2 (1): 49–70. doi:10.2165/00024677-200302010-00005. PMID 15871554. S2CID 209144694. Krattenmacher R (July 2000). "Drospirenone: pharmacology and pharmacokinetics of a unique progestogen". Contraception. 62 (1): 29–38. doi:10.1016/S0010-7824(00)00133-5. PMID 11024226. Larivée N, Suissa S, Khosrow-Khavar F, Tagalakis V, Filion KB (September 2017). "Drospirenone-containing oral contraceptive pills and the risk of venous thromboembolism: a systematic review of observational studies". BJOG. 124 (10): 1490–1499. doi:10.1111/1471-0528.14623. PMID 28276140. Lete I, Chabbert-Buffet N, Jamin C, Lello S, Lobo P, Nappi RE, Pintiaux A (2015). "Haemostatic and metabolic impact of estradiol pills and drospirenone-containing ethinylestradiol pills vs. levonorgestrel-containing ethinylestradiol pills: A literature review". Eur J Contracept Reprod Health Care. 20 (5): 329–43. doi:10.3109/13625187.2015.1050091. PMID 26007631. S2CID 41601833. Li J, Ren J, Sun W (March 2017). "A comparative systematic review of Yasmin (drospirenone pill) versus standard treatment options for symptoms of polycystic ovary syndrome". Eur. J. Obstet. Gynecol. Reprod. Biol. 210: 13–21. doi:10.1016/j.ejogrb.2016.11.013. PMID 27923166. Lopez LM, Kaptein AA, Helmerhorst FM (February 2012). "Oral contraceptives containing drospirenone for premenstrual syndrome". Cochrane Database Syst Rev (2): CD006586. doi:10.1002/14651858.CD006586.pub4. PMID 22336820. Machado RB, Pompei Lde M, Giribela AG, Giribela CG (January 2011). "Drospirenone/ethinylestradiol: a review on efficacy and noncontraceptive benefits". Womens Health. 7 (1): 19–30. doi:10.2217/whe.10.84. PMID 21175386. Mallareddy M, Hanes V, White WB (2007). "Drospirenone, a new progestogen, for postmenopausal women with hypertension". Drugs Aging. 24 (6): 453–66. doi:10.2165/00002512-200724060-00002. PMID 17571911. S2CID 39236155. Motivala A, Pitt B (2007). "Drospirenone for oral contraception and hormone replacement therapy: are its cardiovascular risks and benefits the same as other progestogens?". Drugs. 67 (5): 647–55. doi:10.2165/00003495-200767050-00001. PMID 17385938. S2CID 22985078. Oelkers W (December 2002). "Antimineralocorticoid activity of a novel oral contraceptive containing drospirenone, a unique progestogen resembling natural progesterone". Eur J Contracept Reprod Health Care. 7 Suppl 3: 19–26, discussion 42–3. PMID 12659403. Oelkers W (December 2000). "Drospirenone--a new progestogen with antimineralocorticoid activity, resembling natural progesterone". Eur J Contracept Reprod Health Care. 5 Suppl 3: 17–24. PMID 11246598. Oelkers W (March 2004). "Drospirenone, a progestogen with antimineralocorticoid properties: a short review". Mol. Cell. Endocrinol. 217 (1–2): 255–61. doi:10.1016/j.mce.2003.10.030. PMID 15134826. S2CID 19936032. Oelkers W (February 2002). "The renin-aldosterone system and drospirenone". Gynecol. Endocrinol. 16 (1): 83–7. doi:10.1080/gye.16.1.83.87. PMID 11915587. S2CID 32410408. Oelkers WH (October 2005). "Drospirenone in combination with estrogens: for contraception and hormone replacement therapy". Climacteric. 8 Suppl 3: 19–27. doi:10.1080/13697130500330341. PMID 16203652. S2CID 42837148. Palacios S, Foidart JM, Genazzani AR (November 2006). "Advances in hormone replacement therapy with drospirenone, a unique progestogen with aldosterone receptor antagonism" (PDF). Maturitas. 55 (4): 297–307. doi:10.1016/j.maturitas.2006.07.009. hdl:2268/9932. PMID 16949774. Pérez-López FR (June 2008). "Clinical experiences with drospirenone: from reproductive to postmenopausal years". Maturitas. 60 (2): 78–91. doi:10.1016/j.maturitas.2008.03.009. PMID 18468818. Rapkin AJ, Sorger SN, Winer SA (February 2008). "Drospirenone/ethinyl estradiol". Drugs Today. 44 (2): 133–45. doi:10.1358/dot.2008.44.2.1191057. PMID 18389090. S2CID 32413831. Rapkin AJ, Winer SA (May 2007). "Drospirenone: a novel progestin". Expert Opin Pharmacother. 8 (7): 989–99. doi:10.1517/14656566.8.7.989. PMID 17472544. S2CID 6954183. Rapkin RB, Creinin MD (October 2011). "The combined oral contraceptive pill containing drospirenone and ethinyl estradiol plus levomefolate calcium". Expert Opin Pharmacother. 12 (15): 2403–10. doi:10.1517/14656566.2011.610791. PMID 21877996. S2CID 40231903. Rübig A (October 2003). "Drospirenone: a new cardiovascular-active progestin with antialdosterone and antiandrogenic properties". Climacteric. 6 Suppl 3: 49–54. PMID 15018248. Scheinfeld NS (2007). "Yaz (3 mg drospirenone/20 microg ethinyl estradiol)". Skinmed. 6 (6): 289. doi:10.1111/j.1540-9740.2007.07338.x. PMID 17975349. Sehovic N, Smith KP (May 2010). "Risk of venous thromboembolism with drospirenone in combined oral contraceptive products". Ann Pharmacother. 44 (5): 898–903. doi:10.1345/aph.1M649. PMID 20371756. S2CID 8248469. Shulman LP (June 2006). "A review of drospirenone for safety and tolerability and effects on endometrial safety and lipid parameters contrasted with medroxyprogesterone acetate, levonorgestrel, and micronized progesterone". J Womens Health (Larchmt). 15 (5): 584–90. doi:10.1089/jwh.2006.15.584. PMID 16796485. Simoncini T, Genazzani AR (February 2010). "A review of the cardiovascular and breast actions of drospirenone in preclinical studies". Climacteric. 13 (1): 22–33. doi:10.3109/13697130903437375. PMID 19938948. S2CID 4306359. Sitruk-Ware R (October 2005). "Pharmacology of different progestogens: the special case of drospirenone". Climacteric. 8 Suppl 3: 4–12. doi:10.1080/13697130500330382. PMID 16203650. S2CID 24205704. Thorneycroft IH (November 2002). "Evolution of progestins. Focus on the novel progestin drospirenone". J Reprod Med. 47 (11 Suppl): 975–80. PMID 12497671. Toni I, Neubert A, Botzenhardt S, Gratzki N, Rascher W (September 2013). "Venous thromboembolism in adolescents associated with drospirenone-containing oral contraceptives - two case reports". Klin Padiatr. 225 (5): 266–7. doi:10.1055/s-0033-1353169. PMID 23975850. White WB (February 2007). "Drospirenone with 17beta-estradiol in the postmenopausal woman with hypertension". Climacteric. 10 Suppl 1: 25–31. doi:10.1080/13697130601114933. PMID 17364595. S2CID 9451771. Whitehead M (March 2006). "Hormone replacement therapy with estradiol and drospirenone: an overview of the clinical data". J Br Menopause Soc. 12 Suppl 1: 4–7. doi:10.1258/136218006775992185. PMID 16513012. S2CID 38095916. Wu CQ, Grandi SM, Filion KB, Abenhaim HA, Joseph L, Eisenberg MJ (June 2013). "Drospirenone-containing oral contraceptive pills and the risk of venous and arterial thrombosis: a systematic review". BJOG. 120 (7): 801–10. doi:10.1111/1471-0528.12210. PMID 23530659. S2CID 206904730. Zhao X, Zhang XF, Zhao Y, Lin X, Li NY, Paudel G, Wang QY, Zhang XW, Li XL, Yu J (September 2016). "Effect of combined drospirenone with estradiol for hypertensive postmenopausal women: a systemic review and meta-analysis". Gynecol. Endocrinol. 32 (9): 685–689. doi:10.1080/09513590.2016.1183629. PMID 27176003. S2CID 9116138. "Drospirenone in HRT?". Drug Ther Bull. 47 (4): 41–4. April 2009. doi:10.1136/dtb.2009.03.0011. PMID 19357298. S2CID 1909717. External links "Drospirenone". Drug Information Portal. U.S. National Library of Medicine.
Atracurium besilate
Atracurium besilate, also known as atracurium besylate, is a medication used in addition to other medications to provide skeletal muscle relaxation during surgery or mechanical ventilation. It can also be used to help with endotracheal intubation but suxamethonium (succinylcholine) is generally preferred if this needs to be done quickly. It is given by injection into a vein. Effects are greatest at about 4 minutes and last for up to an hour.Common side effects include flushing of the skin and low blood pressure. Serious side effects may include allergic reactions; however, it has not been associated with malignant hyperthermia. Prolonged paralysis may occur in people with conditions like myasthenia gravis. It is unclear if use in pregnancy is safe for the baby. Atracurium is in the neuromuscular-blocker family of medications and is of the non-depolarizing type. It works by blocking the action of acetylcholine on skeletal muscles.Atracurium was approved for medical use in the United States in 1983. It is on the World Health Organizations List of Essential Medicines. Atracurium is available as a generic medication. Medical uses Atracurium is a medication used in addition to other medications in to provide skeletal muscle relaxation during surgery or mechanical ventilation. It can be used to help with endotracheal intubation but takes up to 2.5 minutes to result in appropriate intubating conditions. Duration of action Neuromuscular-blocking agents can be classified in accordance to their duration of pharmacological action, defined as follows: Side effects Cardiovascular The tetrahydroisoquinolinium class of neuromuscular blocking agents, in general, is associated with histamine release upon rapid administration of a bolus intravenous injection. There are some exceptions to this rule; e.g., cisatracurium (Nimbex) is one such agent that does not elicit histamine release even up to 5xED95 doses. The liberation of histamine is a dose-dependent phenomenon such that, with increasing doses administered at the same rate, there is a greater propensity for eliciting histamine release and its ensuing sequelae. Most commonly, the histamine release following administration of these agents is associated with observable cutaneous flushing (facial face and arms, commonly), hypotension and a consequent reflex tachycardia. These sequelae are very transient effects: The total duration of the cardiovascular effects is no more than one to two minutes, while the facial flush may take around 3–4 minutes to dissipate. Because these effects are so transient, there is no reason to administer adjunctive therapy to ameliorate either the cutaneous or the cardiovascular effects. Bronchospasm Bronchospasm has been reported on occasion with the use of atracurium. However, this particular undesirable effect does not appear to be observed nearly as often as that seen with rapacuronium, which led to the latters withdrawal of approval for clinical use worldwide. The issue of bronchospasm acquired prominence in the neuromuscular-blocking agents arena after the withdrawal from clinical use of rapacuronium (Raplon - a steroidal neuromuscular-blocking agent marketed by Organon) in 2001 after several serious events of bronchospasm, including five unexplained fatalities, following its administration. Bronchospasm was not an unknown phenomenon prior to rapacuronium: occasional reports of bronchospasm have been noted also with the prototypical agents, tubocurarine and succinylcholine, as well as alcuronium, pancuronium, vecuronium, and gallamine. Seizures Seizures rarely occur.Because atracurium undergoes Hofmann elimination as a primary route of chemodegradation, one of the major metabolites from this process is laudanosine, a tertiary amino alkaloid reported to be a modest CNS stimulant with epileptogenic activity and cardiovascular effects such a hypotension and bradycardia. As part of the then fierce marketing battle between the competing pharmaceutical companies (Burroughs Wellcome Co. and Organon, Inc.) with their respective products, erroneous information was quickly and subtly disseminated very shortly after the clinical introduction of atracurium that the clinical use of atracurium was likely to result in a terrible tragedy because of the significant clinical hazard by way of frank seizures induced by the laudanosine by-product - the posited hypothesis being that the laudanosine produced from the chemodegradation of parent atracurium would cross the blood–brain barrier in sufficiently high enough concentrations that lead to epileptogenic foci. Fortunately, both for the public and for atracurium, rapid initial investigations irrefutably failed to find any overt or EEG evidence for a connection between atracurium administration and epileptogenic activity. Indeed, because laudanosine is cleared primarily via renal excretion, a cat study modelling anephric patients went so far as to corroborate that EEG changes, when observed, were evident only at plasma concentrations 8 to 10 times greater than those observed in humans during infusions of atracurium. Thus, the cat study predicted that, following atracurium administration in an anephric patient, laudanosine accumulation and related CNS or cardiovascular toxicity were unlikely - a prediction that correlated very well with a study in patients with kidney failure and undergoing cadaveric renal transplantation. Furthermore, almost a decade later, work by Cardone et al.. confirmed that, in fact, it is the steroidal neuromuscular-blocking agents pancuronium and vecuronium that, when introduced directly into the CNS, were likely to cause acute excitement and seizures, owing to accumulation of cytosolic calcium caused by activation of acetylcholine receptor ion channels. Unlike the two steroidal agents, neither atracurium nor laudanosine caused such accumulation of intracellular calcium. Just over two decades later with availability of atracurium, there is little doubt that laudanosine accumulation and related toxicity will likely never be seen with the doses of atracurium that are generally used.Laudanosine is also a metabolite of cisatracurium that, because of its identical structure to atracurium, undergoes chemodegradation via Hofmann elimination in vivo. Plasma concentrations of laudanosine generated are lower when cisatracurium is used. Pharmacokinetics Atracurium is susceptible to degradation by Hofmann elimination and ester hydrolysis as components of the in vivo metabolic processes. The initial in vitro studies appeared to indicate a major role for ester hydrolysis but, with accumulation of clinical data over time, the preponderance of evidence indicated that Hofmann elimination at physiological pH is the major degradation pathway vindicating the premise for the design of atracurium to undergo an organ-independent metabolism.Hofmann elimination is a temperature- and pH-dependent process, and therefore atracuriums rate of degradation in vivo is highly influenced by body pH and temperature: An increase in body pH favors the elimination process, whereas a decrease in temperature slows down the process. Otherwise, the breakdown process is unaffected by the level of plasma esterase activity, obesity, age, or by the status of renal or hepatic function. On the other hand, excretion of the metabolite, laudanosine, and, to a small extent, atracurium itself is dependent on hepatic and renal functions that tend to be less efficient in the elderly population. The pharmaceutical presentation is a mixture of all ten possible stereoisomers. Although there are four stereocentres, which could give 16 structures, there is a plane of symmetry running through the centre of the diester bridge, and so 6 meso structures (structures that can be superimposed by having the opposite configuration then 180° rotation) are formed. This reduces the number from sixteen to ten. There are three cis-cis isomers (an enantiomeric pair and a meso structure), four cis-trans isomers (two enantiomeric pairs), and three trans-trans isomers (an enantiomeric pair and a meso structure). The proportions of cis−cis, cis−trans, and trans−trans isomers are in the ratio of 10.5 :6.2 :1. [cis-cis isomers ≈ 58% cis-trans isomers ≈ 36% trans-trans isomers ≈ 6%]. One of the three cis-cis structures is marketed as a single-isomer preparation, cisatracurium (trade name Nimbex); it has the configuration 1R, 2R, 1′R, 2′R at the four stereocentres. The beta-blocking drug Nebivolol has ten similar structures with 4 stereocentres and a plane of symmetry, but only two are presented in the pharmaceutical preparation. Intramuscular function parameters ED95: the dose of any given intramuscular-blocking agent required to produce 95% suppression of muscle twitch (e.g., the abductor pollicis) response with balanced anesthesia Clinical duration: difference in time between time of injection and time to 25% recovery from neuromuscular block Train-of-Four (TOF) response: stimulated muscle twitch response in trains of four when stimuli are applied in a burst of four as opposed to a single stimulus, equal depression in depolarizing and fading response with non-depolarizing blocker. 25%-75% recovery index: an indicator of the rate of skeletal muscle recovery - essentially, the difference in time between the time to recovery to 25% and time to recovery to 75% of baseline value T4:T1 ≥ 0.7: a 70% ratio of the fourth twitch to the first twitch in a TOF - provides a measure of the recovery of neuromuscular function T4:T1 ≥ 0.9: a 90% ratio of the fourth twitch to the first twitch in a TOF - provides a measure of the full recovery of neuromuscular function History Atracurium besilate was first made in 1974 by George H. Dewar, a pharmacist and a medicinal chemistry doctoral candidate in John B. Stenlakes medicinal chemistry research group in the Department of Pharmacy at Strathclyde University, Scotland. Dewar first named this compound "33A74" before its eventual emergence in the clinic as atracurium. Atracurium was the culmination of a rational approach to drug design to produce the first non-depolarizing non-steroidal skeletal muscle relaxant that undergoes chemodegradation in vivo. The term chemodegradation was coined by Roger D. Waigh, Ph.D., also a pharmacist and a postdoctoral researcher in Stenlakes research group. Atracurium was licensed by Strathclyde University to the Wellcome Foundation UK, which developed the drug (then known as BW 33A) and its introduction to first human trials in 1979, and then eventually to its first introduction (as a mixture of all ten stereoisomers) into clinical anesthetic practice in the UK, in 1983, under the tradename of Tracrium. The premise to the design of atracurium and several of its congeners stemmed from the knowledge that a bis-quaternary structure is essential for neuromuscular-blocking activity: ideally, therefore, a chemical entity devoid of this bis-quaternary structure via susceptibility to inactive breakdown products by enzymic-independent processes would prove to be invaluable in the clinical use of a drug with a predictable onset and duration of action. Hofmann elimination provided precisely this basis: It is a chemical process in which a suitably activated quaternary ammonium compound can be degraded by the mildly alkaline conditions present at physiological pH and temperature. In effect, Hofmann elimination is a retro-Michael addition chemical process. It is important to note here that the physiological process of Hofmann elimination differs from the non-physiological Hofmann degradation process: the latter is a chemical reaction in which a quaternary ammonium hydroxide solid salt is heated to 100 °C, or an aqueous solution of the salt is boiled. Regardless of which Hofmann process is referenced, the end-products in both situations will be the same: an alkene and a tertiary amine. The approach to utilizing Hofmann elimination as a means to promoting biodegradation had its roots in much earlier observations that the quaternary alkaloid petaline (obtained from the Lebanese plant Leontice leontopetalum) readily underwent facile Hofmann elimination to a tertiary amine called leonticine upon passage through a basic (as opposed to an acidic) ion-exchange resin. Stenlakes research group advanced this concept by systematically synthesizing numerous quaternary ammonium β-aminoesters and β-aminoketones and evaluated them for skeletal muscle relaxant activity: one of these compounds, initially labelled as 33A74, eventually led to further clinical development, and came to be known as atracurium. References External links Neuromuscular+blocking+agents at the US National Library of Medicine Medical Subject Headings (MeSH) "Atracurium besilate". Drug Information Portal. U.S. National Library of Medicine.
Tretinoin
Tretinoin, also known as all-trans retinoic acid (ATRA), is a medication used for the treatment of acne and acute promyelocytic leukemia. For acne, it is applied to the skin as a cream, gel or ointment. For leukemia, it is taken by mouth for up to three months. Topical tretinoin is also the most extensively investigated retinoid therapy for photoaging.Common side effects when used as a cream are limited to the skin and include skin redness, peeling, and sun sensitivity. When used by mouth, side effects include shortness of breath, headache, numbness, depression, skin dryness, itchiness, hair loss, vomiting, muscle pains, and vision changes. Other severe side effects include high white blood cell counts and blood clots. Use during pregnancy is contraindicated due to the risk of birth defects. It is in the retinoid family of medications.Tretinoin was patented in 1957, and approved for medical use in 1962. It is on the World Health Organizations List of Essential Medicines. Tretinoin is available as a generic medication. In 2019, it was the 244th most commonly prescribed medication in the United States, with more than 1 million prescriptions. Medical uses Skin use Tretinoin is most commonly used to treat acne, both inflammatory and noninflammatory. Multiple studies support the efficacy of topical retinoids in the treatment of acne vulgaris. It is sometimes used in conjunction with other topical acne medications to enhance their penetration. In addition to treating active acne, retinoids accelerate the resolution of acne-induced postinflammatory hyperpigmentation. It is also useful as maintenance therapy for people who have responded to their initial treatment, reducing the prolonged use of antibiotics for acne. Leukemia Tretinoin is used to induce remission in people with acute promyelocytic leukemia who have a mutation (the t(15;17) translocation 160 and/or the presence of the PML/RARα gene) and who do not respond to anthracyclines or cannot take that class of drug. It is not used for maintenance therapy.The evidence is very uncertain about the effect of tretinoin in addition to chemotherapy for patients with an acute myeloid leukemia on diarrhoea, nausea/vomiting and heart-related toxicity grades III/IV. Furthermore, tretinoin in addition to chemotherapy probably results in little to no difference in the mortality, relapse, progress, mortality during the trial and infections grade III/IV. Photoaging Photoaging is premature skin aging resulting from prolonged and repeated exposure to solar radiation. Features of photoaging include fine and coarse wrinkles, change in skin pigmentation, and loss of elasticity. In human skin, topical retinoids increase collagen production, induce epidermal hyperplasia, and decrease keratinocyte and melanocyte atypia. Topical tretinoin is the most extensively investigated retinoid therapy for photoaging. Topical tretinoin can be used for mild to severe photoaging in people of all skin types. Several weeks or months of use are typically required before improvement is appreciated. The benefits of topical tretinoin are lost upon discontinuation. Although it has only been studied for a duration of two years, it may be continued indefinitely. A long-term maintenance regimen with a lower concentration or less frequent application may be an alternative to continued use. Side effects Skin use Topical tretinoin is only for use on the skin and should not be applied to eyes or mucosal tissues. Common side effects include skin irritation, redness, swelling, and blistering. If irritation is a problem, a decrease in the frequency of application to every other or every third night can be considered, and the frequency of application can be increased as tolerance improves. The fine skin flaking that is often seen can be gently exfoliated with a washcloth. A non-comedogenic facial moisturizer can also be applied if needed. Delaying application of the retinoid for at least 20 minutes after washing and drying the face may also be helpful. Topical retinoids are not true photosensitizing drugs, but people using topical retinoids have described symptoms of increased sun sensitivity. This is thought to be due to thinning of the stratum corneum leading to a decreased barrier against ultraviolet light exposure, as well as an enhanced sensitivity due to the presence of cutaneous irritation. Leukemia use The oral form of the drug has boxed warnings concerning the risks of retinoic acid syndrome and leukocytosis.Other significant side effects include a risk of thrombosis, benign intracranial hypertension in children, high lipids (hypercholesterolemia and/or hypertriglyceridemia), and liver damage.There are many significant side effects from this drug that include malaise (66%), shivering (63%), hemorrhage (60%), infections (58%), peripheral edema (52%), pain (37%), chest discomfort (32%), edema (29%), disseminated intravascular coagulation (26%), weight increase (23%), injection site reactions (17%), anorexia (17%), weight decrease (17%), and myalgia (14%).Respiratory side effects usually signify retinoic acid syndrome, and include upper respiratory tract disorders (63%), dyspnea (60%), respiratory insufficiency (26%), pleural effusion (20%), pneumonia (14%), rales (14%), and expiratory wheezing (14%), and many others at less than 10%.Around 23% of people taking the drug have reported earache or a feeling of fullness in their ears.Gastrointestinal disorders include bleeding (34%), abdominal pain (31%), diarrhea (23%), constipation (17%), dyspepsia (14%), and swollen belly (11%) and many others at less than 10%.In the cardiovascular system, side effects include arrhythmias (23%), flushing (23%), hypotension (14%), hypertension (11%), phlebitis (11%), and cardiac failure (6%) and for 3% of patients: cardiac arrest, myocardial infarction, enlarged heart, heart murmur, ischemia, stroke, myocarditis, pericarditis, pulmonary hypertension, secondary cardiomyopathy.In the nervous system, side effects include dizziness (20%), paresthesias (17%), anxiety (17%), insomnia (14%), depression (14%), confusion (11%), and many others at less than 10% frequency.In the urinary system, side effects include chronic kidney disease (11%) and several others at less than 10% frequency. Mechanism of action For its use in cancer, its mechanism of action is unknown, but on a cellular level, laboratory tests show that tretinoin forces APL cells to differentiate and stops them from proliferating; in people there is evidence that it forces the primary cancerous promyelocytes to differentiate into their final form, allowing normal cells to take over the bone marrow. Recent study shows that ATRA inhibits and degrades active PIN1.For its use in acne, tretinoin (along with other retinoids) are vitamin A derivatives that act by binding to two nuclear receptor families within keratinocytes: the retinoic acid receptors (RAR) and the retinoid X receptors (RXR). These events contribute to the normalization of follicular keratinization and decreased cohesiveness of keratinocytes, resulting in reduced follicular occlusion and microcomedone formation. The retinoid-receptor complex competes for coactivator proteins of AP-1, a key transcription factor involved in inflammation. Retinoids also down-regulate expression of toll-like receptor (TLR)-2, which has been implicated in the inflammatory response in acne. Moreover, tretinoin and retinoids may enhance the penetration of other topical acne medications.The combination of the 10% benzoyl peroxide and light results in more than 50% degradation of tretinoin in about 2 hours and 95% in 24 hours. This lack of stability in the presence of light and oxidizing agents has led to the development of novel formulations of the drug. When microencapsulated tretinoin is exposed to benzoyl peroxide and light only 1% degradation takes place in about 4 hours and only 13% after 24 hours. Biosynthesis Tretinoin is synthesized from beta-carotene. The beta-carotene is firstly cleaved into beta-carotene 15-15-monooxygenase through site 1 double bond oxidized to epoxide. The epoxide is attacked by water to form diol in site 1. NADH, as a reduction agent, reduce the alcohol group to aldehydes. History Tretinoin was co-developed for its use in acne by James Fulton and Albert Kligman when they were at University of Pennsylvania in the 1960s. Phase I trials, the first conducted on human subjects, were performed on inmates at Holmesburg Prison during a long-running regime of non-therapeutic and unethical testing on prison inmates at Holmesburg. The University of Pennsylvania held the patent for Retin-A, which it licensed to pharmaceutical companies.Treatment of acute promyelocytic leukemia was first introduced at Ruijin Hospital in Shanghai by Wang Zhenyi in a 1988 clinical trial. Etymology The origin of the name tretinoin is uncertain, although several sources agree (one with probability, one with asserted certainty) that it probably comes from trans- + retinoic [acid] + -in, which is plausible given that tretinoin is the all-trans isomer of retinoic acid. The name isotretinoin is the same root tretinoin plus the prefix iso-. Regarding pronunciation, the following variants apply equally to both tretinoin and isotretinoin. Given that retinoic is pronounced , it is natural that is a commonly heard pronunciation. Dictionary transcriptions also include (tri-TIN-oh-in) and . Research Tretinoin has been explored as a treatment for hair loss, potentially as a way to increase the ability of minoxidil to penetrate the scalp, but the evidence is weak and contradictory.It has been used off-label to treat and reduce the appearance of stretch marks. It has also been studied in skin aging. References External links "Tretinoin". Drug Information Portal. U.S. National Library of Medicine. "Tretinoin Topical". MedlinePlus.
Valaciclovir
Valaciclovir, also spelled valacyclovir, is an antiviral medication used to treat outbreaks of herpes simplex or herpes zoster (shingles). It is also used to prevent cytomegalovirus following a kidney transplant in high risk cases. It is taken by mouth.Common side effects include headache and vomiting. Severe side effects may include kidney problems. Use in pregnancy appears to be safe. It is a prodrug, which works after being converted to aciclovir in a persons body.Valaciclovir was patented in 1987 and came into medical use in 1995. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2019, it was the 110th most commonly prescribed medication in the United States, with more than 5 million prescriptions. Medical uses Valaciclovir is used for the treatment of HSV and VZV infections, including: Oral and genital herpes simplex (treatment and prevention) Reduction of HSV transmission from people with recurrent infection to uninfected individuals Herpes zoster (shingles): the typical dosage for treatment of herpes is 1,000 mg orally three times a day for seven consecutive days. Prevention of cytomegalovirus following organ transplantation Prevention of herpesviruses in immunocompromised people (such as those undergoing cancer chemotherapy) Chickenpox in children (ages 2–18)It has shown promise as a treatment for infectious mononucleosis and is preventively administered in suspected cases of herpes B virus exposure.Bells palsy does not seem to benefit from using valaciclovir as its only treatment. Adverse effects Common adverse drug reactions (≥1% of people) associated with valaciclovir are the same as for aciclovir, its active metabolite. They include: nausea, vomiting, diarrhea and headache. Infrequent adverse effects (0.1–1% of patients) include: agitation, vertigo, confusion, dizziness, edema, arthralgia, sore throat, constipation, abdominal pain, rash, weakness and/or renal impairment. Rare adverse effects (<0.1% of patients) include: coma, seizures, neutropenia, leukopenia, tremor, ataxia, encephalopathy, psychotic symptoms, crystalluria, anorexia, fatigue, hepatitis, Stevens–Johnson syndrome, toxic epidermal necrolysis and/or anaphylaxis. Pharmacology Valaciclovir is a prodrug, an esterified version of aciclovir that has greater oral bioavailability (about 55%) than aciclovir. It is converted by esterases to the active drug, aciclovir, and the amino acid valine via hepatic first-pass metabolism. Aciclovir is selectively converted into a monophosphate form by viral thymidine kinase, which is more effective (3000 times) in phosphorylation of aciclovir than cellular thymidine kinase. Subsequently, the monophosphate form is further phosphorylated into a disphosphate by cellular guanylate kinase and then into the active triphosphate form, aciclo-GTP, by cellular kinases. Mechanism of action Aciclo-GTP, the active triphosphate metabolite of aciclovir, is a very potent inhibitor of viral DNA replication. Aciclo-GTP competitively inhibits and inactivates the viral DNA polymerase. Its monophosphate form also incorporates into the viral DNA, resulting in chain termination. It has also been shown that the viral enzymes cannot remove aciclo-GMP from the chain, which results in inhibition of further activity of DNA polymerase. Aciclo-GTP is fairly rapidly metabolized within the cell, possibly by cellular phosphatases.Aciclovir is active against most species in the herpesvirus family. In descending order of activity: Herpes simplex virus type I (HSV-1) Herpes simplex virus type II (HSV-2) Varicella zoster virus (VZV) Epstein–Barr virus (EBV) Cytomegalovirus (CMV)The drug is predominantly active against HSV and, to a lesser extent, VZV. It is only of limited efficacy against EBV and CMV. However, valaciclovir has been shown to lower or eliminate the presence of the Epstein–Barr virus in subjects afflicted with acute mononucleosis, leading to a significant decrease in the severity of symptoms. Valaciclovir and acyclovir act by inhibiting viral DNA replication, but as of 2016 there was little evidence that they are effective against Epstein–Barr virus, they are expensive, they risk causing resistance to antiviral agents, and (in 1% to 10% of cases) can cause unpleasant side effects. Acyclovir therapy does prevent viral latency, but has not proven effective at eradicating latent viruses in nerve ganglia.As of 2005, resistance to valaciclovir has not been significant. Mechanisms of resistance in HSV include deficient viral thymidine kinase and mutations to viral thymidine kinase and/or DNA polymerase that alter substrate sensitivity.It also is used for herpes B virus postexposure prophylaxis. Chemistry Details of the synthesis of valaciclovir were first published by scientists from the Wellcome Foundation. Aciclovir was esterified with a carboxybenzyl protected valine, using dicyclohexylcarbodiimide as the dehydrating agent. In the final step, the protecting group was removed by hydrogenation using a palladium on alumina catalyst. History Valaciclovir was patented in 1987 and came into medical use in 1995. It is available as a generic medication. In 2019, it was the 110th most commonly prescribed medication in the United States, with more than 5 million prescriptions. Society and culture Brand names It is marketed by GlaxoSmithKline under the brand names Valtrex and Zelitrex. Valaciclovir has been available as a generic drug in the U.S. since November 2009. References External links "Valaciclovir". Drug Information Portal. U.S. National Library of Medicine. "Valacyclovir hydrochloride". Drug Information Portal. U.S. National Library of Medicine.
Pralatrexate
Pralatrexate, sold under the brand name Folotyn, is a medication used for the treatment of relapsed or refractory peripheral T-cell lymphoma (PTCL).Pralatrexate was approved for medical use in the United States in September 2009, as the first treatment for Peripheral T-cell Lymphoma (PTCL), an often aggressive type of non-Hodgkins lymphoma. Medical uses Pralatrexate is indicated for the treatment of people with relapsed or refractory peripheral T-cell lymphoma (PTCL). Mechanism Pralatrexate is a dihydrofolate reductase inhibitor. Discovery Research on this class of drugs began in the 1950s at SRI International, where scientists were focused on developing new chemotherapies and antifolates that would be effective against tumor cells.In the late 1970s, researchers at Memorial Sloan Kettering Cancer Center discovered that cancerous cells take in natural folate through a protein identified as plasma membrane transporter (now referred to as "reduced folate carrier type 1" or "RFC-1"). Further research showed that when normal cells evolve into cancerous cells they often overproduce RFC-1 to ensure they get enough folate.A subsequent scientific collaboration was ultimately formed among SRI International, Memorial Sloan Kettering Cancer Center, and the Southern Research Institute with the intention of developing an antifolate with greater therapeutic selectivity – an agent that could be more effectively internalized into tumors (transported into the cells through RFC-1) and would be more toxic to cancer cells than normal cells.This collaboration, supported by the National Cancer Institute, led to the identification of pralatrexate in the mid-1990s. Pralatrexate was later licensed to Allos Therapeutics in 2002 for further development. Allos Therapeutics, Inc. was acquired by Spectrum Pharmaceuticals, Inc. on September 5, 2012. Allos is a wholly owned subsidiary of Spectrum. Society and culture Legal status Pralatrexate was approved for medical use in the United States in September 2009. Economics Some oncologists, patient groups, and insurance companies criticized the cost of $30,000 a month or more, which could reach a total of $126,000 during a course of treatment. References External links "Pralatrexate". Drug Information Portal. U.S. National Library of Medicine. "Pralatrexate". NCI Drug Dictionary. National Cancer Institute. "Pralatrexate". National Cancer Institute.
Nalbuphine
Nalbuphine, sold under the brand names Nubain among others, is an opioid analgesic which is used in the treatment of pain. It is given by injection into a vein, muscle, or fat.Side effects of nalbuphine include sedation, sweatiness, clamminess, nausea, vomiting, dizziness, vertigo, dry mouth, and headache. Unlike other opioids, it has little to no capacity for euphoria or respiratory depression. It also has little to no incidence of dysphoria, dissociation, hallucinations, and related side effects at typical therapeutic doses. Nalbuphine is a mixed agonist/antagonist opioid modulator. Specifically, it acts as a moderate-efficacy partial agonist or antagonist of the μ-opioid receptor (MOR) and as a high-efficacy partial agonist of the κ-opioid receptor (KOR), whereas it has relatively low affinity for the δ-opioid receptor (DOR) and sigma receptors.Nalbuphine was patented in 1963 and was introduced for medical use in the United States in 1979. It is marketed in many countries throughout the world. Medical uses Nalbuphine is indicated for the relief of moderate to severe pain. It can also be used as a supplement to balanced anesthesia, for preoperative and postoperative analgesia, and for obstetrical analgesia during labor and delivery. However, a 2014 Cochrane Systematic Review concluded that from the included studies, there was limited evidence to demonstrate that "0.1 to 0.3mg/kg nalbuphine compared to placebo might be an effective postoperative analgesic" for pain treatment in children. Further research is therefore needed to compare nalbuphine with other postoperative opioids.Although nalbuphine possesses opioid antagonist activity, there is evidence that in nondependent patients it will not antagonize an opioid analgesic administered just before, concurrently, or just after an injection. Therefore, patients receiving an opioid analgesic, general anesthetics, phenothiazines, or other tranquilizers, sedatives, hypnotics, or other CNS depressants (including alcohol) concomitantly with Nalbuphine may exhibit an additive effect. When such combined therapy is contemplated, the dose of one or both agents should be reduced. In addition to the relief of pain, the drug has been studied as a treatment for morphine induced pruritus (itching). Pruritus is a common side effect of morphine or other pure MOR agonist opioid administration. Kjellberg et al. (2001) published a review of clinical trials relating to the prevalence of morphine induced pruritus and its pharmacologic control. The authors state that nalbuphine is an effective anti-pruritic agent against morphine induced pruritus. The effect may be mediated via central nervous system mechanisms. Pan (1998) summarizes the evidence that activation at the pharmacological level of the KOR antagonizes various MOR-mediated actions in the brain. The author states that the neural mechanism for this potentially very general MOR-antagonizing function by the KOR may have broad applications in the treatment of central nervous system mediated diseases. He does not state, however, that nalbuphines pharmacological mechanism of action for pruritus is the result of this interaction between the two opioid receptors. Morphine induced pruritus syndrome may also be caused by release of histamine from mast cells in the skin (Gunion et al. (2004). Paus et al. (2006) report that MORs and KORs are located in skin nerves and keratinocytes. Levy et al. (1989) reviewed the literature on the relationship of opioid mediated histamine release from cutaneous mast cells to the etiology of hypotension, flushing and pruritus. The authors investigated the relative abilities of various opioids to induce histamine release mediated increased capillary permeability and tissue edema (“wheal response”) and cutaneous vasodilatation and local redness (“flare response”) when subjects were intradermally injected with 0.02 ml equimolar concentrations of 5 x 10-4 M. Nalbuphine did not produce either a wheal or flare response. Available forms Nalbuphine is available in two concentrations, 10 mg and 20 mg of nalbuphine hydrochloride per mL. Both strengths contain 0.94% sodium citrate hydrous, 1.26% citric acid anhydrous, 0.1% sodium metabisulfite, and 0.2% of a 9:1 mixture of methylparaben and propylparaben as preservatives; pH is adjusted, if necessary, with hydrochloric acid. The 10 mg/mL strength contains 0.1% sodium chloride. The drug is also available in a sulfite and paraben-free formulation in two concentrations, 10 mg and 20 mg of nalbuphine hydrochloride per mL. One mL of each strength contains 0.94% sodium citrate hydrous, 1.26% citric acid anhydrous; pH is adjusted, if necessary, with hydrochloric acid. The 10 mg/mL strength contains 0.2% sodium chloride. An investigational extended-release oral formulation is under development by Trevi Therapeutics. Side effects Like pure MOR agonists, the mixed agonist/antagonist opioid class of drugs can cause side effects with initial administration of the drug which lessens over time (“tolerance”). This is particularly true for the side effects of nausea, sedation and cognitive symptoms (Jovey et al. 2003). These side effects can in many instances be ameliorated or avoided at the time of drug initiation by titrating the drug from a tolerable starting dose up to the desired therapeutic dose. An important difference between nalbuphine and the pure MOR agonist opioid analgesic drugs is the “ceiling effect” on respiration (but no ceiling on the analgesic effect). Respiratory depression is a potentially fatal side effect from the use of pure MOR agonists. Nalbuphine has limited ability to depress respiratory function (Gal et al. 1982). As reported in the current Nubain Package Insert (2005), the most frequent side effect in 1066 patients treated with nalbuphine was sedation in 381 (36%). Other, less frequent reactions are: feeling sweaty/clammy 99 (9%), nausea/vomiting 68 (6%), dizziness/vertigo 58 (5%), dry mouth 44 (4%), and headache 27 (3%). Other adverse reactions which may occur (reported incidence of 1% or less) are: CNS effects: Nervousness, depression, restlessness, crying, euphoria, flushing, hostility, unusual dreams, confusion, faintness, hallucinations, dysphoria, feeling of heaviness, numbness, tingling, unreality. The incidence of psychotomimetic effects, such as unreality, depersonalization, delusions, dysphoria and hallucinations has been shown to be less than that which occurs with pentazocine. Cardiovascular: Hypertension, hypotension, bradycardia, tachycardia, pulmonary edema. Gastrointestinal: Cramps, dyspepsia, bitter taste. Respiration: Depression, dyspnea, asthma. Dermatological: Itching, burning, urticaria. Obstetric: Pseudo-sinusoidal fetal heart rhythm.Other possible, but rare side effects include speech difficulty, urinary urgency, blurred vision, flushing and warmth. A 2014 Cochrane Systematic Review by Schnabel et al., concluded that due to limited data, analysis of adverse events for children treated with nalbuphine compared to other opioids or placebo for postoperative pain, could not be definitively reported. Overdose In case of overdose or adverse reaction, the immediate intravenous administration of naloxone (Narcan) is a specific antidote. Oxygen, intravenous fluids, vasopressors and other supportive measures should be used as indicated. Pharmacology Pharmacodynamics Nalbuphine is a semisynthetic mixed agonist/antagonist opioid modulator of the phenanthrene or morphinan series. It is structurally related to the widely used opioid antagonists naloxone and naltrexone, and to the potent opioid analgesic oxymorphone. Nalbuphine binds with high affinity to the MOR and KOR, and has relatively low affinity for the DOR. It behaves as a moderate-efficacy partial agonist (or mixed agonist/antagonist) of the MOR and as a high-efficacy partial agonist of the KOR. Nalbuphine has weak or no affinity for the sigma receptor(s) (e.g., Ki > 100,000 nM).Nalbuphine is said to be more morphine-like at lower doses. However at higher doses, it produces more sedation, drunkenness, dysphoria, and dissociation. As such, its effects are dose-dependent. Such effects include sedation (21–36%), dizziness or vertigo (5%), lightheadedness (1%), anxiety (<1%), dysphoria (<1%), euphoria (<1%), confusion (<1%), hallucinations (<1%), depersonalization (1%), unusual dreams (<1%), and feelings of "unreality" (<1%).Nalbuphine is a potent analgesic. Its analgesic potency is essentially equivalent to that of morphine on a milligram basis, which is based on relative potency studies using intramuscular administration (Beaver et al. 1978). Oral administered nalbuphine is reported to be three times more potent than codeine (Okun et al. 1982). Clinical trials studied single dose experimental oral immediate release nalbuphine tablets for analgesic efficacy over a four- to six-hour time period following administration. Nalbuphine in the 15 to 60 mg range had similar analgesic effects to immediate release codeine in the 30 to 60 mg range (Kantor et al. 1984; Sunshine et al. 1983). Schmidt et al. (1985) reviewed the preclinical pharmacology of nalbuphine and reported comparative data relative to other types of opioid compounds. The authors point out that the nalbuphine moiety is approximately ten times more pharmacologically potent than the mixed opioid agonist/antagonist butorphanol on an "antagonist index" scale which quantitates the drugs ability to act both as an analgesic (via opioid KOR agonism) as well as a MOR antagonist. The opioid antagonist activity of nalbuphine is one-fourth as potent as nalorphine and 10 times that of pentazocine. Pharmacokinetics The onset of action of nalbuphine occurs within 2 to 3 minutes after intravenous administration, and in less than 15 minutes following subcutaneous or intramuscular injection. The elimination half-life of nalbuphine is approximately 5 hours on average and in clinical studies the duration of analgesic activity has been reported to range from 3 to 6 hours. Chemistry Nalbuphine is a derivative of morphine and is also known as N-cyclobutylmethyl-14-hydroxydihydronormorphine. History Nalbuphine was first synthesized in 1965 and was introduced for medical use in the United States in 1979.In the search for opioid analgesics with less abuse potential than pure MOR agonist opioids, a number of semisynthetic opioids were developed. These substances are referred to as mixed agonist–antagonists analgesics. Nalbuphine belongs to this group of substances. The mixed agonists-antagonists drug class exerts their analgesic actions by agonistic activity at the KOR. While all drugs in this class possess MOR antagonistic activity leading to less abuse potential, nalbuphine is the only approved drug in the mixed agonist–antagonist class listed in terms of its pharmacological actions and selectivities on opioid receptors as a MOR partial agonist or antagonist as well as a KOR agonist (Gustein et al. 2001). Nubain was approved for marketing in the United States in 1978 and remains as the only opioid analgesic of this type (marketed in the U.S.) not controlled under the Controlled Substances Act (CSA). When the Controlled Substances Act (CSA) was enacted in 1971, nalbuphine was placed in schedule II. Endo Laboratories, Inc. subsequently petitioned the DEA to exclude nalbuphine from all schedules of the CSA in 1973. After receiving a medical and scientific review and a scheduling recommendation from the Department of Health, Education and Welfare, forerunner to the Department of Health and Human Services, nalbuphine was removed from schedule II of the CSA in 1976. Presently, nalbuphine is not a controlled substance under the CSA. Nalbuphine HCL is currently available only as an injectable in the US and the European Union. Nubain, the Astra USA brand name for injectable nalbuphine HCL, was discontinued from being marketed in 2008 in the United States for commercial reasons (Federal Register 2008); however, other commercial suppliers now provide generic injection formulation nalbuphine for the market. Society and culture Brand names Nalbuphine is marketed primarily under the brand names Nubain, Nalpain, and Nalbuphin. It is also marketed under the brand name Nalufin in Egypt and Raltrox in Bangladesh by Opsonin Pharma Limited, under the brand name Rubuphine in India by Rusan Healthcare Pvt Ltd, under the brand name Kinz and Nalbin in Pakistan by Sami and Global Pharmaceuticals, under the brand name Analin by Medicaids in Pakistan, and under the brand name Exnal by Indus Pharma in Pakistan, among many others. Legal status Unlike many other opioids, nalbuphine has a limited potential for euphoria, and in accordance, is rarely abused. This is because whereas MOR agonists produce euphoria, MOR antagonists do not, and KOR agonists like nalbuphine moreover actually produce dysphoria. Nalbuphine was initially designated as a Schedule II controlled substance in the United States along with other opioids upon the introduction of the 1970 Controlled Substances Act. However, its manufacturer, Endo Laboratories, Inc., petitioned the Food and Drug Administration to remove it from Schedule II in 1973, and after a medical and scientific review, nalbuphine was removed completely from the Controlled Substances Act in 1976 and is not a controlled substance in the United States today. For comparison, MOR full agonists are all Schedule II in the United States, whereas the mixed KOR and MOR agonists/antagonists butorphanol and pentazocine are Schedule IV in the United States. In Canada, most opioids are classified as Schedule I, but nalbuphine and butorphanol are both listed as Schedule IV substances. See also Dinalbuphine sebacate Samidorphan Pain management in children == Notes ==
Berotralstat
Berotralstat, sold under the brand name Orladeyo, is a medication used to prevent attacks of hereditary angioedema (HAE) in people aged twelve years and older.The most common side effects include abdominal pain, vomiting, diarrhea, back pain, and heartburn.Berotralstat was approved for medical use in the United States in December 2020, and in the European Union in April 2021. History Berotralstat was approved based on evidence from one clinical trial (Trial 1 /NCT03485911) of 120 participants with hereditary angioedema. The trial was conducted at 40 sites in the United States, the European Union, and Canada. Trial investigators evaluated participants 12 years and older with hereditary angioedema for eight weeks to determine the number of attacks for each participant. The trial enrolled only participants who had at least two attacks during the eight-week period. Participants were assigned to receive one of two doses of berotralstat or placebo once every day for 24 weeks. Neither the participants nor the investigators knew which treatment was being given until after the trial was completed. All participants could use other medications for treatment of attacks. References External links "Berotralstat". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT03485911 for "Efficacy and Safety Study of BCX7353 as an Oral Treatment for the Prevention of Attacks in HAE (APeX-2)" at ClinicalTrials.gov
Factor X
Factor X, also known by the eponym Stuart–Prower factor, is an enzyme (EC 3.4.21.6) of the coagulation cascade. It is a serine endopeptidase (protease group S1, PA clan). Factor X is synthesized in the liver and requires vitamin K for its synthesis. Factor X is activated, by hydrolysis, into factor Xa by both factor IX (with its cofactor, factor VIII in a complex known as intrinsic tenase) and factor VII with its cofactor, tissue factor (a complex known as extrinsic tenase). It is therefore the first member of the final common pathway or thrombin pathway. It acts by cleaving prothrombin in two places (an arg-thr and then an arg-ile bond), which yields the active thrombin. This process is optimized when factor Xa is complexed with activated co-factor V in the prothrombinase complex. Factor Xa is inactivated by protein Z-dependent protease inhibitor (ZPI), a serine protease inhibitor (serpin). The affinity of this protein for factor Xa is increased 1000-fold by the presence of protein Z, while it does not require protein Z for inactivation of factor XI. Defects in protein Z lead to increased factor Xa activity and a propensity for thrombosis. The half life of factor X is 40–45 hours. Structure The first crystal structure of human factor Xa was deposited in May 1993. To date, 191 crystal structures of factor Xa with various inhibitors have been deposited in the protein data bank. The active site of factor Xa is divided into four subpockets as S1, S2, S3 and S4. The S1 subpocket determines the major component of selectivity and binding. The S2 sub-pocket is small, shallow and not well defined. It merges with the S4 subpocket. The S3 sub-pocket is located on the rim of the S1 pocket and is quite exposed to solvent. The S4 sub-pocket has three ligand binding domains: the "hydrophobic box", the "cationic hole" and the water site. Factor Xa inhibitors generally bind in an L-shaped conformation, where one group of the ligand occupies the anionic S1 pocket lined by residues Asp189, Ser195, and Tyr228, and another group of the ligand occupies the aromatic S4 pocket lined by residues Tyr99, Phe174, and Trp215. Typically, a fairly rigid linker group bridges these two interaction sites. Genetics The human factor X gene is located on chromosome 13 (13q34). Role in disease Inborn deficiency of factor X is very rare (1:1,000,000), and may present with epistaxis (nosebleeds), hemarthrosis (bleeding into joints) and gastrointestinal blood loss. Apart from congenital deficiency, low factor X levels may occur occasionally in a number of disease states. For example, factor X deficiency may be seen in amyloidosis, where factor X is adsorbed to the amyloid fibrils in the vasculature. Deficiency of vitamin K or antagonism by warfarin (or similar medication) leads to the production of an inactive factor X. In warfarin therapy, this is desirable to prevent thrombosis. As of late 2007, four out of five emerging anti-coagulation therapeutics targeted this enzyme.Inhibiting Factor Xa would offer an alternate method for anticoagulation. Direct Xa inhibitors are popular anticoagulants. Polymorphisms in Factor X have been associated with an increased prevalence in bacterial infections, suggesting a possible role directly regulating the immune response to bacterial pathogens. Therapeutic use Factor X is part of fresh frozen plasma and the prothrombinase complex. There are two commercially available Factor X concentrates: "Factor X P Behring" manufactured by CSL Behring, and high purity Factor X Coagadex produced by Bio Products Laboratory and approved for use in the United States by the FDA in October 2015, and in the EU in March 2016, after earlier acceptance by CHMP and COMP.Kcentra, manufactured by CSL Behring, is a concentrate containing coagulation Factors II, VII, IX and X, and antithrombotic Proteins C and S. Use in biochemistry The factor Xa protease can be used in biochemistry to cleave off protein tags that improve expression or purification of a protein of interest. Its preferred cleavage site (after the arginine in the sequence Ile-Glu/Asp-Gly-Arg, IEGR or IDGR) can easily be engineered between a tag sequence and the protein of interest. After expression and purification, the tag is then proteolytically removed by factor Xa. Factor Xa Factor Xa is the activated form of the coagulation factor X, also known as thrombokinase and known eponymously as Stuart-Prower factor. Factor X is an enzyme, a serine endopeptidase, which plays a key role at several stages of the coagulation system. Factor X is synthesized in the liver. The most commonly used anticoagulants in clinical practice, warfarin and the heparin series of anticoagulants and fondaparinux, act to inhibit the action of Factor Xa in various degrees. Traditional models of coagulation developed in the 1960s envisaged two separate cascades, the extrinsic (tissue factor (TF)) pathway and the intrinsic pathway. These pathways converge to a common point, the formation of the Factor Xa/Va complex which together with calcium and bound on a phospholipids surface, generate thrombin (Factor IIa) from prothrombin (Factor II). A new model, the cell-based model of anticoagulation appears to explain more fully the steps in coagulation. This model has three stages: 1) initiation of coagulation on TF-bearing cells, 2) amplification of the procoagulant signal by thrombin generated on the TF-bearing cell and 3) propagation of thrombin generation on the platelet surface. Factor Xa plays a key role in all three of these stages.In stage 1, Factor VII binds to the transmembrane protein TF on the surface of cells and is converted to Factor VIIa. The result is a Factor VIIa/TF complex, which catalyzes the activation of Factor X and Factor IX. Factor Xa formed on the surface of the TF-bearing cell interacts with Factor Va to form the prothrombinase complex which generates small amounts of thrombin on the surface of TF-bearing cells. In stage 2, the amplification stage, if enough thrombin has been generated, then activation of platelets and platelet-associated cofactors occurs. In stage 3, thrombin generation, Factor XIa activates free Factor IX on the surface of activated platelets. The activated Factor IXa with Factor VIIIa forms the "tenase" complex. This "tenase" complex activates more Factor X, which in turn forms new prothrombinase complexes with Factor Va. Factor Xa is the prime component of the prothrombinase complex which converts large amounts of prothrombin—the "thrombin burst". Each molecule of Factor Xa can generate 1000 molecules of thrombin. This large burst of thrombin is responsible for fibrin polymerization to form a thrombus. Factor Xa also plays a role in other biological processes that are not directly related to coagulation, like wound healing, tissue remodelling, inflammation, angiogenesis and atherosclerosis. Inhibition of the synthesis or activity of Factor X is the mechanism of action for many anticoagulants in use today. Warfarin, a synthetic derivative of coumarin, is the most widely used oral anticoagulant in the US. In some European countries, other coumarin derivatives (phenprocoumon and acenocoumarol) are used. These agents known as vitamin K antagonists (VKA), inhibit the vitamin K-dependent carboxylation of Factors II (prothrombin), VII, IX, X in the hepatocyte. This carboxylation after the translation is essential for the physiological activity.Heparin (unfractionated heparin) and its derivatives low molecular weight heparin (LMWH) bind to a plasma cofactor, antithrombin (AT) to inactivate several coagulation factors IIa, Xa, XIa and XIIa. The affinity of unfractionated heparin and the various LMWHs for Factor Xa varies considerably. The efficacy of heparin-based anticoagulants increases as selectivity for Factor Xa increases. LMWH shows increased inactivation of Factor Xa compared to unfractionated heparin, and fondaparinux, an agent based on the critical pentasacharide sequence of heparin, shows more selectivity than LMWH. This inactivation of Factor Xa by heparins is termed "indirect" since it relies on the presence of AT and not a direct interaction with Factor Xa. Recently a new series of specific, direct acting inhibitors of Factor Xa has been developed. These include the drugs rivaroxaban, apixaban, betrixaban, LY517717, darexaban (YM150), edoxaban and 813893. These agents have several theoretical advantages over current therapy. They may be given orally. They have rapid onset of action. And they may be more effective against Factor Xa in that they inhibit both free Factor Xa and Factor Xa in the prothrombinase complex. History American and British scientists described deficiency of factor X independently in 1953 and 1956, respectively. As with some other coagulation factors, the factor was initially named after these patients, a Mr Rufus Stuart (1921) and a Miss Audrey Prower (1934). At that time, those investigators could not know that the human genetic defect they had identified would be found in the previously characterized enzyme called thrombokinase. Thrombokinase was the name coined by Paul Morawitz in 1904 to describe the substance that converted prothrombin to thrombin and caused blood to clot. That name embodied an important new concept in understanding blood coagulation – that an enzyme was critically important in the activation of prothrombin. Morawitz believed that his enzyme came from cells such as platelets yet, in keeping with the state of knowledge about enzymes at that time, he had no clear idea about the chemical nature of his thrombokinase or its mechanism of action. Those uncertainties led to decades during which the terms thrombokinase and thromboplastin were both used to describe the activator of prothrombin and led to controversy about its chemical nature and origin.In 1947, J Haskell Milstone isolated a proenzyme from bovine plasma which, when activated, converted prothrombin to thrombin. Following Morawitz’s designation, he called it prothrombokinase and by 1951 had purified the active enzyme, thrombokinase. Over the next several years he showed that thrombokinase was a proteolytic enzyme that, by itself, could activate prothrombin. Its activity was greatly enhanced by addition of calcium, other serum factors, and tissue extracts, which represented the thromboplastins that promoted the conversion of prothrombin to thrombin by their interaction with thrombokinase. In 1964 Milstone summarized his work and that of others: “There are many chemical reactions which are so slow that they would not be of physiological use if they were not accelerated by enzymes. We are now confronted with a reaction, catalyzed by an enzyme, which is still too slow unless aided by accessory factors.” Interactions Factor X has been shown to interact with Tissue factor pathway inhibitor. References External links The MEROPS online database for peptidases and their inhibitors: S01.216 med/3495 at eMedicine Factor X deficiency == Further reading ==
Methoxsalen
Methoxsalen, sold under the brand name Oxsoralen among others, is a medication used to treat psoriasis, eczema, vitiligo, and some cutaneous lymphomas in conjunction with exposing the skin to ultraviolet (UVA) light from lamps or sunlight. Methoxsalen modifies the way skin cells receive the UVA radiation, allegedly clearing up the disease. Levels of individual patient PUVA exposure were originally determined using the Fitzpatrick scale. The scale was developed after patients demonstrated symptoms of phototoxicity after oral ingestion of methoxsalen followed by PUVA therapy. Chemically, methoxsalen belongs to a class of organic natural molecules known as furanocoumarins. They consist of coumarin annulated with furan. It can also be injected and used topically. Natural sources In 1947, methoxsalen was isolated (under the name "ammoidin") from the plant Ammi majus, bishops weed.In 1970, Nielsen extracted 8-methoxypsoralen from four species of the genus Heracleum in the carrot family Apiaceae, including Heracleum mantegazzianum and Heracleum sphondylium. An additional 32 species of the genus Heracleum were found to contain 5-methoxypsoralen (bergapten) or other furanocoumarins. Biosynthesis The biosynthetic pathway is a combination of the shikimate pathway, which produces umbelliferone, and the mevalonate pathway. Synthesis of umbelliferone Umbelliferone is a phenylpropanoid and as such is synthesized from L-phenylalanine, which in turn is produced via the shikimate pathway. Phenylalanine is lysated into cinnamic acid, followed by hydroxylation by cinnamate 4-hydroxylase to yield 4-coumaric acid. The 4-coumaric acid is again hydroxylated by cinnamate/coumarate 2-hydroxylase to yield 2,4-dihydroxy-cinnamic acid (umbellic acid) followed by a bond rotation of the unsaturated bond adjacent to the carboxylic acid group. Finally an intramolecular attack from the hydroxyl group of C2 to the carboxylic acid group closes the ring and forms the lactone umbelliferone. Synthesis of methoxsalen The biosynthetic route then continues with the activation of dimethylallyl pyrophosphate (DMAPP), produced via the mevalonate pathway, to form a carbo-cation via the cleavage of the diphosphates. Once activated, the enzyme umbelliferone 6-prenyltransferase catalyzes a C-alkylation between DMAPP and umbelliferone at the activated position ortho to the phenol, yielding demethylsuberosin. This is then followed by a hydroxylation catalyzed by the enzyme marmesin synthase to yield marmesin. Another hydroxylation is catalyzed by psoralen synthase to yield psoralen. A third hydroxylation by the enzyme psoralen 8-monooxygenase yields xanthotoxol which is followed by a methylation via the enzyme xanthotoxol O-methyltransferase and S-adenosyl methionine to yield methoxsalen. Risks and side effects Patients with high blood pressure or a history of liver problems are at risk for inflammation and irreparable damage to both liver and skin. The eyes must be protected from UVA radiation. Side effects include nausea, headaches, dizziness, and in rare cases insomnia. Methoxsalen has also been classified as an IARC Group 1 carcinogen (known to cause cancer) but is only cancerous when combined with light - UVA radiation. Society and culture Author John Howard Griffin (1920–1980) used the chemical to darken his skin in order to investigate racial segregation in the American South. He wrote the book Black Like Me (1961) about his experiences. References External links "Methoxsalen". Drug Information Portal. U.S. National Library of Medicine.
Paclitaxel
Paclitaxel (PTX), sold under the brand name Taxol among others, is a chemotherapy medication used to treat a number of types of cancer. This includes ovarian cancer, esophageal cancer, breast cancer, lung cancer, Kaposis sarcoma, cervical cancer, and pancreatic cancer. It is administered by intravenous injection. There is also an albumin-bound formulation.Common side effects include hair loss, bone marrow suppression, numbness, allergic reactions, muscle pains, and diarrhea. Other serious side effects include heart problems, increased risk of infection, and lung inflammation. There are concerns that use during pregnancy may cause birth defects. Paclitaxel is in the taxane family of medications. It works by interference with the normal function of microtubules during cell division.Paclitaxel was first isolated in 1971 from the Pacific yew and approved for medical use in 1993. It is on the World Health Organizations List of Essential Medicines. It has been made from precursors, and more recently through cell culture. Medical use Paclitaxel is approved in the UK for ovarian, breast, lung, bladder, prostate, melanoma, esophageal, and other types of solid tumor cancers as well as Kaposis sarcoma.It is recommended in National Institute for Health and Care Excellence (NICE) guidance of June 2001 that it should be used for non-small-cell lung cancer in patients unsuitable for curative treatment, and in first-line and second-line treatment of ovarian cancer. In September 2001, NICE recommended paclitaxel should be available for the treatment of advanced breast cancer after the failure of anthracyclic chemotherapy, but that its first-line use should be limited to clinical trials. In September 2006, NICE recommended paclitaxel should not be used in the adjuvant treatment of early node-positive breast cancer. In 2018, it is approved in the United States for the treatment of breast, pancreatic, ovarian, Kaposis sarcoma and non-small-cell lung cancers. Similar compounds Albumin-bound paclitaxel (trade name Abraxane, also called nab-paclitaxel) is an alternative formulation where paclitaxel is bound to albumin nanoparticles. Much of the clinical toxicity of paclitaxel is associated with the solvent Cremophor EL in which it is dissolved for delivery.Abraxis BioScience developed Abraxane, in which paclitaxel is bonded to albumin as an alternative delivery agent to the often toxic solvent delivery method. This was approved by the FDA in January 2005 for the treatment of breast cancer after failure of combination chemotherapy for metastatic disease or relapse within six months of adjuvant chemotherapy. It has since been approved for locally advanced or metastatic non-small cell lung cancer and metastatic adenocarcinoma of the pancreas as well.Synthetic approaches to paclitaxel production led to the development of docetaxel. Docetaxel has a similar set of clinical uses to paclitaxel, and it is marketed under the brand name Taxotere. Taxanes, including paclitaxel, 10-deacetylbaccatin III, baccatin III, paclitaxel C, and 7-epipaclitaxel, have been found in the leaves and shells of hazel. The finding of these compounds in shells, which are considered discarded material and are mass-produced by many food industries, is of interest for the future availability of paclitaxel. Restenosis Paclitaxel is used as an antiproliferative agent for the prevention of restenosis (recurrent narrowing) of coronary and peripheral stents; locally delivered to the wall of the artery, a paclitaxel coating limits the growth of neointima (scar tissue) within stents. Paclitaxel drug-eluting stents for coronary artery placement are sold under the trade name Taxus by Boston Scientific in the United States. Paclitaxel drug-eluting stents for femoropopliteal artery placement are also available. Side effects Common side effects include nausea and vomiting, loss of appetite, change in taste, thinned or brittle hair, pain in the joints of the arms or legs lasting two to three days, changes in the color of the nails, and tingling in the hands or toes. More serious side effects such as unusual bruising or bleeding, pain, redness or swelling at the injection site, hand-foot syndrome, change in normal bowel habits for more than two days, fever, chills, cough, sore throat, difficulty swallowing, dizziness, shortness of breath, severe exhaustion, skin rash, facial flushing, female infertility by ovarian damage, and chest pain can also occur. Neuropathy may also occur.Dexamethasone is given prior to paclitaxel infusion to mitigate some of the side effects.A number of these side effects are associated with the excipient used, Cremophor EL, a polyoxyethylated castor oil, and allergies to cyclosporine, teniposide, and other drugs containing polyoxyethylated castor oil may increase the risk of adverse reactions to paclitaxel. Mechanism of action Paclitaxel is one of several cytoskeletal drugs that target tubulin. Paclitaxel-treated cells have defects in mitotic spindle assembly, chromosome segregation, and cell division. Unlike other tubulin-targeting drugs, such as colchicine, that inhibit microtubule assembly, paclitaxel stabilizes the microtubule polymer and protects it from disassembly. Chromosomes are thus unable to achieve a metaphase spindle configuration. This blocks the progression of mitosis and prolonged activation of the mitotic checkpoint triggers apoptosis or reversion to the G0-phase of the cell cycle without cell division.The ability of paclitaxel to inhibit spindle function is generally attributed to its suppression of microtubule dynamics, but other studies have demonstrated that suppression of dynamics occurs at concentrations lower than those needed to block mitosis. At the higher therapeutic concentrations, paclitaxel appears to suppress microtubule detachment from centrosomes, a process normally activated during mitosis. Paclitaxel binds to the beta-tubulin subunits of microtubules. Chemistry The nomenclature for paclitaxel is structured on a tetracyclic 17-atom skeleton. There are a total of 11 stereocenters. The active stereoisomer is (−)-paclitaxel (shown here). Production Bark processing From 1967 to 1993, almost all paclitaxel produced was derived from bark of the Pacific yew, Taxus brevifolia, the harvesting of which kills the tree in the process. The processes used were descendants of the original isolation method of Monroe Wall and Mansukh Wani; by 1987, the U.S. National Cancer Institute (NCI) had contracted Hauser Chemical Research of Boulder, Colorado, to handle bark on the scale needed for phase II and III trials. While both the size of the wild population of the Pacific yew and the magnitude of the eventual demand for paclitaxel were uncertain, it was clear that an alternative, sustainable source of the natural product would be needed. Initial attempts to broaden its sourcing used needles from the tree, or material from other related Taxus species, including cultivated ones, but these attempts were challenged by the relatively low and often highly variable yields obtained. Early in the 1990s, coincident with increased sensitivity to the ecology of the forests of the Pacific Northwest, paclitaxel was successfully extracted on a clinically useful scale from these sources. Semisynthesis Concurrently, synthetic chemists in the U.S. and France had been interested in paclitaxel, beginning in the late 1970s. As noted, by 1992 extensive efforts were underway to accomplish the total synthesis of paclitaxel, efforts motivated by the desire to generate new chemical understanding rather than to achieve practical commercial production. In contrast, the French group of Pierre Potier at the Centre national de la recherche scientifique (CNRS) addressed the matter of overall process yield, showing that it was feasible to isolate relatively large quantities of the compound 10-deacetylbaccatin from the European yew, Taxus baccata, which grew on the CNRS campus and whose needles were available in large quantity. By virtue of its structure, 10-deacetylbaccatin was seen as a viable starting material for a short semisynthesis to produce paclitaxel. By 1988, Poitier and collaborators had published a semisynthetic route from needles of the European yew to paclitaxel.The view of the NCI, however, was that even this route was not practical. The group of Robert A. Holton had also pursued a practical semisynthetic production route; by late 1989, Holtons group had developed a semisynthetic route to paclitaxel with twice the yield of the Potier process. Florida State University, where Holton worked, signed a deal with Bristol-Myers Squibb (BMS) to license their semisynthesis and future patents. In 1992, Holton patented an improved process with an 80% yield, and BMS took the process in-house and started to manufacture paclitaxel in Ireland from 10-deacetylbaccatin isolated from the needles of the European yew. In early 1993, BMS announced that it would cease reliance on Pacific yew bark by the end of 1995, effectively terminating ecological controversy over its use. This announcement also made good their commitment to develop an alternative supply route, made to the NCI in their cooperative research and development agreement (CRADA) application of 1989. As of 2013, BMS was using the semisynthetic method utilizing needles from the European yew to produce paclitaxel. Another company which worked with BMS until 2012, Phyton Biotech, Inc., uses plant cell fermentation (PCF) technology. By cultivating a specific Taxus cell line in fermentation tanks, they no longer need ongoing sourcing of material from actual yew tree plantations. Paclitaxel is then captured directly from the suspension broth by a resin allowing concentration to highly enriched powder containing about 40% paclitaxel. The compound is then purified by one chromatographic step followed by crystallization. Compared to the semisynthesis method, PCF eliminates the need for many hazardous chemicals and saves a considerable amount of energy.In 1993, paclitaxel was discovered as a natural product in a newly described endophytic fungus living in the yew tree. It has since been reported in a number of other endophytic fungi, including Nodulisporium sylviforme, Alternaria taxi, Cladosporium cladosporioides MD2, Metarhizium anisopliae, Aspergillus candidus MD3, Mucor rouxianus, Chaetomella raphigera, Phyllosticta tabernaemontanae, Phomopsis, Pestalotiopsis pauciseta, Phyllosticta citricarpa, Podocarpus sp., Fusarium solani, Pestalotiopsis terminaliae, Pestalotiopsis breviseta, Botryodiplodia theobromae, Gliocladium sp., Alternaria alternata var. monosporus, Cladosporium cladosporioides, Nigrospora sp., Pestalotiopsis versicolor, and Taxomyces andreanae. However, there has been contradictory evidence for its production by endophytes, with other studies finding independent production is unlikely. Biosynthesis Taxol is a tetracyclic diterpene, and the biosynthesis of diterpenes starts with a FPP molecule being elongated by the addition of an IPP molecule in order to form geranylgeranyl diphosphate (GGPP). The biosynthesis of Taxol contains nineteen steps. These 19 steps can be considered in several steps, with the first step being the formation of the taxane skeleton, which then undergoes a series of oxygenations. Following the oxygenations, two acetylations and a benzoylation occur on the intermediate. The oxygenation of the taxane core is believed to occur on C5 and C10, C2 and C9, C13 followed by C7, and a C1 hydroxylation later on in the pathway. Later in the pathway, an oxidation at C9 forms a ketone functional group and an oxetane, forming the intermediate baccatin III. The final steps of the pathway include the formation of a C13-side chain which is attached to baccatin III. The biosynthesis of Taxol is illustrated in more detail in the figure, with steps 1-7 all occurring in the enzyme taxadiene synthase (TS on the figure). Taxols biosynthesis begins with E,E,E-GGPP losing pyrophosphate via an SN1 mechanism (step 1 in the figure). The double-bond attacks the cation via electrophilic addition, yielding a tertiary cation and creating the first ring closure (step 2). Another electrophilic attack occurs, further cyclizing the structure by creating the first 6-membered ring and creating another tertiary cation (step 3). An intramolecular proton transfer occurs, attacking the verticillyl cation (step 4) and creating a double bond, yielding a tertiary cation. An electrophilic cyclization occurs in step 5, and an intramolecular proton transfer attacks the taxenyl cation (step 6). This forms the fused ring structure intermediate known as taxadiene. Taxadiene then undergoes a series of 10 oxidations via NADPH, forming the intermediate taxadiene-5α-acetoxy-10β-ol (multiple steps later in the figure). A series of hydroxylations and esterficiations occur, forming the intermediate 10-deacetyl-baccatin III, which undergoes a further series of esterifications and a side-chain hydroxylation. This finally yields the product taxol. Total synthesis By 1992, at least thirty academic research teams globally were working to achieve a total synthesis of this natural product, with the synthesis proceeding from simple natural products and other readily available starting materials. This total synthesis effort was motivated primarily by the desire to generate new chemical understanding, rather than with an expectation of the practical commercial production of paclitaxel. The first laboratories to complete the total synthesis from much less complex starting materials were the research groups of Robert A. Holton, who had the first article to be accepted for publication, and of K. C. Nicolaou who had the first article to appear in print (by a week, on 7 February 1994). Though the Holton submission preceded the Nicolaou by a month (21 December 1993 versus 24 January 1994), the near coincidence of the publications arising from each of these massive, multiyear efforts—11–18 authors appearing on each of the February 1994 publications—has led the ending of the race to be termed a "tie" or a "photo finish", though each group has argued that their synthetic strategy and tactics were superior.As of 2006, five additional research groups had reported successful total syntheses of paclitaxel: Wender et al. in 1997, and Kuwajima et al. and Mukaiyama et al. in 1998 with further linear syntheses, and Danishefsky et al. in 1996 and Takahashi et al. in 2006 with further convergent syntheses. As of that date, all strategies had aimed to prepare a 10-deacetylbaccatin-type core containing the ABCD ring system, followed generally by last stage addition of the "tail" to the 13-hydroxyl group.While the "political climate surrounding [paclitaxel] and [the Pacific yew] in the early 1990s ... helped bolster [a] link between total synthesis and the [paclitaxel] supply problem," and though total synthesis activities were a requisite to explore the structure-activity relationships of paclitaxel via generation of analogs for testing, the total synthesis efforts were never seen "as a serious commercial route" to provide significant quantities of the natural product for medical testing or therapeutic use. History The discovery of paclitaxel began in 1962 as a result of a NCI-funded screening program. A number of years later it was isolated from the bark of the Pacific yew, Taxus brevifolia, hence its name "taxol".The discovery was made by Monroe E. Wall and Mansukh C. Wani at the Research Triangle Institute, Research Triangle Park, North Carolina, in 1971. These scientists isolated the natural product from the bark of the Pacific yew tree, determined its structure and named it "taxol", and arranged for its first biological testing. The compound was then developed commercially by BMS, who had the generic name assigned as "paclitaxel". Plant screening program In 1955, the NCI in the United States set up the Cancer Chemotherapy National Service Center (CCNSC) to act as a public screening center for anticancer activity in compounds submitted by external institutions and companies. Although the majority of compounds screened were of synthetic origin, one chemist, Jonathan Hartwell, who was employed there from 1958 onwards, had experience with natural product derived compounds, and began a plant screening operation. After some years of informal arrangements, in July 1960, the NCI commissioned the United States Department of Agriculture (USDA) botanists to collect samples from about 1,000 plant species per year. On 21 August 1962, one of those botanists, Arthur S. Barclay, collected bark from a single Pacific yew tree in a forest north of the town of Packwood, Washington, as part of a four-month trip to collect material from over 200 different species. The material was then processed by a number of specialist CCNSC subcontractors, and one of the trees samples was found to be cytotoxic in a cellular assay on 22 May 1964.Accordingly, in late 1964 or early 1965, the fractionation and isolation laboratory run by Monroe E. Wall in Research Triangle Park, North Carolina, began work on fresh Taxus samples, isolating the active ingredient in September 1966 and announcing their findings at an April 1967 American Chemical Society meeting in Miami Beach. They named the pure compound taxol in June 1967. Wall and his colleague Wani published their results, including the chemical structure, in 1971.The NCI continued to commission work to collect more Taxus bark and to isolate increasing quantities of taxol. By 1969, 28 kg (62 lb) of crude extract had been isolated from almost 1,200 kg (2,600 lb) of bark, although this ultimately yielded only 10 g (0.35 oz) of pure material, but for several years, no use was made of the compound by the NCI. In 1975, it was shown to be active in another in vitro system; two years later, a new department head reviewed the data and finally recommended taxol be moved on to the next stage in the discovery process. This required increasing quantities of purified taxol, up to 600 g (21 oz), and in 1977 a further request for 7,000 lb (3,200 kg) of bark was made. In 1978, two NCI researchers published a report showing taxol was mildly effective in leukaemic mice. In November 1978, taxol was shown to be effective in xenograft studies. Meanwhile, taxol began to be well known in the cell biology, as well as the cancer community, with a publication in early 1979 by Susan B. Horwitz, a molecular pharmacologist at Albert Einstein College of Medicine, showing taxol had a previously unknown mechanism of action involving the stabilization of microtubules. Together with formulation problems, this increased interest from researchers meant that, by 1980, the NCI envisaged needing to collect 20,000 lb (9,100 kg) of bark. Animal toxicology studies were complete by June 1982, and in November NCI applied for the IND necessary to begin clinical trials in humans. Early clinical trials, supply and the transfer to BMS Phase I clinical trials began in April 1984, and the decision to start Phase II trials was made a year later. These larger trials needed more bark and collection of a further 12,000 pounds was commissioned, which enabled some phase II trials to begin by the end of 1986. But by then it was recognized that the demand for taxol might be substantial and that more than 60,000 pounds of bark might be needed as a minimum. This unprecedentedly large amount brought ecological concerns about the impact on yew populations into focus for the first time, as local politicians and foresters expressed unease at the program.The first public report from a phase II trial in May 1988 showed promising effects in melanoma and refractory ovarian cancer. At this point, Gordon Cragg of the NCIs Natural Product Branch calculated the synthesis of enough taxol to treat all the ovarian cancer and melanoma cases in the US would require the destruction of 360,000 trees annually. For the first time, serious consideration was given to the problem of supply. Because of the practical and, in particular, the financial scale of the program needed, the NCI decided to seek association with a pharmaceutical company, and in August 1989, it published a Cooperative Research and Development Agreement (CRADA) offering its current stock and supply from current bark stocks, and proprietary access to the data so far collected, to a company willing to commit to providing the funds to collect further raw material, isolate taxol, and fund a large proportion of clinical trials. In the words of Goodman and Welsh, authors of a substantial scholarly book on taxol, "The NCI was thinking, not of collaboration, ... but of a hand-over of taxol (and its problems)".Although the offer was widely advertised, only four companies responded to the CRADA, including the American firm Bristol-Myers Squibb (BMS), which was selected as the partner in December 1989. The choice of BMS later became controversial and was the subject of Congressional hearings in 1991 and 1992. While it seems clear the NCI had little choice but to seek a commercial partner, there was also controversy about the terms of the deal, eventually leading to a report by the General Accounting Office in 2003, which concluded the NIH had failed to ensure value for money. In related CRADAs with the USDA and Department of the Interior, Bristol-Myers Squibb was given exclusive first refusal on all Federal supplies of Taxus brevifolia. This exclusive contract lead to some criticism for giving BMS a "cancer monopoly". Eighteen months after the CRADA, BMS filed a new drug application (NDA), which was given FDA approval at the very end of 1992. Although there was no patent on the compound, the provisions of the Waxman-Hatch Act gave Bristol-Myers Squibb five years exclusive marketing rights. In 1990, BMS applied to trademark the name taxol as Taxol(R). This was controversially approved in 1992. At the same time, paclitaxel replaced taxol as the generic (INN) name of the compound. Critics, including the journal Nature, argued the name taxol had been used for more than two decades and in more than 600 scientific articles and suggested the trademark should not have been awarded and the BMS should renounce its rights to it. BMS argued changing the name would cause confusion among oncologists and possibly endanger the health of patients. BMS has continued to defend its rights to the name in the courts. BMS has also been criticized for misrepresentation by Goodman and Walsh, who quote from a company report saying "It was not until 1971 that ... testing ... enabled the isolation of paclitaxel, initially described as compound 17". This quote is, strictly speaking, accurate: the objection seems to be that this misleadingly neglects to explain that it was the scientist doing the isolation who named the compound taxol and it was not referred to in any other way for more than twenty years. Annual sales peaked in 2000, reaching US$1.6 billion; paclitaxel is now available in generic form. Society and culture As of 2006, the cost to the NHS per patient in early breast cancer, assuming four cycles of treatment, was about £4,000 (approx. $6,000). Research Caffeine has been speculated to inhibit paclitaxel-induced apoptosis in colorectal cancer cells.Aside from its direct clinical use, paclitaxel is used extensively in biological and biomedical research as a microtubule stabilizer. In general, in vitro assays involving microtubules, such as motility assays, rely on paclitaxel to maintain microtubule integrity in the absence of the various nucleating factors and other stabilizing elements found in the cell. For example, it is used for in vitro tests of drugs that aim to alter the behavior of microtubule motor proteins, or for studies of mutant motor proteins. Moreover, Paclitaxel has been used in vitro to inhibit insulin fibrillation; in a molar ratio of 10:1 (insulin:paclitaxel), it hindered insulin fibrillation near 70%. Iso-thermal titration calorimetry (ITC) findings indicated a spontaneous tendency of paclitaxel to interact with insulin through hydrogen bonds and van der Waals forces. Also, the inhibitory role of paclitaxel is attributed to its impact on the colloidal stability of protein solution, as it was observed that paclitaxel inhibited lysozyme fibrillation by inducing the formation of "off-pathway" oligomeric intermediates and increasing the colloidal stability subsequently. Paclitaxel is sometimes used for in vivo studies as well; it can be fed to test organisms, such as fruit flies, or injected into individual cells, to inhibit microtubule disassembly or to increase the number of microtubules in the cell. Paclitaxel induces remyelination in a demyelinating mouse in vivo and inhibits hPAD2 in vitro though its methyl ester side chain. Angiotech Pharmaceuticals Inc. began phase II clinical trials in 1999 as a multiple sclerosis treatment but in 2002, reported that the results showed no statistical significance.In 2016 in vitro multi-drug resistant mouse tumor cells were treated with paclitaxel encased in exosomes. Doses 98% less than common dosing had the same effect. Also, dye-marked exosomes were able to mark tumor cells, potentially aiding in diagnosis. Additional images References Further reading External links "Paclitaxel". Drug Information Portal. U.S. National Library of Medicine. "Paclitaxel". National Cancer Institute. 5 October 2006. "Paclitaxel". NCI Drug Dictionary. 2 February 2011. Molecule of the Month: TAXOL by Neil Edwards, University of Bristol. A Tale of Taxol from Florida State University. Berenson, Alex (October 1, 2006). "Hope, at $4,200 a Dose". The New York Times. Retrieved 2007-03-31.
Isotretinoin
Isotretinoin, also known as 13-cis-retinoic acid and sold under the brand name Accutane among others, is a medication primarily used to treat severe acne. It is also used to prevent certain skin cancers (squamous-cell carcinoma), and in the treatment of other cancers. It is used to treat harlequin-type ichthyosis, a usually lethal skin disease, and lamellar ichthyosis. It is a retinoid, meaning it is related to vitamin A, and is found in small quantities naturally in the body. Its isomer, tretinoin, is also an acne drug. The most common adverse effects are dry lips (cheilitis), dry and fragile skin, and an increased susceptibility to sunburn. Uncommon and rare side effects include muscle aches and pains (myalgias), and headaches. Isotretinoin is known to cause birth defects due to in-utero exposure because of the molecules close resemblance to retinoic acid, a natural vitamin A derivative that controls normal embryonic development. It is also associated with psychiatric side effects, most commonly depression but also, more rarely, psychosis and unusual behaviours. Other rare side effects include hyperostosis and premature epiphyseal closure, which have been reported to be persistent. In the United States, a special procedure is required to obtain the pharmaceutical. In most other countries, a consent form is required which explains these risks. In other countries, it is prescribed like any other medicine from a dermatologist (after proper blood tests). Women taking isotretinoin must not get pregnant during and for one month after the discontinuation of isotretinoin therapy. Sexual abstinence or effective contraception is advised during this period and may be mandated by clinicians in both the US and EU. Barrier methods by themselves (e.g., condoms) are not considered adequate due to the unacceptable failure rates of approximately 3%. Women who become pregnant while taking isotretinoin therapy are generally counseled to have an abortion. Isotretinoin was patented in 1969 and approved for medical use in 1982. It sold well, but in 2009, Roche decided to discontinue manufacturing due to diminishing market share due to the availability of the many generic versions and the settling of multiple lawsuits over side effects. It continues to be manufactured as of 2019 by Sun Pharma, Viatris, Teva Pharmaceuticals, Akorn, and Dr. Reddys Laboratories. Medical uses Isotretinoin is used primarily for severe cystic acne and acne that has not responded to other treatments. Many dermatologists also support its use for treatment of lesser degrees of acne that prove resistant to other treatments, or that produce physical or psychological scarring. Isotretinoin is not indicated for treatment of prepubertal acne and is not recommended in children less than 12 years of age.It is also somewhat effective for hidradenitis suppurativa and some cases of severe rosacea. It can also be used to help treat harlequin ichthyosis, lamellar ichthyosis and is used in xeroderma pigmentosum cases to relieve keratoses. Isotretinoin has been used to treat the extremely rare condition fibrodysplasia ossificans progressiva. It is also used for the treatment of neuroblastoma, a form of nerve cancer. Isotretinoin therapy has furthermore proven effective against genital warts in experimental use, but is rarely used for this indication as there are more effective treatments. Isotretinoin may represent an efficacious and safe alternative systemic form of therapy for recalcitrant condylomata acuminata (RCA) of the cervix. In most countries this therapy is currently unapproved and only used if other therapies failed. Prescribing restrictions Isotretinoin is a teratogen; there is about a 20–35% risk for congenital defects in infants exposed to the drug in utero, and about 30–60% of children exposed to isotretinoin prenatally have been reported to show neurocognitive impairment. Because of this, there are strict controls on prescribing isotretinoin to women who may become pregnant and women who become pregnant while taking isotretinoin are strongly advised to terminate their pregnancies.In most countries, isotretinoin can only be prescribed by dermatologists or specialist physicians; some countries also allow limited prescription by general practitioners and family doctors. In the United Kingdom and Australia, isotretinoin may be prescribed only by or under the supervision of a consultant dermatologist. Because severe cystic acne has the potential to cause permanent scarring over a short period, restrictions on its more immediate availability have proved contentious. In New Zealand, isotretinoin can be prescribed by any doctor but subsidised only when prescribed by a vocationally-registered general practitioner, dermatologist or nurse practitioner.In the United States, since March 2006 the dispensing of isotretinoin is run through a website called iPLEDGE. The United States Food and Drug Administration (FDA) required the companies marketing the drug in the US, which at the time that iPLEDGE was launched were Roche, Mylan, Barr, and Ranbaxy, to put this website in place as a risk evaluation and mitigation strategy. These companies formed a group called the Isotretinoin Products Manufacturing Group, and it hired Covance to run the website. Prescribers, pharmacists, and all people to whom the drug is prescribed need to register on the site and log information into it. Women with child-bearing potential must commit to using two forms of effective contraception simultaneously for the duration of isotretinoin therapy and for a month immediately preceding and a month immediately following therapy. Additionally, they must have two negative pregnancy tests 30 days apart and have negative pregnancy tests before each prescription is written. Adverse effects Increasingly higher dosages will result in higher toxicity, resembling vitamin A toxicity. Adverse effects include: Possible permanent effects Isotretinoin may stop long bone growth in young people who are still growing. Premature epiphyseal closure can occur in people with acne receiving recommended doses of Accutane.Generally, though, premature epiphyseal closure seems to be primarily related to: high doses of isotretinoin beyond the recommended dose of 1 mg/kg/day long-duration beyond the usual course of what is required for an acne patient for treatment (usually 5–7 months) early onset of treatment (young teenage age 12–14 or younger)Isotretinoin is known to cause meibomian gland dysfunction which causes persistent keratoconjunctivitis sicca (dry eye). Problems with the meibomian and salivary glands are likely due to the non-selective apoptosis of the cells of the exocrine glands. Decreased night vision has been reported to persist in some people after discontinuation of isotretinoin therapy. Sexual Isotretinoin is also associated with sexual side effects, namely erectile dysfunction and reduced libido. In October 2017, the UK MHRA issued a Drug Safety Update to physicians in response to reports of these problems. This was in response to an EU review, published in August 2017, which states that a plausible physiological explanation of these side effects "may be a reduction in plasma testosterone". The review also stated that "the product information should be updated to include ‘sexual dysfunction including erectile dysfunction and decreased libido’ as an undesirable effect with an unknown frequency". There have also been reports of spermatogenesis disorders, such as oligospermia. 27 cases of sexual dysfunction report either negative dechallenge or positive dechallenge. Skin The most common side effects are mucocutaneous: dry lips, skin and nose. Other common mucocutaneous side effects are inflammation and chapping of the lips (cheilitis), redness of the skin (erythema), rashes, peeling, eczema (dermatitis), itching (pruritus) and nose bleeds (epistaxis). Absence of dryness of the lips is considered an indication of non-compliance with treatment (not taking the drug as advised), as it occurs in almost all people who take it.Regular use of lip balm and moisturizer is recommended throughout a course of treatment to reduce these problems. The dose may need to be decreased to reduce the severity of these side effects. The skin becomes more fragile—especially to frictional forces—and may not heal as quickly as normal. Wound healing is delayed. For this reason, elective surgery, waxing of hair, tattooing, tattoo removal, piercings, dermabrasion, exfoliation, etc., are not recommended. Treatment of acne scars is generally deferred until 12 months after completion of a course of isotretinoin. Teratogenicity Isotretinoin is a teratogen highly likely to cause birth defects if taken by women during pregnancy or even a short time before conception. A few of the more common birth defects this drug can cause are hearing and visual impairment, missing or malformed earlobes, facial dysmorphism, and abnormalities in brain function. Isotretinoin is classified as FDA Pregnancy Category X and ADEC Category X, and use is contraindicated in pregnancy. In the EU, isotretinoin (oral) is contraindicated in pregnancy and must not be taken by women able to have children unless the conditions of a pregnancy prevention programme are met.The manufacturer recommends pregnancy be ruled out two weeks prior to commencement of isotretinoin, and women should use two simultaneous forms of effective contraception at least one month prior to commencement, during, and for at least one month following isotretinoin therapy.In the US, around 2000 women became pregnant while taking the drug between 1982 and 2000, with most pregnancies ending in abortion or miscarriage. About 160 babies with birth defects were born. After the FDA put the more strict iPLEDGE program in place for the companies marketing the drug in the US, in 2011, 155 pregnancies occurred among 129,544 women of childbearing potential taking isotrentinoin (0.12%).People taking isotretinoin are not permitted to donate blood during and for at least one month after discontinuation of therapy due to its teratogenicity. Psychological effects Rare psychological side effects may include depression, worsening of pre-existing depression, aggressive tendencies, irritable mood and anxiety. Very rare effects include abnormal behaviour, psychosis, suicidal ideation, suicide attempts and suicide. In a total of 5577 adverse reactions reported to the UKs MHRA up to 31 March 2017, the plurality (1207, or 22%) concerned psychiatric effects. There were 85 reports of suicidal ideation, 56 of suicide and 43 of suicide attempts.The association between isotretinoin use and psychopathology has been controversial. Beginning in 1983, isolated case reports emerged suggesting mood change, particularly depression, occurring during or soon after isotretinoin use. A number of studies have been conducted since then of the drugs effect on depression, psychosis, suicidal thoughts and other psychological effects. Depression and suicidality Isotretinoin is the only non-psychiatric drug on the FDAs top 10 list of drugs associated with depression and is also within the top 10 for suicide attempts. A black box warning for suicide, depression and psychosis has been present on isotretinoins packaging in the United States since 2005. In March 2018, European Medicines Agency issued a warning on a possible risk of neuropsychiatric disorders (such as depression, anxiety and mood changes) following the use of oral retinoids, including isotretinoin, though the limitations of the available data did not allow them to clearly establish whether this risk was due to the use of retinoids.In 2012, a systematic review covering all articles in the literature related to isotretinoin, depression and suicide, as well as articles related to class effect, dose response, and biologic plausibility found that the literature reviewed was consistent with an association of isotretinoin administration and depression and with suicide in a subgroup of vulnerable individuals. Following this systematic review, in a 2014 review a group of Australian dermatologists and psychiatrists collaborated on a set of recommendations for safe prescribing of isotretinoin. However, whether isotretinoin use is causally associated with mental illness remains controversial.Evidence for depression being causally associated with isotretinoin use includes 41 reports of positive challenge/dechallenge/rechallenge with isotretinoin, involving administering isotretinoin, withdrawing the drug, and then re-administering it. The majority of these cases had no psychiatric history. There is also a temporal relationship between the development of depression and initiation of isotretinoin treatment, with most cases developing after 1–2 months of treatment. Further, higher doses of isotretinoin increase the risk of developing depression, with 25% of people showing depression on a dose of 3 mg/kg/day as compared with 3–4% at normal doses. Studies have uncovered several biological processes which may credibly explain the affective changes induced by isotretinoin. Psychosis Isotretinoin has also been linked to psychosis. Many of the side effects of isotretinoin mimic hypervitaminosis A, which has been associated with psychotic symptoms. The dopamine hypothesis of schizophrenia and psychosis suggests that an increase in dopaminergic stimulation or sensitivity in the limbic system causes psychotic symptoms.It has been suggested that dysregulation of retinoid receptors by retinoids such as isotretinoin may cause schizophrenia. The evidence for this is threefold: transcriptional activation of the dopamine D2 receptor – in addition to serotonin and glutamate receptors – is regulated by retinoic acid; schizophrenia and the retinoid cascade have been linked to the same gene loci; and retinoid dysfunction causes congenital anomalies identical to those observed in people with schizophrenia. Further, the expression of dopamine receptors has indeed been shown to be regulated by retinoic acid. Musculoskeletal Isotretinoin has a number of muscoloskeletal effects. Myalgia (muscular pain) and arthralgia (joint pain) are rare side effects. Retinoids, such as high dose etretinate, are well known to cause bone changes, the most common type of which is hyperostotic changes (excessive bone growth), especially in growing children and adolescents. Other problems include premature epiphyseal closure and calcification of tendons and ligaments. The bones of the spine and feet are most commonly affected. Risk factors for skeletal effects include older age, greater dosage and longer course of treatment. Most bone changes cause no symptoms and may only be noticed using X-ray imaging. Gastrointestinal Isotretinoin may cause non-specific gastrointestinal symptoms including nausea, diarrhea and abdominal pain. The drug is associated with inflammatory bowel disease (IBD)—ulcerative colitis, but not Crohns disease. There are also reports of people developing irritable bowel syndrome (IBS) and worsening of existing IBS. Eyes Isotretinoin and other retinoids are well known to affect the eyes. Dry eyes are very common during treatment and is caused by isotretinoins apoptotic effect on the meibomian glands. Some people develop contact lens intolerance as a result. In some people, these changes are long-lasting or irreversible and represent Meibomian Gland Dysfunction (MGD). Other common effects on the eyes include inflammation of the eyelid (blepharitis), red eye caused by conjunctivitis and irritation of the eye. More rare ocular side effects include blurred vision, decreased night vision (which may be permanent), colour blindness, development of corneal opacities, inflammation of the cornea (keratitis), swelling of the optic disk (papilloedema, associated with IIH), photophobia and other visual disturbances. Pharmacology Mechanism of action Isotretinoins exact mechanism of action is unknown, but several studies have shown that isotretinoin induces apoptosis (programmatic cell death) in various cells in the body. Cell death may be instigated in the meibomian glands, hypothalamic cells, hippocampus cells and—important for treatment of acne—in sebaceous gland cells. Isotretinoin has a low affinity for retinoic acid receptors (RAR) and retinoid X receptors (RXR), but may be converted intracellularly to metabolites that act as agonists of RAR and RXR nuclear receptors.One study suggests the drug amplifies production of neutrophil gelatinase-associated lipocalin (NGAL) in the skin, which has been shown to reduce sebum production by inducing apoptosis in sebaceous gland cells, while exhibiting an antimicrobial effect on Cutibacterium acnes. The drug decreases the size and sebum output of the sebaceous glands. Isotretinoin is the only available acne drug that affects all four major pathogenic processes in acne, which distinguishes it from alternative treatments (such as antibiotics) and accounts for its efficacy in severe, nodulocystic cases. The effect of isotretinoin on sebum production can be temporary, or remission of the disease can be "complete and prolonged."Isotretinoin has been speculated to down-regulate the enzyme telomerase and hTERT, inhibiting "cellular immortalization and tumorigenesis." In a 2007 study, isotretinoin was proven to inhibit the action of the metalloprotease MMP-9 (gelatinase) in sebum without any influence in the action of TIMP1 and TIMP2 (the tissue inhibitors of metalloproteases). It is already known that metalloproteases play an important role in the pathogenesis of acne. CNS activities A possible biological basis for the case reports of depression involves decreased metabolism in the orbitofrontal cortex (OFC) of the frontal lobe. It has also been found that decreased OFC metabolism was correlated with headaches. People reporting headache as a side effect often report comorbid neuropsychiatric symptoms, especially depression; a statistically significant relationship between headache and depression has been established. It is suggested that people sensitive to isotretinoin-induced CNS effects may also be susceptible to other psychiatric side effects such as depression.Studies in mice and rats have found that retinoids, including isotretinoin, bind to dopaminergic receptors in the central nervous system. Isotretinoin may affect dopaminergic neurotransmission by disrupting the structure of dopamine receptors and decreasing dopaminergic activity. The dopaminergic system is implicated in numerous psychological disorders, including depression. Isotretinoin is also thought to affect the serotonergic system – it increases expression of 5-HT1A receptors in the pre-synaptic neuron, which inhibit serotonin secretion. Isotretinoin also directly and indirectly increases the translation of the serotonin transporter protein (SERT), leading to increased reuptake and consequently reduced synaptic availability of serotonin.Inhibition of hippocampal neurogenesis may also play a role in the development of isotretinoin-induced depression. A further effect of isotretinoin on the brain involves retinoic acid function in the hypothalamus, the hormone regulatory centre of the brain and part of the hypothalamus-pituitary-adrenal axis, a key part of the bodys stress response. Other brain regions regulated by retinoic acid and potentially disrupted by isotretinoin include the frontal cortex and the striatum. Pharmacokinetics and pharmacodynamics Oral isotretinoin is best absorbed when taken with a high-fat meal, because it has a high level of lipophilicity. The efficacy of isotretinoin doubles when taken after a high-fat meal compared to when taken without food. Due to isotretinoins molecular relationship to vitamin A, it should not be taken with vitamin A supplements due to the danger of toxicity through cumulative overdosing. Accutane also negatively interacts with tetracycline, another class of acne drug, and with micro-dosed (mini-pill) progesterone preparations, norethisterone/ethinylestradiol (OrthoNovum 7/7/7), St. Johns Wort, phenytoin, and systemic corticosteroids. Isotretinoin is primarily (99.9%) bound to plasma proteins, mostly albumin. Three metabolites of isotretinoin are detectable in human plasma after oral administration: 4-oxo-isotretinoin, retinoid acid (tretinoin), and 4-oxo-retinoic acid (4-oxo-tretinoin). Isotretinoin also oxidizes, irreversibly, to 4-oxo-isotretinoin—which forms its geometric isomer 4-oxo-tretinoin. After an orally-administered, 80 mg dose of liquid suspension 14C-isotretinoin, 14C-activity in blood declines with a half-life of 90 hours. The metabolites of isotretinoin and its conjugates are then excreted in the subjects urine and faeces in relatively equal amounts. After a single, 80 mg oral dose of Isotretinoin to 74 healthy adult subjects under fed conditions, the mean ±SD elimination half-life (t1/2) of isotretinoin and 4-oxo-isotretinoin were 21.0 ± 8.2 hours and 24.0 ± 5.3 hours, respectively. After both single and multiple doses, the observed accumulation ratios of isotretinoin ranged from 0.90 to 5.43 in people with cystic acne. History The compound 13-cis retinoic acid was first studied in the 1960s at Roche Laboratories in Switzerland by Werner Bollag as a treatment for skin cancer. Experiments completed in 1971 showed that the compound was likely to be ineffective for cancer but, surprisingly, that it could be useful to treat acne. However, they also showed that the compound was likely to cause birth defects, so in light of the events around thalidomide, Roche abandoned the product. In 1979, the New England Journal of Medicine published an article demonstrating the drugs effectiveness as a treatment of cystic and conglobate acne on fourteen patients, thirteen of which experienced complete clearing of their disease. Roche resumed work on the drug. In clinical trials, subjects were carefully screened to avoid including women who were or might become pregnant. Roches New Drug Application for isotretinoin for the treatment of acne included data showing that the drug caused birth defects in rabbits. The FDA approved the application in 1982. Scientists involved in the clinical trials published articles warning of birth defects at the same time the drug was launched in the US, but nonetheless, isotretinoin was taken up quickly and widely, both among dermatologists and general practitioners. Cases of birth defects showed up in the first year, leading the FDA to begin publishing case reports and to Roche sending warning letters to doctors and placing warning stickers on drug bottles, and including stronger warnings on the label. Lawsuits against Roche started to be filed. In 1983 the FDAs advisory committee was convened and recommended stronger measures, which the FDA took and were that time unprecedented: warning blood banks not to accept blood from people taking the drug and adding a warning to the label advising women to start taking contraceptives a month before starting the drug. However, the use of the drug continued to grow, as did the number of babies born with birth defects. In 1985 the label was updated to include a boxed warning. In early 1988 the FDA called for another advisory committee, and FDA employees prepared an internal memo estimating that around 1,000 babies had been born with birth defects due to isotretinoin, that up to around 1,000 miscarriages had been caused, and that between 5,000 and 7,000 women had had abortions due to isotretinoin. The memo was leaked to the New York Times a few days before the meeting, leading to a storm of media attention. In the committee meeting, dermatologists and Roche each argued to keep the drug on the market but to increase education efforts; pediatricians and the Centers for Disease Control and Prevention (CDC) argued to withdraw the drug from the market. The committee recommended restricting physicians who could prescribe the drug and requiring a second opinion before it could be prescribed. The FDA, believing it did not have authority under the law to restrict who had the right to prescribe the drug, kept the drug on the market but took further unprecedented measures: it required Roche to make warnings yet more visible and graphic, provide doctors with informed consent forms to be used when prescribing the drug, and to conduct follow up studies to test whether the measures were reducing exposure of pregnant women to the drug. Roche implemented those measures, and offered to pay for contraception counseling and pregnancy testing for women prescribed the drug; the program was called the "Pregnancy Prevention Program". A CDC report published in 2000 showed problems with the Pregnancy Prevention Program and showed that the increase in prescriptions was from off-label use, and prompted Roche to revamp its program, renaming it the "Targeted Pregnancy Prevention Program" and adding label changes like requirements for two pregnancy tests, two kinds of contraception, and for doctors to provide pharmacists with prescriptions directly; providing additional educational materials, and providing free pregnancy tests. The FDA had another advisory meeting in late 2000 that again debated how to prevent pregnant women from being exposed to the drug; dermatologists testified about the remarkable efficacy of the drug, the psychological impact of acne, and demanded autonomy to prescribe the drug; others argued that the drug be withdrawn or much stricter measures be taken. In 2001 the FDA announced a new regulatory scheme called SMART (the System to Manage Accutane Related Teratogenicity) that required Roche to provide defined training materials to doctors, and for doctors to sign and return a letter to Roche acknowledging that they had reviewed the training materials, for Roche to then send stickers to doctors, which doctors would have to place on prescriptions they give people after they have confirmed a negative pregnancy test; prescriptions could only be written for 30 days and could not be renewed, thus requiring a new pregnancy test for each prescription.In February 2002, Roches patents for isotretinoin expired, and there are now many other companies selling cheaper generic versions of the drug. On June 29, 2009, Roche Pharmaceuticals, the original creator and distributor of isotretinoin, officially discontinued both the manufacture and distribution of their Accutane brand in the United States due to what the company described as business reasons related to low market share (below 5%), coupled with the high cost of defending personal injury lawsuits brought by some people who took the drug. Generic isotretinoin will remain available in the United States through various manufacturers. Roche USA continues to defend Accutane and claims to have treated over 13 million people since its introduction in 1982. F. Hoffmann-La Roche Ltd. apparently will continue to manufacture and distribute Roaccutane outside of the United States.Among others, actor James Marshall sued Roche over allegedly Accutane-related disease that resulted in removal of his colon. The jury, however, decided that James Marshall had a pre-existing bowel disease.Several trials over inflammatory bowel disease claims have been held in the United States thus far, with many of them resulting in multimillion-dollar judgments against the makers of isotretinoin. Society and culture Brands As of 2017 isotretinoin was marketed under many brand names worldwide: A-Cnotren, Absorica, Accuran, Accutane, Accutin, Acne Free, Acnecutan, Acnegen, Acnemin, Acneone, Acneral, Acnestar, Acnetane, Acnetin A, Acnetrait, Acnetrex, Acnogen, Acnotin, Acnotren, Acretin, Actaven, Acugen, Acutret, Acutrex, Ai Si Jie, Aisoskin, Aknal, Aknefug Iso, Aknenormin, Aknesil, Aknetrent, Amnesteem, Atlacne, Atretin, Axotret, Casius, Ciscutan, Claravis, Contracné, Curacne, Curacné, Curakne, Curatane, Cuticilin, Decutan, Dercutane, Effederm, Epuris, Eudyna, Farmacne, Flexresan, Flitr
Isotretinoin
ion, I-Ret, Inerta, Inflader, Inotrin, Isac, Isdiben, Isoacne, Isobest, Isocural, Isoderm, Isoface, IsoGalen, Isogeril, Isolve, Isoprotil, Isoriac, Isosupra, Isosupra Lidose, Isotane, Isotina, Isotinon, Isotren, Isotret, Isotretinoin, Isotretinoina, Isotretinoína, Isotretinoine, Isotretinoïne, Isotrétinoïne, Isotretinoinum, Isotrex, Isotrin, Isotroin, Izotek, Izotziaja, Lisacne, Locatret, Mayesta, Myorisan, Neotrex, Netlook, Nimegen, Noitron, Noroseptan, Novacne, Oralne, Oraret, Oratane, Piplex, Policano, Procuta, Reducar, Retacnyl, Retin A, Roaccutan, Roaccutane, Roacnetan, Roacta, Roacutan, Rocne, Rocta, Sotret, Stiefotrex, Tai Er Si, Teweisi, Tretin, Tretinac, Tretinex, Tretiva, Tufacne, Zenatane, Zerocutan, Zonatian ME, and Zoretanin.As of 2017 it was marketed as a topical combination drug with erythromycin under the brand names Isotrex Eritromicina, Isotrexin, and Munderm. Research While excessive bone growth has been raised as a possible side effect, a 2006 review found little evidence for this. See also Retinoid Etretinate Hypervitaminosis A syndrome References External links Drugs.com Isotretinoin Information DermNet treatments/isotretinoin
Pertuzumab
Pertuzumab, sold under the brand name Perjeta, is a monoclonal antibody used in combination with trastuzumab and docetaxel for the treatment of metastatic HER2-positive breast cancer; it also used in the same combination as a neoadjuvant in early HER2-positive breast cancer.Side effects in more than half the people taking it include diarrhea, hair loss, and loss of neutrophils; more than 10% experience loss of red blood cells, hypersensitivity or allergic reaction, infusion reactions, decreased appetite, insomnia, distortions in the sense of taste, inflammation of the mouth or lips, constipation, rashes, nail disease, and muscle pain. Women who are pregnant or planning on getting pregnant should not take it, it was not studied in people with certain heart conditions and should be used in caution in such people, and it should not be used with an anthracycline. It is unknown if pertuzumab interacts with doxorubicin.It is the first-in-class of a kind of drug called a "HER dimerization inhibitor" — it inhibits the dimerization of HER2 with other HER receptors, which prevents them from signalling in ways that promote cell growth and proliferation.It was discovered and developed by Genentech and was first approved in 2012. Medical uses Pertuzumab is administered as an intravenous infusion in combination with trastuzumab and docetaxel as a first line treatment for HER2-positive metastatic breast cancer. It is also used in the same combination as a neoadjuvant (given to reduce the size of a tumor, prior to surgery or radiation) for HER2-positive early breast cancer; as of 2016 this use had not been shown to increase survival.As of 2016, pertuzumab has not been studied in people with a left ventricular ejection fraction value of ≤ 50% normal, a prior history of congestive heart failure, or conditions that could impair left ventricular function like uncontrolled hypertension, recent heart attacks, or serious cardiac arrhythmia. Caution should be used combining pertuzumab with an anthracycline. There is also no safety data available for use of pertuzumab in combination with doxorubicin.Women of child-bearing age should use contraception while taking pertuzumab; it may damage the fetus in pregnant women, and it may be secreted in breast milk. Adverse effects In clinical trials of the three-agent combination therapy in metastatic breast cancer, adverse effects occurring in more than half the people taking it included diarrhea, hair loss, and loss of neutrophils; more than 10% of people experienced loss of neutrophils with fever, and loss of leukocytes. After docetaxel was dropped in some people, the most common adverse effects were diarrhea (28.1%), upper respiratory tract infection (18.3%), rash (18.3%), headache (17.0%), fatigue (13.4%), swelling of nasal passages and throat (often due to catching the common cold) (17.0%), weakness (13.4%), itchiness (13.7%), joint pain (11.4%), nausea (12.7%), pain in an extremity (13.4%), back pain (12.1%) and cough (12.1%).In clinical trials of the neoadjuvant use of the combination, more than 50% of people had hair loss and loss of neutrophils.In both uses, more than 10% of people additionally experienced: loss of red blood cells, hypersensitivity or allergic reaction, infusion reactions, decreased appetite, insomnia, distortions in the sense of taste, inflammation of the mouth or lips, constipation, rashes, nail disease, and muscle pain. Pharmacology The metabolism of pertuzumab has not been directly studied; in general antibodies are cleared principally by catabolism. The median clearance of pertuzumab was 0.235 liters/day and the median half-life was 18 days. Mechanism of action HER2 is an extracellular receptor—a receptor tyrosine kinase - that when activated, sets off signal transduction through several pathways that stimulate cell proliferation and cell growth; if overexpressed it can cause uncontrollable growth. HER2 positive breast cancer is caused by ERBB2 gene amplification that results in overexpression of HER2 in approximately 15-30% of breast cancer tumors.Like many receptors HER2 normally combines another protein in order to function (a process called dimerization); it can bind with a second HER2 receptor (acting as a homodimer) and it can heterodimerize with a different receptor of the HER family. The most potent dimer for activating signalling pathways is HER2/HER3.The epitope for pertuzumab is the domain of HER2 where it binds to HER3, and pertuzumab prevents the HER2/HER3 dimer from forming, which blocks signalling by the dimer. Trastuzumab is another monoclonal antibody against HER2; its epitope is the domain where HER2 binds to another HER2 protein. The two mAbs together prevent HER2 from functioning. Chemistry and manufacturing Pertuzumab is an immunoglobulin G1 with a variable region against the human HER2 protein, a human-mouse monoclonal 2C4 heavy chain, disulfide bound with a human-mouse monoclonal 2C4 κ-chain.It is manufactured recombinantly in CHO cells. History The monoclonal antibody 2C4 appears to have first been published in 1990 by scientists from Genentech, the same year that F. Hoffmann-La Roche AG acquired a majority stake in Genentech.By 2003, Genentech understood that 2C4 prevented HER2 dimerizing with other HER receptors and had begun Phase I trials, aiming for a broad range of cancers, not just ones overexpressing HER2. It was the first known HER dimerization inhibitor.In 2005, Genentech presented poor results of Phase II trials of pertuzumab as a single agent in prostate, breast, and ovarian cancers, and said that it intended to continue developing it in combination with other drugs for ovarian cancer.In 2007, Genentech dropped the trade name Omnitarg.In March 2009, Roche acquired Genentech.In 2012, the results were published of the CLEOPATRA trial, a randomized placebo-controlled Phase III trial of pertuzumab in combination with trastuzumab and docetaxel in HER2-positive metastatic breast cancer. Pertuzumab received US FDA approval for the treatment of HER2-positive metastatic breast cancer later that year. Results of a Phase II trial in the neoadjuvant setting, NeoSphere, published in 2012, and results of a Phase II cardiac safety study in the same population, Tryphaena, published in 2013. The FDA approved the neoadjuvant indication in 2013. Pertuzumab was approved for medical use in the European Union in 2013. Society and culture Economics As of 2016, in the US each cycle of the three-drug combination given every three weeks costs around US$8,500, not including ancillary care costs.In the UK, a NICE evaluation in 2015, made a preliminary finding that the drug combination was not cost effective, and NICE rejected the drug in the neoadjuvant setting in May 2016, primarily because it was unknown if the drug combination provided a survival benefit. This decision was subsequently reversed six months later and pertuzumab became the first new breast cancer drug to be approved by NICE for routine NHS funding in almost a decade after Roche pledged to provide the drug to the NHS at an undisclosed discount for patients in the neoadjuvant setting and to share the long–term financial risks. References Further reading Dean L (2015). "Pertuzumab Therapy and ERBB2 (HER2) Genotype". In Pratt VM, McLeod HL, Rubinstein WS, et al. (eds.). Medical Genetics Summaries. National Center for Biotechnology Information (NCBI). PMID 28520364. Bookshelf ID: NBK315949. External links "Pertuzumab". Drug Information Portal. U.S. National Library of Medicine.
Misoprostol
Misoprostol is a synthetic prostaglandin medication used to prevent and treat stomach and duodenal ulcers, induce labor, cause an abortion, and treat postpartum bleeding due to poor contraction of the uterus. Misoprostol is taken by mouth when used to prevent gastric ulcers in persons taking NSAIDs. For abortions it is used by itself and with mifepristone or methotrexate. By itself, effectiveness for abortion is between 66% and 90%. For labor induction or abortion, it is taken by mouth, dissolved in the mouth, or placed in the vagina. For postpartum bleeding it may also be used rectally.Common side effects include diarrhea and abdominal pain. It is pregnancy category X meaning that it is known to result in negative outcomes for the fetus if taken during pregnancy. In rare cases, uterine rupture may occur. It is a prostaglandin analogue—specifically, a synthetic prostaglandin E1 (PGE1).Misoprostol was developed in 1973. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. Medical uses Ulcer prevention Misoprostol is used for the prevention of NSAID-induced gastric ulcers. It acts upon gastric parietal cells, inhibiting the secretion of gastric acid by G-protein coupled receptor-mediated inhibition of adenylate cyclase, which leads to decreased intracellular cyclic AMP levels and decreased proton pump activity at the apical surface of the parietal cell. Because other classes of drugs, especially H2-receptor antagonists and proton pump inhibitors, are more effective for the treatment of acute peptic ulcers, misoprostol is only indicated for use by people who are both taking NSAIDs and are at high risk for NSAID-induced ulcers, including the elderly and people with ulcer complications. Misoprostol is sometimes coprescribed with NSAIDs to prevent their common adverse effect of gastric ulceration (e.g. with diclofenac in Arthrotec).However, even in the treatment of NSAID-induced ulcers, omeprazole proved to be at least as effective as misoprostol, but was significantly better tolerated, so misoprostol should not be considered a first-line treatment. Misoprostol-induced diarrhea and the need for multiple daily doses (typically four) are the main issues impairing compliance with therapy. Labor induction Misoprostol is commonly used for labor induction. It causes uterine contractions and the ripening (effacement or thinning) of the cervix. It can be less expensive than the other commonly used ripening agent, dinoprostone.Oxytocin has long been used as the standard agent for labor induction, but does not work well when the cervix is not yet ripe. Misoprostol also may be used in conjunction with oxytocin.Between 2002 and 2012, a misoprostol vaginal insert was studied, and was approved in the EU. It was not approved for use in the United States, and the US FDA still considers cervical ripening and labor induction to be outside of the approved uses for misoprostol, because no company has sent the FDA scientific proof that misoprostol is safe and effective for these uses. Myomectomy When administered prior to myomectomy in women with uterine fibroids, misoprostol reduces operative blood loss and requirement of blood transfusion. Abortion Misoprostol is used either alone or in conjunction with another medication (mifepristone or methotrexate) for medical abortions as an alternative to surgical abortion. Medical abortion has the advantage of being less invasive, and more autonomous, self-directed, and discreet. It is preferred by some women because it feels more "natural," as the drugs induce a miscarriage. It is also more easily accessible in places where abortion is illegal. The World Health Organization provides clear guidelines on the use, benefits and risks of misoprostol for abortions.Misoprostol is most effective when it is used in combination with methotrexate or mifepristone (RU-486). Mifepristone inhibits the signals of pregnancy hormones, eventually causing the uterine lining to degrade, similar to a period, which cause the embryo to detach from the uterus walls. Misoprostol then dilates the cervix and induces muscle contractions which clear the uterus. Misoprostol alone is less effective (typically 88% up to eight-weeks gestation). It is not inherently unsafe if medically supervised, but 1% of women will have heavy bleeding requiring medical attention, some women may have ectopic pregnancy, and the 12% of pregnancies that continue after misoprostol failure are more likely to have birth defects and are usually followed up with a more effective method of abortion.Most large studies recommend a protocol for the use of misoprostol in combination with mifepristone. Together they are effective in around 95% for early pregnancies. Misoprostol alone may be more effective in earlier gestation. WHO guidelines recommend for pregnancies up to 12 weeks to use 12 tablets of 200 mcg (micrograms). The woman should put 4 tablets of misoprostol under the tongue or far up the vagina and let them dissolve for 30 minutes. The woman should wait 3 hours and repeat with 4 pills under the tongue or in the vagina for 30 minutes. She should wait 3 hours and repeat once more. It works in 90% after first attempt and, in case of failure, the attempt may be repeated after a minimum of 3 days.Misoprostol can also be used to dilate the cervix in preparation for a surgical abortion, particularly in the second trimester (either alone or in combination with laminaria stents). Vaginal misoprostol can also be used to facilitate intrauterine device insertion after previous insertion failure.Misoprostol by mouth is the least effective treatment for producing complete abortion in a period of 24 hours due to the livers first-pass effect which reduces the bioavailability of the misoprostol. Vaginal and sublingual routes result in greater efficacy and extended duration of action because these routes of administration allow the drug to be directly absorbed into circulation by bypassing the liver first-pass effect.Hematocrit or Hb tests and Rh testing are recommended before use for abortion confirmation of pregnancy. Following use, it is recommended that people attend a follow-up visit 2 weeks after treatment. If used for treatment of complete abortion, a pregnancy test, physical examination of the uterus, and ultrasound should be performed to ensure success of treatment. Surgical management is possible in the case of failed treatment. Early pregnancy loss Misoprostol may be used to complete a miscarriage or missed abortion when the body does not expel the embryo or fetus on its own. Compared to no medication or placebo, it could decrease the time to complete expulsion. Use of a single dose of misoprostol vaginally or buccally is preferred, with additional doses as needed. It also can be used in combination with mifepristone, with a similar regimen to medical abortion.Misoprostol is regularly used in some Canadian hospitals for labour induction for fetal deaths early in pregnancy, and for termination of pregnancy for fetal anomalies. A low dose is used initially, then doubled for the remaining doses until delivery. In the case of a previous Caesarian section, however, lower doses are used. Postpartum bleeding Misoprostol is also used to prevent and treat post-partum bleeding. Orally administered misoprostol was marginally less effective than oxytocin. The use of rectally administered misoprostol is optimal in cases of bleeding; it was shown to be associated with lower rates of side effects compared to other routes. Rectally administered misoprostol was reported in a variety of case reports and randomised controlled trials. However, it is inexpensive and thermostable (thus does not require refrigeration like oxytocin), making it a cost-effective and valuable drug to use in the developing world. A randomised control trial of misoprostol use found a 38% reduction in maternal deaths due to post partum haemorrhage in resource-poor communities. Misoprostol is recommended due to its cost, effectiveness, stability, and low rate of side effects. Oxytocin must also be given by injection, while misprostol can be given orally or rectally for this use, making it much more useful in areas where nurses and physicians are less available. Insertion of intrauterine contraceptive device In women with prior caesarean section or prior failure of insertion of an intrauterine contraceptive device, pre-procedure administration of misoprostol reduces the rate of failure of insertion of intrauterine contraceptive device. However, due to a higher rate of adverse effects, routine use of misoprostol for this purpose in other women is not supported by the data. Other For cervical ripening in advance of endometrial biopsy to reduce the need for use of a tenaculum or cervical dilator.There is limited evidence supporting the use of misoprostol for the treatment of trigeminal neuralgia in patients with multiple sclerosis. Adverse effects The most commonly reported adverse effect of taking misoprostol by mouth for the prevention of stomach ulcers is diarrhea. In clinical trials, an average 13% of people reported diarrhea, which was dose-related and usually developed early in the course of therapy (after 13 days) and was usually self-limiting (often resolving within 8 days), but sometimes (in 2% of people) required discontinuation of misoprostol.The next most commonly reported adverse effects of taking misoprostol by mouth for the prevention of gastric ulcers are: abdominal pain, nausea, flatulence, headache, dyspepsia, vomiting, and constipation, but none of these adverse effects occurred more often than when taking placebos. In practice, fever is almost universal when multiple doses are given every 4 to 6 hours.There are increased side effects with sublingual or oral misoprostol, compared to a low dose (400 ug) vaginal misoprostol. However, low dose vaginal misoprostol was linked with low complete abortion rate. The study concluded that sublingually administered misoprostol dosed at 600 ug or 400 ug had greater instances of fever and diarrhea due to its quicker onset of action, higher peak concentration and bioavailability in comparison to vaginal or oral misoprostol.For the indication of medical abortion, bleeding and cramping is commonly experienced after administration of misoprostol. Bleeding and cramping is likely to be greater than that experienced with menses, however, emergency care is advised if bleeding is excessive.Misoprostol should not be taken by pregnant women with wanted pregnancies to reduce the risk of NSAID-induced gastric ulcers because it increases uterine tone and contractions in pregnancy, which may cause partial or complete abortions, and because its use in pregnancy has been associated with birth defects.All cervical ripening and induction agents can cause uterine hyperstimulation, which can negatively affect the blood supply to the fetus and increases the risk of complications such as uterine rupture. Concern has been raised that uterine hyperstimulation that occurs during a misoprostol-induced labor is more difficult to treat than hyperstimulation during labors induced by other drugs. Because the complications are rare, it is difficult to determine if misoprostol causes a higher risk than do other cervical ripening agents. One estimate is that it would require around 61,000 people enrolled in randomized controlled trials to detect a difference in serious fetal complications and about 155,000 people to detect a difference in serious maternal complications. Contraindications It is recommended that medical treatment for missed abortion with misoprostol should only be considered in people without the following contraindications: suspected ectopic pregnancy, use of non-steroidal drugs, signs of pelvic infections or sepsis, unstable hemodynamics, known allergy to misoprostol, previous caesarean section, mitral stenosis, hypertension, glaucoma, bronchial asthma, and remote areas without a hospital nearby. Pharmacology Mechanism of action Misoprostol, a prostaglandin analogue, binds to myometrial cells to cause strong myometrial contractions leading to expulsion of tissue. This agent also causes cervical ripening with softening and dilation of the cervix. Misoprostol binds to and stimulates prostaglandin EP2 receptors, prostaglandin EP3 receptor and prostaglandin EP4 receptor but not Prostaglandin EP1 receptor and therefore is expected to have a more restricted range of physiological and potentially toxic actions than prostaglandin E2 or other analogs which activate all four prostaglandin receptors. Society and culture A letter from Searle, inventor of the drug, generated some controversy over the use of misoprostol in labor inductions. The American College of Obstetricians and Gynecologists holds that substantial evidence supports the use of misoprostol for induction of labor, a position it reaffirmed in 2000 in response to the Searle letter. It is on the World Health Organizations List of Essential Medicines.The largest medical malpractice award of nearly $70 million was awarded due to the use of misoprostol to induce labor in a California hospital.A vaginal form of the medication is sold in the EU under the names Misodel and Mysodelle for use in labor induction. Black market Misoprostol is used for self-induced abortions in Brazil, where black market prices exceed US$100 per dose. Illegal medically unsupervised misoprostol abortions in Brazil are associated with a lower complication rate than other forms of illegal self-induced abortion, but are still associated with a higher complication rate than legal, medically supervised surgical and medical abortions. Failed misoprostol abortions are associated with birth defects in some cases. Low-income and immigrant populations in New York City have also been observed to use self-administered misoprostol to induce abortions, as this method is much cheaper than a surgical abortion (about $2 per dose). The drug is readily available in Mexico. Use of misoprostol has also increased in Texas in response to increased regulation of abortion providers. References External links "Misoprostol". Drug Information Portal. U.S. National Library of Medicine. The Mechanism of Action and Pharmacology of Mifepristone, Misoprostol, and Methotrexate
Esterified estrogens/methyltestosterone
Esterified estrogens/methyltestosterone (EEs/MT), sold under brand names such as Covaryx, Eemt, Essian, Estratest, Menogen, and Syntest, is a hormonal preparation that combines esterified estrogens (EEs) with methyltestosterone (MT) in one tablet and is used in menopausal hormone therapy. Medical uses EEs/MT is used to treat menopausal women who suffer from hot flashes, but do not get relief from estrogen-only therapy. Available forms EEs/MT is sold in tablet form, with either 1.25 mg EEs/2.5 mg MT or 0.625 mg EEs/1.25 mg MT available. Pharmacology The product is a combination of esterified estrogens, an estrogen, and low-dose methyltestosterone, an androgen/anabolic steroid, in a single tablet. History EEs/MT was first marketed in the United States in 1965 by Reid-Provident Laboratories, which as 100% of Reid-Rowell, Inc. stock was acquired by the Belgian pharmaceutical company Solvay in 1986. There has been some controversy surrounding the drug in recent years as to its status with the U.S. Food and Drug Administration. Solvay sponsored a clinical trial of EEs/MT in the United States to determine whether the product is superior to treatment with esterified estrogens tablets. EEs/MT was supplied by Solvay. In March 2009 Solvay announced that, based on a variety of business factors, it would discontinue supplying Estratest and Estratest HS tablets, and would stop accepting orders for the product on March 31, 2009. See also Conjugated estrogens/methyltestosterone List of combined sex-hormonal preparations References External links The products web site
Levamlodipine
Levamlodipine (INN), also known as levoamlodipine or S-amlodipine is a pharmacologically active enantiomer of amlodipine. Amlodipine belongs to the dihydropyridine group of calcium channel blocker used as an antihypertensive and antianginal agent. Levamlodipine is currently marketed in Russia under the brand name EsCordi Cor (Actavis Pharma), in Brazil under the brand name Novanlo (Biolab Sanus) and in India under the trade names Eslo (Zuventus Healthcare Ltd.), Asomex (Emcure Pharmaceutical Ltd.), and Espin (Intas Pharmaceuticals Ltd.). In December 2019 Levamlodipine received US FDA approval under the name "Conjupri". Mechanism of action Amlodipine blocks the transmembrane influx of calcium into the vascular and cardiac smooth muscles resulting in vasodilation and hence a fall in blood pressure. Levamlodipine is an allosteric modulator and acts on the L-type of calcium channels. Receptor binding studies have shown that out of the two forms only the (S)-enantiomer of amlodipine binds to and blocks L-type calcium channels whereas the (R)-enantiomer has no activity on these channels.The precise mechanisms by which levamlodipine relieves angina have not been fully explored, but are thought to include the following: Decreases peripheral resistance by arteriolar vasodilatation leading to the reduction in oxygen requirement and energy consumption of cardiac smooth muscles. Decreases coronary vascular resistance and can lead to an increase in coronary blood flow. Pharmacokinetics and metabolism Administration of levamlodipine (2.5 mg) as a single dose gives maximum plasma concentration (Cmax) of 8.3 to 9.3 ng/mL in 2 to 3 hrs (Tmax). It is extensively (about 90%) converted to inactive metabolites via hepatic metabolism with 10% of the parent compound and 60% of the metabolites excreted in the urine. Levamlodipine shows approximately 93% plasma protein binding in hypertensive patients. The mean AUC0–t value (t = 48 hrs) of levamlodipine tablets (2.5 mg) is 95±14 ng·hr/mL. The plasma elimination half-life of levamlodipine has been found to be 31±13 hrs. Clinical experience Various clinical studies have shown that levamlodipine has more selectivity and better efficacy than (R)-amlodipine. In pooled data, from three comparative studies conducted in 200 patients with mild to moderate hypertension, 2.5 mg of levamlodipine was found to be equivalent in its blood pressure lowering efficacy to 5 mg of amlodipine. The average reduction in systolic BP was 19±3 vs 19±4, 20±2 vs 19±3 and 20±2 vs 19±3 mm of Hg recorded in standing, supine and sitting position respectively for levamlodipine compared to racemic amlodipine. The studies also reported a significant reduction in total cholesterol and triglyceride levels with levamlodipine, which was not seen with amlodipine.Efficacy and safety of levamlodipine (2.5 mg, once daily) has been evaluated in the patients with isolated systolic hypertension (ISH). Levamlodipine effectively reduced the systolic BP (mean reduction 22±14 mm of Hg) in all grades of ISH. After 28 days of the treatment, overall responder rate was 73%. It significantly reduced the systolic and diastolic BP within 4 weeks with a responder rate of 96.5%.Elderly hypertensives with diabetes mellitus exhibits higher response to levamlodipine therapy than non-diabetic patients. Levamlodipine is an effective switch-over option for the elderly patients who experience oedema and other adverse events with racemic amlodipine. Safety and tolerability The use of racemic amlodipine is commonly associated with adverse events like peripheral edema and other side effects like headache, dizziness, flushing and abdominal pain. Controlled clinical trials showed that levamlodipine is rarely associated with these side effects. No controlled clinical study of levamlodipine has been performed in patients with hepatic impairment and renal impairment. Clinical studies in patients with normal liver function have shown that there is no elevation in the hepatic enzymes with the use of levamlodipine. However, caution should be taken while administering levamlodipine to such patients. In a postmarketing surveillance study, levamlodipine (2.5/5 mg) was found to be well tolerated (n = 1859) in patients with hypertension. Out of 314 patients, who reported peripheral edema with conventional amlodipine were switched over to levamlodipine and edema was resolved in 310 patients (98.72%) at the end of 4 weeks. Only in 4 patients was edema sustained. Only 30 patients (out of 1859) reported side effects. These side effects included vertigo, tachycardia, cough, headache, fever, mild difficulty in breathing and edema. Adverse events were mild in nature and no serious adverse events were reported. == References ==
Flavoxate
Flavoxate is an anticholinergic with antimuscarinic effects. Its muscle relaxant properties may be due to a direct action on the smooth muscle rather than by antagonizing muscarinic receptors. Clinical uses Flavoxate is used to treat urinary bladder spasms. It is available under the trade name Urispas (Paladin)(india), Genurin (by Recordati, Italy) in Italy and KSA, Uritac by El Saad company in Syria, under the name Bladderon by Nippon Shinyaku of Japan, or Bladuril in Chile, Utispas ( Apex Pharma) in Nepal. Flavoxate is indicated for symptomatic relief of interstitial cystitis, dysuria, urgency, nocturia, suprapubic pain, frequency and incontinence as may occur in cystitis, prostatitis, urethritis, urethrocystitis/urethrotrigonitis. Side effects Flavoxate is generally well tolerated, but can potentially cause vomiting, upset stomach, dry mouth or throat, blurred vision, eye pain, and increased sensitivity of the eyes to light. Contraindications Flavoxate is contraindicated in patients who have any of the following obstructive conditions: pyloric or duodenal obstruction, obstructive intestinal lesions or ileus, achalasia, gastrointestinal hemorrhage and obstructive uropathies of the lower urinary tract. References == Further reading ==
Lanadelumab
Lanadelumab (INN; trade name Takhzyro) is a human monoclonal antibody (class IgG1 kappa) that targets plasma kallikrein (pKal) in order to promote prevention of angioedema in patients with hereditary angioedema. Lanadelumab, was approved in the United States as the first monoclonal antibody indicated for prophylactic treatment to prevent hereditary angioedema (HAE) attacks. Takhzyro is the first treatment for hereditary angioedema (HEA) prevention made by using cells within a lab, not human plasma. The US Food and Drug Administration approved the use of lanadelumab on 23 August 2018 for patients that are 12 years and older and have either type I or type II hereditary angioedema (HEA). Administration of the medication is done through 1 subcutaneous injection at a dose of 300 milligrams every 2 weeks (every 4-week dosing can be considered in specific patients).In phase 1 clinical trials Lanadelumab was well tolerated and was reported to reduce cleavage of kininogen in the plasma of patients with hereditary angioedema and decrease the number of patients experiencing attacks of angioedema. Lanadelumabs approval in the United States was spearheaded by the data presented in the phase 1b, multicenter, double blind, placebo controlled, multi-ascending-dose trial. Through this trial, Lanadelumab was given Priority Review, Breakthrough Therapy, Orphan Drug designation by the FDA. The phase 3 HELP study evaluated efficacy and safety of lanadelumab. This drug was produced by Dyax Corp and currently under development by Shire.Common side effects include pain associated with injection site reactions, injection site bruising, upper respiratory infection, headache, rash, myalgia, dizziness, and diarrhea. Medical use In the United States, lanadelumab is indicated for patients 12 years and older for the prophylaxis of hereditary angioedema (HAE) attacks. There is no data on the efficacy or safety of lanadelumab in patients under the age of 12 years old. Lanadelumab was not studied in pregnant or breastfeeding women. Adverse events In a phase 3 randomized controlled trial, which examined the efficacy and safety of lanadelumab in preventing hereditary angioedema attacks, the most common adverse events noted in patients being treated were: Injection site pain in 42.9% of patients Viral upper respiratory tract infection in 23.8% of patients Headache in 20.2% of patients Injection site erythema in 95% of patients Injection site bruising in 7.1% of patients Dizziness in 6.0% of patients Mechanism of action Lanadelumab works by binding to an enzyme within the plasma, kallikrein, to inhibit its activity. Kallikrein is a protease that functions to cleave kininogen, subsequently creating kininogen and bradykinin, a potent vasodilator.Patients have hereditary angioedema (HAE) because of a deficiency or dysfunctional C1 inhibitor, which is an enzyme that regulates the activity of the kallikrein-kinin cascade. Poor regulation of the C1 inhibitor results in increased levels of kallikrein and subsequent proteolysis of kininogen. The proteolysis of the kininogen forces an upscaled production of bradykinin and kininogen within the patient. Increased bradykinin levels cause vasodilation, increased vascular permeability, and the succeeding angioedema and pain associated with hereditary angioedema attacks. Efficacy trial The phase 3 trial that analyzed the efficacy of lanadelumab is called Effect of Lanadelumab compared with Placebo on Prevention of Hereditary Angioedema Attacks, also known as the HELP study. The objective of the randomized controlled trial was to examine the effectiveness of lanadelumab in preventing hereditary angioedema attacks. There were 125 patients studied over a 26-week period in the randomized, double-blind, parallel-group, placebo-controlled trial. Patients were randomized to receive either lanadelumab treatment or placebo in a 1:2 ratio. Subjects randomized to receive lanadelumab were further randomized 1:1:1 ratio to receive doses of either 150 mg every 4 weeks, 300 mg every 4 weeks, or 300 mg every 2 weeks. Patients on the medication had a statistically significant reduction in hereditary angioedema attack rates per month. Patients that took lanadelumab every 2 weeks had 83% less moderate to severe attacks. The study results proved that all three dosing regimens for lanadelumab were more effective than placebo. References External links "Lanadelumab". Drug Information Portal. U.S. National Library of Medicine.
Olopatadine
Olopatadine, sold under the brand name Opatanol among others, is a medication used to decrease the symptoms of allergic conjunctivitis and allergic rhinitis (hay fever). It is used as eye drops or as a nasal spray. The eye drops generally result in an improvement within half an hour.Common side effects include headache, sore throat, eye discomfort, change in taste. More significant side effects may include sleepiness. It is unclear if use during pregnancy or breastfeeding is safe. It is an antihistamine and mast cell stabilizer.Olopatadine was patented in 1986 and came into medical use in 1997. It is available as a generic medication. In 2017, it was the 270th most commonly prescribed medication in the United States, with more than one million prescriptions. Side effects Some known side effects include headache (7% of occurrence), eye burning and/or stinging (5%), blurred vision, dry eyes, foreign body sensation, hyperemia, keratitis, eyelid edema, pruritus, asthenia, sore throat (pharyngitis), rhinitis, sinusitis, taste perversion, and vomiting. Chemistry Synthesis Pharmacology Pharmacodynamics Olopatadine acts as a selective antagonist of the histamine H1 receptor, thus stabilizing mast cells and inhibiting histamine release. History Olopatadine was patented in 1986 by Kyowa Hakko Kogyo and came into medical use in 1997.In the United States, Pataday Twice Daily Relief was first approved by the FDA in 1996, under the name Patanol as a prescription drug and was indicated for the treatment of the signs and symptoms of allergic conjunctivitis (referring to ocular redness and itching due to allergies). Pataday – now Pataday Once Daily Relief – was first approved by the FDA in 2004, as a prescription drug and was indicated for the treatment of ocular itching associated with allergic conjunctivitis. These drugs are mast cell stabilizers, which work by preventing the release of histamine and therefore prevent or control allergic disorders.In February 2020, Pataday Twice Daily Relief and Pataday Once Daily Relief were switched to be over-the-counter drugs in the United States when the FDA granted the approvals of the nonprescription products to Alcon. Society and culture Brand names Brand names include Pazeo, Pataday, Patanol S, Patanol, Opatanol, Olopat, Patanase. It is also available as an oral tablet in Japan under the tradename Allelock, manufactured by Kyowa Hakko Kogyo. References External links "Olopatadine". Drug Information Portal. U.S. National Library of Medicine. "Olopatadine hydrochloride". Drug Information Portal. U.S. National Library of Medicine. "Olopatadine Nasal Spray". MedlinePlus.
Palivizumab
Palivizumab, sold under the brand name Synagis, is a monoclonal antibody produced by recombinant DNA technology used to prevent severe disease caused by respiratory syncytial virus (RSV) infections. It is recommended for infants at high-risk for RSV due to conditions such as prematurity or other medical problems including heart or lung diseases.The most common side effects include fever and rash.Palivizumab is a humanized monoclonal antibody (IgG) directed against an epitope in the A antigenic site of the F protein of RSV. In two phase III clinical trials in the pediatric population, palivizumab reduced the risk of hospitalization due to RSV infection by 55% and 45%. Palivizumab is dosed once a month via intramuscular (IM) injection, to be administered throughout the duration of the RSV season, which in based on past trends has started in Mid-September to Mid-November.Palivizumab targets the fusion protein of RSV, inhibiting its entry into the cell and thereby preventing infection. Palivizumab was approved for medical use in 1998. Medical use Palivizumab is indicated for the prevention of serious lower respiratory tract disease requiring hospitalization caused by the respiratory syncytial virus (RSV) in children at high risk for RSV disease: children born at 35 weeks of gestation or less and less than six months of age at the onset of the RSV season; children less than two years of age and requiring treatment for bronchopulmonary dysplasia within the last six months; children less than two years of age and with hemodynamically significant congenital heart disease.The American Academy of Pediatrics has published guidelines for the use of palivizumab. The most recent updates to these recommendations are based on new information regarding RSV seasonality, palivizumab pharmacokinetics, the incidence of bronchiolitis hospitalizations, the effect of gestational age and other risk factors on RSV hospitalization rates, the mortality of children hospitalized with RSV infection, the effect of prophylaxis on wheezing, and palivizumab-resistant RSV isolates. RSV Prophylaxis All infants younger than one year who were born at <29 weeks (i.e. ≤28 weeks, 6 days) of gestation are recommended to use palivizumab. Infants younger than one year with bronchopulmonary dysplasia (i.e. who were born at <32 weeks gestation and required supplemental oxygen for the first 28 days after birth) and infants younger than two years with bronchopulmonary dysplasia who require medical therapy (e.g. supplemental oxygen, glucocorticoids, diuretics) within six months of the anticipated RSV season are recommended to use palivizumab as prophylaxis. A Cochrane review shows evidence that palivizumab RSV prophylaxis is effective at reducing the frequency of hospitalization in children with RSV infection.Since the risk of RSV decreases after the first year following birth, the use of palivizumab for children more than 12 months of age is generally not recommended with the exception of premature infants who need supplemental oxygen, bronchodilator therapy, or steroid therapy at the time of their second RSV season. RSV Prophylaxis Target Groups Infants younger than one year of age with hemodynamically significant congenital heart disease. Infants younger than one year of age with neuromuscular disorders impairing the ability to clear secretions from the upper airways or pulmonary abnormalities. Children younger than two years of age who are immunocompromised (e.g. those with severe combined immunodeficiency; those younger than two years of age who have undergone lung transplantation or hematopoietic stem cell transplantation) during the RSV season. Children with Down syndrome who have additional risk factors for lower respiratory tract infections such as congenital heart disease, chronic lung disease, or premature birth. Alaska Native and American Indian infants.Decisions regarding palivizumab prophylaxis for children in these groups should be made on a case-by-case basis. RSV Treatment Because palivizumab is a passive antibody, it is ineffective in the treatment of RSV infection, and its administration is not recommended for this indication. A 2019 Cochrane review found no differences in palivizumab and placebo on outcomes of mortality, length of hospital stay, and adverse events in infants and children aged up to 3 years old with RSV. Larger RCTs will be required before palivizumab can be recommended as a treatment option. If an infant has an RSV infection despite the use of palivizumab during the RSV season, monthly doses of palivizumab may be discontinued for the rest of the RSV season due to the low risk of re-hospitalization. Current studies are in progress to determine new treatments for RSV rather than solely prophylaxis. Mechanism of Action Palivizumab is a monoclonal antibody that targets the fusion (F) glycoprotein on the surface of RSV, and deactivates it. The F protein is a membrane protein responsible for fusing the virus with its target cell and is highly conserved among subgroups of RSV. Deactivating the F protein prevents the virus from fusing with its targets cell membrane and prevents the virus from entering the host cell. Pharmacodynamics Palivizumab has demonstrated a significantly higher affinity and potency in neutralizing both A and B subtypes of RSV when compared with RSV-IGIV. Treatment with 2.5 mg/kg of palivizumab led to a serum concentration of 25-30 μg/mL in cotton rats and reduced RSV titers by 99% in their lungs. Pharmacokinetics Absorption A 2008 meta-analysis found that palivizumab absorption was quicker in the pediatric population compared to adults (ka = 1.01/day vs. ka = 0.373/day). The intramuscular bioavailability of this drug is approximately 70% in healthy young adults. Current recommendation for RSV immunoprophylaxis is administration of 5 x 15 mg/kg doses of palivizumab to maintain body concentrations above 40 μg/mL. Distribution The volume of distribution is approximately 4.1 liters. Clearance Palivizumab has a drug clearance (CL) of approximately 198 ml/day. The half-life of this drug is approximately 20 days with three doses sustaining body concentrations that will last the entire RSV season (5 to 6 months). A 2008 meta-analysis estimated clearance in the pediatric population by considering maturation of CL and body weight which showed a significant reduction compared to adults. Side effects Palivizumab use may cause side effects, which include, but are not limited to: Sore throat Runny nose Redness or irritation at the injection site Vomiting DiarrheaSome more serious side effects include: Severe skin rash Itching Hives (urticaria) Difficulty breathing Contraindications Contraindications for the use of palivizumab include hypersensitivity reactions upon exposure to palivizumab. Serious cases of anaphylaxis have been reported after exposure to palivizumab. Signs of hypersensitivity include hives, shortness of breath, hypotension, and unresponsiveness. No other contraindications for palivizumab have been reported. Further studies are needed to determine if any drug-drug interactions exist as none have been conducted as of yet. Cost Palivizumab is a relatively expensive medication, with a 100-mg vial ranging from $904 to $1866. Multiple studies done by both the manufacturer and independent researchers to determine the cost-effectiveness of palivizumab have found conflicting results. The heterogeneity between these studies makes them difficult to compare. Given that there is no consensus about the cost-effectiveness of palivizumab, usage largely depends on the location of care and individual risk factors.A 2013 meta-analysis reported that palivizumab prophylaxis was a dominant strategy with an incremental cost-effectiveness ratio of $2,526,203 per quality-adjusted life-year (QALY). It also showed an incremental cost-effectiveness ratio for preterm infants between $5188 and $791,265 per QALY, from the payer perspective. However, as previously stated, the cost-effectiveness of palivizumab is undecided, and this meta-analysis is only one example of society can benefit from palivizumab prophylaxis. History The disease burden of RSV in young infants and its global prevalence have prompted attempts for vaccine development. As of 2019, there was no approved vaccine for RSV prevention. A formalin-inactivated RSV vaccine (FIRSV) was studied in the 1960s. The immunized children who were exposed to the virus in the community developed an enhanced form of RSV disease presented by wheezing, fever, and bronchopneumonia. This enhanced form of the disease led to 80% hospitalization in the recipients of FIRSV compared to 5% in the control group. Additionally, 2 fatalities occurred among the vaccine recipients upon reinfection in subsequent years. Subsequent attempts to develop an attenuated live virus vaccine with optimal immune response and minimal reactogenicity have been unsuccessful. Further research on animal subjects suggested that intravenously administered immunoglobulin with high RSV neutralizing activity can protect against RSV infection. In 1995, the U.S. Food and Drug Administration (FDA) approved the use of RespiGam (RSV-IGIV) for the prevention of serious lower respiratory tract infection caused by RSV in children younger than 24 months of age with bronchopulmonary dysplasia or a history of premature birth. The success of the RSV-IGIV demonstrated efficacy in immunoprophylaxis and prompted research into further technologies. Thus, Palivizumab was developed as an antibody that was found to be fifty times more potent than its predecessor. This antibody has been widely used for RSV since 1998 when it was approved. Palivizumab, originally known as MEDI-493, was developed as an RSV immune prophylaxis tool that was easier to administer and more effective than the current tools of that time (the 1990s). It was developed over a 10-year period by MedImmune Inc. by combining human and mouse DNA. Specifically, antibody production was stimulated in a mouse model following immunization with RSV. The antibody-producing B cells were isolated from the mouses spleen and fused with mouse myeloma cell lines. The antibodies were then humanized by cloning and sequencing the DNA from both the heavy and light chains of the monoclonal antibody. Overall, the monoclonal antibody is 95% similar to other human antibodies with the other 5% having DNA origins from the original mouse. References External links "Palivizumab". Drug Information Portal. U.S. National Library of Medicine.
Lorlatinib
Lorlatinib, sold under the brand name Lorbrena in the United States, Canada, and Japan, and Lorviqua in the European Union, is an anti-cancer drug developed by Pfizer. It is an orally administered inhibitor of ALK and ROS1, two enzymes that play a role in the development of cancer. Medical uses Lorlatinib is approved in the US and in Europe for the second- or third-line treatment of ALK-positive metastatic non-small-cell lung cancer (NSCLC). It is the only ALK inhibitor with meaningful activity against ALK G1202R mutation in lung cancer. Contraindications Lorlatinib must not be combined with strong inducers (i.e. activators) of the liver enzymes CYP3A4/5 if it can be avoided, as serious cases of liver toxicity have been observed under combination with the CYP3A4/5 inducer rifampicin. Side effects The most common side effects in studies were high blood cholesterol (84% of patients), high blood triglycerides (67%), edema (55%), peripheral neuropathy (48%), cognitive effects (29%), fatigue (28%), weight gain (26%), and mood effects (23%). Serious side effects led to dose reduction in 23% of patients and in termination of lorlatinib treatment in 3% of patients. Interactions Lorlatinib is metabolized by the enzymes CYP3A4/5. Therefore, CYP3A4/5 inducers such as rifampicin, carbamazepine or St Johns wort decrease its concentrations in the blood plasma and can reduce its effectiveness. Additionally, the combination of lorlatinib with rifampicin showed liver toxicity in studies. Inhibitors of these enzymes such as ketoconazole or grapefruit juice increase lorlatinib plasma concentrations, leading to higher toxicity. Lorlatinib is also a (moderate) CYP3A4/5 inducer, so that drugs that are metabolized by these enzymes are broken down more quickly when combined with lorlatinib. Examples include midazolam and ciclosporin.Interactions via other enzymes have only been studied in vitro. According to these findings, lorlatinib may inhibit CYP2C9, UGT1A1 and several transport proteins, induce CYP2B6, and has probably no relevant effect on CYP1A2. Pharmacology Mechanism of action Lorlatinib is a small molecule kinase inhibitor of ALK and ROS1 as well as a number of other kinases. It is active in vitro against many mutated forms of ALK. Pharmacokinetics The drug is swallowed in the form of tablets. It reaches highest blood plasma concentrations 1.2 hours after a single dose, or 2 hours after ingestion when taken regularly. Its absolute bioavailability is 80.8%. Intake with fatty food increases its availability by 5%, which is not considered clinically significant. When in the bloodstream, 66% of the substance are bound to plasma proteins. Lorlatinib is able to cross the blood-brain barrier.Lorlatinib is inactivated by oxidation, mainly through CYP3A4, and by glucuronidation, mainly through UGT1A4. Other CYPs and UGTs play a minor role. Lorlatinib and its metabolites are excreted with a half-life of 23.6 hours after a single dose; 47.7% into the urine (of which less than 1% in unchanged form), and 40.9% into the faeces (9.1% unchanged). Chemistry Lorlatinib is a white to off-white powder. It has high solubility in 0.1 M hydrochloric acid and very low solubility at a pH over 4.5. History Clinical studies Several clinical trials were orchestrated. Lorbrena was analyzed in a clinical trial of 296 patients with ALK+ NSCLC whose cancer had migrated to multiple parts of the body including the brain. A trial comparing lorlatinib with crizotinib was conducted, with a primary endpoint of "progression-free survival", which is the period of time a patient is in remission (the tumor ceases growth). Preclinical studies are investigating lorlatinib for treatment of neuroblastoma. In 2017, Pfizer announced that lorlatinib was shown to have activity against lung and brain tumors in people with ALK or ROS1 positive advanced non-small-cell lung cancer. Approval In 2015, FDA granted Pfizer orphan drug status for lorlatinib for the treatment of NSCLC. In 2018, the FDA approved lortalinib for second- or third-line treatment of ALK-positive metastatic NSCLC. In February 2019, the European CHMP of EMA recommended the granting of a conditional marketing authorisation. In May 2019 the European Commission approved lorlatinib for the 28 countries of the EU, also as a second- or third-line treatment. References External links "Lorlatinib". Drug Information Portal. U.S. National Library of Medicine.
Tiopronin
Tiopronin, sold under the brand name Thiola, is a medication used to control the rate of cystine precipitation and excretion in the disease cystinuria. Due to the rarity of the disorder, tiopronin falls under the classification of an orphan drug. It is somewhat similar to penicillamine in both chemistry and pharmacology.A generic version of tiopronin is available in the United States as of April 2021. Uses Tiopronin is used primarily for cystinuria and is well known in the cystinuric community. Depending on the severity of a persons cystinuria, tiopronin may be taken for life, possibly starting in early childhood. The drug works by reacting with urinary cysteine to form a more soluble, disulfide linked, tiopronin-cysteine complex. Side effects Tiopronin may present a variety of side effects, which are broadly similar to those of D-penicillamine and other compounds containing active sulfhydryl groups. Its pharmacokinetics have been studied. Society and culture In the U.S., the drug was marketed by Mission Pharmacal at $1.50 per pill, but in 2014 the rights were bought by Retrophin, owned by Martin Shkreli, and the price increased to $30 per pill for a 100 mg capsule.In 2016 Imprimis Pharmaceuticals introduced a lower cost version marketed as a compounded drug. Research It may also be used for Wilsons disease (an overload of copper in the body), and has also been investigated for the treatment of arthritis, though tiopronin is not an anti-inflammatory.Tiopronin is also sometimes used as a stabilizing agent for metal nanoparticles. The thiol group binds to the nanoparticles, preventing coagulation. References External links "Tiopronin". Drug Information Portal. U.S. National Library of Medicine.
Botulinum toxin
Botulinum toxin, often shortened to BoNT, is a neurotoxic protein produced by the bacterium Clostridium botulinum and related species. It prevents the release of the neurotransmitter acetylcholine from axon endings at the neuromuscular junction, thus causing flaccid paralysis. The toxin causes the disease botulism. The toxin is also used commercially for medical and cosmetic purposes. The seven main types of botulinum toxin are named types A to G (A, B, C1, C2, D, E, F and G). New types are occasionally found. Types A and B are capable of causing disease in humans, and are also used commercially and medically. Types C–G are less common; types E and F can cause disease in humans, while the other types cause disease in other animals. Botulinum toxin types A and B are used in medicine to treat various muscle spasms. Botulinum toxins are among the most potent toxins known. Intoxication can occur naturally as a result of either wound or intestinal infection or by ingesting formed toxin in food. The estimated human lethal dose of type A toxin is 1.3–2.1 ng/kg intravenously or intramuscularly, 10–13 ng/kg when inhaled, or 1000 ng/kg when taken by mouth. Commercial forms are marketed under the brand names Botox (onabotulinumtoxinA), Dysport/Azzalure (abobotulinumtoxinA), Xeomin/Bocouture (incobotulinumtoxinA), and Jeuveau (prabotulinumtoxinA). Medical uses Botulinum toxin is used to treat a number of therapeutic indications, many of which are not part of the approved drug label. Muscle spasticity Botulinum toxin is used to treat a number of disorders characterized by overactive muscle movement, including cerebral palsy, post-stroke spasticity, post-spinal cord injury spasticity, spasms of the head and neck, eyelid, vagina, limbs, jaw, and vocal cords. Similarly, botulinum toxin is used to relax the clenching of muscles, including those of the esophagus, jaw, lower urinary tract and bladder, or clenching of the anus which can exacerbate anal fissure. Botulinum toxin appears to be effective for refractory overactive bladder. Other muscle disorders Strabismus, otherwise known as improper eye alignment, is caused by imbalances in the actions of muscles that rotate the eyes. This condition can sometimes be relieved by weakening a muscle that pulls too strongly, or pulls against one that has been weakened by disease or trauma. Muscles weakened by toxin injection recover from paralysis after several months, so injection might seem to need to be repeated, but muscles adapt to the lengths at which they are chronically held, so that if a paralyzed muscle is stretched by its antagonist, it grows longer, while the antagonist shortens, yielding a permanent effect. If binocular vision is good, the brain mechanism of motor fusion, which aligns the eyes on a target visible to both, can stabilize the corrected alignment.In January 2014, botulinum toxin was approved by UKs Medicines and Healthcare products Regulatory Agency for treatment of restricted ankle motion due to lower-limb spasticity associated with stroke in adults.On 29 July 2016, the U.S. Food and Drug Administration (FDA) approved abobotulinumtoxinA for injection for the treatment of lower-limb spasticity in pediatric patients two years of age and older. AbobotulinumtoxinA is the first and only FDA-approved botulinum toxin for the treatment of pediatric lower limb spasticity. In the U.S., the FDA approves the text of the labels of prescription medicines and for which medical conditions the drug manufacturer may sell the drug. However, prescribers may freely prescribe them for any condition they wish, also known as off-label use. Botulinum toxins have been used off-label for several pediatric conditions, including infantile esotropia. Excessive sweating AbobotulinumtoxinA (BTX-A) has been approved for the treatment of excessive underarm sweating of unknown cause, which cannot be managed by topical agents. Migraine In 2010, the FDA approved intramuscular botulinum toxin injections for prophylactic treatment of chronic migraine headache. Cosmetic Indications In cosmetic applications, botulinum toxin is considered relatively safe and effective for reduction of facial wrinkles, especially in the uppermost third of the face. Commercial forms are marketed under the brand names Botox Cosmetic/Vistabel from Allergan, Dysport/Azzalure from Galderma and Ipsen, Xeomin/Bocouture from Merz, Jeuveau/Nuceiva from Evolus, manufactured by Daewoong in South Korea. DaxibotulinumtoxinA (Daxxify) was approved for medical use in the United States. In Europe, Letybo is also available, marketed by Croma and manufactured by Hugel in South Korea, along with the first liquid formulated botulinum toxin in Europe, Alluzience, from Galderma and Ipsen. The effects of current botulinum toxin injections for glabellar lines (11s lines between the eyes) typically last two to four months and in some cases, product-dependent, with some patients experiencing a longer duration of effect of up to 6 months or longer. Injection of botulinum toxin into the muscles under facial wrinkles causes relaxation of those muscles, resulting in the smoothing of the overlying skin. Smoothing of wrinkles is usually visible three to five days after injection, with maximum effect typically a week following injection. Muscles can be treated repeatedly to maintain the smoothed appearance. Other Botulinum toxin is also used to treat disorders of hyperactive nerves including excessive sweating, neuropathic pain, and some allergy symptoms. In addition to these uses, botulinum toxin is being evaluated for use in treating chronic pain. Studies show that botulinum toxin may be injected into arthritic shoulder joints to reduce chronic pain and improve range of motion. The use of botulinum toxin A in children with cerebral palsy is safe in the upper and lower limb muscles. Side effects While botulinum toxin is generally considered safe in a clinical setting, serious side effects from its use can occur. Most commonly, botulinum toxin can be injected into the wrong muscle group or with time spread from the injection site, causing temporary paralysis of unintended muscles.Side effects from cosmetic use generally result from unintended paralysis of facial muscles. These include partial facial paralysis, muscle weakness, and trouble swallowing. Side effects are not limited to direct paralysis, however, and can also include headaches, flu-like symptoms, and allergic reactions. Just as cosmetic treatments only last a number of months, paralysis side effects can have the same durations. At least in some cases, these effects are reported to dissipate in the weeks after treatment. Bruising at the site of injection is not a side effect of the toxin, but rather of the mode of administration, and is reported as preventable if the clinician applies pressure to the injection site; when it occurs, it is reported in specific cases to last 7–11 days. When injecting the masseter muscle of the jaw, loss of muscle function can result in a loss or reduction of power to chew solid foods. With continued high doses, the muscles can atrophy or lose strength; research has shown that those muscles rebuild after a break from Botox.Side effects from therapeutic use can be much more varied depending on the location of injection and the dose of toxin injected. In general, side effects from therapeutic use can be more serious than those that arise during cosmetic use. These can arise from paralysis of critical muscle groups and can include arrhythmia, heart attack, and in some cases, seizures, respiratory arrest, and death. Additionally, side effects common in cosmetic use are also common in therapeutic use, including trouble swallowing, muscle weakness, allergic reactions, and flu-like syndromes.In response to the occurrence of these side effects, in 2008, the FDA notified the public of the potential dangers of the botulinum toxin as a therapeutic. Namely, the toxin can spread to areas distant from the site of injection and paralyze unintended muscle groups, especially when used for treating muscle spasticity in children treated for cerebral palsy. In 2009, the FDA announced that boxed warnings would be added to available botulinum toxin products, warning of their ability to spread from the injection site. However, the clinical use of botulinum toxin A in cerebral palsy children has been proven to be safe with minimal side effects. Additionally, the FDA announced name changes to several botulinum toxin products, to emphasize that the products are not interchangeable and require different doses for proper use. Botox and Botox Cosmetic were given the INN of onabotulinumtoxinA, Myobloc as rimabotulinumtoxinB, and Dysport retained its INN of abobotulinumtoxinA. In conjunction with this, the FDA issued a communication to health care professionals reiterating the new drug names and the approved uses for each. A similar warning was issued by Health Canada in 2009, warning that botulinum toxin products can spread to other parts of the body. Role in disease Botulinum toxin produced by Clostridium botulinum is the cause of botulism. Humans most commonly ingest the toxin from eating improperly canned foods in which C. botulinum has grown. However, the toxin can also be introduced through an infected wound. In infants, the bacteria can sometimes grow in the intestines and produce botulinum toxin within the intestine and can cause a condition known as floppy baby syndrome. In all cases, the toxin can then spread, blocking nerves and muscle function. In severe cases, the toxin can block nerves controlling the respiratory system or heart, resulting in death. Botulism can be difficult to diagnose, as it may appear similar to diseases such as Guillain–Barré syndrome, myasthenia gravis, and stroke. Other tests, such as brain scan and spinal fluid examination, may help to rule out other causes. If the symptoms of botulism are diagnosed early, various treatments can be administered. In an effort to remove contaminated food that remains in the gut, enemas or induced vomiting may be used. For wound infections, infected material may be removed surgically. Botulinum antitoxin is available and may be used to prevent the worsening of symptoms, though it will not reverse existing nerve damage. In severe cases, mechanical respiration may be used to support patients with respiratory failure. The nerve damage heals over time, generally over weeks to months. With proper treatment, the case fatality rate for botulinum poisoning can be greatly reduced.Two preparations of botulinum antitoxins are available for treatment of botulism. Trivalent (serotypes A, B, E) botulinum antitoxin is derived from equine sources using whole antibodies. The second antitoxin is heptavalent botulinum antitoxin (serotypes A, B, C, D, E, F, G), which is derived from equine antibodies that have been altered to make them less immunogenic. This antitoxin is effective against all main strains of botulism. Mechanism of action Botulinum toxin exerts its effect by cleaving key proteins required for nerve activation. First, the toxin binds specifically to nerves that use the neurotransmitter acetylcholine. Once bound to the nerve terminal, the neuron takes up the toxin into a vesicle by receptor-mediated endocytosis. As the vesicle moves farther into the cell, it acidifies, activating a portion of the toxin that triggers it to push across the vesicle membrane and into the cell cytoplasm. BoNTs recognize distinct classes of receptors simultaneously (gangliosides, synaptotagmin and SV2). Once inside the cytoplasm, the toxin cleaves SNARE proteins (proteins that mediate vesicle fusion, with their target membrane bound compartments) meaning that the acetylcholine vesicles cannot bind to the intracellular cell membrane, preventing the cell from releasing vesicles of neurotransmitter. This stops nerve signaling, leading to paralysis.The toxin itself is released from the bacterium as a single chain, then becomes activated when cleaved by its own proteases. The active form consists of a two-chain protein composed of a 100-kDa heavy chain polypeptide joined via disulfide bond to a 50-kDa light chain polypeptide. The heavy chain contains domains with several functions; it has the domain responsible for binding specifically to presynaptic nerve terminals, as well as the domain responsible for mediating translocation of the light chain into the cell cytoplasm as the vacuole acidifies. The light chain is a M27-family zinc metalloprotease and is the active part of the toxin. It is translocated into the host cell cytoplasm where it cleaves the host protein SNAP-25, a member of the SNARE protein family, which is responsible for fusion. The cleaved SNAP-25 cannot mediate fusion of vesicles with the host cell membrane, thus preventing the release of the neurotransmitter acetylcholine from axon endings. This blockage is slowly reversed as the toxin loses activity and the SNARE proteins are slowly regenerated by the affected cell.The seven toxin serotypes (A–G) are traditionally separated by their antigenicity. They have different tertiary structures and sequence differences. While the different toxin types all target members of the SNARE family, different toxin types target different SNARE family members. The A, B, and E serotypes cause human botulism, with the activities of types A and B enduring longest in vivo (from several weeks to months). Existing toxin types can recombine to create "hybrid" (mosaic, chimeric) types. Examples include BoNT/CD, BoNT/DC, and BoNT/FA, with the first letter indicating the light chain type and the latter indicating the heavy chain type. BoNT/FA received considerable attention under the name "BoNT/H", as it was mistakenly thought it could not be neutralized by any existing antitoxin.Botulinum toxins are closely related to tetanus toxin; the two are collectively known as Clostridium neurotoxins and the light chain is classified by MEROPS as family M27. Nonclassical types include BoNT/X (P0DPK1), which is toxic in mice and possibly in humans; a BoNT/J (A0A242DI27) found in cow Enterococcus; and a BoNT/Wo (A0A069CUU9) found in the rice-colonizing Weissella oryzae. History Initial descriptions and discovery of Clostridium botulinum One of the earliest recorded outbreaks of foodborne botulism occurred in 1793 in the village of Wildbad in what is now Baden-Württemberg, Germany. Thirteen people became sick and six died after eating pork stomach filled with blood sausage, a local delicacy. Additional cases of fatal food poisoning in Württemberg led the authorities to issue a public warning against consuming smoked blood sausages in 1802 and to collect case reports of "sausage poisoning". Between 1817 and 1822, the German physician Justinus Kerner published the first complete description of the symptoms of botulism, based on extensive clinical observations and animal experiments. He concluded that the toxin develops in bad sausages under anaerobic conditions, is a biological substance, acts on the nervous system, and is lethal even in small amounts. Kerner hypothesized that this "sausage toxin" could be used to treat a variety of diseases caused by an overactive nervous system, making him the first to suggest that it could be used therapeutically. In 1870, the German physician Müller coined the term "botulism" to describe the disease caused by sausage poisoning, from the Latin word botulus, meaning "sausage".In 1895 Émile van Ermengem, a Belgian microbiologist, discovered what is now called Clostridium botulinum and confirmed that a toxin produced by the bacteria causes botulism. On 14 December 1895, there was a large outbreak of botulism in the Belgian village of Ellezelles that occurred at a funeral where people ate pickled and smoked ham; three of them died. By examining the contaminated ham and performing autopsies on the people who died after eating it, van Ermengem isolated an anaerobic microorganism that he called Bacillus botulinus. He also performed experiments on animals with ham extracts, isolated bacterial cultures, and toxins extracts from the bacteria. From these he concluded that the bacteria themselves do not cause foodborne botulism, but rather produce a toxin that causes the disease after it is ingested. As a result of Kerners and van Ermengems research, it was thought that only contaminated meat or fish could cause botulism. This idea was refuted in 1904 when a botulism outbreak occurred in Darmstadt, Germany, because of canned white beans. In 1910, the German microbiologist J. Leuchs published a paper showing that the outbreaks in Ellezelles and Darmstadt were caused by different strains of Bacillus botulinus and that the toxins were serologically distinct. In 1917, Bacillus botulinus was renamed Clostridium botulinum, as it was decided that term Bacillus should only refer to a group of aerobic microorganisms, while Clostridium would be only used to describe a group of anaerobic microorganisms. In 1919, Georgina Burke used toxin-antitoxin reactions to identify two strains of Clostridium botulinum, which she designated A and B. Food canning Over the next three decades, 1895–1925, as food canning was approaching a billion-dollar-a-year industry, botulism was becoming a public health hazard. Karl Friedrich Meyer, a Swiss-American veterinary scientist, created a center at the Hooper Foundation in San Francisco, where he developed techniques for growing the organism and extracting the toxin, and conversely, for preventing organism growth and toxin production, and inactivating the toxin by heating. The California canning industry was thereby preserved. World War II With the outbreak of World War II, weaponization of botulinum toxin was investigated at Fort Detrick in Maryland. Carl Lamanna and James Duff developed the concentration and crystallization techniques that Edward J. Schantz used to create the first clinical product. When the Armys Chemical Corps was disbanded, Schantz moved to the Food Research Institute in Wisconsin, where he manufactured toxin for experimental use and provided it to the academic community. The mechanism of botulinum toxin action – blocking the release of the neurotransmitter acetylcholine from nerve endings – was elucidated in the mid-20th century, and remains an important research topic. Nearly all toxin treatments are based on this effect in various body tissues. Strabismus Ophthalmologists specializing in eye muscle disorders (strabismus) had developed the method of EMG-guided injection (using the electromyogram, the electrical signal from an activated muscle, to guide injection) of local anesthetics as a diagnostic technique for evaluating an individual muscles contribution to an eye movement. Because strabismus surgery frequently needed repeating, a search was undertaken for non-surgical, injection treatments using various anesthetics, alcohols, enzymes, enzyme blockers, and snake neurotoxins. Finally, inspired by Daniel B. Drachmans work with chicks at Johns Hopkins, Alan B. Scott and colleagues injected botulinum toxin into monkey extraocular muscles. The result was remarkable; a few picograms induced paralysis that was confined to the target muscle, long in duration, and without side effects. After working out techniques for freeze-drying, buffering with albumin, and assuring sterility, potency, and safety, Scott applied to the FDA for investigational drug use, and began manufacturing botulinum type A neurotoxin in his San Francisco lab. He injected the first strabismus patients in 1977, reported its clinical utility in 1980, and had soon trained hundreds of ophthalmologists in EMG-guided injection of the drug he named Oculinum ("eye aligner"). In 1986, Oculinum Inc, Scotts micromanufacturer and distributor of botulinum toxin, was unable to obtain product liability insurance, and could no longer supply the drug. As supplies became exhausted, patients who had come to rely on periodic injections became desperate. For four months, as liability issues were resolved, American blepharospasm patients traveled to Canadian eye centers for their injections.Based on data from thousands of patients collected by 240 investigators, Oculinum Inc (which was soon acquired by Allergan) received FDA approval in 1989 to market Oculinum for clinical use in the United States to treat adult strabismus and blepharospasm. Allergan then began using the trademark Botox. This original approval was granted under the 1983 US Orphan Drug Act. Cosmetics The effect of BTX-A on reducing and eliminating forehead wrinkles was first described and published by Richard Clark, MD, a plastic surgeon from Sacramento, California. In 1987 Clark was challenged with eliminating the disfigurement caused by only the right side of the forehead muscles functioning after the left side of the forehead was paralyzed during a facelift procedure. This patient had desired to look better from her facelift, but was experiencing bizarre unilateral right forehead eyebrow elevation while the left eyebrow drooped, and she constantly demonstrated deep expressive right forehead wrinkles while the left side was perfectly smooth due to the paralysis. Clark was aware that Botulinum toxin was safely being used to treat babies with strabismus and he requested and was granted FDA approval to experiment with Botulinum toxin to paralyze the moving and wrinkling normal functioning right forehead muscles to make both sides of the forehead appear the same. This study and case report of the cosmetic use of Botulinum toxin to treat a cosmetic complication of a cosmetic surgery was the first report on the specific treatment of wrinkles and was published in the journal Plastic and Reconstructive Surgery in 1989. Editors of the journal of the American Society of Plastic Surgeons have clearly stated "the first described use of the toxin in aesthetic circumstances was by Clark and Berris in 1989."Jean and Alastair Carruthers observed that blepharospasm patients who received injections around the eyes and upper face also enjoyed diminished facial glabellar lines ("frown lines" between the eyebrows). Alastair Carruthers reported that others at the time also noticed these effects and discussed the cosmetic potential of botulinum toxin. Unlike other investigators, the Carruthers did more than just talk about the possibility of using botulinum toxin cosmetically. They conducted a clinical study on otherwise normal individuals whose only concern was their eyebrow furrow. They performed their study during 1987-1989 and presented their results at the 1990 annual meeting of the American Society for Dermatologic Surgery. Their findings were subsequently published in 1992. Chronic pain William J. Binder reported in 2000, that patients who had cosmetic injections around the face reported relief from chronic headache. This was initially thought to be an indirect effect of reduced muscle tension, but the toxin is now known to inhibit release of peripheral nociceptive neurotransmitters, suppressing the central pain processing systems responsible for migraine headache. Society and culture Economics As of 2018, botulinum toxin injections are the most common cosmetic operation, with 7.4 million procedures in the United States, according to the American Society of Plastic Surgeons. Qualifications for Botox injectors vary by county, state, and country. Botox cosmetic providers include dermatologists, plastic surgeons, aesthetic spa physicians, dentists, nurse practitioners, nurses, and physician assistants.The global market for botulinum toxin products, driven by their cosmetic applications, was forecast to reach $2.9 billion by 2018. The facial aesthetics market, of which they are a component, was forecast to reach $4.7 billion ($2 billion in the U.S.) in the same timeframe. Global Market In 2019, 6,271,488 Botulinum Toxin procedures were administered worldwide. The Global Botulinum Toxin market size was US$4.83 billion in 2019 and is projected to reach US$7.71 billion by 2027.US Market In 2020, 4,401,536 Botulinum Toxin Type A procedures were administered. In 2019 the botulinum Toxin market made US$3.19 billion.Botox cost Botox cost is generally determined by the number of units administered (avg. $10.00 - $30.00 per unit) or by the area ($200–1000) and depends on expertise of a physician, clinic location, number of units, and treatment complexity.Insurance Botox for medical purposes is usually covered by insurance if deemed medically necessary by your doctor and covers a plethora of medical problems including overactive bladder (OAB), urinary incontinence due to neurologic conditions, headaches and migraines, TMJ, spasticity in adult patients, cervical dystonia in adult patients, severe axillary hyperhidrosis (or other areas of the body), blepharospasm, upper or lower limb spasticity.Migraines For migraine induced headaches the FDA-recommended dosage is 155 units and costs between $300 to $600 per treatment out of pocket when covered by insurance.Hyperhidrosis Botox for excessive sweating is FDA approved.Cosmetic Standard areas for aesthetics botox injections include facial and other areas that can form fine lines and wrinkles due to every day muscle contractions and/or facial expressions such as smiling, frowning, squinting, and raising eyebrows. These areas include the glabellar region between the eyebrows, horizontal lines on the forehead, crows feet around the eyes, and even circular bands that form around the neck secondary to platysmal hyperactivity. Bioterrorism Botulinum toxin has been recognized as a potential agent for use in bioterrorism. It can be absorbed through the eyes, mucous membranes, respiratory tract, and non-intact skin. The effects of botulinum toxin are different from those of nerve agents involved insofar in that botulism symptoms develop relatively slowly (over several days), while nerve agent effects are generally much more rapid. Evidence suggests that nerve exposure (simulated by injection of atropine and pralidoxime) will increase mortality by enhancing botulinum toxins mechanism of toxicity. With regard to detection, protocols using NBC detection equipment (such as M-8 paper or the ICAM) will not indicate a "positive" when samples containing botulinum toxin are tested. To confirm a diagnosis of botulinum toxin poisoning, therapeutically or to provide evidence in death investigations, botulinum toxin may be quantitated by immunoassay of human biological fluids; serum levels of 12–24 mouse LD50 units per milliliter have been detected in poisoned patients.Japanese doomsday cult Aum Shinrikyo produced botulinum toxin and spread it as an aerosol in downtown Tokyo during the 1990s, but the attacks caused no fatalities.During the early 1980s, German and French newspapers reported that the police had raided a Baader-Meinhof gang safe house in Paris and had found a makeshift laboratory that contained flasks full of Clostridium botulinum, which makes botulinum toxin. Their reports were later found to be incorrect; no such lab was ever found. Brand names Botulinum toxin A is sold under the brand names Jeuveau, Botox, and Xeomin. Botulinum toxin B is sold under the brand name Myobloc.In the United States, botulinum toxin products are manufactured by a variety of companies, for both therapeutic and cosmetic use. A U.S. supplier reported in its company materials in 2011 that it could "supply the worlds requirements for 25 indications approved by Government agencies around the world" with less than one gram of raw botulinum toxin. Myobloc or Neurobloc, a botulinum toxin type B product, is produced by Solstice Neurosciences, a subsidiary of US WorldMeds. AbobotulinumtoxinA), a therapeutic formulation of the type A toxin manufactured
Botulinum toxin
by Galderma in the United Kingdom, is licensed for the treatment of focal dystonias and certain cosmetic uses in the U.S. and other countries.Besides the three primary U.S. manufacturers, numerous other botulinum toxin producers are known. Xeomin, manufactured in Germany by Merz, is also available for both therapeutic and cosmetic use in the U.S. Lanzhou Institute of Biological Products in China manufactures a BTX-A product; as of 2014, it was the only BTX-A approved in China. BTX-A is also sold as Lantox and Prosigne on the global market. Neuronox, a BTX-A product, was introduced by Medy-Tox Inc. of South Korea in 2009. Toxin production Botulism toxins are produced by bacteria of the genus Clostridium, namely C. botulinum, C. butyricum, C. baratii and C. argentinense, which are widely distributed, including in soil and dust. Also, the bacteria can be found inside homes on floors, carpet, and countertops even after cleaning. Food-borne botulism results, indirectly, from ingestion of food contaminated with Clostridium spores, where exposure to an anaerobic environment allows the spores to germinate, after which the bacteria can multiply and produce toxin. Critically, ingestion of toxin rather than spores or vegetative bacteria causes botulism. Botulism is nevertheless known to be transmitted through canned foods not cooked correctly before canning or after can opening, so is preventable. Infant botulism arising from consumption of honey or any other food that can carry these spores can be prevented by eliminating these foods from diets of children less than 12 months old. Organism and toxin susceptibilities Proper refrigeration at temperatures below 3 °C (38 °F) slows the growth of C. botulinum. The organism is also susceptible to high salt, high oxygen, and low pH levels. The toxin itself is rapidly destroyed by heat, such as in thorough cooking. The spores that produce the toxin are heat-tolerant and will survive boiling water for an extended period of time.The botulinum toxin is denatured and thus deactivated at temperatures greater than 85 °C (185 °F) for five minutes. As a zinc metalloprotease (see below), the toxins activity is also susceptible, post-exposure, to inhibition by protease inhibitors, e.g., zinc-coordinating hydroxamates. Research Blepharospasm and strabismus University-based ophthalmologists in the US and Canada further refined the use of botulinum toxin as a therapeutic agent. By 1985, a scientific protocol of injection sites and dosage had been empirically determined for treatment of blepharospasm and strabismus. Side effects in treatment of this condition were deemed to be rare, mild and treatable. The beneficial effects of the injection lasted only 4–6 months. Thus, blepharospasm patients required re-injection two or three times a year.In 1986, Scotts micromanufacturer and distributor of Botox was no longer able to supply the drug because of an inability to obtain product liability insurance. Patients became desperate, as supplies of Botox were gradually consumed, forcing him to abandon patients who would have been due for their next injection. For a period of four months, American blepharospasm patients had to arrange to have their injections performed by participating doctors at Canadian eye centers until the liability issues could be resolved.In December 1989, Botox was approved by the U.S. FDA for the treatment of strabismus, blepharospasm, and hemifacial spasm in patients over 12 years old.Botox has not been approved for any pediatric use. It has, however, been used off-label by physicians for several conditions, including spastic conditions in pediatric patients with cerebral palsy, a therapeutic course that has resulted in patient deaths. In the case of treatment of infantile esotropia in patients younger than 12 years of age, several studies have yielded differing results. Cosmetic The effect of BTX-A on reducing and eliminating forehead wrinkles was first described and published by Richard Clark, MD a plastic surgeon from Sacramento, California. In 1987 Clark was challenged with eliminating the disfigurement caused by only the right side of the forehead muscles functioning after the left side of the forehead was paralyzed during a facelift procedure. This patient had desired to look better from her facelift, but was experiencing bizarre unilateral right forehead eyebrow elevation while the left eyebrow drooped and she emoted with deep expressive right forehead wrinkles while the left side was perfectly smooth due to the paralysis. Clark was aware that Botulinum toxin was safely being used to treat babies with strabismus and he requested and was granted FDA approval to experiment with Botulinum toxin to paralyze the moving and wrinkling normal functioning right forehead muscles to make both sides of the forehead appear the same. This study and case report of the Cosmetic use of Botulinum toxin to treat a Cosmetic complication of a Cosmetic surgery was the first report on the specific treatment of wrinkles and was published in the journal Plastic and Reconstructive Surgery in 1989. Editors of the journal of the American Society of Plastic Surgeons have clearly stated "the first described use of the toxin in aesthetic circumstances was by Clark and Berris in 1989."JD and JA Carruthers also studied and reported in 1992 the use of BTX-A as a cosmetic treatment.[78] They conducted a study of patients whose only concern was their glabellar forehead wrinkle or furrow. Study participants were otherwise normal. Sixteen of seventeen patients available for follow-up demonstrated a cosmetic improvement. This study was reported at a meeting in 1991. The study for the treatment of glabellar frown lines was published in 1992. This result was subsequently confirmed by other groups (Brin, and the Columbia University group under Monte Keen). The FDA announced regulatory approval of botulinum toxin type A (Botox Cosmetic) to temporarily improve the appearance of moderate-to-severe frown lines between the eyebrows (glabellar lines) in 2002 after extensive clinical trials. Well before this, the cosmetic use of botulinum toxin type A became widespread. The results of Botox Cosmetic can last up to four months and may vary with each patient. The U.S. Food and Drug Administration (FDA) approved an alternative product-safety testing method in response to increasing public concern that LD50 testing was required for each batch sold in the market.BTX-A has also been used in the treatment of gummy smiles, the material is injected into the hyperactive muscles of upper lip, which causes a reduction in the upward movement of lip thus resulting in a smile with a less exposure of gingiva. Botox is usually injected in the three lip elevator muscles that converge on the lateral side of the ala of the nose; the levator labii superioris (LLS), the levator labii superioris alaeque nasi muscle (LLSAN), and the zygomaticus minor (ZMi). Upper motor neuron syndrome BTX-A is now a common treatment for muscles affected by the upper motor neuron syndrome (UMNS), such as cerebral palsy, for muscles with an impaired ability to effectively lengthen. Muscles affected by UMNS frequently are limited by weakness, loss of reciprocal inhibition, decreased movement control, and hypertonicity (including spasticity). In January 2014, Botulinum toxin was approved by UKs Medicines and Healthcare products Regulatory Agency (MHRA) for the treatment of ankle disability due to lower limb spasticity associated with stroke in adults. Joint motion may be restricted by severe muscle imbalance related to the syndrome, when some muscles are markedly hypertonic, and lack effective active lengthening. Injecting an overactive muscle to decrease its level of contraction can allow improved reciprocal motion, so improved ability to move and exercise. Sialorrhea Sialorrhea is a condition where oral secretions are unable to be eliminated, causing pooling of saliva in the mouth. This condition can be caused by various neurological syndromes such as Bells_palsy, intellectual disability, and cerebral palsy. Injection of BTX-A into salivary glands is useful in reducing the secretions. Cervical dystonia BTX-A is commonly used to treat cervical dystonia, but it can become ineffective after a time. Botulinum toxin type B (BTX-B) received FDA approval for treatment of cervical dystonia on 21 December 2000. Brand names for BTX-B are Myobloc in the United States, and Neurobloc in the European Union. Chronic migraine Onabotulinumtoxin A (trade name Botox) received FDA approval for treatment of chronic migraines on 15 October 2010. The toxin is injected into the head and neck to treat these chronic headaches. Approval followed evidence presented to the agency from two studies funded by Allergan showing a very slight improvement in incidence of chronic migraines for those with migraines undergoing the Botox treatment.Since then, several randomized control trials have shown botulinum toxin type A to improve headache symptoms and quality of life when used prophylactically for patients with chronic migraine who exhibit headache characteristics consistent with: pressure perceived from outside source, shorter total duration of chronic migraines (<30 years), "detoxification" of patients with coexisting chronic daily headache due to medication overuse, and no current history of other preventive headache medications. Depression A few small trials have found benefits in people with depression. Research is based on the facial feedback hypothesis. Premature ejaculation The drug for the treatment of premature ejaculation has been under development since 7 August 2013, and is in Phase II of the FDA trials. References External links BotDB: extensive resources on BoNT structures, inhibitors, kinetics, and literature Overview of all the structural information available in the PDB for UniProt: P0DPI1 (Botulinum neurotoxin type A) at the PDBe-KB. Overview of all the structural information available in the PDB for UniProt: P10844 (Botulinum neurotoxin type B) at the PDBe-KB. Overview of all the structural information available in the PDB for UniProt: A0A0X1KH89 (Bontoxilysin A) at the PDBe-KB. "OnabotulinumtoxinA". Drug Information Portal. U.S. National Library of Medicine. "RimabotulinumtoxinB". Drug Information Portal. U.S. National Library of Medicine. "AbobotulinumtoxinA". Drug Information Portal. U.S. National Library of Medicine. "AbobotulinumtoxinA Injection". MedlinePlus. "IncobotulinumtoxinA Injection". MedlinePlus. "OnabotulinumtoxinA Injection". MedlinePlus. "PrabotulinumtoxinA-xvfs Injection". MedlinePlus. "RimabotulinumtoxinB Injection". MedlinePlus.
Belumosudil
Belumosudil, sold under the brand name Rezurock among others, is a medication used for the treatment of chronic graft versus host disease (cGvHD).It is in the class of drugs known as serine/threonine kinase inhibitors. Specifically, it is an inhibitor of Rho-associated coiled-coil kinase 2 (ROCK2; ROCK-II). Belumosudil binds to and inhibits the serine/threonine kinase activity of ROCK2. This inhibits ROCK2-mediated signaling pathways which play major roles in pro- and anti-inflammatory immune cell responses. A genomic study in human primary cells demonstrated that the drug also has effects on oxidative phosphorylation, WNT signaling, angiogenesis, and KRAS signaling.The most common side effects include infections, asthenia, nausea, diarrhea, dyspnea, cough, edema, hemorrhage, abdominal pain, musculoskeletal pain, headache, phosphate decreased, gamma glutamyl transferase increased, lymphocytes decreased, and hypertension.Belumosudil was approved for medical use in the United States in July 2021. Medical uses Belumosudil is indicated for the treatment of people aged 12 years and older with chronic graft-versus-host disease (chronic GVHD) after failure of at least two prior lines of systemic therapy. History Originally developed by Surface Logix, Inc, belumosudil was later acquired by Kadmon Corporation. By July 2020, the drug completed Phase II clinical studies for cGvHD, IPF, and psoriasis.cGvHD is a complication that can follow allogeneic stem cell or hematopoietic stem cell transplantation where the transplanted cells (graft) attack healthy cells (host). This causes inflammation and fibrosis in multiple tissues. Two cytokines controlled by the ROCK2 signaling pathway, IL-17 and IL-21, have a major role in the cGvHD response. In a 2016 report using both mouse models and a limited human clinical trial ROCK2 inhibition with belumosudil targeted both the immunologic and fibrotic components of cGvHD and reversed the symptoms of the disease.In October 2017, belumosudil was granted orphan drug status in the United States for treatment of patients with cGvHD.Efficacy of belumosudil was evaluated in clinical trial NCT03640481, a randomized, open-label, multicenter dose-ranging trial that included 65 patients with chronic GVHD who were treated with belumosudil 200 mg taken orally once daily.On 16 July 2021, the U.S. Food and Drug Administration (FDA) approved belumosudil for adult and pediatric patients 12 years and older with chronic graft-versus-host disease (chronic GVHD) after failure of at least two prior lines of systemic therapy. Research IPF is a progressive fibrotic disease where the lining of the lungs become thickened and scarred. Increased ROCK activity has been found in the lungs of humans and animals with IPF. Treatment with belumosudil reduced lung fibrosis in a bleomycin mouse model study.Psoriasis is an inflammatory skin condition where patients experiences eruptions and remissions of thickened, erythematous, and scaly patches of skin. Down-regulation of pro-inflammatory responses was observed with KD025 treatment in Phase 2 clinical studies in patients with moderate to severe psoriasis. References External links "Belumosudil". Drug Information Portal. U.S. National Library of Medicine.
Pertuzumab/trastuzumab/hyaluronidase
Pertuzumab/trastuzumab/hyaluronidase, sold under the brand name Phesgo, is a fixed-dose combination medication to treat adults with HER2-positive breast cancer that has spread to other parts of the body, and for treatment of adults with early HER2-positive breast cancer. It contains pertuzumab, trastuzumab, and hyaluronidase–zzxf. It is injected under the skin via subcutaneous injection in the thigh. In the European Union, Phesgo contains the active ingredients pertuzumab and trastuzumab along with the enzyme vorhyaluronidase alfa.The most common side effects include alopecia (hair loss), nausea, diarrhea, anemia (reduced number of red blood cells) and asthenia (lack of energy). It can cause worsening of chemotherapy induced neutropenia (low level of white blood cells). It may cause harm to a developing fetus or a newborn baby.HER2-positive breast cancer, which makes up approximately one-fifth of breast cancers, has too much of a protein called human epidermal growth factor receptor 2 (HER2), which promotes the growth of cancer cells. Pertuzumab and trastuzumab bind to sites on HER2 and disrupt signaling to stop cancer cell growth. Medical uses The fixed-dose combination is indicated for the treatment of early breast cancer (EBC): Use in combination with chemotherapy for:the neoadjuvant treatment of adults with HER2-positive, locally advanced, inflammatory, or early stage breast cancer (either greater than two cm in diameter or node positive) as part of a complete treatment regimen for early breast cancer; the adjuvant treatment of adults with HER2-positive early breast cancer at high risk of recurrence.and for the treatment of metastatic breast cancer (MBC): Use in combination with docetaxel for the treatment of adults with HER2-positive metastatic breast cancer (MBC) who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease. Adverse effects The FDA label includes a boxed warning about the risk of potential heart failure, fetal harm, and lung toxicity. History The fixed-dose combination of pertuzumab, trastuzumab, and hyaluronidase was approved for medical use in the United States in June 2020.The FDAs approval was based on the results of a non-inferiority study in participants with HER2-positive early breast cancer, which demonstrated the fixed-dose combination of pertuzumab, trastuzumab, and hyaluronidase had comparable efficacy and safety as IV pertuzumab and IV trastuzumab, except for administration-related reactions, which were higher with the fixed-dose combination due to the subcutaneous route of administration.Efficacy was investigated in FeDeriCa (NCT03493854), an open-label, multicenter, randomized trial enrolling 500 participants with operable or locally advanced HER2-positive breast cancer. Participants were randomized to receive neoadjuvant chemotherapy with concurrent administration of either the fixed-dose combination of pertuzumab, trastuzumab, and hyaluronidase or intravenous pertuzumab and intravenous trastuzumab during the neoadjuvant and adjuvant therapies.The primary endpoint of FeDeriCa was non-inferiority of cycle 7 pertuzumab serum trough concentration comparing the fixed-dose combination of pertuzumab, trastuzumab, and hyaluronidase to intravenous pertuzumab. Secondary endpoints included cycle 7 trastuzumab serum trough concentration, pathological complete response (pCR), and safety. The fixed-dose combination showed non-inferior pertuzumab and trastuzumab serum trough concentrations compared to intravenous pertuzumab and trastuzumab. The pCR rate was 59.7% (95% CI: 53.3, 65.8) in the pertuzumab/trastuzumab/hyaluronidase arm and 59.5% (95% CI: 53.2, 65.6) in the intravenous pertuzumab and intravenous trastuzumab arm. The safety profile of the fixed-dose combination of pertuzumab, trastuzumab, and hyaluronidase is comparable to intravenous pertuzumab and trastuzumab, except for increased administration-related reactions.The FDA granted approval of Phesgo to Genentech Inc. Society and culture Legal status On 12 November 2020, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Phesgo, intended for the treatment of early and metastatic breast cancer. The applicant for this medicinal product is Roche Registration GmbH. Phesgo was approved for medical use in the European Union in December 2020. References Further reading "AusPAR: Pertuzumab/trastuzumab". Therapeutic Goods Administration (TGA). 11 October 2021. External links "Pertuzumab". Drug Information Portal. U.S. National Library of Medicine. "Trastuzumab". Drug Information Portal. U.S. National Library of Medicine. "Hyaluronidase". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT03493854 for "A Study to Evaluate the Pharmacokinetics, Efficacy, and Safety of Subcutaneous Administration of the Fixed-Dose Combination of Pertuzumab and Trastuzumab in Combination With Chemotherapy in Participants With HER2-Positive Early Breast Cancer (FeDeriCa)" at ClinicalTrials.gov
Tretinoin/benzoyl peroxide
Tretinoin/benzoyl peroxide, sold under the brand name Twyneo, is a fixed-dose combination medication used for the treatment of acne. It contains tretinoin, a vitamin A derivative, and benzoyl peroxide, an oxidizing agent.The combination was approved for medical use in the United States in July 2021. References External links "Tretinoin". Drug Information Portal. U.S. National Library of Medicine. "Benzoyl peroxide". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT03761784 for "A Study of S6G5T-3 in the Treatment of Acne Vulgaris" at ClinicalTrials.gov Clinical trial number NCT03761810 for "A Study of S6G5T 3 in the Treatment of Acne Vulgaris" at ClinicalTrials.gov
Omeprazole/amoxicillin/rifabutin
Omeprazole/amoxicillin/rifabutin, sold under the brand name Talicia, is a fixed-dose combination medication used for the treatment of Helicobacter pylori infection. It is taken by mouth.It was approved for medical use in the United States in November 2019. References External links "Omeprazole". Drug Information Portal. U.S. National Library of Medicine. "Amoxicillin". Drug Information Portal. U.S. National Library of Medicine. "Rifabutin". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT03198507 for "ERADICATE Hp2 - Treating Helicobacter Pylori With RHB-105 Compared to Active Comparator (ERADICATE Hp2)" at ClinicalTrials.gov Clinical trial number NCT01980095 for "ERADICATE Hp - Treating Helicobacter Pylori With RHB-105 (ERADICATE Hp)" at ClinicalTrials.gov
Piroxicam
Piroxicam is a nonsteroidal anti-inflammatory drug (NSAID) of the oxicam class used to relieve the symptoms of painful inflammatory conditions like arthritis. Piroxicam works by preventing the production of endogenous prostaglandins which are involved in the mediation of pain, stiffness, tenderness and swelling. The medicine is available as capsules, tablets and (not in all countries) as a prescription-free gel 0.5%. It is also available in a betadex formulation, which allows a more rapid absorption of piroxicam from the digestive tract. Piroxicam is one of the few NSAIDs that can be given parenteral routes.It was patented in 1968 by Pfizer and approved for medical use in 1979. It became generic in 1992, and is marketed worldwide under many brandnames. Medical uses It is used in the treatment of certain inflammatory conditions like rheumatoid and osteoarthritis, primary dysmenorrhoea, postoperative pain; and act as an analgesic, especially where there is an inflammatory component. The European Medicines Agency issued a review of its use in 2007 and recommended that its use be limited to the treatment of chronic inflammatory conditions, as it is only in these circumstances that its risk-benefit ratio proves to be favourable. Adverse effects → As with other NSAIDs the principal side effects include: digestive complaints like nausea, discomfort, diarrhoea and bleeds or ulceration of the stomach, as well as headache, dizziness, nervousness, depression, drowsiness, insomnia, vertigo, hearing disturbances (such as tinnitus), high blood pressure, oedema, light sensitivity, skin reactions (including, albeit rarely, Stevens–Johnson syndrome and toxic epidermal necrolysis) and rarely, kidney failure, pancreatitis, liver damage, visual disturbances, pulmonary eosinophilia and fibrosing alveolitis. Compared to other NSAIDs it is more prone to causing gastrointestinal disturbances and serious skin reactions.In October 2020, the U.S. Food and Drug Administration (FDA) required the drug label to be updated for all nonsteroidal anti-inflammatory medications to describe the risk of kidney problems in unborn babies that result in low amniotic fluid. They recommend avoiding NSAIDs in pregnant women at 20 weeks or later in pregnancy. Mechanism of action Piroxicam is an NSAID and, as such, is a non-selective COX inhibitor possessing both analgesic and antipyretic properties. Chemical properties Piroxicam exists as alkenol tautomer in organic solvents and as zwitterionic form in water. History The project that produced piroxicam began in 1962 at Pfizer; the first clinical trial results were reported in 1977, and the product launched in 1980 under the brand name "Feldene". Major patents expired in 1992 and the drug is marketed worldwide under many brandnames. See also Meloxicam Isoxicam Lornoxicam References Further reading Dean L (2019). "Piroxicam Therapy and CYP2C9 Genotype". In Pratt VM, McLeod HL, Rubinstein WS, et al. (eds.). Medical Genetics Summaries. National Center for Biotechnology Information (NCBI). PMID 30742401. Bookshelf ID: NBK537367.
Vortioxetine
Vortioxetine, sold under the brand names Trintellix and Brintellix among others, is a medication used to treat major depressive disorder. Effectiveness is viewed as similar to that of other antidepressants. In the United Kingdom, it is only recommended in people who have not improved sufficiently on two other antidepressants. It is taken by mouth.Common side effects include nausea, vomiting, constipation, and sexual dysfunction. Serious side effects may include suicide in those under the age of 25, serotonin syndrome, bleeding, mania, and SIADH. A withdrawal syndrome may occur if the medication is abruptly stopped or the dose is decreased. Use during pregnancy and breastfeeding is not generally recommended. It is classified as a serotonin modulator and stimulator. How it works is not entirely clear but is believed to be related to increasing serotonin levels and possibly interacting with certain receptors for serotonin.It was approved for medical use in the United States in 2013. In 2017, it was the 312th most commonly prescribed medication in the United States, with more than one million prescriptions. Medical uses Vortioxetine is used as a treatment for major depressive disorder. Effectiveness appears to be similar to other antidepressants and in terms of effect size has been described as modest. Vortioxetine may be used when other treatments have failed. A 2017 Cochrane review on vortioxetine determined that the place for it in the treatment of severe depression is unclear due to low-quality evidence and that more study is needed comparing vortioxetine to selective serotonin reuptake inhibitors (SSRIs) which are typical first-line treatments.Vortioxetine is also used off-label for anxiety. A 2016 review found it was not useful in generalized anxiety disorder at 2.5, 5, and 10 mg doses (15 and 20 mg doses were not tested). A 2019 meta-analysis found that vortioxetine didnt produce statistically significant results over placebo in the symptoms, quality of life and remission rates of generalized anxiety disorder, but it was well-tolerated. However, a 2018 meta-analysis supported use and efficacy of vortioxetine for generalized anxiety disorder, though stated that more research was necessary to strengthen the evidence. A 2021 systematic review and meta-analysis concluded that there was uncertainty about the effectiveness of vortioxetine for anxiety due to existing evidence being very low-quality. In a 2020 network meta-analysis of randomized controlled trials, vortioxetine was associated with among the lowest remission rates for generalized anxiety disorder of the included medications (odds ratio = 1.30 for vortioxetine, range of odds ratios for other agents = 1.13–2.70). Dosage The recommended starting dosage of vortioxetine is 10 mg/day. The dosage should then be increased as tolerated to 20 mg/day. For individuals who dont tolerate higher doses, 5 mg/day may be considered. The maximum recommended dose of vortioxetine in known CYP2D6 poor metabolizers is 10 mg/day. Similarly, the dose should be reduced by half in those taking strong CYP2D6 inhibitors. Vortioxetine can be discontinued abruptly without tapering, but it is recommended that at doses of 15 to 20 mg/day it be tapered first to 10 mg/day one week prior to full discontinuation if possible. Available forms Vortioxetine is available in the form of 5, 10, and 20 mg immediate-release, film-coated oral tablets. Contraindications Vortioxetine is contraindicated in those with hypersensitivity to vortioxetine or to any other components of vortioxetine tablets. It is also contraindicated in those taking monoamine oxidase inhibitors (MAOIs) due to the possibility of serotonin syndrome. Adverse effects The most common side effects reported with vortioxetine are nausea, vomiting, constipation, and sexual dysfunction, among others. With the exceptions of nausea and sexual dysfunction, these side effects were reported by less than or equal to 10% of study participants given vortioxetine. Significant percentages of placebo-treated participants also report these side effects. Discontinuation of treatment due to adverse effects in clinical trials was 8% with vortioxetine versus 3% with placebo.Sexual dysfunction, such as decreased libido, abnormal orgasm, delayed ejaculation, and erectile dysfunction, are well-known side effects of SSRIs and serotonin–norepinephrine reuptake inhibitors (SNRIs). In clinical trials, sexual dysfunction occurred more often with vortioxetine than with placebo and appeared to be dose-dependent. The specific incidences of treatment-emergent sexual dysfunction as measured with the Arizona Sexual Experience Scale (ASEX) were 14 to 20% for placebo and 16 to 34% for vortioxetine over a dosage range of 5 to 20 mg/day. The incidence of sexual dysfunction with vortioxetine was similar to that with the SNRI duloxetine, which had an incidence of 26 to 28% at the used dosage of 60 mg/day. However, treatment-emergent sexual dysfunction caused by a prior SSRI was better improved by switching to vortioxetine than by switching to the SSRI escitalopram. In another study, vortioxetine at a dosage of 10 mg/day though not at 20 mg/day produced less sexual dysfunction than the SSRI paroxetine. These findings suggest that although vortioxetine can still cause sexual dysfunction itself, it may cause somewhat less sexual dysfunction than SSRIs and might be a useful alternative option for people experiencing sexual dysfunction with these medications. The rates of voluntarily or spontaneously reported sexual dysfunction with vortioxetine are much lower than with the ASEX, ranging from <1 to 5% for vortioxetine versus <1 to 2% for placebo in clinical trials. Significant changes in body weight (gain or loss) were not observed with vortioxetine in clinical trials. Vortioxetine might cause less emotional blunting than SSRIs and SNRIs based on a couple of preliminary clinical studies.If vortioxetine is used in combination with other serotonergic drugs like MAOIs or SSRIs, this may result in serotonin syndrome. Interactions Vortioxetine is metabolized primarily by the cytochrome P450 enzyme CYP2D6. Inhibitors and inducers of CYP2D6 may modify the pharmacokinetics of vortioxetine and necessitate dosage adjustments.Bupropion, a strong CYP2D6 inhibitor, has been found to increase peak levels of vortioxetine by 2.1-fold and total vortioxetine levels by 2.3-fold (bupropion dosed at 300 mg/day and vortioxetine dosed at 10 mg/day). The incidence of side effects with vortioxetine, like nausea, headache, vomiting, and insomnia, was correspondingly increased with the combination. Other strong CYP2D6 inhibitors, like fluoxetine, paroxetine, and quinidine, may have similar influences on the pharmacokinetics of vortioxetine, and it is recommended that the dosage of vortioxetine be reduced by half when it is administered in combination with such medications. Lesser interactions have additionally been identified for vortioxetine with the cytochrome P450 inhibitors ketoconazole and fluconazole.Rifampicin, a strong and broad cytochrome P450 inducer (though notably not of CYP2D6), has been found to decrease peak levels of vortioxetine by 51% and total levels of vortioxetine by 72% (rifampicin dosed at 600 mg/day and vortioxetine at 20 mg/day). Similar influences on vortioxetine pharmacokinetics may also occur with other strong cytochrome P450 inducers like carbamazepine and phenytoin. As such, it is recommended that increasing vortioxetine dosage be considered when it is given in combination with strong cytochrome P450 inducers. The maximum recommended dose should not exceed three times the original vortioxetine dose.Vortioxetine and its metabolites show no meaningful interactions with a variety of assessed cytochrome P450 enzymes and transporters (e.g., P-glycoprotein) and hence vortioxetine is not expected to importantly influence the pharmacokinetics of other medications.The combination of vortioxetine with MAOIs, including other MAOIs like linezolid and intravenous methylene blue, may cause serotonin syndrome and is contraindicated. The risk of serotonin syndrome may also be increased when vortioxetine is combined with other serotonergic drugs, like SSRIs, SNRIs, tricyclic antidepressants (TCAs), triptans, tramadol, tryptophan, buspirone, St Johns wort, fentanyl, and lithium, among others. However, vortioxetine is not considered to be contraindicated with serotonergic medications besides MAOIs. Pharmacology Pharmacodynamics Vortioxetine increases serotonin concentrations in the brain by inhibiting its reuptake in the synapse, and also modulates (activates or blocks) certain serotonin receptors. This puts it in the class of serotonin modulators and stimulators, which also includes vilazodone. More specifically, vortioxetine is a serotonin reuptake inhibitor, agonist of the serotonin 5-HT1A receptor, partial agonist of the 5-HT1B receptor, and antagonist of the serotonin 5-HT1D, 5-HT3, and 5-HT7 receptors, as well as an apparent ligand of the β1-adrenergic receptor. In terms of functional activity however, vortioxetine appears to be much more potent on serotonin reuptake inhibition and 5-HT3 receptor antagonism than for its interactions with the other serotonin receptors. Whereas vortioxetine has IC50 or EC50 values of 5.4 nM for the SERT and 12 nM for the 5-HT3 receptor, its values are 120 to 450 nM for the 5-HT1A, 5-HT1B, 5-HT1D, and 5-HT7 receptors. This translates to about 22- to 83-fold selectivity for SERT inhibition and 10- to 38-fold selectivity for 5-HT3 antagonism over activities at the other serotonin receptors.It has been claimed that the serotonin transporter (SERT) and 5-HT3 receptor may be primarily occupied at lower clinical doses of vortioxetine and that the 5-HT1B, 5-HT1A, and 5-HT7 receptors may additionally be occupied at higher doses. Occupancy of the serotonin transporter with vortioxetine in young men was found to be highest in the raphe nucleus with median occupancies of 25%, 53%, and 98% after 9 days of administration with 2.5, 10, and 60 mg/day vortioxetine. In another study, serotonin transporter occupancy in men was 50%, 65%, and ≥80% for 5, 10, and 20 mg/day vortioxetine.Based on its clinical efficacy (e.g., at 5 mg/day), it appears that vortioxetine may produce antidepressant effects at SERT occupancy as low as 50%. This is in apparent contrast to SSRIs and SNRIs, which appear to require a minimum of 70 to 80% occupancy for antidepressant efficacy. These findings are suggestive that the antidepressant effects of vortioxetine may be mediated by serotonin receptor interactions in addition to serotonin reuptake inhibition. A study found no significant occupancy of the 5-HT1A receptor with vortioxetine at 30 mg/day for 9 days, which suggests that at least this specific serotonin receptor may not be involved in the clinical pharmacology of vortioxetine. However, methodological concerns were noted that may limit the interpretability of this result. Occupancy of other serotonin receptors like 5-HT3 and 5-HT7 by vortioxetine in humans does not seem to have been studied. In relation to the preceding, the contribution of serotonin receptor interactions to the antidepressant effects of vortioxetine is unknown and remains to be established. Uncertainties remain about whether vortioxetine is indeed a clinically multimodal antidepressant or whether it is effectively "[just] another selective serotonin reuptake inhibitor".Antagonism of the 5-HT3 receptor has been found to enhance the increase in brain serotonin levels produced by serotonin reuptake inhibition in animal studies. Whether or not the 5-HT3 receptor antagonism of vortioxetine likewise does this in humans or contributes to its clinical antidepressant efficacy is unclear. SSRIs and 5-HT1A receptor agonists often produce nausea as a side effect, whereas 5-HT3 receptor antagonists like ondansetron are antiemetics and have been found to be effective in treating SSRI-induced nausea. It was thought that the 5-HT3 receptor antagonism of vortioxetine would reduce the incidence of nausea relative to SSRIs. However, clinical trials found significant and dose-dependent rates of nausea with vortioxetine that appeared to be comparable to those found with the SNRI duloxetine. Pharmacokinetics Vortioxetine is well-absorbed when taken orally and has an oral bioavailability of 75%. It is systemically detectable after a single oral dose by 0.781 hours. Peak levels of vortioxetine are reached within 7 to 11 hours post-dose with single or multiple doses. Steady-state levels of vortioxetine are generally reached within 2 weeks of administration, with 90% of individuals reaching 90% of steady state after 12 days of administration. Steady-state peak levels of vortioxetine with doses of 5, 10, and 20 mg/day were 9, 18, and 33 ng/mL, respectively. The accumulation index of vortioxetine (area-under-the-curve levels after a single dose versus at steady state) is 5 to 6. A loading dose given intravenously has been found to achieve steady-state levels more rapidly with oral vortioxetine therapy. The pharmacokinetics of vortioxetine are known to be linear and dose proportional over a range of 2.5 to 75 mg for single doses and 2.5 to 60 mg for multiple doses. Food has no influence on the pharmacokinetics of vortioxetine.The apparent volume of distribution of vortioxetine is large and ranges from 2,500 to 3,400 L after single or multiple doses of 5 to 20 mg vortioxetine, with extensive extravascular distribution. The plasma protein binding of vortioxetine is approximately 98 or 99%, with about 1.25 ± 0.48% free or unbound.Vortioxetine is extensively metabolized by oxidation via cytochrome P450 enzymes and subsequent glucuronidation via UDP-glucuronosyltransferase. CYP2D6 is the primary enzyme involved in the metabolism of vortioxetine, but others including CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, and CYP3A4/5 are also involved. It is also metabolized by alcohol dehydrogenase, aldehyde dehydrogenase, and aldehyde oxidase. Six metabolites of vortioxetine have been identified. The major metabolite of vortioxetine (Lu AA34443) is inactive and its minor active metabolite (Lu AA39835) is not thought to cross the blood–brain barrier. The remaining metabolites are glucuronide conjugates. Hence, vortioxetine itself is thought to be primarily responsible for its pharmacological activity.The estimated total clearance of vortioxetine ranges from 30 to 41 L/h. The elimination half-life of vortioxetine is 66 hours, with a range of 59 to 69 hours after single or multiple doses. Elimination of vortioxetine is almost entirely via the liver (99%) rather than the kidneys (<1%). Approximately 85% of vortioxetine was recovered in a single-dose excretion study after 15 days, with 59% in urine and 26% in feces. Pharmacogenomics Genetic variations in cytochrome P450 enzymes can influence exposure to vortioxetine. CYP2D6 extensive metabolizers have approximately 2-fold higher clearance of vortioxetine than CYP2D6 poor metabolizers. The estimated clearance rates were 52.9, 34.1, 26.6, and 18.1 L/h for CYP2D6 ultra-rapid metabolizers, extensive metabolizers, intermediate metabolizers, and poor metabolizers. Area-under-the-curve levels of vortioxetine were 35.5% lower in CYP2D6 ultra-rapid metabolizers than in extensive metabolizers, though with significant overlap due to interindividual variability. Dosage adjustment for CYP2D6 ultra-rapid metabolizers is considered to not be necessary. Vortioxetine exposure in CYP2D6 poor metabolizers is expected to be approximately twice as high as in extensive metabolizers. Depending on the individual response, dosage adjustment may be considered for CYP2D6 poor metabolizers, with a maximum recommended dosage of 10 mg/day for known such individuals. In addition to CYP2D6, CYP2C19 extensive metabolizers have 1.4-fold higher clearance of vortioxetine than poor metabolizers. However, this is not considered to be clinically important and dose adjustment is not considered to be necessary based on CYP2C19 status. Chemistry Vortioxetine (1-[2-(2,4-dimethylphenylsulfanyl)phenyl]piperazine) is a bis-aryl-sulfanyl amine as well as piperazine derivative. The acid dissociation constant (pKa) values for vortioxetine hydrobromide were determined to be 9.1 (± 0.1) and 3.0 (± 0.2) according to an Australian Public Assessment Report. History Vortioxetine was discovered by scientists at Lundbeck who reported the rationale and synthesis for the drug (then called Lu AA21004) in a 2011 paper.In 2007, the compound was in Phase II clinical trials, and Lundbeck and Takeda entered into a partnership in which Takeda paid Lundbeck $40 million up-front, with promises of up to $345 million in milestone payments, and Takeda agreed to pay most of the remaining cost of developing the drug. The companies agreed to co-promote the drug in the US and Japan, and that Lundbeck would receive a royalty on all such sales. The deal included another drug candidate, tedatioxetine (Lu AA24530), and could be expanded to include two other Lundbeck compounds.Vortioxetine was approved by the U.S. Food and Drug Administration (FDA) for the treatment of major depressive disorder (MDD) in adults in September 2013, and it was approved in Europe later that year. Society and culture It is made by the pharmaceutical companies Lundbeck and Takeda. Names Vortioxetine was previously sold under the brand name Brintellix in the United States, but on May 2, 2016, the US FDA approved a name change to Trintellix in order to avoid confusion with the blood-thinning medication Brilinta (ticagrelor). Research Vortioxetine was under development for the treatment of generalized anxiety disorder and attention-deficit hyperactivity disorder (ADHD) but development for these indications was discontinued. As of August 2021, vortioxetine remains in development for the treatment of anxiety disorders, binge-eating disorder, and bipolar disorder. It is in phase II clinical trials for these indications. There is also interest in vortioxetine for the potential treatment of social phobia, neuropathic pain, and for cognitive enhancement in major depression. References External links "Vortioxetine". Drug Information Portal. U.S. National Library of Medicine. "Vortioxetine hydrobromide". Drug Information Portal. U.S. National Library of Medicine.
Fexofenadine
Fexofenadine, sold under the brand name Allegra among others, is an antihistamine pharmaceutical drug used in the treatment of allergy symptoms, such as hay fever and urticaria.Therapeutically, fexofenadine is a selective peripheral H1 blocker. It is classified as a second-generation antihistamine because it is less able to pass the blood–brain barrier and cause sedation, compared to first-generation antihistamines.It was patented in 1979 and came into medical use in 1996. It is on the World Health Organizations List of Essential Medicines. Fexofenadine has been manufactured in generic form since 2011. In 2019, it was the 283rd most commonly prescribed medication in the United States, with more than 1 million prescriptions. Medical uses Fexofenadine is used for relief from physical symptoms associated with seasonal allergic rhinitis and for treatment of chronic urticaria. It does not cure, but rather prevents the aggravation of allergic rhinitis and chronic idiopathic urticaria, and reduces the severity of the symptoms associated with those conditions, providing relief from repeated sneezing, runny nose, itchy eyes or skin, and general body fatigue. In a 2018 review, fexofenadine, along with levocetirizine, desloratadine, and cetirizine, was cited to be a safe to use for individuals with inherited long QT syndrome. Efficacy For the treatment of allergic rhinitis, fexofenadine is similarly effective to cetirizine, but is associated with less drowsiness than cetirizine. Fexofenadine was also shown to inhibit histamine-induced wheal and flare to a significantly greater degree than loratadine or desloratadine, but was slightly less effective than levocetirizine.Fexofenadine at doses above 120 mg a day does not appear to provide additional efficacy in the treatment of allergic rhinitis. Side effects The most common side effects include headache, back and muscle pain, miosis or pinpoint pupils, nausea, drowsiness, and menstrual cramps. Anxiety and insomnia have also been rarely reported. The most common side effects demonstrated during clinical trials were cough, upper respiratory tract infection, fever, and otitis media for children ages 6 to 11 and fatigue for children ages 6 months to 5 years. Overdose The safety profile of fexofenadine is quite favorable, as no cardiovascular or sedative effects have been shown to occur even when taking 10 times the recommended dose. Research on humans ranges from a single 800-mg dose, to a twice-daily, 690-mg dose for a month, with no clinically significant adverse effects, when compared to a placebo. No deaths occurred in testing on mice, at 5000 mg/kg body weight, which is 110 times the maximum recommended dose for an adult human. If overdose were to occur, supportive measures are recommended. Theoretically, an overdose could present as dizziness, dry mouth, and/or drowsiness, consistent with an exaggeration of the usual side effects. Hemodialysis does not appear to be an effective means of removing fexofenadine from the blood. Pharmacology Pharmacodynamics Fexofenadine is a selective peripheral H1 receptor antagonist. Blockage prevents the activation of the H1 receptors by histamine, preventing the symptoms associated with allergies from occurring. Fexofenadine does not readily cross the blood–brain barrier, so is less likely to cause drowsiness in comparison to other antihistamines that readily cross that barrier (i.e., first-generation antihistamines such as diphenhydramine). In general, fexofenadine takes about an hour to take effect, though this may be affected by the choice of dosage form and the presence of certain foods.Fexofenadine also exhibits no anticholinergic, antidopaminergic, alpha 1-adrenergic, or beta-adrenergic receptor-blocking effects. Pharmacokinetics Absorption: After oral application, maximum plasma concentrations are reached after 2–3 hours. Fexofenadine should not be taken with a high-fat meal, as mean concentrations of fexofenadine in the bloodstream are seen to be reduced from 20 to 60% depending on form of medication (tablet, ODT, or suspension). Distribution: Fexofenadine is 60–70% bound to plasma proteins, mostly albumin. Metabolism: Fexofenadine is a substrate of CYP3A4, but only about 5% is metabolized by the liver, indicating that hepatic metabolism is relatively minor in clearance from the body. Elimination: Most of the substance is eliminated unchanged via the feces (80%) and urine (11–12%). Interactions Taking erythromycin or ketoconazole while taking fexofenadine does increase the plasma levels of fexofenadine, but this increase does not influence the QT interval. The reason for this effect is likely due to transport-related effects, specifically involving p-glycoprotein (p-gp). Both erythromycin and ketoconazole are inhibitors of p-gp, a transporter protein involved in preventing the intestinal absorption of fexofenadine. When p-gp is inhibited, fexofenadine may be better absorbed by the body, increasing its plasma concentration by more than intended.Fexofenadine is not to be taken with apple, orange, or grapefruit juice because they could decrease absorption of the drug. Therefore, it should be taken with water. Grapefruit juice can significantly reduce the plasma concentration of fexofenadine.Antacids containing aluminum or magnesium should not be taken within 15 minutes of fexofenadine, as they reduce its absorption by almost 50%. This is not thought to be due to a change in pH (in fact, absorption can actually increase under increasingly alkaline pH), but rather due to the formation of metal complexes with charged/polar moieties on fexofenadine. As suggested by Shehnaza et al (2014), various sites of the molecule are thought to be responsible for this interaction, including the piperidine nitrogen, the carboxylic acid (-COOH) group, and both hydroxyl (-OH) groups. History The older antihistaminic agent terfenadine was found to metabolize into the related carboxylic acid, fexofenadine. Fexofenadine was found to retain all of the biological activity of its parent, while giving fewer adverse reactions in patients, so terfenadine was replaced in the market by its metabolite. Fexofenadine was originally synthesized in 1993 by Massachusetts-based biotechnology company Sepracor, which then sold the development rights to Hoechst Marion Roussel (now part of Sanofi-Aventis), and was later approved by the U.S. Food and Drug Administration (FDA) in 1996. Albany Molecular Research Inc. (AMRI) holds the patents to the intermediates and production of fexofenadine HCl, along with Roussel. Since that time, it has achieved blockbuster drug status with global sales of US$1.87B in 2004 (with $1.49B coming from the United States). AMRI received royalty payments from Aventis that enabled the growth of AMRI.In January 2011, the FDA approved over-the-counter sales of fexofenadine in the United States, and Sanofi Aventis version became available in March 2011. Society and culture Brand names Fexofenadine is marketed under many brand names worldwide as of January 2017, including: Agimfast, Alafree, Alanil, Alercas, Alerfedine, Alerix, Alertam, Alexia, Allegix, Allegra, Allegratab, Allemax, Allerfast, Allerfen, Allerfexo, Allergo, Allergyna, Allerphast, Allevia, Alrin, Alterfast, Aller-Fex, Altifex, Altiva, Aspen, Axodin, Axofen, BiXin, Bosnum, Dinafex, Elwigra, Ewofex, Fastel, Fastofen, Fastway, Fe Min, Feksine, Fenadex, Fenadin, Fenafex, Fenax, Fenofex, Fentradol, Fesler, Fexadyne, Fexal, Fexalar, Fexallegra, Fexaway, Fexet, Fexgen, Fexidine, Fexigra, Fexine, Fexo, Fexodane, Fexodine, Fexodis, Fexofast, Fexofen, Fexofenaderm, Fexofenadin, Fexofenadina, Fexofenadine, Fexofénadine, Fexofep, Fexofin, Fexogen, Fexomin, Fexon, Fexona, Fexonadinea, Fexoquit, Fexoral, Fexoril, Fexostad, Fexotine, Fexovid, Fixal, Fixit, Fixodin, Flexofen, Foxin, Fynadin, Glodas, Hasalfast, Histafree, Imexofen, Kofixir, Lai Duo Fei, Mayfex, Min Jie, Nefoxef, Neofex, Nolargy, Nosedex, Odafen, Oregra, Radifex, Raltiva, Rapido, Rhinogan, Ridrinal, Rinofen, Rinolast, Ritch, Rui Fei, Sailexi, Tefodine, Telfadin, Telfast, Telfastin, Telfexo, Tellerge, Terfemax, Ternafast, Tocimat, Tofexo, Torfast, Treathay, Vifas, Vifasesh, X-Dine, Xergic, and Zefeksal.As of January 2017, it is marketed as a combination drug with pseudoephedrine under brand names including: Alerfedine D, Allegra-D, Allergyna-D, Altiva-D, Dellegra, Fexo Plus, Fexofed, Fixal Plus, Ridrinal D, Rinolast D, and Telfast D.As of January 2017, it is marketed as a combination drug with montelukast under brand names including Fexokast, Histakind-M, Monten-FX, Montolife-FX, Montair-FX and Novamont-FX. References External links "Fexofenadine". Drug Information Portal. U.S. National Library of Medicine. "Fexofenadine hydrochloride". Drug Information Portal. U.S. National Library of Medicine.
Alprazolam
Alprazolam, sold under the brand name Xanax, among others, is a fast-acting, potent tranquilizer of medium duration in the triazolobenzodiazepine (TBZD) class, which are benzodiazepines (BZDs) fused with a triazole ring. It is most commonly used in short-term management of anxiety disorders, specifically panic disorder or generalized anxiety disorder (GAD). Other uses include the treatment of chemotherapy-induced nausea, together with other treatments. GAD improvement occurs generally within a week. Alprazolam is generally taken by mouth.Common side effects include sleepiness, depression, headaches, feeling tired, dry mouth, and memory problems. Some of the sedation and tiredness may improve within a few days. Due to concerns about misuse, some do not recommend alprazolam as an initial treatment for panic disorder. Withdrawal or rebound symptoms may occur if use is suddenly decreased; gradually decreasing the dose over weeks or months may be required. Other rare risks include suicide and a twofold increased risk of all-cause mortality. Alprazolam, like other benzodiazepines, acts through the GABAA receptor.Alprazolam was patented in 1971 and approved for medical use in the United States in 1981. Alprazolam is a Schedule IV controlled substance and is a common drug of abuse. It is available as a generic medication. In 2020, it was the 37th most-commonly-prescribed medication in the United States, with more than 16 million prescriptions. Medical uses Alprazolam is mostly used in short-term management of anxiety disorders, panic disorders, and nausea due to chemotherapy. Alprazolam is indicated for the treatment of generalized anxiety disorder and panic disorder with or without agoraphobia in adults. The FDA label advises that the physician should periodically reassess the usefulness of the drug. Panic disorder Alprazolam is effective in the relief of moderate to severe anxiety and panic attacks. However, it is not a first-line treatment since the development of selective serotonin reuptake inhibitors. Alprazolam is not recommended in Australia for the treatment of panic disorder because of concerns regarding tolerance, dependence, and abuse. Most evidence shows that the benefits of alprazolam in treating panic disorder last only four to ten weeks. However, people with panic disorder have been treated on an open basis for up to eight months without apparent loss of benefit.Alprazolam is recommended by the World Federation of Societies of Biological Psychiatry (WFSBP) for treatment-resistant cases of panic disorder where there is no history of tolerance or dependence. Anxiety disorders Anxiety associated with depression is responsive to alprazolam. Clinical studies have shown that the effectiveness is limited to 4 months for anxiety disorders. However, the research into antidepressant properties of alprazolam is poor and has only assessed its short-term effects against depression. In one study, some long term, high-dosage users of alprazolam developed reversible depression. In the US, alprazolam is FDA-approved for the management of anxiety disorders (a condition corresponding most closely to the APA Diagnostic and Statistical Manual DSM-IV-TR diagnosis of generalized anxiety disorder) or the short-term relief of symptoms of anxiety. In the UK, alprazolam is recommended for the short-term treatment (2–4 weeks) of severe acute anxiety. Nausea due to chemotherapy Alprazolam may be used in combination with other medications for chemotherapy-induced nausea and vomiting. Contraindications Benzodiazepines require special precaution if used in children and in alcohol- or drug-dependent individuals. Particular care should be taken in pregnant or elderly people, people with substance use disorder history (particularly alcohol dependence), and people with comorbid psychiatric disorders. The use of alprazolam should be avoided or carefully monitored by medical professionals in individuals with: myasthenia gravis, acute narrow-angle glaucoma, severe liver deficiencies (e.g., cirrhosis), severe sleep apnea, pre-existing respiratory depression, marked neuromuscular respiratory, acute pulmonary insufficiency, chronic psychosis, hypersensitivity or allergy to alprazolam or other benzodiazepines, and borderline personality disorder (where it may induce suicidality and dyscontrol).Like all central nervous system depressants, alprazolam in larger-than-normal doses can cause significant deterioration in alertness and increase drowsiness, especially in those unaccustomed to the drugs effects.Elderly individuals should be cautious in the use of alprazolam due to the possibility of increased susceptibility to side-effects, especially loss of coordination and drowsiness. Side effects Sedative drugs, including alprazolam, have been associated with an increased risk of death.Possible side effects include: Anterograde amnesia and concentration problems Ataxia, slurred speech Disinhibition Drowsiness, dizziness, lightheadedness, fatigue, unsteadiness, and impaired coordination, vertigo Dry mouth (infrequent) Hallucinations (rare) Jaundice (very rare) Seizures (less common) Skin rash, respiratory depression, constipation Suicidal ideation or suicide Urinary retention (infrequent) Muscle weaknessIn September 2020, the U.S. Food and Drug Administration (FDA) required the boxed warning be updated for all benzodiazepine medicines to describe the risks of abuse, misuse, addiction, physical dependence, and withdrawal reactions consistently across all the medicines in the class. Paradoxical reactions Although unusual, the following paradoxical reactions have been shown to occur: Aggression Mania, agitation, hyperactivity, and restlessness Rage, hostility Twitches and tremor Food and drug interactions Alprazolam is primarily metabolized via CYP3A4. Combining CYP3A4 inhibitors such as cimetidine, erythromycin, norfluoxetine, fluvoxamine, itraconazole, ketoconazole, nefazodone, propoxyphene, and ritonavir delay the hepatic clearance of alprazolam, which may result in its accumulation and increased severity of its side effects.Imipramine and desipramine have been reported to increase an average of 31% and 20% respectively by the concomitant administration of alprazolam tablets. Combined oral contraceptive pills reduce the clearance of alprazolam, which may lead to increased plasma levels of alprazolam and accumulation.Alcohol is one of the most common interactions; alcohol and alprazolam taken in combination have a synergistic effect on one another, which can cause severe sedation, behavioral changes, and intoxication. The more alcohol and alprazolam taken, the worse the interaction. Combination of alprazolam with the herb kava can result in the development of a semi-comatose state. Plants in the genus Hypericum (including St. Johns wort) conversely can lower the plasma levels of alprazolam and reduce its therapeutic effect. Pregnancy and breastfeeding Benzodiazepines cross the placenta, enter the fetus, and are also excreted in breast milk. Chronic administration of diazepam, another benzodiazepine, to nursing mothers has been reported to cause their infants to become lethargic and to lose weight.The use of alprazolam during pregnancy is associated with congenital abnormalities, and use in the last trimester may cause fetal drug dependence and withdrawal symptoms in the post-natal period as well as neonatal flaccidity and respiratory problems. However, in long-term users of benzodiazepines, abrupt discontinuation due to concerns of teratogenesis has a high risk of causing extreme withdrawal symptoms and a severe rebound effect of the underlying mental health disorder. Spontaneous abortions may also result from abrupt withdrawal of psychotropic medications, including benzodiazepines. Overdose The maximum recommended daily dose is 10 milligrams per day.Overdoses of alprazolam can be mild to severe depending on the quantity ingested and if other drugs are taken in combination.Alprazolam overdoses cause excess central nervous system (CNS) depression and may include one or more of the following symptoms: Coma and death if alprazolam is combined with other substances. Fainting Hypotension (low blood pressure) Hypoventilation (shallow breathing) Impaired motor functions Dizziness Impaired balance Impaired or absent reflexes Muscle weakness Orthostatic hypotension (fainting while standing up too quickly) Somnolence (drowsiness) Dependence and withdrawal The potential for misuse among those taking it for medical reasons is controversial, with some expert reviews stating that the risk is low and similar to that of other benzodiazepine drugs. Others state that there is a substantial risk of misuse and dependence in both patients and non-medical users and that the short half-life and rapid onset of action may increase the risk of misuse. Compared to the large number of prescriptions, relatively few individuals increase their dose on their own initiative or engage in drug-seeking behavior.Alprazolam, like other benzodiazepines, binds to specific sites on the GABAA (gamma-aminobutyric acid) receptor. When bound to these sites, which are referred to as benzodiazepine receptors, it modulates the effect of GABAA receptors and, thus, of GABAergic neurons. Long-term use causes adaptive changes in the benzodiazepine receptors, making them less sensitive to stimulation and thus making the drugs less potent.Withdrawal and rebound symptoms commonly occur and necessitate a gradual reduction in dosage to minimize withdrawal effects when discontinuing.Not all withdrawal effects are evidence of true dependence or withdrawal. Recurrence of symptoms such as anxiety may simply indicate that the drug was having its expected anti-anxiety effect and that, in the absence of the drug, the symptom has returned to pretreatment levels. If the symptoms are more severe or frequent, the person may be experiencing a rebound effect due to the removal of the drug. Either of these can occur without the person actually being drug dependent.Alprazolam and other benzodiazepines may also cause the development of physical dependence, tolerance, and benzodiazepine withdrawal symptoms during rapid dose reduction or cessation of therapy after long-term treatment. There is a higher chance of withdrawal reactions if the drug is administered in a higher dosage than recommended, or if a person stops taking the medication altogether without slowly allowing the body to adjust to a lower-dosage regimen.In 1992, Romach and colleagues reported that dose escalation is not a characteristic of long-term alprazolam users and that the majority of long-term alprazolam users change their initial pattern of regular use to one of symptom control only when required.Some common symptoms of alprazolam discontinuation include malaise, weakness, insomnia, tachycardia, lightheadedness, and dizziness.Those taking more than 4 mg per day have an increased potential for dependence. This medication may cause withdrawal symptoms upon abrupt withdrawal or rapid tapering, which in some cases have been known to cause seizures, as well as marked delirium similar to that produced by the anticholinergic tropane alkaloids of Datura (scopolamine and atropine). The discontinuation of this medication may also cause a reaction called rebound anxiety. In a 1983 study, only 5% of patients who had abruptly stopped taking long-acting benzodiazepines after less than 8 months demonstrated withdrawal symptoms, but 43% of those who had been taking them for more than 8 months did. With alprazolam – a short-acting benzodiazepine – taken for 8 weeks, 65% of patients experienced significant rebound anxiety. To some degree, these older benzodiazepines are self-tapering.The benzodiazepines diazepam and oxazepam have been found to produce fewer withdrawal reactions than alprazolam, temazepam, or lorazepam. Factors that determine the risk of psychological dependence or physical dependence and the severity of the benzodiazepine withdrawal symptoms during dose reduction of alprazolam include: dosage used, length of use, frequency of dosing, personality characteristics of the individual, previous use of cross-dependent/cross-tolerant drugs (alcohol or other sedative-hypnotic drugs), current use of cross-dependent/-tolerant drugs, use of other short-acting, high-potency benzodiazepines, and method of discontinuation. Pharmacology Alprazolam is a positive allosteric modulator of the gamma-aminobutyric acid (GABA) type A receptor. When it binds to the receptor, effects of GABA are enhanced leading to inhibition of neurons in the brain. This results in effects including reduced anxiety, muscle relaxant, antidepressant and anticonvulsant activity. The activity of alprazolam in the central nervous system is dose dependent. Mechanism of action Alprazolam is classed as a high-potency triazolobenzodiazepine: a benzodiazepine with a triazole ring attached to its structure. As a benzodiazepine, alprazolam produces a variety of therapeutic and adverse effects by binding to the GABAA benzodiazepine receptor site and modulating its function; GABA receptors are the most prolific inhibitory receptor within the brain. The GABA chemical and receptor system mediates inhibitory or calming effects of alprazolam on the nervous system. Binding of alprazolam to the GABAA receptor, a chloride ion channel, enhances the effects of GABA, a neurotransmitter. When GABA binds the GABAA receptor the channel opens and chloride enters the cell which makes it more resistant to depolarisation. Therefore, alprazolam has a depressant effect on synaptic transmission to reduce anxiety.The GABAA receptor is made up of 5 subunits out of a possible 19, and GABAA receptors made up of different combinations of subunits have different properties, different locations within the brain, and, importantly, different activities with regard to benzodiazepines. Alprazolam and other triazolobenzodiazepines such as triazolam that have a triazole ring fused to their diazepine ring appear to have antidepressant properties. This is perhaps due to the similarities shared with tricyclic antidepressants, as they have two benzene rings fused to a diazepine ring. Alprazolam causes a marked suppression of the hypothalamic–pituitary–adrenal axis. The therapeutic properties of alprazolam are similar to other benzodiazepines and include anxiolytic, anticonvulsant, muscle relaxant, hypnotic and amnesic; however, it is used mainly as an anxiolytic. Giving alprazolam, as compared to lorazepam, has been demonstrated to elicit a statistically significant increase in extracellular dopamine D1 and D2 concentrations in the striatum. Pharmacokinetics Alprazolam is taken orally, and is absorbed well – 80% of alprazolam binds to proteins in the serum (the majority binding to albumin). The concentration of alprazolam peaks after one to two hours.Alprazolam is metabolized in the liver, mostly by the enzyme cytochrome P450 3A4 (CYP3A4). Two major metabolites are produced: 4-hydroxyalprazolam and α-hydroxyalprazolam, as well as an inactive benzophenone. The low concentrations and low potencies of 4-hydroxyalprazolam and α-hydroxyalprazolam indicate that they have little to no contribution to the effects of alprazolam.The metabolites, as well as some unmetabolized alprazolam, are filtered out by the kidneys and are excreted in the urine. Chemistry Physical properties Alprazolam is a triazole and benzodiazepine derivative substituted with a phenyl group at position 6, with a chlorine atom at position 8 and with a methyl group at position 1. It is an analogue of triazolam, the difference between them being the absence of a chlorine atom in the ortho position of the phenyl ring. It is slightly soluble in chloroform, soluble in alcohol, slightly soluble in acetone and insoluble in water. It has a melting point of 228–229.5 °C (442.4–445.1 °F; 501.1–502.6 K). Synthesis For the synthesis of alprazolam the same method can be used as for triazolam, excepting that it starts from 2-amino-5-chlorobenzophenone. However, an alternative easier synthesis starting with 2,6-dichloro-4-phenylquinoline has been suggested, in which it reacts with hydrazine giving 6-chloro-2-hydrazino-4-phenylquinoline. Boiling the mixture with triethyl orthoacetate results in cyclization with the formation of the triazole ring. The product undergoes oxidative degradation in the presence of periodate and ruthenium dioxide in acetone solution, giving 2-[4-(3-methyl-1,2,4-triazolo)]-5-chlorobenzophenone. Oxy-methylation with formaldehyde results in a product that is treated with phosphorus tribromide, when 2-[4-(3-methyl-5-bromomethyl-1,2,4-triazolo)]-5-chlorobenzophenone is obtained. By substituting the bromine atom with an amino group conferred by ammonia, it forms alprazolam triazolobenzophenone, following which an intermolecular heterocyclization takes place to obtain alprazolam. Detection Quantification of alprazolam in blood and plasma samples may be necessary to confirm a diagnosis of intoxication in hospitalized patients, or to provide evidence in the case of crimes e.g., impaired driving arrest, or to assist in a thorough forensic investigation, e.g., in a medicolegal death investigation. Blood or plasma alprazolam concentrations are usually in a range of 10–100 μg/L in persons receiving the drug therapeutically, 100–300 μg/L in those arrested for impaired driving, and 300–2,000 μg/L in victims of acute overdosage. Most of the commercial immunoassays used for the benzodiazepine class of drugs cross-react with alprazolam, but confirmation and quantitative determination are usually done by chromatographic techniques. Forms of alprazolam Alprazolam regular release and orally disintegrating tablets are available as 0.25 mg, 0.5 mg, 1 mg, and 2 mg tablets, while extended release tablets are available as 0.5 mg, 1 mg, 2 mg, and 3 mg. Liquid alprazolam is available in a 1 mg/mL oral concentrate. Inactive ingredients in alprazolam tablets and solutions include microcrystalline cellulose, corn starch, docusate sodium, povidone, sodium starch glycolate, lactose monohydrate, magnesium stearate, colloidal silicon dioxide, and sodium benzoate. In addition, the 0.25 mg tablet contains D&C Yellow No. 10 and the 0.5 mg tablet contains FD&C Yellow No. 6 and D&C Yellow No. 10. Society and culture Patent Alprazolam is covered under U.S. Patent 3,987,052, which was filed on 29 October 1969, granted on 19 October 1976, and expired in September 1993. Recreational use There is a risk of misuse and dependence in both patients and non-medical users of alprazolam; alprazolams high affinity binding, high potency, and rapid onset increase its abuse potential. The physical dependence and withdrawal syndrome of alprazolam also add to its addictive nature. In the small subgroup of individuals who escalate their doses there is usually a history of alcohol or other substance use disorders. Despite this, most prescribed alprazolam users do not use their medication recreationally, and the long-term use of benzodiazepines does not generally correlate with the need for dose escalation. However, based on US findings from the Treatment Episode Data Set (TEDS), an annual compilation of patient characteristics in substance abuse treatment facilities in the United States, admissions due to "primary tranquilizer" (including, but not limited to, benzodiazepine-type) drug use increased 79% from 1992 to 2002, suggesting that misuse of benzodiazepines may be on the rise. In 2011, The New York Times reported, "The Centers for Disease Control and Prevention last year reported an 89 percent increase in emergency room visits nationwide related to nonmedical benzodiazepine use between 2004 and 2008."Alprazolam is one of the most commonly prescribed and misused benzodiazepines in the United States. A large-scale nationwide U.S. government study conducted by SAMHSA found that, in the U.S., benzodiazepines are recreationally the most frequently used pharmaceuticals due to their widespread availability, accounting for 35% of all drug-related visits to hospital emergency and urgent care facilities. Men and women are equally likely to use benzodiazepines recreationally. The report found that alprazolam is the most common benzodiazepine for recreational use, followed by clonazepam, lorazepam, and diazepam. The number of emergency department visits due to benzodiazepines increased by 36% between 2004 and 2006. Regarding the significant increases detected, it is worthwhile to consider that the number of pharmaceuticals dispensed for legitimate therapeutic uses may be increasing over time, and DAWN estimates are not adjusted to take such increases into account. Nor do DAWN estimates take into account the increases in the population or in ED use between 2004 and 2006. Those at a particularly high risk for misuse and dependence are people with a history of alcoholism or drug abuse and/or dependence and people with borderline personality disorder.Alprazolam, along with other benzodiazepines, is often used with other recreational drugs. These uses include aids to relieve the panic or distress of dysphoric ("bad trip") reactions to psychedelic drugs, such as LSD, and the drug-induced agitation and insomnia in the "comedown" stages of stimulant use, such as amphetamine, cocaine, and MDMA allowing sleep. Alprazolam may also be used with other depressant drugs, such as ethanol, heroin, and other opioids, in an attempt to enhance their psychological effects. Alprazolam may be used in conjunction with cannabis, with users citing a synergistic effect achieved after consuming the combination. The poly-drug use of powerful depressant drugs poses the highest level of health concerns due to a significant increase in the likelihood of experiencing an overdose, which may cause fatal respiratory depression.A 1990 study found that diazepam has a higher misuse potential relative to many other benzodiazepines and that some data suggest that alprazolam and lorazepam resemble diazepam in this respect.Anecdotally, injection of alprazolam has been reported, causing dangerous damage to blood vessels, closure of blood vessels (embolization) and decay of muscle tissue (rhabdomyolysis). Alprazolam is not very soluble in water—when crushed in water it does not fully dissolve (40 µg/ml of H2O at pH 7). There are also reports of alprazolam being snorted. Due to the low weight of a dose, alprazolam, in one case, was distributed on blotter paper in a manner similar to LSD. Popular culture Slang terms for alprazolam vary from place to place. Some of the more common terms are modified versions of the trade name "Xanax", such as Xannies (or Xanies) and the phonetic equivalent of Zannies; references to their drug classes, such as benzos or downers; or remark upon their shape or color (most commonly a straight, perforated tablet or an oval-shaped pill): bars, ladders, Xanbars, Xans, Z-bars, handle bars, beans, footballs, planks, poles, sticks, blues, or blue footballs. Availability Alprazolam is available in English-speaking countries under the following brand names: Alprax, Alprocontin, Alzam, Alzolam, Anzilum, Apo-Alpraz, Helex, Kalma, Mylan-Alprazolam, Niravam, Novo-Alprazol, Nu-Alpraz, Pacyl, Restyl, Tranax, Trika, Xycalm, Xanax, Xanor, Zolam, Zopax.In December 2013, in anticipation of the rescheduling of alprazolam to Schedule 8 in Australia, Pfizer Australia announced they would be discontinuing the Xanax brand in Australia as it was no longer commercially viable. Legal status Alprazolam has varied legal status depending on jurisdiction: In the United States, alprazolam is a prescription drug and is assigned to Schedule IV of the Controlled Substances Act by the Drug Enforcement Administration. Under the UK drug misuse classification system, benzodiazepines are Class C drugs (Schedule 4). In the UK, alprazolam is not available on the NHS and can only be obtained on a private prescription. In Ireland, alprazolam is a Schedule 4 medicine. In Sweden, alprazolam is a prescription drug in List IV (Schedule 4) under the Narcotics Drugs Act (1968). In the Netherlands, alprazolam is a List 2 substance of the Opium Law and is available for prescription. In Germany, alprazolam can be prescribed normally in doses up to 1 mg. Higher doses are scheduled as Anlage III drugs and require a special prescription form. In Australia, alprazolam was originally a Schedule 4 (Prescription Only) medication; however, as of February 2014, it has become a Schedule 8 medication, subjecting it to more rigorous prescribing requirements. In the Philippines, alprazolam is legally classified as a "dangerous drug" under the Comprehensive Dangerous Drugs Act of 2002, along with other schedule drugs listed in the 1971 Convention on Psychotropic Substances. The importation of dangerous drugs including alprazolam, requires authorization from the Philippine Drug Enforcement Agency.Internationally, alprazolam is included under the United Nations Convention on Psychotropic Substances as Schedule IV. References External links "Alprazolam". Drug Information Portal. U.S. National Library of Medicine.
Nitroglycerin
Nitroglycerin (NG), (alternative spelling nitroglycerine) also known as trinitroglycerin (TNG), nitro, glyceryl trinitrate (GTN), Nobel Oil, or 1,2,3-trinitroxypropane, is a dense, colorless, oily, explosive liquid most commonly produced by nitrating glycerol with white fuming nitric acid under conditions appropriate to the formation of the nitric acid ester. Chemically, the substance is an organic nitrate compound rather than a nitro compound, but the traditional name is retained. Invented in 1847 by Ascanio Sobrero, nitroglycerin has been used ever since as an active ingredient in the manufacture of explosives, namely dynamite, and as such it is employed in the construction, demolition, and mining industries. Since the 1880s, it has been used by the military as an active ingredient and gelatinizer for nitrocellulose in some solid propellants such as cordite and ballistite. It is a major component in double-based smokeless propellants used by reloaders. Combined with nitrocellulose, hundreds of powder combinations are used by rifle, pistol, and shotgun reloaders. Nitroglycerin has been used for over 130 years in medicine as a potent vasodilator (dilation of the vascular system) to treat heart conditions, such as angina pectoris and chronic heart failure. Though it was previously known that these beneficial effects are due to nitroglycerin being converted to nitric oxide, a potent venodilator, the enzyme for this conversion was only discovered to be mitochondrial aldehyde dehydrogenase (ALDH2) in 2002. Nitroglycerin is available in sublingual tablets, sprays, ointments, and patches. History Nitroglycerin was the first practical explosive produced that was stronger than black powder. It was first synthesized by the Italian chemist Ascanio Sobrero in 1847, working under Théophile-Jules Pelouze at the University of Turin. Sobrero initially called his discovery pyroglycerine and warned vigorously against its use as an explosive.Nitroglycerin was later adopted as a commercially useful explosive by Alfred Nobel, who experimented with safer ways to handle the dangerous compound after his younger brother, Emil Oskar Nobel, and several factory workers were killed in an explosion at the Nobels armaments factory in 1864 in Heleneborg, Sweden. One year later, Nobel founded Alfred Nobel and Company in Germany and built an isolated factory in the Krümmel hills of Geesthacht near Hamburg. This business exported a liquid combination of nitroglycerin and gunpowder called "Blasting Oil", but this was extremely unstable and difficult to handle, as evidenced in numerous catastrophes. The buildings of the Krümmel factory were destroyed twice.In April 1866, three crates of nitroglycerin were shipped to California for the Central Pacific Railroad, which planned to experiment with it as a blasting explosive to expedite the construction of the 1,659-foot-long (506 m) Summit Tunnel through the Sierra Nevada Mountains. One of the crates exploded, destroying a Wells Fargo company office in San Francisco and killing 15 people. This led to a complete ban on the transportation of liquid nitroglycerin in California. The on-site manufacture of nitroglycerin was thus required for the remaining hard-rock drilling and blasting required for the completion of the First Transcontinental Railroad in North America.In June 1869, two one-ton wagons loaded with nitroglycerin, then known locally as Powder-Oil, exploded in the road at the North Wales village of Cwm-y-glo. The explosion led to the loss of six lives, many injuries and much damage to the village. Little trace was found of the two horses. The UK Government was so alarmed at the damage caused and what could have happened in a city location (these two tons were part of a larger load coming from Germany via Liverpool) that they soon passed The Nitro-Glycerine Act of 1869. Liquid nitroglycerin was widely banned elsewhere, as well, and these legal restrictions led to Alfred Nobel and his companys developing dynamite in 1867. This was made by mixing nitroglycerin with diatomaceous earth ("Kieselguhr" in German) found in the Krümmel hills. Similar mixtures, such as "dualine" (1867), "lithofracteur" (1869), and "gelignite" (1875), were formed by mixing nitroglycerin with other inert absorbents, and many combinations were tried by other companies in attempts to get around Nobels tightly held patents for dynamite. Dynamite mixtures containing nitrocellulose, which increases the viscosity of the mix, are commonly known as "gelatins". Following the discovery that amyl nitrite helped alleviate chest pain, the physician William Murrell experimented with the use of nitroglycerin to alleviate angina pectoris and to reduce the blood pressure. He began treating his patients with small diluted doses of nitroglycerin in 1878, and this treatment was soon adopted into widespread use after Murrell published his results in the journal The Lancet in 1879. A few months before his death in 1896, Alfred Nobel was prescribed nitroglycerin for this heart condition, writing to a friend: "Isnt it the irony of fate that I have been prescribed nitro-glycerin, to be taken internally! They call it Trinitrin, so as not to scare the chemist and the public." The medical establishment also used the name "glyceryl trinitrate" for the same reason. Wartime production rates Large quantities of nitroglycerin were manufactured during World War I and World War II for use as military propellants and in military engineering work. During World War I, HM Factory, Gretna, the largest propellant factory in the United Kingdom, produced about 800 tonnes of cordite RDB per week. This amount required at least 336 tonnes of nitroglycerin per week (assuming no losses in production). The Royal Navy had its own factory at the Royal Navy Cordite Factory, Holton Heath, in Dorset, England. A large cordite factory was also built in Canada during World War I. The Canadian Explosives Limited cordite factory at Nobel, Ontario, was designed to produce 1,500,000 lb (680 t) of cordite per month, requiring about 286 tonnes of nitroglycerin per month. Instability and desensitization In its undiluted form, nitroglycerin is a contact explosive, with physical shock causing it to explode. If it has not been adequately purified during manufacture it can degrade over time to even more unstable forms. This makes nitroglycerin highly dangerous to transport or use. In its undiluted form, it is one of the worlds most powerful explosives, comparable to the more recently developed RDX and PETN. Early in its history, liquid nitroglycerin was found to be "desensitized" by freezing it at a temperature below 45 to 55 °F (7 to 13 °C) depending on its purity. Its sensitivity to shock while frozen is somewhat unpredictable: "It is more insensitive to the shock from a fulminate cap or a rifle ball when in that condition but on the other hand it appears to be more liable to explode on breaking, crushing, tamping, etc." Frozen nitroglycerine is much less energetic than liquid, and so must be thawed before use. Thawing it out can be extremely sensitizing, especially if impurities are present or the warming is too rapid. Ethylene glycol dinitrate or another polynitrate may be added to lower the melting point and thereby avoid the necessity of thawing frozen explosive.Chemically "desensitizing" nitroglycerin is possible to a point where it can be considered about as "safe" as modern high explosives, such as by the addition of ethanol, acetone, or dinitrotoluene. The nitroglycerin may have to be extracted from the desensitizer chemical to restore its effectiveness before use, for example by adding water to draw off ethanol used as a desensitizer. Detonation Nitroglycerin and any diluents can deflagrate (burn). The explosive power of nitroglycerin derives from detonation: energy from the initial decomposition causes a strong pressure wave that detonates the surrounding fuel. This is a self-sustained shock wave that propagates through the explosive medium at 30 times the speed of sound as a near-instantaneous pressure-induced decomposition of the fuel into a white-hot gas. Detonation of nitroglycerin generates gases that would occupy more than 1,200 times the original volume at ordinary room temperature and pressure. The heat liberated raises the temperature to about 5,000 °C (9,000 °F). This is entirely different from deflagration, which depends solely upon available fuel regardless of pressure or shock. The decomposition results in a much higher ratio of energy to gas moles released compared to other explosives, making it one of the hottest detonating high explosives. Manufacturing Nitroglycerin can be produced by acid-catalyzed nitration of glycerol (glycerin). The industrial manufacturing process often reacts glycerol with a nearly 1:1 mixture of concentrated sulfuric acid and concentrated nitric acid. This can be produced by mixing white fuming nitric acid—a quite expensive pure nitric acid in which the oxides of nitrogen have been removed, as opposed to red fuming nitric acid, which contains nitrogen oxides—and concentrated sulfuric acid. More often, this mixture is attained by the cheaper method of mixing fuming sulfuric acid, also known as oleum—sulfuric acid containing excess sulfur trioxide—and azeotropic nitric acid (consisting of about 70% nitric acid, with the rest being water). The sulfuric acid produces protonated nitric acid species, which are attacked by glycerols nucleophilic oxygen atoms. The nitro group is thus added as an ester C−O−NO2 and water is produced. This is different from an electrophilic aromatic substitution reaction in which nitronium ions are the electrophile. The addition of glycerol results in an exothermic reaction (i.e., heat is produced), as usual for mixed-acid nitrations. If the mixture becomes too hot, it results in a runaway reaction, a state of accelerated nitration accompanied by the destructive oxidation of organic materials by the hot nitric acid and the release of poisonous nitrogen dioxide gas at high risk of an explosion. Thus, the glycerin mixture is added slowly to the reaction vessel containing the mixed acid (not acid to glycerin). The nitrator is cooled with cold water or some other coolant mixture and maintained throughout the glycerin addition at about 22 °C (72 °F), hot enough for esterification to occur at a fast rate but cold enough to avoid runaway reaction. The nitrator vessel, often constructed of iron or lead and generally stirred with compressed air, has an emergency trap door at its base, which hangs over a large pool of very cold water and into which the whole reaction mixture (called the charge) can be dumped to prevent an explosion, a process referred to as drowning. If the temperature of the charge exceeds about 30 °C (86 °F) (actual value varying by country) or brown fumes are seen in the nitrators vent, then it is immediately drowned. Use as an explosive and a propellant The main use of nitroglycerin, by tonnage, is in explosives such as dynamite and in propellants. Nitroglycerin is an oily liquid that may explode when subjected to heat, shock, or flame. Alfred Nobel developed the use of nitroglycerin as a blasting explosive by mixing nitroglycerin with inert absorbents, particularly "Kieselgur", or diatomaceous earth. He named this explosive dynamite and patented it in 1867. It was supplied ready for use in the form of sticks, individually wrapped in greased waterproof paper. Dynamite and similar explosives were widely adopted for civil engineering tasks, such as in drilling highway and railroad tunnels, for mining, for clearing farmland of stumps, in quarrying, and in demolition work. Likewise, military engineers have used dynamite for construction and demolition work. Nitroglycerin was also used as an ingredient in military propellants for use in firearms. Nitroglycerin has been used in conjunction with hydraulic fracturing, a process used to recover oil and gas from shale formations. The technique involves displacing and detonating nitroglycerin in natural or hydraulically induced fracture systems, or displacing and detonating nitroglycerin in hydraulically induced fractures followed by wellbore shots using pelletized TNT.Nitroglycerin has an advantage over some other high explosives that on detonation it produces practically no visible smoke. Therefore, it is useful as an ingredient in the formulation of various kinds of smokeless powder.Its sensitivity has limited the usefulness of nitroglycerin as a military explosive, and less sensitive explosives such as TNT, RDX, and HMX have largely replaced it in munitions. It remains important in military engineering, and combat engineers still use dynamite. Alfred Nobel then developed ballistite, by combining nitroglycerin and guncotton. He patented it in 1887. Ballistite was adopted by a number of European governments, as a military propellant. Italy was the first to adopt it. The British government and the Commonwealth governments adopted cordite instead, which had been developed by Sir Frederick Abel and Sir James Dewar of the United Kingdom in 1889. The original Cordite Mk I consisted of 58% nitroglycerin, 37% guncotton, and 5.0% petroleum jelly. Ballistite and cordite were both manufactured in the form of "cords". Smokeless powders were originally developed using nitrocellulose as the sole explosive ingredient. Therefore, they were known as single-base propellants. A range of smokeless powders that contains both nitrocellulose and nitroglycerin, known as double-base propellants, were also developed. Smokeless powders were originally supplied only for military use, but they were also soon developed for civilian use and were quickly adopted for sports. Some are known as sporting powders. Triple-base propellants contain nitrocellulose, nitroglycerin, and nitroguanidine, but are reserved mainly for extremely high-caliber ammunition rounds such as those used in tank cannons and naval artillery. Blasting gelatin, also known as gelignite, was invented by Nobel in 1875, using nitroglycerin, wood pulp, and sodium or potassium nitrate. This was an early, low-cost, flexible explosive. Medical use Nitroglycerin belongs to a group of drugs called nitrates, which includes many other nitrates like isosorbide dinitrate (Isordil) and isosorbide mononitrate (Imdur, Ismo, Monoket). These agents all exert their effect by being converted to nitric oxide in the body by mitochondrial aldehyde dehydrogenase (ALDH2), and nitric oxide is a potent natural vasodilator. In medicine, nitroglycerin is probably most commonly prescribed for angina pectoris, a painful symptom of ischemic heart disease caused by inadequate flow of blood and oxygen to the heart and as a potent antihypertensive agent. Nitroglycerin corrects the imbalance between the flow of oxygen and blood to the heart and the heart’s energy demand. There are plenty of formulations on the market at different doses. At low doses, nitroglycerin dilates veins more than arteries, thereby reducing preload (volume of blood in the heart after filling); this is thought to be its primary mechanism of action. By decreasing preload, the heart has less blood to pump, which decreases oxygen requirement since the heart does not have to work as hard. Additionally, having a smaller preload reduces the ventricular transmural pressure (pressure exerted on the walls of the heart), which decreases the compression of heart arteries to allow more blood to flow through the heart. At higher doses, it also dilates arteries, thereby reducing afterload (decreasing the pressure against which the heart must pump). An improved ratio of myocardial oxygen demand to supply leads to the following therapeutic effects during episodes of angina pectoris: subsiding of chest pain, decrease of blood pressure, increase of heart rate, and orthostatic hypotension. Patients experiencing angina when doing certain physical activities can often prevent symptoms by taking nitroglycerin 5 to 10 minutes before the activity. Overdoses may generate methemoglobinemia.Nitroglycerin is available in tablets, ointment, solution for intravenous use, transdermal patches, or sprays administered sublingually. Some forms of nitroglycerin last much longer in the body than others. Nitroglycerin as well as the onset and duration of action of each form is different. The sublingual or tablet spray of nitroglycerin has a two minute onset and twenty five minute duration of action. The oral formulation of nitroglycerin has a thirty five minute onset and a duration of action of 4-8 hours. The transdermal patch has an onset of thirty minutes and a duration of action of ten to twelve hours. Continuous exposure to nitrates has been shown to cause the body to stop responding normally to this medicine. Experts recommend that the patches be removed at night, allowing the body a few hours to restore its responsiveness to nitrates. Shorter-acting preparations of nitroglycerin can be used several times a day with less risk of developing tolerance. Nitroglycerin was first used by William Murrell to treat angina attacks in 1878, with the discovery published that same year. Industrial exposure Infrequent exposure to high doses of nitroglycerin can cause severe headaches known as "NG head" or "bang head". These headaches can be severe enough to incapacitate some people; however, humans develop a tolerance to and dependence on nitroglycerin after long-term exposure. Although rare, withdrawal can be fatal. Withdrawal symptoms include chest pain and other heart problems. These symptoms may be relieved with re-exposure to nitroglycerin or other suitable organic nitrates.For workers in nitroglycerin (NTG) manufacturing facilities, the effects of withdrawal sometimes include "Sunday heart attacks" in those experiencing regular nitroglycerin exposure in the workplace, leading to the development of tolerance for the venodilating effects. Over the weekend, the workers lose the tolerance, and when they are re-exposed on Monday, the drastic vasodilation produces a fast heart rate, dizziness, and a headache. This is referred to as "Monday disease."People can be exposed to nitroglycerin in the workplace by breathing it in, skin absorption, swallowing it, or eye contact. The Occupational Safety and Health Administration has set the legal limit (permissible exposure limit) for nitroglycerin exposure in the workplace as 0.2 ppm (2 mg/m3) skin exposure over an 8-hour workday. The National Institute for Occupational Safety and Health has set a recommended exposure limit of 0.1 mg/m3 skin exposure over an 8-hour workday. At levels of 75 mg/m3, nitroglycerin is immediately dangerous to life and health. See also References External links "Nitroglycerine! Terrible Explosion and Loss of Lives in San Francisco". Central Pacific Railroad Photographic History Museum. Retrieved 23 March 2005. – 1866 Newspaper article WebBook page for C3H5N3O9 CDC - NIOSH Pocket Guide to Chemical Hazards The Tallini Tales of Destruction Detailed and horrific stories of the historical use of nitroglycerin-filled torpedoes to restart petroleum wells. Dynamite and TNT at The Periodic Table of Videos (University of Nottingham)
Topiramate
Topiramate, sold under the brand name Topamax among others, is a carbonic anhydrase inhibitor medication used to treat epilepsy and prevent migraines. It has also been used in alcohol dependence. For epilepsy this includes treatment for generalized or focal seizures. It is taken by mouth.Common side effects include tingling, feeling tired, loss of appetite, abdominal pain, weight loss, and decreased cognitive function such as trouble concentrating. Serious side effects may include suicide, increased ammonia levels resulting in encephalopathy, and kidney stones. Use in pregnancy may result in harm to the baby and use during breastfeeding is not recommended. How it works is unclear.Topiramate was approved for medical use in the United States in 1996. It is available as a generic medication. In 2020, it was the 57th most commonly prescribed medication in the United States, with more than 11 million prescriptions. Medical uses Topiramate is used to treat epilepsy in children and adults, and it was originally used as an anticonvulsant. In children, it is indicated for the treatment of Lennox-Gastaut syndrome, a disorder that causes seizures and developmental delay. It is most frequently prescribed for the prevention of migraines as it decreases the frequency of attacks. Topiramate is used to treat medication overuse headache and is recommended by the European Federation of Neurological Societies as one of the few medications showing effectiveness for this indication. Pain A 2018 review found topiramate of no use in chronic low back pain. Topiramate has not been shown to work as a pain medicine in diabetic neuropathy, the only neuropathic condition in which it has been adequately tested. Other One common off-label use for topiramate is in the treatment of bipolar disorder. A review published in 2010 suggested a benefit of topiramate in the treatment of symptoms of borderline personality disorder, however the authors noted that this was based only on one randomized controlled trial and requires replication.Topiramate has been used as a treatment for alcoholism. The Veterans Affairs and the Department of Defense 2015 guideline on substance use disorders lists topiramate as a "strong for" in its recommendations for alcohol use disorder.Other uses include treatment of obesity, binge eating disorder, and off-setting weight gain induced by taking antipsychotic medications. In 2012, the combination of phentermine/topiramate was approved in the United States for weight loss. It is being studied as a potential treatment for post traumatic stress disorder.There is some evidence for the use of topiramate in the management of cravings related to withdrawal from Dextromethorphan. Adverse effects People taking topiramate should be aware of the following risks: Avoid activities requiring mental alertness and coordination until drug effects are realized. Topiramate may impair heat regulation, especially in children. Use caution with activities leading to an increased core temperature, such as strenuous exercise, exposure to extreme heat, or dehydration. Topiramate may cause visual field defects. Topiramate may decrease effectiveness of oestrogen-containing oral contraceptives. Taking topiramate in the first trimester of pregnancy may increase risk of cleft lip/cleft palate in infant. As is the case for all antiepileptic drugs, it is advisable not to suddenly discontinue topiramate as there is a theoretical risk of rebound seizures. Frequency Adverse effects by incidence:Very common (>10% incidence) adverse effects include: Common (1-10% incidence) adverse effects include: Rarely, the inhibition of carbonic anhydrase may be strong enough to cause metabolic acidosis of clinical importance.The U.S. Food and Drug Administration (FDA) has notified prescribers that topiramate can cause acute myopia and secondary angle closure glaucoma in a small subset of people who take topiramate regularly. The symptoms, which typically begin in the first month of use, include blurred vision and eye pain. Discontinuation of topiramate may halt the progression of the ocular damage and may reverse the visual impairment. Preliminary data suggests that, as with several other anti-epileptic drugs, topiramate carries an increased risk of congenital malformations. This might be particularly important for women who take topiramate to prevent migraine attacks. In March 2011, the FDA notified healthcare professionals and patients of an increased risk of development of cleft lip and/or cleft palate (oral clefts) in infants born to women treated with Topamax (topiramate) during pregnancy and placed it in Pregnancy Category D.Topiramate has been associated with a statistically significant increase in suicidality, and "suicidal thoughts or actions" is now listed as one of the possible side effects of the drug "in a very small number of people, about 1 in 500." Overdose Symptoms of acute and acute on chronic exposure to topiramate range from asymptomatic to status epilepticus, including in patients with no seizure history. In children, overdose may also result in hallucinations. Topiramate has been deemed the primary substance that led to fatal overdoses in cases that were complicated by polydrug exposure. The most common signs of overdose are dilated pupils, somnolence, dizziness, psychomotor agitation, and abnormal, uncoordinated body movements.Symptoms of overdose may include but are not limited to: A specific antidote is not available. Treatment is entirely supportive. Interactions Topiramate has many drug-drug interactions. Some of the most common are listed below: As topiramate inhibits carbonic anhydrase, use with other inhibitors of carbonic anhydrase (e.g. acetazolamide) increases the risk of kidney stones. Enzyme inducers (e.g. carbamazepine) can increase the elimination of topiramate, possibly necessitating dose escalations of topiramate. Topiramate may increase the plasma-levels of phenytoin. Topiramate itself is a weak inhibitor of CYP2C19 and induces CYP3A4; a decrease in plasma levels of estrogens and digoxin has been noted during topiramate therapy. This can reduce the effectiveness of oral contraceptives (birth control pills); use of alternative birth control methods is recommended. Neither intrauterine devices (IUDs) nor Depo-Provera are affected by topiramate. Alcohol may cause increased sedation or drowsiness, and increase the risk of having a seizure. As topiramate may result in acidosis other treatments that also do so may worsen this effect. Oligohidrosis and hyperthermia were reported in post-marketing reports about topiramate; antimuscarinic drugs (like trospium) can aggravate these disorders. Pharmacology The topiramate molecule is a sulfamate modified sugar, more specifically, fructose diacetonide, an unusual chemical structure for a pharmaceutical. Topiramate is quickly absorbed after oral use. It has a half life of 21 hours and a steady state of the drug is reached in 4 days in patients with normal renal function. Most of the drug (70%) is excreted in the urine unchanged. The remainder is extensively metabolized by hydroxylation, hydrolysis, and glucuronidation. Six metabolites have been identified in humans, none of which constitutes more than 5% of an administered dose. Several cellular targets have been proposed to be relevant to the therapeutic activity of topiramate. These include (1) voltage-gated sodium channels; (2) high-voltage-activated calcium channels; (3) GABA-A receptors; (4) AMPA/kainate receptors; and (5) carbonic anhydrase isoenzymes. There is evidence that topiramate may alter the activity of its targets by modifying their phosphorylation state instead of by a direct action. The effect on sodium channels could be of particular relevance for seizure protection. Although topiramate does inhibit high-voltage-activated calcium channels, the relevance to clinical activity is uncertain. Effects on specific GABA-A receptor isoforms could also contribute to the antiseizure activity of the drug. Topiramate selectively inhibits cytosolic (type II) and membrane associated (type IV) forms of carbonic anhydrase. The action on carbonic anhydrase isoenzymes may contribute to the drugs side-effects, including its propensity to cause metabolic acidosis and calcium phosphate kidney stones. Topiramate inhibits maximal seizure activity in electroconvulsive therapy and in pentylenetetrazol-induced seizures as well as partial and secondarily generalized tonic-clonic seizures in the kindling model, findings predictive of a broad spectrum of activities clinically. Its action on mitochondrial permeability transition pores has been proposed as a mechanism.While many anticonvulsants have been associated with apoptosis in young animals, animal experiments have found that topiramate is one of the very few anticonvulsants [see: levetiracetam, carbamazepine, lamotrigine] that do not induce apoptosis in young animals at doses needed to produce an anticonvulsant effect. Detection in body fluids Blood, serum, or plasma topiramate concentrations may be measured using immunoassay or chromatographic methods to monitor therapy, confirm a diagnosis of poisoning in hospitalized patients, or to assist in a medicolegal death investigation. Plasma levels are usually less than 10 mg/L during therapeutic administration, but can range from 10 to 150 mg/L in overdose victims. History Topiramate was discovered in 1979 by Bruce E. Maryanoff and Joseph F. Gardocki during their research work at McNeil Pharmaceuticals. Topiramate was first sold in 1996. Mylan Pharmaceuticals was granted final approval by the FDA for the sale of generic topiramate in the United States and the generic version was made available in September 2006. The last patent for topiramate in the U.S. was for use in children and expired on 28 February 2009. References External links "Topiramate". Drug Information Portal. U.S. National Library of Medicine.
Eravacycline
Eravacycline (TP-434, Xerava) is a synthetic halogenated tetracycline class antibiotic by Tetraphase Pharmaceuticals. It is closely related to tigecycline. It has a broad spectrum of activity including many multi-drug resistant strains of bacteria. Phase III studies in complicated intra-abdominal infections (cIAI) and complicated urinary tract infections (cUTI) were recently completed with mixed results. Eravacycline was granted fast track designation by the FDA and is currently available in USA. Medical uses Eravacycline has shown broad spectrum of activity against a variety of Gram-positive and Gram-negative bacteria, including multi-drug resistant strains, such as methicillin-resistant Staphylococcus aureus (MRSA) and carbapenem-resistant Enterobacteriaceae. It is currently being formulated as for intravenous and oral administration. Spectrum of activity Gram-positive organisms Staphylococcus aureus (both methicillin-resistant and sensitive strains) Streptococcus pneumoniae Enterococcus faecalis Enterococcus faecium (including vancomycin resistant strains) Gram-negative organisms Acinetobacter baumannii Stenotrophomonas maltophilia Haemophilus influenzae Moraxella catarrhalis Neisseria gonorrhoeae Enterobacteriaceae Escherichia coli (including ESBL-producing strains) Klebsiella pneumoniae (including carbapenem resistant strains) Klebsiella oxytoca Enterobacter species Citrobacter species Proteus mirabilis Serratia marcescensSimilar to other tetracycline derivatives, eravacycline is poorly active against Pseudomonas aeruginosa with a MIC90 = 16 mcg/mL (range 0.06-64 mcg/mL). Eravacycline maintains in-vitro activity against Enterobacteriaceae carrying the mcr-1 gene responsible for polymyxin b/colistin resistance. Clinical trials Current and past clinical trial information: https://clinicaltrials.gov/ct2/results?cond=&term=eravacycline&cntry1=&state1=&recrs= Phase 3 trials Complicated Intra-abdominal infections (IGNITE 1) The IGNITE 1 trial compared twice-daily IV eravacycline to once-daily ertapenem for the treatment of cIAI. A total of 541 patients were included and eravacycline demonstrated noninferiority to ertapenem. An additional pivotal phase 3 study (IGNITE 4) is planned for late 2016 with initial results likely available in the fourth quarter of 2017. Complicated Intra-abdominal Infections (IGNITE 4) IGNITE 4 assessed twice-daily intravenous eravacycline(1.0 mg/kg every 12 hours) compared to those receiving meropenem (1g every 8 hours). The study enrolled 500 adult patients with the primary endpoint being clinical response at the test-of-cure visit which is 25–31 days after initial dosing. Primary efficiency analysis was conducted using a 12.5% non-inferiority margin in the microbiological intent-to-treat (micro-ITT) population. On July 25, 2017, Tetraphase pharmaceuticals released top line data via press showing clinical cure rates in the micro-ITT population to be 90.8% and 91.2% for eravacycline (n=195) and meropenem (n=205), respectively (95% CI: -6.3%,5.3%). Primary analysis was conducted using a 12.5% non-inferiority margin of the modified intent-to-treat (MITT) and clinically evaluable (CE) patient populations. Clinical cure rates in the MITT population were 92.4% and 91.6% for eravacycline (n=250) and meropenem (n=249), respectively (95% CI: -4.1%,5.8%). Clinical cure rates in the CE population were 96.9% and 96.1% for eravacycline (n=225) and meropenem (n=231), respectively (95% CI: -2.9%,4.5%). Eravacycline met the primary efficacy endpoints according to the FDA and EMA guidelines. The secondary analyses were consistent with, and supportive of, the primary outcome according to Tetraphase. There were no treatment-related serious adverse events (SAEs) in the trial. Treatment-emergent adverse event (TEAEs) rates were similar in both treatment groups with the most commonly reported drug-related adverse events (AEs) for eravacycline were infusion site reactions, nausea and vomiting, each occurring at a rate of less than 5%. The most common Gram-negative pathogens in the study included Escherichia coli, Klebsiella pneumoniae, Pseudomonas and Bacteroides. Full data from IGNITE4 will become available as the company prepares to submit its New Drug Application (NDA) in the first quarter of 2018 for Eravacycline treatment of Complicated Intra-abdominal Infections. Complicated Urinary Tract infections (IGNITE 2) The IGNITE 2 trial compared 7 days of IV eravacycline to IV levofloxacin with the option to convert patients in either group to oral therapy after 3 days for cUTI. Overall, eravacyline was inferior to levofloxacin in response rate (60.4 vs 66.9%); however it was noted that patients who completed therapy with the IV formulation had higher response rates, suggesting formulation issues with the oral option. Due to the performance of the IV formulation, an additional phase 3 trial is planned to support a supplemental NDA for the cUTI indication. Complicated Urinary Tract Infections (IGNITE 3) IGNITE3 is currently ongoing starting January 2017 with expected completion December 2018. This study is evaluating IV eravacycline (1.5 mg/kg every 24 hours) compared to ertapenem (1g every 24 hours) for the treatment of cUTI. IGNITE3 is currently enrolling approximately 1,000 patients who will be randomized 1:1 to receive intravenous eravacycline or ertapenem for a minimum of 5 days, and will then be eligible for transition to oral levofloxacin. The primary endpoints are Proportion of Participants in the microbiological Intent-to-treat (micro-ITT) Population demonstrating Clinical Cure and Microbiologic Success at the End of Intravenous (EOI) Visit [Time Frame: EOI visit (within 1 day of the completion of intravenous study drug treatment) ] & Proportion of Participants in the micro-ITT Population Demonstrating Clinical Cure and Microbiologic Success at the Test-Of-Cure (TOC) Visit [ Time Frame: TOC visit (14–17 days after randomization) ]. With secondary endpoints(outcomes) testing Proportion of Participants in the microbiological Modified Intent-To-Treat (micro-MITT) Population and the Microbiologically Evaluable (ME) Population Demonstrating Microbiologic Success at the TOC Visit [ Time Frame: TOC visit (14–17 days after randomization) ] Commercial information Eravacycline is under development by Tetraphase Pharmaceuticals Inc. It is marketed under trade name Xerava in United States. References External links "Tetraphase Announces Top-Line Results From IGNITE2 Phase 3 Clinical Trial of Eravacycline in cUTI: Eravacycline Did Not Achieve Primary Endpoint in Pivotal Portion of cUTI Trial" Tetraphase pipeline Process R&D of Eravacycline: The First Fully Synthetic Fluorocycline in Clinical Development
Factor VIII (medication)
Factor VIII is a medication used to treat and prevent bleeding in people with hemophilia A and other causes of low factor VIII. Certain preparations may also be used in those with von Willebrands disease. It is given by slow injection into a vein.Side effects include skin flushing, shortness of breath, fever, and red blood cell breakdown. Allergic reactions including anaphylaxis may occur. It is unclear if use during pregnancy is safe for the baby. A purified factor VIII concentrate is made from human blood plasma. A recombinant version is also available. People may develop antibodies to factor VIII such that this medication becomes less effective.Factor VIII was first identified in the 1940s and became available as a medication in the 1960s. Recombinant factor VIII was first made in 1984 and approved for medical use in the United States in 1992. It is on the World Health Organizations List of Essential Medicines. Available forms Factor VIII is delivered by intravenous infusion. History This transfer of a plasma byproduct into the blood stream of a hemophiliac often led to the transmission of diseases such as HIV and hepatitis before purification methods were improved. In the early 1990s, pharmaceutical companies began to produce recombinant synthesized factor products, which now prevent nearly all forms of disease transmission during replacement therapy. Society and culture Economics The cost of Factor VIII and similar clotting factors has been described as "highly expensive". The cost of the clotting factors is 80% of all medical costs for people with hemophilia. They are so expensive that gene therapy for haemophilia might be less expensive, especially for people with severe hemophilia. See also Damoctocog alfa pegol, a recombinant antihemophilic factor VIII Efmoroctocog alfa, a recombinant antihemophilic factor VIII Moroctocog alfa, a recombinant antihemophilic factor VIII Susoctocog alfa, a recombinant antihemophilic factor VIII Turoctocog alfa, a recombinant antihemophilic factor VIII References External links "Blood-coagulation factor VIII, procoagulant". Drug Information Portal. U.S. National Library of Medicine. "Beroctocog alfa". Drug Information Portal. U.S. National Library of Medicine. "Antihemophilic Factor (Recombinant) Monograph for Professionals". Drugs.com. "Antihemophilic Factor (Recombinant), Porcine Sequence Monograph for Professionals". Drugs.com. "Antihemophilic Factor (recombinant), Fc Fusion Protein Monograph for Professionals". Drugs.com. "Antihemophilic Factor (recombinant), Glycopegylated-exei Monograph for Professionals". Drugs.com.
Satralizumab
Satralizumab, sold under the brand name Enspryng, is a humanized monoclonal antibody medication that is used for the treatment of neuromyelitis optica spectrum disorder (NMOSD), a rare autoimmune disease. The drug is being developed by Chugai Pharmaceutical, a subsidiary of Roche.The most common side effects include the common cold (nasopharyngitis), headache, upper respiratory tract infection, inflammation of the lining of the stomach, rash, joint pain, extremity pain, fatigue and nausea.Satralizumab regulates inflammation by inhibiting the interleukin-6 (IL-6) receptor, a key mediator of the immune response.The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication. Medical uses Satralizumab is indicated for the treatment of neuromyelitis optica spectrum disorder (NMOSD) in adults with a particular antibody – people who are anti-aquaporin-4 or AQP4 antibody-positive.NMOSD is a rare autoimmune disease of the central nervous system that mainly affects the optic nerves and spinal cord. In people with NMOSD, the bodys immune system mistakenly attacks healthy cells and proteins in the body, most often those in the optic nerves and spinal cord. Individuals with NMOSD typically have attacks of optic neuritis, which causes eye pain and vision loss. Approximately 50% of people with NMOSD have permanent visual impairment and paralysis caused by NMOSD attacks. Estimates vary, but NMOSD is thought to impact approximately 4,000 to 8,000 Americans.NMOSD can be associated with antibodies that bind to a protein called aquaporin-4 (AQP4). Binding of the anti-AQP4 antibody appears to activate other components of the immune system, causing inflammation and damage to the central nervous system. Contraindications Vaccination with live-attenuated or live vaccines is not recommended during treatment and should be administered at least four weeks before starting satralizumab. Side effects The most common side effects observed were the common cold (nasopharyngitis), headache, upper respiratory tract infection, inflammation of the lining of the stomach, rash, joint pain, extremity pain, fatigue and nausea.The FDA label for satralizumab includes a warning for increased risk of infection, including serious and potentially fatal infections – such as potential reactivation of hepatitis B and tuberculosis. Other warnings and precautions for satralizumab include elevated liver enzymes, decreased neutrophil counts and hypersensitivity reactions. Pharmacology Mechanism of action Satralizumab is a humanized IgG2 monoclonal antibody that binds to soluble and membrane-bound human interleukin-6 (IL-6) receptors and thereby prevents IL-6-mediated signal transmission through these receptors.IL-6 is a pleiotropic cytokine that is produced by a large number of cell types and is involved in a variety of inflammatory processes. Patients with NMO and NMOSD have elevated levels of IL-6 in cerebro-spinal fluid and serum during periods of active disease. Some of the pro-inflammatory processes involved in NMOSD are thought to involve IL-6, including the formation of pathological autoantibodies against aquaporin-4 (AQP4), and the permeability of the blood-brain barrier to mediators of inflammation. Efficacy The effectiveness and safety of satralizumab for the treatment of neuromyelitis optica spectrum disorder (NMOSD) were demonstrated in two 96-week clinical studies.A study of satralizumab as monotherapy for NMOSD included 95 adult participants, 64 of whom had antibodies against AQP4 (i.e. were anti-AQP4 positive). During this study, treatment with satralizumab reduced the number of NMOSD relapses by 74% in participants who were anti-AQP4 positive compared to treatment with a placebo (inactive treatment).A study of satralizumab as an adjuvant to immunosuppressant treatment for NMOSD included 76 adult participants; 52 were anti-AQP4 positive. Immunosuppressant treatment in combination with satralizumab reduced the rate of relapses in participants who were anti-AQP4 positive by four-fifths compared to immunosuppressant treatment alone.The U.S. Food and Drug Administration (FDA) approved satralizumab based on evidence from two clinical trials (Trial 1/ NCT02073279 and Trial 2/NCT02028884) of 116 participants with NMOSD who were anti-aquaporin-4 (AQP4) antibody positive. The trials were conducted at 62 sites in the United States, Canada, Europe and Asia. Participants received at random either satralizumab or placebo injections according to the schedule. Neither the participants nor the healthcare providers knew which treatment was being given. In the second trial, all participants were also receiving their current immunosuppressive medications for the treatment of NMOSD. The benefit of satralizumab was evaluated by measuring the time to the first attack and comparing it to placebo.There was no evidence of a benefit in participants who were anti-AQP4 antibody negative in either trial. Society and culture Legal status Satralizumab was approved for the treatment of AQP4-IgG-seropositive NMOSD in Canada, Japan, and Switzerland.Satralizumab was approved for medical use in the United States in August 2020. The U.S. Food and Drug Administration (FDA) granted the application for satralizumab fast track and orphan drug designations. The FDA granted the approval of Enspryng to Genentech Inc. Satralizumab is the third approved treatment for NMOSD in the United States. Names Satralizumab is the international nonproprietary name (INN) and the United States Adopted Name (USAN). References External links "Satralizumab". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT02028884 for "Efficacy and Safety Study of Satralizumab (SA237) as Add-on Therapy to Treat Participants With Neuromyelitis Optica (NMO) and NMO Spectrum Disorder (NMOSD)" at ClinicalTrials.gov</ref> Clinical trial number NCT02073279 for "Efficacy and Safety Study of Satralizumab (SA237) as Monotherapy to Treat Participants With Neuromyelitis Optica (NMO) and Neuromyelitis Optica Spectrum Disorder (NMOSD)" at ClinicalTrials.gov
Safinamide
Safinamide (INN; brand name Xadago) is a drug used as an add-on treatment for Parkinsons disease with "off" episodes; it has multiple modes of action, including the inhibition of monoamine oxidase B.It was approved in the European Union in February 2015, in the United States in March 2017, and in Canada in January 2019. Medical uses Safinamide is used to treat idiopathic Parkinsons disease as add-on for people taking a stable dose of levodopa (L-dopa) alone or in combination with other Parkinson drugs, to help with "off" episodes when levodopa stops working. Contraindications Safinamide is contraindicated in people with severe liver impairment, with albinism, retinitis pigmentosa, severe diabetic neuropathy, uveitis and other disorders of the retina. Combination with other monoamine oxidase (MAO) inhibitors and pethidine is also contraindicated.It is not safe for women to take during pregnancy. It is excreted in breast milk and the effects on infants are unknown. Adverse effects Common adverse events in clinical trials (in more than 1% of people) included nausea, dizziness, tiredness, sleeplessness, orthostatic hypotension (low blood pressure), and headache. There was no significant difference in the occurrence of these effects between safinamide and placebo.In experiments with rats (but not in those with monkeys), retinopathies have been observed. Overdose Expected overdose effects are hypertension (high blood pressure), orthostatic hypotension, hallucinations, psychomotor agitation, nausea, vomiting, and dyskinesia. In studies, a single person was suspected to have overdosed for a month; symptoms were confusion, drowsiness and mydriasis (dilation of the pupils) and subsided completely after the drug was discontinued. No specific antidote is available. Interactions As a MAO inhibitor, safinamide can theoretically cause hypertensive crises, serotonin syndrome and other severe side effects when combined with other MAO inhibitors or with drugs that are known to interact with MAO inhibitors, such as pethidine, dextromethorphan, selective serotonin reuptake inhibitors (SSRIs), serotonin–noradrenaline reuptake inhibitors (SNRIs), tricyclic and tetracyclic antidepressants. An interaction with tyramine, a substance found in various foods, could be expected by the same reasoning but has been excluded in studies.Safinamide should not be given with opioids; some fatal reactions have occurred.Another theoretical interaction is with drugs with affinity to the transporter protein ABCG2 (also known as BCRP), such as pitavastatin, pravastatin, ciprofloxacin, methotrexate, and diclofenac; a study with the latter has shown no clinical relevance. A study testing possible interactions with amidase inhibitors is part of the post-authorisation development plan. There are no relevant interactions related to cytochrome P450 (CYP) liver enzymes, although one inactivation pathway of safinamide seems to be mediated by CYP3A4. Pharmacology Mechanisms of action Like the older antiparkinson drugs selegiline and rasagiline, safinamide is a selective monoamine oxidase B inhibitor, reducing degradation of dopamine; in contrast to the other two, its action is reversible. Safinamide also inhibits glutamate release and dopamine and serotonin reuptake. It binds to the sigma receptors as well, with IC50 values for binding inhibition of 19 nM for σ1 and 1,590 nM for σ2. Additionally, it blocks sodium and calcium channels, the relevance of which for its antiparkinson action is however unknown. Pharmacokinetics Safinamide is absorbed quickly and nearly completely from the gut and reaches highest blood plasma concentrations after 1.8 to 2.8 hours. There is no relevant first-pass metabolism; total bioavailability is 95%. The substance is bound to plasma proteins to 88–90%.The metabolism is not well understood. The principal step is mediated by amidases which have not been identified, and produces safinamide acid (NW-1153). Other relevant metabolites are O-debenzylated safinamide (NW-1199), the N-dealkylated amine which is then oxidized to a carboxylic acid (NW-1689), and the glucuronide of the latter. In tests with liver microsomes, dealkylation seemed to be mediated by CYP3A4, but other CYP enzymes appear to be involved as well. Safinamide acid binds to the organic anion transporter 3 (OAT3), but this has probably no clinical relevance. Safinamide itself transiently binds to ABCG2. No other transporter affinities have been found in preliminary studies.Safinamide is eliminated, mainly (>90%) in form of its metabolites, via the kidney, with an elimination half-life of 20 to 30 hours. Only 1.5% are found in the stool. History The compound was originally discovered at Farmitalia-Carlo Erba, which was acquired by Pharmacia in 1993. In 1995, Pharmacia merged with Upjohn. Safinamide was first disclosed in 1998. In the course of a major restructuring in the same year, all rights for safinamide were transferred to the newly formed company Newron Pharmaceuticals, which developed the drug until it was sold to Merck KGaA in 2006.In 2007, a Phase III clinical trial was started, scheduled to run until 2011. In October 2011 Merck, now Merck-Serono, announced that they would give all rights to develop the compound back to Newron because they wanted to prioritise other projects and had corrected their estimates for safinamides market potential downwards.The US Food and Drug Administration (FDA) refused to file Newrons application in 2014 on formal grounds. Newron re-applied in December 2014. In spring 2015, following a commercial agreement between Newron and the Italian pharmaceutical company Zambon, the European Medicines Agency (EMA) approved the drug. In the following years, the drug has been launched in several European countries. Safinamide is the first antiparkinson medication to be approved for ten years. Safinamide was approved by US FDA in March 2017 for people with Parkinsons taking levodopa/carbidopa during "off" episodes. Research Potential additional uses might be restless legs syndrome (RLS) and epilepsy. Safinamide was being tested in Phase II trials in 2008, but no results are available. When used as an adjunct to parkinsonian medication, safinamide was found to be efficacious in reducing pain in PD. References External links "Safinamide". Drug Information Portal. U.S. National Library of Medicine. "Safinamide mesylate". Drug Information Portal. U.S. National Library of Medicine.
Antacid
An antacid is a substance which neutralizes stomach acidity and is used to relieve heartburn, indigestion or an upset stomach. Some antacids have been used in the treatment of constipation and diarrhea. Marketed antacids contain salts of aluminum, calcium, magnesium, or sodium. Some preparations contain a combination of two salts, such as magnesium carbonate and aluminium hydroxide (e.g. hydrotalcite). Medical uses Antacids are available over the counter and are taken by mouth to quickly relieve occasional heartburn, the major symptom of gastroesophageal reflux disease and indigestion. Treatment with antacids alone is symptomatic and only justified for minor symptoms. Alternative uses for antacids include constipation, diarrhea, hyperphosphatemia, and urinary alkalization. Some antacids are also used as an adjunct to pancreatic enzyme replacement therapy in the treatment of pancreatic insufficiency.Non-particulate antacids (sodium citrate, magnesium trisilicate) increase gastric pH with little or no effect on gastric volume, and therefore may see some limited use in pre-operative procedures. Sodium citrate should be given within 1 hour of surgery to be the most effective. Side effects Conventional effervescent tablets contain a significant amount of sodium and are associated with increased odds of adverse cardiovascular events according to an 2013 study. Alternative sodium-free formulations containing magnesium salts may cause diarrhea, whereas those containing calcium or aluminum may cause constipation. Rarely, long-term use of calcium carbonate may cause kidney stones. Long-term use of antacids containing aluminum may increase the risk of developing osteoporosis. In vitro studies have found a potential for acid rebound to occur due to antacid overuse, however the significance of this finding has been called into question. Properties of antacids When an excess amount of acid is produced in the stomach, the natural mucous barrier that protects the lining of the stomach can degrade, leading to pain and irritation. There is also potential for the development of acid reflux, which can cause pain and damage to the esophagus. Antacids contain alkaline ions that chemically neutralize stomach gastric acid, reducing damage to the stomach lining and esophagus, and relieving pain. Some antacids also inhibit pepsin, an enzyme that can damage the esophagus in acid reflux.Antacids do not directly inhibit acid secretion, and thus are distinct from acid-reducing drugs like H2-receptor antagonists or proton pump inhibitors. Antacids do not kill the bacteria Helicobacter pylori, which causes most ulcers. Interactions Antacids are known to interact with several oral medications, including fluoroquinolone and tetracycline antibiotics, iron, itraconazole, and prednisone. Metal chelation is responsible for some of these interactions (e.g. fluoroquinolones, tetracyclines), leading to decreased absorption of the chelated drug. Some interactions may be due to the pH increase observed in the stomach following antacid ingestion, leading to increased absorption of weak acids, and decreased absorption of weak bases. Antacids also cause an increase in pH of the urine (alkalization), which may cause increased blood concentrations of weak bases, and increased excretion of weak acids.A proposed method to mitigate the effects of stomach acidity and chelation on drug absorption is to space out the administration of antacids with interacting medications, however this method has not been well studied for drugs affected by urine alkalization.There are concerns regarding interactions between delayed-release tablets and antacids, as antacids may increase the stomach pH to a point at which the coating of the delayed-release tablet will dissolve, leading to degradation of the drug if it is pH sensitive. Formulations Antacids may be formulated with other active ingredients such as simethicone to control gas, or alginic acid to act as a physical barrier to acid. Liquids Several liquid antacid preparations are marketed. Common liquid preparations include milk of magnesia and magnesium/aluminum combinations. A potential advantage of using a liquid preparation over a tablet is that liquids may provide quicker relief, however this may coincide with a shorter duration of action. Tablets Chewable tablets Chewable tablets are one of the most common forms of antacids, and are readily available over-the-counter. Upon reaching the stomach, the tablet powder will dissolve in the stomach acid, allowing the cations to be released and neutralize excess stomach acid. Common salts available in tablet form include those of calcium, magnesium, aluminum, and sodium.Some common brand are Tums, Gaviscon chewable tablets and Maalox chewable tablets. Effervescent tablets Effervescent tablets are tablets which are designed to dissolve in water, and then release carbon dioxide. Common ingredients include citric acid and sodium bicarbonate, which react when in contact with water to produce carbon dioxide. Effervescent antacids may also contain aspirin, sodium carbonate, or tartaric acid. Those containing aspirin may cause further gastric irritation and ulceration due to aspirins effects on the mucous membrane of the stomach.Common brands include Alka-Seltzer, Gaviscon, and Eno. References External links The dictionary definition of antacid at Wiktionary
Mitoxantrone
Mitoxantrone (INN, BAN, USAN; also known as Mitozantrone in Australia; trade name Novantrone) is an anthracenedione antineoplastic agent. Uses Mitoxantrone is used to treat certain types of cancer, mostly acute myeloid leukemia. It improves the survival rate of children suffering from acute lymphoblastic leukemia relapse.The combination of mitoxantrone and prednisone is approved as a second-line treatment for metastatic hormone-refractory prostate cancer. Until recently this combination was the first line of treatment; however, a combination of docetaxel and prednisone improves survival rates and lengthens the disease-free period.Mitoxantrone is also used to treat multiple sclerosis (MS), most notably the subset of the disease known as secondary-progressive MS. In the absence of a cure, mitoxantrone is effective in slowing the progression of secondary-progressive MS and extending the time between relapses in both relapsing-remitting MS and progressive-relapsing MS. Side effects Mitoxantrone, as with other drugs in its class, may cause adverse reactions of varying severity, including nausea, vomiting, hair loss, heart damage and immunosuppression, possibly with delayed onset. Cardiomyopathy is a particularly concerning effect as it is irreversible; thus regular monitoring with echocardiograms or MUGA scans is recommended for patients. Because of the risk of cardiomyopathy, mitoxantrone carries a limit on the cumulative lifetime dose (based on body surface area) in MS patients. Mechanism of action Mitoxantrone is a type II topoisomerase inhibitor; it disrupts DNA synthesis and DNA repair in both healthy cells and cancer cells by intercalation between DNA bases. It is also classified as an antibiotic. See also Pixantrone, a mitoxantrone analogue under development Losoxantrone References External links "Mitoxantrone". Drug Information Portal. U.S. National Library of Medicine.