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Amlodipine/benazepril | Amlodipine/benazepril, sold under the brand name Lotrel among others, is a medication used to treat high blood pressure. It is a combination of amlodipine, a calcium channel blocker and benazepril, an angiotensin converting enzyme inhibitor. It may be used if a single agent is not sufficient. It is taken by mouth.Common side effects include cough, dizziness, and swelling. Serious side effects may include angioedema, myocardial infarction, high blood potassium, liver problems, and low blood pressure. Use in pregnancy is not recommended. Amlodipine works by increasing the size of arteries while benazepril works by decreasing renin-angiotensin-aldosterone system activity.The combination was approved for medical use in the United States in 1995. It is available as a generic medication. In 2019, it was the 213th most commonly prescribed medication in the United States, with more than 2 million prescriptions.
Medical uses
It is used to treat high blood pressure. It is not a first line treatment.
References
External links
"Amlodipine mixture with Benazepril". Drug Information Portal. U.S. National Library of Medicine. |
Pegfilgrastim | Pegfilgrastim, sold under the brand name Neulasta among others, is a PEGylated form of the recombinant human granulocyte colony-stimulating factor (GCSF) analog filgrastim. It serves to stimulate the production of white blood cells (neutrophils). Pegfilgrastim was developed by Amgen.Pegfilgrastim treatment can be used to stimulate bone marrow to produce more neutrophils to fight infection in patients undergoing chemotherapy.Pegfilgrastim has a human half-life of 15 to 80 hours, much longer than the parent filgrastim (3–4 hours).Pegfilgrastim was approved for medical use in the United States in January 2002, in the European Union in August 2002, and in Australia in September 2002.
Medical uses
Pegfilgrastim is indicated to decrease the incidence of infection, as manifested by febrile neutropenia, in people with non-myeloid malignancies receiving myelosuppressive anti-cancer drugs associated with a clinically significant incidence of febrile neutropenia; and to increase survival in people acutely exposed to myelosuppressive doses of radiation (hematopoietic subsyndrome of acute radiation syndrome).
Biosimilars
Ristempa was approved for medical use in Australia in January 2017.Tezmota was approved for medical use in Australia in March 2018.Pegfilgrastim-jmdb (Fulphila) was approved for medical use in the United States in June 2018.Fulphila was approved for medical use in Australia in August 2018.Pelgraz was approved for medical use in the European Union in September 2018.Udenyca was approved for medical use in the European Union in September 2018.On November 2, 2018, Coherus Biosciences received FDA approval for its biosimilar, pegfilgrastim-cbqv (Udenyca). The push to receive approval and begin production of Udenyca was due in large part to the quickly increasing cost of Neulasta, which has nearly tripled since its release in 2002.Pelmeg was approved for medical use in the European Union in November 2018.Fulphila was approved for medical use in the European Union in November 2018.Ziextenzo was approved for medical use in the European Union in November 2018.Fulphila was approved for medical use in Canada in December 2018.Grasustek was approved for medical use in the European Union in June 2019.Ziextenzo was approved for medical use in Australia in July 2019.Pelgraz was approved for medical use in Australia in August 2019.Lapelga and Neutropeg were approved for medical use in Australia in August 2019.Pegfilgrastim-bmez (Ziextenzo) was approved for medical use in the United States in November 2019.Cegfila was approved for medical use in the European Union in December 2019.Ziextenzo was approved for medical use in Canada in April 2020.Pegfilgrastim-apgf (Nyvepria) was approved for medical use in the United States in June 2020. Nyvepria was approved for medical use in the European Union in November 2020.Nyvepria was approved for medical use in Canada in October 2020.Stimufend was approved for medical use in the European Union in March 2022.Pegfilgrastim-pbbk (Fylnetra) was approved for medical use in the United States in May 2022.Pegfilgramstim-fpgk (Stimufend) was approved for medical use in the United States in September 2022.
References
External links
"Pegfilgrastim". Drug Information Portal. U.S. National Library of Medicine.
"FDA notifies Amgen of misbranding of its biological product Neulasta". U.S. Food and Drug Administration (FDA). 14 July 2021. |
Aluminium chloride | Aluminium chloride, also known as aluminium trichloride, is an inorganic compound with the formula AlCl3. It forms hexahydrate with the formula [Al(H2O)6]Cl3, containing six water molecules of hydration. Both are colourless crystals, but samples are often contaminated with iron(III) chloride, giving a yellow color.
The anhydrous material is important commercially. It has a low melting and boiling point. It is mainly produced and consumed in the production of aluminium metal, but large amounts are also used in other areas of the chemical industry. The compound is often cited as a Lewis acid. It is an example of an inorganic compound that reversibly changes from a polymer to a monomer at mild temperature.
Structure
Anhydrous
AlCl3 adopts three structures, depending on the temperature and the state (solid, liquid, gas). Solid AlCl3 has a sheet-like layered structure with cubic close-packed chloride ions. In this framework, the Al centres exhibit octahedral coordination geometry. Yttrium(III) chloride adopts the same structure, as do a range of other compounds. When aluminium trichloride is in its melted state, it exists as the dimer Al2Cl6, with tetracoordinate aluminium. This change in structure is related to the lower density of the liquid phase (1.78 g/cm3) versus solid aluminium trichloride (2.48 g/cm3). Al2Cl6 dimers are also found in the vapour phase. At higher temperatures, the Al2Cl6 dimers dissociate into trigonal planar AlCl3 monomer, which is structurally analogous to BF3. The melt conducts electricity poorly, unlike more ionic halides such as sodium chloride.
Aluminium chloride monomer belongs to the point group D3h in its monomeric form and D2h in its dimeric form.
Hexahydrate
The hexahydrate consists of octahedral [Al(H2O)6]3+ cation centers and chloride anions (Cl−) as counterions. Hydrogen bonds link the cation and anions.
The hydrated form of aluminium chloride has an octahedral molecular geometry, with the central aluminium ion surrounded by six water ligand molecules. Being coordinatively saturated, the hydrate is of little value as a catalyst in Friedel-Crafts alkylation and related reactions.
Uses
Alkylation and acylation of arenes
AlCl3 is a common Lewis-acid catalyst for Friedel-Crafts reactions, both acylations and alkylations. Important products are detergents and ethylbenzene. These types of reactions are the major use for aluminium chloride, for example, in the preparation of anthraquinone (used in the dyestuffs industry) from benzene and phosgene. In the general Friedel-Crafts reaction, an acyl chloride or alkyl halide reacts with an aromatic system as shown:
The alkylation reaction is more widely used than the acylation reaction, although its practice is more technically demanding. For both reactions, the aluminium chloride, as well as other materials and the equipment, should be dry, although a trace of moisture is necessary for the reaction to proceed. Detailed procedures are available for alkylation and acylation of arenes.
A general problem with the Friedel-Crafts reaction is that the aluminium chloride catalyst sometimes is required in full stoichiometric quantities, because it complexes strongly with the products. This complication sometimes generates a large amount of corrosive waste. For these and similar reasons, the use of aluminium chloride has often been displaced by zeolites.Aluminium chloride can also be used to introduce aldehyde groups onto aromatic rings, for example via the Gattermann-Koch reaction which uses carbon monoxide, hydrogen chloride and a copper(I) chloride co-catalyst.
Other applications in organic and organometallic synthesis
Aluminium chloride finds a wide variety of other applications in organic chemistry. For example, it can catalyse the "ene reaction", such as the addition of 3-buten-2-one (methyl vinyl ketone) to carvone:
It is used to induce a variety of hydrocarbon couplings and rearrangements.Aluminium chloride combined with aluminium in the presence of an arene can be used to synthesize bis(arene) metal complexes, e.g. bis(benzene)chromium, from certain metal halides via the so-called Fischer-Hafner synthesis. Dichlorophenylphosphine is prepared by reaction of benzene and phosphorus trichloride catalyzed by aluminium chloride.
Reactions
Anhydrous aluminium chloride is a powerful Lewis acid, capable of forming Lewis acid-base adducts with even weak Lewis bases such as benzophenone and mesitylene. It forms tetrachloroaluminate ([AlCl4]−) in the presence of chloride ions.
Aluminium chloride reacts with calcium and magnesium hydrides in tetrahydrofuran forming tetrahydroaluminates.
Reactions with water
Anhydrous aluminium chloride is hygroscopic, having a very pronounced affinity for water. It fumes in moist air and hisses when mixed with liquid water as the Cl− ligands are displaced with H2O molecules to form the hexahydrate [Al(H2O)6]Cl3. The anhydrous phase cannot be regained on heating the hexahydrate. Instead HCl is lost leaving aluminium hydroxide or alumina (aluminium oxide):
[Al(H2O)6]Cl3 → Al(OH)3 + 3 HCl + 3 H2OLike metal aquo complexes, aqueous AlCl3 is acidic owing to the ionization of the aquo ligands:
[Al(H2O)6]3+ ⇌ [Al(OH)(H2O)5]2+ + H+Aqueous solutions behave similarly to other aluminium salts containing hydrated Al3+ ions, giving a gelatinous precipitate of aluminium hydroxide upon reaction with dilute sodium hydroxide:
AlCl3 + 3 NaOH → Al(OH)3 + 3 NaCl
Synthesis
Aluminium chloride is manufactured on a large scale by the exothermic reaction of aluminium metal with chlorine or hydrogen chloride at temperatures between 650 to 750 °C (1,202 to 1,382 °F).
2 Al + 3 Cl2 → 2 AlCl3
2 Al + 6 HCl → 2 AlCl3 + 3 H2Aluminium chloride may be formed via a single displacement reaction between copper chloride and aluminium metal.
2 Al + 3 CuCl2 → 2 AlCl3 + 3 CuIn the US in 1993, approximately 21,000 tons were produced, not counting the amounts consumed in the production of aluminium.Hydrated aluminium trichloride is prepared by dissolving aluminium oxides in hydrochloric acid. Metallic aluminium also readily dissolves in hydrochloric acid ─ releasing hydrogen gas and generating considerable heat. Heating this solid does not produce anhydrous aluminium trichloride, the hexahydrate decomposes to aluminium hydroxide when heated:
[Al(H2O)6]Cl3 → Al(OH)3 + 3 HCl + 3 H2OAluminium also forms a lower chloride, aluminium(I) chloride (AlCl), but this is very unstable and only known in the vapour phase.
Natural occurrence
Anhydrous aluminium chloride is not found as a mineral. The hexahydrate, however, is known as the rare mineral chloraluminite. A more complex, basic and hydrated aluminium chloride mineral is cadwaladerite.
Safety
Anhydrous AlCl3 reacts vigorously with bases, so suitable precautions are required.
It can cause irritation to the eyes, skin, and the respiratory system if inhaled or on contact.
See also
Aluminium monochloride
References
External links
International Chemical Safety Card 1125
Index of Organic Synthesis procedures that utilize AlCl3
The period 3 chlorides
MSDS Archived 2011-07-22 at the Wayback Machine
Government of Canada Fact Sheets and Frequently Asked Questions: Aluminum Salts |
ACE inhibitor and thiazide combination | An ACE inhibitor and thiazide combination is a drug combination used to treat hypertension (high blood pressure). They are given by mouth. ACE inhibitors reduce the activity of angiotensin-converting enzyme (ACE) which produces angiotensin II, a hormone that constricts blood vessels. Thiazides are a class of diuretics that inhibit the thiazide receptor, thereby increasing urine production and reducing excess water and salt in the body. Several organizations recommend combination therapy for hypertension in cases of failure of a single drug to achieve target blood pressure, or even as a first line treatment for some patients.
Examples
Enalapril/hydrochlorothiazide (trade name Enalapril comp), wherein enalapril is the ACE inhibitor and hydrochlorothiazide is the thiazide.
Quinapril/hydrochlorothiazide (trade name Accuretic)
Lisinopril/hydrochlorothiazide is marketed as Prinzide, Zestoretic, and many others.
Fosinopril/hydrochlorothiazide
Fosinopril/hydrochlorothiazide (trade name Monopril HCT) has a boxed warning about its risk to cause morbidity and mortality in the baby when being used during pregnancy (2nd and 3rd trimesters).FDA modified its labeling on February, 2009 to include a precaution of drug interaction with gold. "Nitritoid reactions (symptoms include facial flushing, nausea, vomiting and hypotension) have been reported rarely in patients on therapy with injectable gold (sodium aurothiomalate) and concomitant ACE inhibitor therapy including Monopril/Monopril HCT."
See also
Perindopril/indapamide, a combination of an ACE inhibitor and a thiazide-like diuretic
== References == |
Trospium chloride | Trospium chloride is used to treat overactive bladder.It has side effects typical of drugs like it, namely dry mouth, stomach upset, and constipation; these side effects cause problems with people taking their medicine as directed. However it doesnt cause central nervous system side effects like other drugs of its class. It is pregnancy category C and is excreted somewhat in breast milk.Chemically it is a quaternary ammonium cation which causes it to stay in periphery rather than crossing the blood-brain barrier. It works by causing the smooth muscle in the bladder to relax.It was patented in 1966 and approved for medical use in 1974. It was first approved in the US in 2004, and an extended release version with once-daily dosing was brought to market in 2007. It became generic in Europe in 2009 and in the US the first extended-release generic was approved in 2012.
Medical uses
Trospium chloride is used for the treatment of overactive bladder with symptoms of urge incontinence and frequent urination.It shouldnt be used with people who retain urine, who have severe digestive conditions, myasthenia gravis, narrow-angle glaucoma, or tachyarrhythmia.It should be used in caution with people who have problems with their autonomous nervous system (dysautonomia) or who have gastroesophageal reflux disease, or in whom fast heart rates are undesirable, such as people with hyperthyroidism, coronary artery disease and congestive heart failure.Trospium chloride is rated Pregnancy Category C, as there are no adequate and well-controlled studies of trospium chloride in pregnant women and there were signs of harm to the fetus in animal studies. The drug was excreted somewhat in the milk of nursing mothers. The drug was studied in children.
Side effects
Side effects are typical of gastrointestinal effects of anticholinergic drugs, and include dry mouth, indigestion, and constipation. These side effects lead to problems with adherence, especially for older people.
The only CNS side effect is headache, which was very rare. Tachycardia is a rare side effect.
Mechanism of action
Trospium chloride is a muscarinic antagonist. Trospium chloride blocks the effect of acetylcholine on muscarinic receptors organs that are responsive to the compounds, including the bladder. Its parasympatholytic action relaxes the smooth muscle in the bladder. Receptor assays showed that trospium chloride has negligible affinity for nicotinic receptors as compared to muscarinic receptors at concentrations obtained from therapeutic doses.
Pharmacokinetics
After oral administration, less than 10% of the dose is absorbed. Mean absolute bioavailability of a 20 mg dose is 9.6% (range: 4.0 to 16.1%). Peak plasma concentrations (Cmax) occur between 5 and 6 hours post-dose. Mean Cmax increases greater than dose-proportionally; a 3-fold and 4-fold increase in Cmax was observed for dose increases from 20 mg to 40 mg and from 20 mg to 60 mg, respectively. AUC exhibits dose linearity for single doses up to 60 mg. Trospium chloride exhibits diurnal variability in exposure with a decrease in Cmax and AUC of up to 59% and 33%, respectively, for evening relative to morning doses.Administration with a high fat meal resulted in reduced absorption, with AUC and Cmax values 70 to 80% lower than those obtained when trospium chloride was administered while fasting. Therefore, it is recommended that trospium chloride should be taken at least one hour prior to meals or on an empty stomach.Protein binding ranged from 50 to 85% when concentration levels of trospium chloride (0.5 to 50 ng/mL) were incubated with human serum in vitro. The 3H-trospium chloride ratio of plasma to whole blood was 1.6:1. This ratio indicates that the majority of 3H-trospium chloride is distributed in plasma. The apparent volume of distribution for a 20 mg oral dose is 395 (± 140) liters.The metabolic pathway of trospium in humans has not been fully defined. Of the 10% of the dose absorbed, metabolites account for approximately 40% of the excreted dose following oral administration. The major metabolic pathway is hypothesized as ester hydrolysis with subsequent conjugation of benzylic acid to form azoniaspironortropanol with glucuronic acid. Cytochrome P450 is not expected to contribute significantly to the elimination of trospium. Data taken from in vitro human liver microsomes investigating the inhibitory effect of trospium on seven cytochrome P450 isoenzyme substrates (CYP1A2, 2A6, 2C9, 2C19, 2D6, 2E1, and 3A4) suggest a lack of inhibition at clinically relevant concentrations.The plasma half-life for trospium chloride following oral administration is approximately 20 hours. After oral administration of an immediate-release formulation of 14C-trospium chloride, the majority of the dose (85.2%) was recovered in feces and a smaller amount (5.8% of the dose) was recovered in urine; 60% of the radioactivity excreted in urine was unchanged trospium. The mean renal clearance for trospium (29 L/hour) is 4-fold higher than average glomerular filtration rate, indicating that active tubular secretion is a major route of elimination for trospium. There may be competition for elimination with other compounds that are also renally eliminated.
Chemical properties
Anticholinergic drugs used to treat overactive bladder were all amines as of 2003. Quaternary ammonium cations in general are more hydrophilic than other amines and dont cross membranes well, so they tend to be poorly absorbed from the digestive system, and to not cross the blood-brain barrier. Oxybutynin, tolterodine, darifenacin, and solifenacin are tertiary amines while trospium chloride and propantheline are quaternary amines.
History
The synthesis of trospium was described by scientists from Dr. Robert Pfleger Chemische Fabrik GmbH, Heinz Bertholdt, Robert Pfleger, and Wolfram Schulz, in US. Pat. No. 3,480,626 (the US equivalent to DE119442), and its activity was first published in the literature in 1967.The first regulatory approval was granted in Germany in August 1999 to Madaus AG for Regurin 20 mg Tablets.: 13 Madaus is considered the originator for regulatory filings worldwide. The German filing was recognized throughout Europe under the Mutual Recognition Procedure.: 13 Madaus licensed the US rights to trospium chloride to Interneuron in 1999 and Interneuron ran clinical trials in the US to win FDA approval. Interneuron changed its name to Indevus in 2002 Indevus entered into a partnership with Odyssey Pharmaceuticals, a subsidiary of Pliva, to market the drug in April 2004, and won FDA approval for the drug, which it branded as Sanctura, in May 2004. The approval earned Indevus a milestone payment of $120M from Pliva, which had already paid Indevus $30 million at signing; the market for overactive bladder therapies was estimated to be worth $1.1 billion in 2004. In 2005 Pliva exited the relationship, selling its rights to Esprit Pharma, and in September 2007 Allergan acquired Esprit, and negotiated a new agreement with Indevus under which Allergan would completely take over the US manufacturing, regulatory approvals, and marketing. A month before, Indevus had received FDA approval for an extended release formulation that allowed once a day dosing, Sanctura XR. Indevus had developed intellectual property around the extended release formulation which it licensed to Madaus for most of the world.In 2012 the FDS approved the first generic version of the extended release formulation, granting approval to the ANDA that Watson Pharmaceuticals had filed in 2009. Annual sales in the US at that time were $67M. European patents had expired in 2009.As of 2016, the drug is available worldwide under many brand names and formulations, including oral, extended release, suppositories, and injections.
Society and culture
Marketing rights to the drug became subject to parallel import litigation in Europe in the case of Speciality European Pharma Ltd v Doncaster Pharmaceuticals Group Ltd / Madaus GmbH (Case No. A3/2014/0205) which was resolved in March 2015. Madaus had exclusively licensed the right to use the Regurin trademark to Speciality European Pharma Ltd. In 2009, when European patents expired on the drug, Doncaster Pharmaceuticals Group, a well known parallel importer, which had been selling the drug in the UK under another label, Ceris, which was used in France, began to put stickers on their packaging with the Regurin name. Speciality and Madaus sued and initially won based on the argument that 90% of prescriptions were already generic, but Doncaster appealed and won the appeal based on the argument that it could not charge a premium with a generic label. The case has broad implications for trade in the EU.
Research
In 2007 Indevus partnered with Alkermes to develop and test an inhaled form of trospium chloride as a treatment for COPD; it was in Phase II trials at that time.
References
External links
Trospium chloride at the US National Library of Medicine Medical Subject Headings (MeSH) |
Caffeine | Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is used as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine to the adenosine A1 receptor, which enhances release of the neurotransmitter acetylcholine. Caffeine also increases cyclic AMP levels through nonselective inhibition of phosphodiesterase.Caffeine is a bitter, white crystalline purine, a methylxanthine alkaloid, and is chemically related to the adenine and guanine bases of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). It is found in the seeds, fruits, nuts, or leaves of a number of plants native to Africa, East Asia and South America, and helps to protect them against herbivores and from competition by preventing the germination of nearby seeds, as well as encouraging consumption by select animals such as honey bees. The best-known source of caffeine is the coffee bean, the seed of the Coffea plant. People may drink beverages containing caffeine to relieve or prevent drowsiness and to improve cognitive performance. To make these drinks, caffeine is extracted by steeping the plant product in water, a process called infusion. Caffeine-containing drinks, such as coffee, tea, and cola, are consumed globally in high volumes. In 2020, almost 10 million tonnes of coffee beans were consumed globally. Caffeine is the worlds most widely consumed psychoactive drug. Unlike most other psychoactive substances, caffeine remains largely unregulated and legal in nearly all parts of the world. Caffeine is also an outlier as its use is seen as socially acceptable in most cultures and even encouraged in others, particularly in the Western world.
Caffeine has both positive and negative health effects. It can treat and prevent the premature infant breathing disorders bronchopulmonary dysplasia of prematurity and apnea of prematurity. Caffeine citrate is on the WHO Model List of Essential Medicines. It may confer a modest protective effect against some diseases, including Parkinsons disease. Some people experience sleep disruption or anxiety if they consume caffeine, but others show little disturbance. Evidence of a risk during pregnancy is equivocal; some authorities recommend that pregnant women limit caffeine to the equivalent of two cups of coffee per day or less. Caffeine can produce a mild form of drug dependence – associated with withdrawal symptoms such as sleepiness, headache, and irritability – when an individual stops using caffeine after repeated daily intake. Tolerance to the autonomic effects of increased blood pressure and heart rate, and increased urine output, develops with chronic use (i.e., these symptoms become less pronounced or do not occur following consistent use).Caffeine is classified by the US Food and Drug Administration as generally recognized as safe. Toxic doses, over 10 grams per day for an adult, are much higher than the typical dose of under 500 milligrams per day. The European Food Safety Authority reported that up to 400 mg of caffeine per day (around 5.7 mg/kg of body mass per day) does not raise safety concerns for non-pregnant adults, while intakes up to 200 mg per day for pregnant and lactating women do not raise safety concerns for the fetus or the breast-fed infants. A cup of coffee contains 80–175 mg of caffeine, depending on what "bean" (seed) is used, how it is roasted (darker roasts have less caffeine), and how it is prepared (e.g., drip, percolation, or espresso). Thus it requires roughly 50–100 ordinary cups of coffee to reach the toxic dose. However, pure powdered caffeine, which is available as a dietary supplement, can be lethal in tablespoon-sized amounts.
Use
Medical
Caffeine is used in:
Bronchopulmonary dysplasia in premature infants for both prevention and treatment. It may improve weight gain during therapy and reduce the incidence of cerebral palsy as well as reduce language and cognitive delay. On the other hand, subtle long-term side effects are possible.
Apnea of prematurity as a primary treatment, but not prevention.
Orthostatic hypotension treatment.
Some people use caffeine-containing beverages such as coffee or tea to try to treat their asthma. Evidence to support this practice is poor. It appears that caffeine in low doses improves airway function in people with asthma, increasing forced expiratory volume (FEV1) by 5% to 18%, with this effect lasting for up to four hours.
The addition of caffeine (100–130 mg) to commonly prescribed pain relievers such as paracetamol or ibuprofen modestly improves the proportion of people who achieve pain relief.
Consumption of caffeine after abdominal surgery shortens the time to recovery of normal bowel function and shortens length of hospital stay.
Caffeine was formerly used as a second-line treatment for ADHD. It is considered less effective than methylphenidate or amphetamine but more so than placebo for children with ADHD. Children, adolescents, and adults with ADHD are more likely to consume caffeine, perhaps as a form of self-medication.
Enhancing performance
Cognitive performance
Caffeine is a central nervous system stimulant that may reduce fatigue and drowsiness. At normal doses, caffeine has variable effects on learning and memory, but it generally improves reaction time, wakefulness, concentration, and motor coordination. The amount of caffeine needed to produce these effects varies from person to person, depending on body size and degree of tolerance. The desired effects arise approximately one hour after consumption, and the desired effects of a moderate dose usually subside after about three or four hours.Caffeine can delay or prevent sleep and improves task performance during sleep deprivation. Shift workers who use caffeine make fewer mistakes that could result from drowsiness.Caffeine in a dose dependent manner increases alertness in both fatigued and normal individuals.A systematic review and meta-analysis from 2014 found that concurrent caffeine and L-theanine use has synergistic psychoactive effects that promote alertness, attention, and task switching; these effects are most pronounced during the first hour post-dose.
Physical performance
Caffeine is a proven ergogenic aid in humans. Caffeine improves athletic performance in aerobic (especially endurance sports) and anaerobic conditions. Moderate doses of caffeine (around 5 mg/kg) can improve sprint performance, cycling and running time trial performance, endurance (i.e., it delays the onset of muscle fatigue and central fatigue), and cycling power output. Caffeine increases basal metabolic rate in adults. Caffeine ingestion prior to aerobic exercise increases fat oxidation, particularly in persons with low physical fitness.Caffeine improves muscular strength and power, and may enhance muscular endurance. Caffeine also enhances performance on anaerobic tests. Caffeine consumption before constant load exercise is associated with reduced perceived exertion. While this effect is not present during exercise-to-exhaustion exercise, performance is significantly enhanced. This is congruent with caffeine reducing perceived exertion, because exercise-to-exhaustion should end at the same point of fatigue. Caffeine also improves power output and reduces time to completion in aerobic time trials, an effect positively (but not exclusively) associated with longer duration exercise.
Specific populations
Adults
For the general population of healthy adults, Health Canada advises a daily intake of no more than 400 mg. This limit was found to be safe by a 2017 systematic review on caffeine toxicology.
Children
In healthy children, moderate caffeine intake under 400 mg produces effects that are "modest and typically innocuous". As early as 6 months old, infants can metabolize caffeine at the same rate as that of adults. Higher doses of caffeine (>400 mg) can cause physiological, psychological and behavioral harm, particularly for children with psychiatric or cardiac conditions. There is no evidence that coffee stunts a childs growth. The American Academy of Pediatrics recommends that caffeine consumption is not appropriate for children and adolescents and should be avoided. This recommendation is based on a clinical report released by American Academy of Pediatrics in 2011 with a review of 45 publications from 1994 to 2011 and includes inputs from various stakeholders (Pediatricians, Committee on nutrition, Canadian Pediatric Society, Centers for Disease Control & Prevention, Food and Drug Administration, Sports Medicine & Fitness committee, National Federations of High School Associations). For children age 12 and under, Health Canada recommends a maximum daily caffeine intake of no more than 2.5 milligrams per kilogram of body weight. Based on average body weights of children, this translates to the following age-based intake limits:
Adolescents
Health Canada has not developed advice for adolescents because of insufficient data. However, they suggest that daily caffeine intake for this age group be no more than 2.5 mg/kg body weight. This is because the maximum adult caffeine dose may not be appropriate for light-weight adolescents or for younger adolescents who are still growing. The daily dose of 2.5 mg/kg body weight would not cause adverse health effects in the majority of adolescent caffeine consumers. This is a conservative suggestion since older and heavier-weight adolescents may be able to consume adult doses of caffeine without experiencing adverse effects.
Pregnancy and breastfeeding
The metabolism of caffeine is reduced in pregnancy, especially in the third trimester, and the half-life of caffeine during pregnancy can be increased up to 15 hours (as compared to 2.5 to 4.5 hours in non-pregnant adults). Current evidence regarding the effects of caffeine on pregnancy and for breastfeeding are inconclusive. There is limited primary and secondary advice for, or against, caffeine use during pregnancy and its effects on the fetus or newborn.The UK Food Standards Agency has recommended that pregnant women should limit their caffeine intake, out of prudence, to less than 200 mg of caffeine a day – the equivalent of two cups of instant coffee, or one and a half to two cups of fresh coffee. The American Congress of Obstetricians and Gynecologists (ACOG) concluded in 2010 that caffeine consumption is safe up to 200 mg per day in pregnant women. For women who breastfeed, are pregnant, or may become pregnant, Health Canada recommends a maximum daily caffeine intake of no more than 300 mg, or a little over two 8 oz (237 mL) cups of coffee. A 2017 systematic review on caffeine toxicology found evidence supporting that caffeine consumption up to 300 mg/day for pregnant women is generally not associated with adverse reproductive or developmental effect.There are conflicting reports in the scientific literature about caffeine use during pregnancy. A 2011 review found that caffeine during pregnancy does not appear to increase the risk of congenital malformations, miscarriage or growth retardation even when consumed in moderate to high amounts. Other reviews, however, concluded that there is some evidence that higher caffeine intake by pregnant women may be associated with a higher risk of giving birth to a low birth weight baby, and may be associated with a higher risk of pregnancy loss. A systematic review, analyzing the results of observational studies, suggests that women who consume large amounts of caffeine (greater than 300 mg/day) prior to becoming pregnant may have a higher risk of experiencing pregnancy loss.
Adverse effects
Physical
Caffeine in coffee and other caffeinated drinks can affect gastrointestinal motility and gastric acid secretion. In postmenopausal women, high caffeine consumption can accelerate bone loss.Acute ingestion of caffeine in large doses (at least 250–300 mg, equivalent to the amount found in 2–3 cups of coffee or 5–8 cups of tea) results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. This increase is due to both a diuresis (increase in water excretion) and a natriuresis (increase in saline excretion); it is mediated via proximal tubular adenosine receptor blockade. The acute increase in urinary output may increase the risk of dehydration. However, chronic users of caffeine develop a tolerance to this effect and experience no increase in urinary output.
Psychological
Minor undesired symptoms from caffeine ingestion not sufficiently severe to warrant a psychiatric diagnosis are common and include mild anxiety, jitteriness, insomnia, increased sleep latency, and reduced coordination. Caffeine can have negative effects on anxiety disorders. According to a 2011 literature review, caffeine use may induce anxiety and panic disorders in people with Parkinsons disease. At high doses, typically greater than 300 mg, caffeine can both cause and worsen anxiety. For some people, discontinuing caffeine use can significantly reduce anxiety.In moderate doses, caffeine has been associated with reduced symptoms of depression and lower suicide risk. Two reviews indicate that increased consumption of coffee and caffeine may reduce the risk of depression.Some textbooks state that caffeine is a mild euphoriant, while others state that it is not a euphoriant.Caffeine-induced anxiety disorder is a subclass of the DSM-5 diagnosis of substance/medication-induced anxiety disorder.
Reinforcement disorders
Addiction
Whether caffeine can result in an addictive disorder depends on how addiction is defined. Compulsive caffeine consumption under any circumstances has not been observed, and caffeine is therefore not generally considered addictive. However, some diagnostic models, such as the ICDM-9 and ICD-10, include a classification of caffeine addiction under a broader diagnostic model. Some state that certain users can become addicted and therefore unable to decrease use even though they know there are negative health effects.Caffeine does not appear to be a reinforcing stimulus, and some degree of aversion may actually occur, with people preferring placebo over caffeine in a study on drug abuse liability published in an NIDA research monograph. Some state that research does not provide support for an underlying biochemical mechanism for caffeine addiction. Other research states it can affect the reward system."Caffeine addiction" was added to the ICDM-9 and ICD-10. However, its addition was contested with claims that this diagnostic model of caffeine addiction is not supported by evidence. The American Psychiatric Associations DSM-5 does not include the diagnosis of a caffeine addiction but proposes criteria for the disorder for more study.
Dependence and withdrawal
Withdrawal can cause mild to clinically significant distress or impairment in daily functioning. The frequency at which this occurs is self-reported at 11%, but in lab tests only half of the people who report withdrawal actually experience it, casting doubt on many claims of dependence. Mild physical dependence and withdrawal symptoms may occur upon abstinence, with greater than 100 mg caffeine per day, although these symptoms last no longer than a day. Some symptoms associated with psychological dependence may also occur during withdrawal. The diagnostic criteria for caffeine withdrawal require a previous prolonged daily use of caffeine. Following 24 hours of a marked reduction in consumption, a minimum of 3 of these signs or symptoms is required to meet withdrawal criteria: difficulty concentrating, depressed mood/irritability, flu-like symptoms, headache, and fatigue. Additionally, the signs and symptoms must disrupt important areas of functioning and are not associated with effects of another condition.The ICD-11 includes caffeine dependence as a distinct diagnostic category, which closely mirrors the DSM-5s proposed set of criteria for "caffeine-use disorder". Caffeine use disorder refers to dependence on caffeine characterized by failure to control caffeine consumption despite negative physiological consequences. The APA, which published the DSM-5, acknowledged that there was sufficient evidence in order to create a diagnostic model of caffeine dependence for the DSM-5, but they noted that the clinical significance of the disorder is unclear. Due to this inconclusive evidence on clinical significance, the DSM-5 classifies caffeine-use disorder as a "condition for further study".Tolerance to the effects of caffeine occurs for caffeine-induced elevations in blood pressure and the subjective feelings of nervousness. Sensitization, the process whereby effects become more prominent with use, occurs for positive effects such as feelings of alertness and wellbeing. Tolerance varies for daily, regular caffeine users and high caffeine users. High doses of caffeine (750 to 1200 mg/day spread throughout the day) have been shown to produce complete tolerance to some, but not all of the effects of caffeine. Doses as low as 100 mg/day, such as a 6 oz (170 g) cup of coffee or two to three 12 oz (340 g) servings of caffeinated soft-drink, may continue to cause sleep disruption, among other intolerances. Non-regular caffeine users have the least caffeine tolerance for sleep disruption. Some coffee drinkers develop tolerance to its undesired sleep-disrupting effects, but others apparently do not.
Risk of other diseases
A protective effect of caffeine against Alzheimers disease and dementia is possible but the evidence is inconclusive. It may protect people from liver cirrhosis. Caffeine may lessen the severity of acute mountain sickness if taken a few hours prior to attaining a high altitude. One meta analysis has found that caffeine consumption is associated with a reduced risk of type 2 diabetes. Regular caffeine consumption may reduce the risk of developing Parkinsons disease and may slow the progression of Parkinsons disease.Caffeine increases intraocular pressure in those with glaucoma but does not appear to affect normal individuals.The DSM-5 also includes other caffeine-induced disorders consisting of caffeine-induced anxiety disorder, caffeine-induced sleep disorder and unspecified caffeine-related disorders. The first two disorders are classified under "Anxiety Disorder" and "Sleep-Wake Disorder" because they share similar characteristics. Other disorders that present with significant distress and impairment of daily functioning that warrant clinical attention but do not meet the criteria to be diagnosed under any specific disorders are listed under "Unspecified Caffeine-Related Disorders".
Overdose
Consumption of 1–1.5 grams (1,000–1,500 mg) per day is associated with a condition known as caffeinism. Caffeinism usually combines caffeine dependency with a wide range of unpleasant symptoms including nervousness, irritability, restlessness, insomnia, headaches, and palpitations after caffeine use.Caffeine overdose can result in a state of central nervous system overstimulation known as caffeine intoxication, a clinically significant temporary condition that develops during, or shortly after, the consumption of caffeine. This syndrome typically occurs only after ingestion of large amounts of caffeine, well over the amounts found in typical caffeinated beverages and caffeine tablets (e.g., more than 400–500 mg at a time). According to the DSM-5, caffeine intoxication may be diagnosed if five (or more) of the following symptoms develop after recent consumption of caffeine: restlessness, nervousness, excitement, insomnia, flushed face, diuresis (increased production of urine), gastrointestinal disturbance, muscle twitching, rambling flow of thought and speech, tachycardia (increased heart rate) or cardiac arrythmia, periods of inexhaustibility, and psychomotor agitation.According to the International Classification of Diseases (ICD-11), cases of very high caffeine intake (e.g. > 5 g) may result in caffeine intoxication with symptoms including mania, depression, lapses in judgment, disorientation, disinhibition, delusions, hallucinations or psychosis, and rhabdomyolysis (breakdown of skeletal muscle tissue).
Energy drinks
High caffeine consumption in energy drinks (At least 1 liter or 320 mg of caffeine) was associated with short-term cardiovascular side effects including hypertension, prolonged QT interval and heart palpitations. These cardiovascular side effects were not seen with smaller amounts of caffeine consumption in energy drinks (less than 200 mg).
Severe intoxication
As of 2007 there is no known antidote or reversal agent for caffeine intoxication, treatment of mild caffeine intoxication is directed toward symptom relief; severe intoxication may require peritoneal dialysis, hemodialysis, or hemofiltration. Intralipid infusion therapy is indicated in cases of imminent risk of cardiac arrest in order to scavenge the free serum caffeine.
Lethal dose
Death from caffeine ingestion appears to be rare, and most commonly caused by an intentional overdose of medications. In 2016, 3702 caffeine-related exposures were reported to Poison Control Centers in the United States, of which 846 required treatment at a medical facility, and 16 had a major outcome; and several caffeine-related deaths are reported in case studies. The LD50 of caffeine in rats is 192 milligrams per kilogram, the fatal dose in humans is estimated to be 150–200 milligrams per kilogram (2.2 lb) of body mass (75–100 cups of coffee for a 70 kg (150 lb) adult). There are cases where doses as low as 57 milligrams per kilogram have been fatal. A number of fatalities have been caused by overdoses of readily available powdered caffeine supplements, for which the estimated lethal amount is less than a tablespoon. The lethal dose is lower in individuals whose ability to metabolize caffeine is impaired due to genetics or chronic liver disease. A death was reported in 2013 of a man with liver cirrhosis who overdosed on caffeinated mints.
Interactions
Caffeine is a substrate for CYP1A2, and interacts with many substances through this and other mechanisms.
Alcohol
According to DSST, alcohol provides a reduction in performance and caffeine has a significant improvement in performance. When alcohol and caffeine are consumed jointly, the effects produced by caffeine are affected, but the alcohol effects remain the same. For example, when additional caffeine is added, the drug effect produced by alcohol is not reduced. However, the jitteriness and alertness given by caffeine is decreased when additional alcohol is consumed. Alcohol consumption alone reduces both inhibitory and activational aspects of behavioral control. Caffeine antagonizes the activational aspect of behavioral control, but has no effect on the inhibitory behavioral control. The Dietary Guidelines for Americans recommend avoidance of concomitant consumption of alcohol and caffeine, as this may lead to increased alcohol consumption, with a higher risk of alcohol-associated injury.
Tobacco
Smoking tobacco increases caffeine clearance by 56%. Cigarette smoking induces the cytochrome P450 1A2 enzyme that breaks down caffeine, which may lead to increased caffeine tolerance and coffee consumption for regular smokers.
Birth control
Birth control pills can extend the half-life of caffeine, requiring greater attention to caffeine consumption.
Medications
Caffeine sometimes increases the effectiveness of some medications, such as those for headaches. Caffeine was determined to increase the potency of some over-the-counter analgesic medications by 40%.The pharmacological effects of adenosine may be blunted in individuals taking large quantities of methylxanthines like caffeine. Some other examples of methylxanthines include the medications theophylline and aminophylline, which are prescribed to relieve symptoms of asthma or COPD.
Pharmacology
Pharmacodynamics
In the absence of caffeine and when a person is awake and alert, little adenosine is present in (CNS) neurons. With a continued wakeful state, over time adenosine accumulates in the neuronal synapse, in turn binding to and activating adenosine receptors found on certain CNS neurons; when activated, these receptors produce a cellular response that ultimately increases drowsiness. When caffeine is consumed, it antagonizes adenosine receptors; in other words, caffeine prevents adenosine from activating the receptor by blocking the location on the receptor where adenosine binds to it. As a result, caffeine temporarily prevents or relieves drowsiness, and thus maintains or restores alertness.
Receptor and ion channel targets
Caffeine is an antagonist of adenosine A2A receptors, and knockout mouse studies have specifically implicated antagonism of the A2A receptor as responsible for the wakefulness-promoting effects of caffeine. Antagonism of A2A receptors in the ventrolateral preoptic area (VLPO) reduces inhibitory GABA neurotransmission to the tuberomammillary nucleus, a histaminergic projection nucleus that activation-dependently promotes arousal. This disinhibition of the tuberomammillary nucleus is the downstream mechanism by which caffeine produces wakefulness-promoting effects. Caffeine is an antagonist of all four adenosine receptor subtypes (A1, A2A, A2B, and A3), although with varying potencies. The affinity (KD) values of caffeine for the human adenosine receptors are 12 μM at A1, 2.4 μM at A2A, 13 μM at A2B, and 80 μM at A3.Antagonism of adenosine receptors by caffeine also stimulates the medullary vagal, vasomotor, and respiratory centers, which increases respiratory rate, reduces heart rate, and constricts blood vessels. Adenosine receptor antagonism also promotes neurotransmitter release (e.g., monoamines and acetylcholine), which endows caffeine with its stimulant effects; adenosine acts as an inhibitory neurotransmitter that suppresses activity in the central nervous system. Heart palpitations are caused by blockade of the A1 receptor.Because caffeine is both water- and lipid-soluble, it readily crosses the blood–brain barrier that separates the bloodstream from the interior of the brain. Once in the brain, the principal mode of action is as a nonselective antagonist of adenosine receptors (in other words, an agent that reduces the effects of adenosine). The caffeine molecule is structurally similar to adenosine, and is capable of binding to adenosine receptors on the surface of cells without activating them, thereby acting as a competitive antagonist.In addition to its activity at adenosine receptors, caffeine is an inositol trisphosphate receptor 1 antagonist and a voltage-independent activator of the ryanodine receptors (RYR1, RYR2, and RYR3). It is also a competitive antagonist of the ionotropic glycine receptor.
Effects on striatal dopamine
While caffeine does not directly bind to any dopamine receptors, it influences the binding activity of dopamine at its receptors in the striatum by binding to adenosine receptors that have formed GPCR heteromers with dopamine receptors, specifically the A1–D1 receptor heterodimer (this is a receptor complex with 1 adenosine A1 receptor and 1 dopamine D1 receptor) and the A2A–D2 receptor heterotetramer (this is a receptor complex with 2 adenosine A2A receptors and 2 dopamine D2 receptors). The A2A–D2 receptor heterotetramer has been identified as a primary pharmacological target of caffeine, primarily because it mediates some of its psychostimulant effects and its pharmacodynamic interactions with dopaminergic psychostimulants.Caffeine also causes the release of dopamine in the dorsal striatum and nucleus accumbens core (a substructure within the ventral striatum), but not the nucleus accumbens shell, by antagonizing A1 receptors in the axon terminal of dopamine neurons and A1–A2A heterodimers (a receptor complex composed of 1 adenosine A1 receptor and 1 adenosine A2A receptor) in the axon terminal of glutamate neurons. During chronic caffeine use, caffeine-induced dopamine release within the nucleus accumbens core is markedly reduced due to drug tolerance.
Enzyme targets
Caffeine, like other xanthines, also acts as a phosphodiesterase inhibitor. As a competitive nonselective phosphodiesterase inhibitor, caffeine raises intracellular cyclic AMP, activates protein kinase A, inhibits TNF-alpha and leukotriene synthesis, and reduces inflammation and innate immunity. Caffeine also affects the cholinergic system where it is a moderate inhibitor of the enzyme acetylcholinesterase.
Pharmacokinetics
Caffeine from coffee or other beverages is absorbed by the small intestine within 45 minutes of ingestion and distributed throughout all bodily tissues. Peak blood concentration is reached within 1–2 hours. It is eliminated by first-order kinetics. Caffeine can also be absorbed rectally, evidenced by suppositories of ergotamine tartrate and caffeine (for the relief of migraine) and of chlorobutanol and caffeine (for the treatment of hyperemesis). However, rectal absorption is less efficient than oral: the maximum concentration (Cmax) and total amount absorbed (AUC) are both about 30% (i.e., 1/3.5) of the oral amounts.Caffeines biological half-life – the time required for the body to eliminate one-half of a dose – varies widely among individuals according to factors such as pregnancy, other drugs, liver enzyme function level (needed for caffeine metabolism) and age. In healthy adults, caffeines half-life is between 3 and 7 hours. The half-life is decreased by 30-50% in adult male smokers, approximately doubled in women taking oral contraceptives, and prolonged in the last trimester of pregnancy. In newborns the half-life can be 80 hours |
Caffeine | or more, dropping very rapidly with age, possibly to less than the adult value by age 6 months. The antidepressant fluvoxamine (Luvox) reduces the clearance of caffeine by more than 90%, and increases its elimination half-life more than tenfold; from 4.9 hours to 56 hours.Caffeine is metabolized in the liver by the cytochrome P450 oxidase enzyme system, in particular, by the CYP1A2 isozyme, into three dimethylxanthines, each of which has its own effects on the body:
Paraxanthine (84%): Increases lipolysis, leading to elevated glycerol and free fatty acid levels in blood plasma.
Theobromine (12%): Dilates blood vessels and increases urine volume. Theobromine is also the principal alkaloid in the cocoa bean (chocolate).
Theophylline (4%): Relaxes smooth muscles of the bronchi, and is used to treat asthma. The therapeutic dose of theophylline, however, is many times greater than the levels attained from caffeine metabolism.1,3,7-Trimethyluric acid is a minor caffeine metabolite. 7-Methylxanthine is also a metabolite of caffeine. Each of the above metabolites is further metabolized and then excreted in the urine. Caffeine can accumulate in individuals with severe liver disease, increasing its half-life.A 2011 review found that increased caffeine intake was associated with a variation in two genes that increase the rate of caffeine catabolism. Subjects who had this mutation on both chromosomes consumed 40 mg more caffeine per day than others. This is presumably due to the need for a higher intake to achieve a comparable desired effect, not that the gene led to a disposition for greater incentive of habituation.
Chemistry
Pure anhydrous caffeine is a bitter-tasting, white, odorless powder with a melting point of 235–238 °C. Caffeine is moderately soluble in water at room temperature (2 g/100 mL), but very soluble in boiling water (66 g/100 mL). It is also moderately soluble in ethanol (1.5 g/100 mL). It is weakly basic (pKa of conjugate acid = ~0.6) requiring strong acid to protonate it. Caffeine does not contain any stereogenic centers and hence is classified as an achiral molecule.The xanthine core of caffeine contains two fused rings, a pyrimidinedione and imidazole. The pyrimidinedione in turn contains two amide functional groups that exist predominantly in a zwitterionic resonance the location from which the nitrogen atoms are double bonded to their adjacent amide carbons atoms. Hence all six of the atoms within the pyrimidinedione ring system are sp2 hybridized and planar. Therefore, the fused 5,6 ring core of caffeine contains a total of ten pi electrons and hence according to Hückels rule is aromatic.
Synthesis
The biosynthesis of caffeine is an example of convergent evolution among different species.Caffeine may be synthesized in the lab starting with dimethylurea and malonic acid.Commercial supplies of caffeine are not usually manufactured synthetically because the chemical is readily available as a byproduct of decaffeination.
Decaffeination
Extraction of caffeine from coffee, to produce caffeine and decaffeinated coffee, can be performed using a number of solvents. Following are main methods:
Water extraction: Coffee beans are soaked in water. The water, which contains many other compounds in addition to caffeine and contributes to the flavor of coffee, is then passed through activated charcoal, which removes the caffeine. The water can then be put back with the beans and evaporated dry, leaving decaffeinated coffee with its original flavor. Coffee manufacturers recover the caffeine and resell it for use in soft drinks and over-the-counter caffeine tablets.
Supercritical carbon dioxide extraction: Supercritical carbon dioxide is an excellent nonpolar solvent for caffeine, and is safer than the organic solvents that are otherwise used. The extraction process is simple: CO2 is forced through the green coffee beans at temperatures above 31.1 °C and pressures above 73 atm. Under these conditions, CO2 is in a "supercritical" state: It has gaslike properties that allow it to penetrate deep into the beans but also liquid-like properties that dissolve 97–99% of the caffeine. The caffeine-laden CO2 is then sprayed with high-pressure water to remove the caffeine. The caffeine can then be isolated by charcoal adsorption (as above) or by distillation, recrystallization, or reverse osmosis.
Extraction by organic solvents: Certain organic solvents such as ethyl acetate present much less health and environmental hazard than chlorinated and aromatic organic solvents used formerly. Another method is to use triglyceride oils obtained from spent coffee grounds."Decaffeinated" coffees do in fact contain caffeine in many cases – some commercially available decaffeinated coffee products contain considerable levels. One study found that decaffeinated coffee contained 10 mg of caffeine per cup, compared to approximately 85 mg of caffeine per cup for regular coffee.
Detection in body fluids
Caffeine can be quantified in blood, plasma, or serum to monitor therapy in neonates, confirm a diagnosis of poisoning, or facilitate a medicolegal death investigation. Plasma caffeine levels are usually in the range of 2–10 mg/L in coffee drinkers, 12–36 mg/L in neonates receiving treatment for apnea, and 40–400 mg/L in victims of acute overdosage. Urinary caffeine concentration is frequently measured in competitive sports programs, for which a level in excess of 15 mg/L is usually considered to represent abuse.
Analogs
Some analog substances have been created which mimic caffeines properties with either function or structure or both. Of the latter group are the xanthines DMPX and 8-chlorotheophylline, which is an ingredient in dramamine. Members of a class of nitrogen substituted xanthines are often proposed as potential alternatives to caffeine. Many other xanthine analogues constituting the adenosine receptor antagonist class have also been elucidated.Some other caffeine analogs:
Dipropylcyclopentylxanthine
8-Cyclopentyl-1,3-dimethylxanthine
8-Phenyltheophylline
Precipitation of tannins
Caffeine, as do other alkaloids such as cinchonine, quinine or strychnine, precipitates polyphenols and tannins. This property can be used in a quantitation method.
Natural occurrence
Around thirty plant species are known to contain caffeine. Common sources are the "beans" (seeds) of the two cultivated coffee plants, Coffea arabica and Coffea canephora (the quantity varies, but 1.3% is a typical value); and of the cocoa plant, Theobroma cacao; the leaves of the tea plant; and kola nuts. Other sources include the leaves of yaupon holly, South American holly yerba mate, and Amazonian holly guayusa; and seeds from Amazonian maple guarana berries. Temperate climates around the world have produced unrelated caffeine-containing plants.
Caffeine in plants acts as a natural pesticide: it can paralyze and kill predator insects feeding on the plant. High caffeine levels are found in coffee seedlings when they are developing foliage and lack mechanical protection. In addition, high caffeine levels are found in the surrounding soil of coffee seedlings, which inhibits seed germination of nearby coffee seedlings, thus giving seedlings with the highest caffeine levels fewer competitors for existing resources for survival. Caffeine is stored in tea leaves in two places. Firstly, in the cell vacuoles where it is complexed with polyphenols. This caffeine probably is released into the mouth parts of insects, to discourage herbivory. Secondly, around the vascular bundles, where it probably inhibits pathogenic fungi from entering and colonizing the vascular bundles. Caffeine in nectar may improve the reproductive success of the pollen producing plants by enhancing the reward memory of pollinators such as honey bees.The differing perceptions in the effects of ingesting beverages made from various plants containing caffeine could be explained by the fact that these beverages also contain varying mixtures of other methylxanthine alkaloids, including the cardiac stimulants theophylline and theobromine, and polyphenols that can form insoluble complexes with caffeine.
Products
Products containing caffeine include coffee, tea, soft drinks ("colas"), energy drinks, other beverages, chocolate, caffeine tablets, other oral products, and inhalation products. According to a 2020 study in the United States, coffee is the major source of caffeine intake in middle-aged adults, while soft drinks and tea are the major sources in adolescents. Energy drinks are more commonly consumed as a source of caffeine in adolescents as compared to adults.
Beverages
Coffee
The worlds primary source of caffeine is the coffee "bean" (the seed of the coffee plant), from which coffee is brewed. Caffeine content in coffee varies widely depending on the type of coffee bean and the method of preparation used; even beans within a given bush can show variations in concentration. In general, one serving of coffee ranges from 80 to 100 milligrams, for a single shot (30 milliliters) of arabica-variety espresso, to approximately 100–125 milligrams for a cup (120 milliliters) of drip coffee. Arabica coffee typically contains half the caffeine of the robusta variety.
In general, dark-roast coffee has very slightly less caffeine than lighter roasts because the roasting process reduces caffeine content of the bean by a small amount.
Tea
Tea contains more caffeine than coffee by dry weight. A typical serving, however, contains much less, since less of the product is used as compared to an equivalent serving of coffee. Also contributing to caffeine content are growing conditions, processing techniques, and other variables. Thus, teas contain varying amounts of caffeine.Tea contains small amounts of theobromine and slightly higher levels of theophylline than coffee. Preparation and many other factors have a significant impact on tea, and color is a very poor indicator of caffeine content. Teas like the pale Japanese green tea, gyokuro, for example, contain far more caffeine than much darker teas like lapsang souchong, which has very little.
Soft drinks and energy drinks
Caffeine is also a common ingredient of soft drinks, such as cola, originally prepared from kola nuts. Soft drinks typically contain 0 to 55 milligrams of caffeine per 12 ounce serving. By contrast, energy drinks, such as Red Bull, can start at 80 milligrams of caffeine per serving. The caffeine in these drinks either originates from the ingredients used or is an additive derived from the product of decaffeination or from chemical synthesis. Guarana, a prime ingredient of energy drinks, contains large amounts of caffeine with small amounts of theobromine and theophylline in a naturally occurring slow-release excipient.
Other beverages
Mate is a drink popular in many parts of South America. Its preparation consists of filling a gourd with the leaves of the South American holly yerba mate, pouring hot but not boiling water over the leaves, and drinking with a straw, the bombilla, which acts as a filter so as to draw only the liquid and not the yerba leaves.
Guaraná is a soft drink originating in Brazil made from the seeds of the Guaraná fruit.
The leaves of Ilex guayusa, the Ecuadorian holly tree, are placed in boiling water to make a guayusa tea.
The leaves of Ilex vomitoria, the yaupon holly tree, are placed in boiling water to make a yaupon tea.
Commercially prepared coffee-flavoured milk beverages are popular in Australia. Examples include Oaks Ice Coffee and Farmers Union Iced Coffee. The amount of caffeine in these beverages can vary widely. Caffeine concentrations can differ significantly from the manufacturers claims.
Chocolate
Chocolate derived from cocoa beans contains a small amount of caffeine. The weak stimulant effect of chocolate may be due to a combination of theobromine and theophylline, as well as caffeine. A typical 28-gram serving of a milk chocolate bar has about as much caffeine as a cup of decaffeinated coffee. By weight, dark chocolate has one to two times the amount of caffeine as coffee: 80–160 mg per 100 g. Higher percentages of cocoa such as 90% amount to 200 mg per 100 g approximately and thus, a 100-gram 85% cocoa chocolate bar contains about 195 mg caffeine.
Tablets
Tablets offer several advantages over coffee, tea, and other caffeinated beverages, including convenience, known dosage, and avoidance of concomitant intake of sugar, acids, and fluids. A use of caffeine in this form is said to improve mental alertness. These tablets are commonly used by students studying for their exams and by people who work or drive for long hours.
Other oral products
One U.S. company is marketing oral dissolvable caffeine strips. Another intake route is SpazzStick, a caffeinated lip balm. Alert Energy Caffeine Gum was introduced in the United States in 2013, but was voluntarily withdrawn after an announcement of an investigation by the FDA of the health effects of added caffeine in foods.
Inhalants
There are several products being marketed that offer inhalers that deliver proprietary blends of supplements, with caffeine being a key ingredient. In 2012, the FDA sent a warning letter to one of the companies marketing these inhalers, expressing concerns for the lack of safety information available about inhaled caffeine.
Combinations with other drugs
Some beverages combine alcohol with caffeine to create a caffeinated alcoholic drink. The stimulant effects of caffeine may mask the depressant effects of alcohol, potentially reducing the users awareness of their level of intoxication. Such beverages have been the subject of bans due to safety concerns. In particular, the United States Food and Drug Administration has classified caffeine added to malt liquor beverages as an "unsafe food additive".
Ya ba contains a combination of methamphetamine and caffeine.
Painkillers such as propyphenazone/paracetamol/caffeine combine caffeine with an analgesic.
History
Discovery and spread of use
According to Chinese legend, the Chinese emperor Shennong, reputed to have reigned in about 3000 BCE, inadvertently discovered tea when he noted that when certain leaves fell into boiling water, a fragrant and restorative drink resulted. Shennong is also mentioned in Lu Yus Cha Jing, a famous early work on the subject of tea.The earliest credible evidence of either coffee drinking or knowledge of the coffee plant appears in the middle of the fifteenth century, in the Sufi monasteries of the Yemen in southern Arabia. From Mocha, coffee spread to Egypt and North Africa, and by the 16th century, it had reached the rest of the Middle East, Persia and Turkey. From the Middle East, coffee drinking spread to Italy, then to the rest of Europe, and coffee plants were transported by the Dutch to the East Indies and to the Americas.Kola nut use appears to have ancient origins. It is chewed in many West African cultures, in both private and social settings, to restore vitality and ease hunger pangs.
The earliest evidence of cocoa bean use comes from residue found in an ancient Mayan pot dated to 600 BCE. Also, chocolate was consumed in a bitter and spicy drink called xocolatl, often seasoned with vanilla, chile pepper, and achiote. Xocolatl was believed to fight fatigue, a belief probably attributable to the theobromine and caffeine content. Chocolate was an important luxury good throughout pre-Columbian Mesoamerica, and cocoa beans were often used as currency.Xocolatl was introduced to Europe by the Spaniards, and became a popular beverage by 1700. The Spaniards also introduced the cacao tree into the West Indies and the Philippines.The leaves and stems of the yaupon holly (Ilex vomitoria) were used by Native Americans to brew a tea called asi or the "black drink". Archaeologists have found evidence of this use far into antiquity, possibly dating to Late Archaic times.
Chemical identification, isolation, and synthesis
In 1819, the German chemist Friedlieb Ferdinand Runge isolated relatively pure caffeine for the first time; he called it "Kaffebase" (i.e., a base that exists in coffee). According to Runge, he did this at the behest of Johann Wolfgang von Goethe. In 1821, caffeine was isolated both by the French chemist Pierre Jean Robiquet and by another pair of French chemists, Pierre-Joseph Pelletier and Joseph Bienaimé Caventou, according to Swedish chemist Jöns Jacob Berzelius in his yearly journal. Furthermore, Berzelius stated that the French chemists had made their discoveries independently of any knowledge of Runges or each others work. However, Berzelius later acknowledged Runges priority in the extraction of caffeine, stating: "However, at this point, it should not remain unmentioned that Runge (in his Phytochemical Discoveries, 1820, pages 146–147) specified the same method and described caffeine under the name Caffeebase a year earlier than Robiquet, to whom the discovery of this substance is usually attributed, having made the first oral announcement about it at a meeting of the Pharmacy Society in Paris."
Pelletiers article on caffeine was the first to use the term in print (in the French form Caféine from the French word for coffee: café). It corroborates Berzeliuss account:
Caffeine, noun (feminine). Crystallizable substance discovered in coffee in 1821 by Mr. Robiquet. During the same period – while they were searching for quinine in coffee because coffee is considered by several doctors to be a medicine that reduces fevers and because coffee belongs to the same family as the cinchona [quinine] tree – on their part, Messrs. Pelletier and Caventou obtained caffeine; but because their research had a different goal and because their research had not been finished, they left priority on this subject to Mr. Robiquet. We do not know why Mr. Robiquet has not published the analysis of coffee which he read to the Pharmacy Society. Its publication would have allowed us to make caffeine better known and give us accurate ideas of coffees composition...
Robiquet was one of the first to isolate and describe the properties of pure caffeine, whereas Pelletier was the first to perform an elemental analysis.In 1827, M. Oudry isolated "théine" from tea, but in 1838 it was proved by Mulder and by Carl Jobst that theine was actually the same as caffeine.
In 1895, German chemist Hermann Emil Fischer (1852–1919) first synthesized caffeine from its chemical components (i.e. a "total synthesis"), and two years later, he also derived the structural formula of the compound. This was part of the work for which Fischer was awarded the Nobel Prize in 1902.
Historic regulations
Because it was recognized that coffee contained some compound that acted as a stimulant, first coffee and later also caffeine has sometimes been subject to regulation. For example, in the 16th century Islamists in Mecca and in the Ottoman Empire made coffee illegal for some classes. Charles II of England tried to ban it in 1676, Frederick II of Prussia banned it in 1777, and coffee was banned in Sweden at various times between 1756 and 1823.
In 1911, caffeine became the focus of one of the earliest documented health scares, when the US government seized 40 barrels and 20 kegs of Coca-Cola syrup in Chattanooga, Tennessee, alleging the caffeine in its drink was "injurious to health". Although the Supreme Court later ruled in favor of Coca-Cola in United States v. Forty Barrels & Twenty Kegs of Coca-Cola, two bills were introduced to the U.S. House of Representatives in 1912 to amend the Pure Food and Drug Act, adding caffeine to the list of "habit-forming" and "deleterious" substances, which must be listed on a products label.
Society and culture
Regulations
United States
The Food and Drug Administration (FDA) in the United States currently allows only beverages containing less than 0.02% caffeine; but caffeine powder, which is sold as a dietary supplement, is unregulated. It is a regulatory requirement that the label of most prepackaged foods must declare a list of ingredients, including food additives such as caffeine, in descending order of proportion. However, there is no regulatory provision for mandatory quantitative labeling of caffeine, (e.g., milligrams caffeine per stated serving size). There are a number of food ingredients that naturally contain caffeine. These ingredients must appear in food ingredient lists. However, as is the case for "food additive caffeine", there is no requirement to identify the quantitative amount of caffeine in composite foods containing ingredients that are natural sources of caffeine. While coffee or chocolate are broadly recognized as caffeine sources, some ingredients (e.g., guarana, yerba maté) are likely less recognized as caffeine sources. For these natural sources of caffeine, there is no regulatory provision requiring that a food label identify the presence of caffeine nor state the amount of caffeine present in the food.
Consumption
Global consumption of caffeine has been estimated at 120,000 tonnes per year, making it the worlds most popular psychoactive substance. This amounts to an average of one serving of a caffeinated beverage for every person every day. The consumption of caffeine has remained stable between 1997 and 2015. Coffee, tea and soft drinks are the most important caffeine sources, with energy drinks contributing little to the total caffeine intake across all age groups.
Religions
Until recently, the Seventh-day Adventist Church asked for its members to "abstain from caffeinated drinks", but has removed this from baptismal vows (while still recommending abstention as policy). Some from these religions believe that one is not supposed to consume a non-medical, psychoactive substance, or believe that one is not supposed to consume a substance that is addictive. The Church of Jesus Christ of Latter-day Saints has said the following with regard to caffeinated beverages: "... the Church revelation spelling out health practices (Doctrine and Covenants 89) does not mention the use of caffeine. The Churchs health guidelines prohibit alcoholic drinks, smoking or chewing of tobacco, and hot drinks – taught by Church leaders to refer specifically to tea and coffee."Gaudiya Vaishnavas generally also abstain from caffeine, because they believe it clouds the mind and overstimulates the senses. To be initiated under a guru, one must have had no caffeine, alcohol, nicotine or other drugs, for at least a year.Caffeinated beverages are widely consumed by Muslims today. In the 16th century, some Muslim authorities made unsuccessful attempts to ban them as forbidden "intoxicating beverages" under Islamic dietary laws.
Other organisms
Recently discovered bacteria Pseudomonas putida CBB5 can live on pure caffeine and can cleave caffeine into carbon dioxide and ammonia.Caffeine is toxic to birds and to dogs and cats, and has a pronounced adverse effect on mollusks, various insects, and spiders. This is at least partly due to a poor ability to metabolize the compound, causing higher levels for a given dose per unit weight. Caffeine has also been found to enhance the reward memory of honey bees.
Research
Caffeine has been used to double chromosomes in haploid wheat.
See also
Theobromine
Theophylline
Methylliberine
Adderall
Amphetamine
Cocaine
Nootropic
Wakefulness-promoting agent
References
Notes
Citations
Bibliography
Bersten I (1999). Coffee, Sex & Health: A history of anti-coffee crusaders and sexual hysteria. Sydney: Helian Books. ISBN 978-0-9577581-0-0.
Carpenter M (2015). Caffeinated: How Our Daily Habit Helps, Hurts, and Hooks Us. Plume. ISBN 978-0142181805.
Pendergrast M (2001) [1999]. Uncommon Grounds: The History of Coffee and How It Transformed Our World. London: Texere. ISBN 978-1-58799-088-5.
Pollan M (2021). This Is Your Mind on Plants. Penguin Press. ISBN 9780593296905.
External links
GMD MS Spectrum
Caffeine: ChemSub Online
Caffeine at The Periodic Table of Videos (University of Nottingham) |
Lisinopril | Lisinopril is a medication of the angiotensin-converting enzyme (ACE) inhibitor and is used to treat high blood pressure, heart failure, and after heart attacks. For high blood pressure it is usually a first-line treatment. It is also used to prevent kidney problems in people with diabetes mellitus. Lisinopril is taken by mouth. Full effect may take up to four weeks to occur.Common side effects include headache, dizziness, feeling tired, cough, nausea, and rash. Serious side effects may include low blood pressure, liver problems, high blood potassium, and angioedema. Use is not recommended during the entire duration of pregnancy as it may harm the baby. Lisinopril works by inhibiting the renin–angiotensin–aldosterone system.Lisinopril was patented in 1978 and approved for medical use in the United States in 1987. It is available as a generic medication. In 2020, it was the fourth most commonly prescribed medication in the United States, with more than 88 million prescriptions. In July 2016, an oral solution formulation of lisinopril was approved for use in the United States.
Structure–activity relationships
Lisinopril has a proline group that is responsible for the availability of the drug in oral formulation. The carboxylate group interacts with zinc ions to inhibit the ACE enzyme found in the kidneys and lungs. The other substituents participate in binding the same enzyme. Unlike Captopril, another ACE Inhibitor, Lisinopril lacks a thiol group.
Medical uses
Lisinopril is typically used for the treatment of high blood pressure, congestive heart failure, and diabetic nephropathy and after acute myocardial infarction (heart attack). Lisinopril is part of the ACE inhibitors drug class. Compared to other drugs within the same class such as captopril and enalapril, lisinopril has a longer duration of action.
FDA-approved Indications:
Lisinopril is approved by the US Food and Drug Administration (FDA) to manage hypertension in adult and pediatric patients six years and older.
as adjunctive therapy in the treatment of heart failure.
It is recommended as a treatment of ST-segment elevation myocardial infarction (STEMI) within 24 hours in hemodynamically stable patients to improve survival.The lisinopril is started at 5 or 10 mg and titrated upwards to 40 mg once daily maximum. The usual effective maintenance dosage is 20mg administered in a single daily dose.A review concluded that lisinopril was effective for treatment of proteinuric kidney disease, including diabetic proteinuria.In people of sub-Saharan African descent, calcium-channel blockers or thiazide diuretics may more effectively lower blood pressure than ACE inhibitors such as lisinopril, although convincing evidence is lacking that these drugs differ in their effect on morbidity or mortality in such persons.
Kidney problems
In patients with moderate to severe kidney disease, lisinopril and other ACE inhibitors are superior to angiotensin II receptor blockers and other antihypertensive drugs for prevention of death, fatal cardiac events, and kidney injury. Dose reduction may be required when creatinine clearance is less than or equal to 30mL/min. Since lisinopril is removed by dialysis, dosing changes must also be considered for people on dialysis.
Pregnancy and breastfeeding
Animal and human data have revealed evidence of lethal harm to the embryo and teratogenicity associated with ACE inhibitors. No controlled data in human pregnancy are available. Birth defects have been associated with use of lisinopril in any trimester. Death and increased toxicity to the fetus and newly born child have been reported with the use of lisinopril in the second and third trimesters. The label states, "When pregnancy is detected, discontinue Zestril as soon as possible." The manufacturer recommends mothers should not breastfeed while taking this medication because of the current lack of safety data.
Contraindications
Lisinopril is contraindicated in people who have a history of angioedema (hereditary or idiopathic) or who have diabetes and are taking aliskiren.
Adverse effects
The incidence of adverse effects varies according to which disease state the patient is being treated for.People taking lisinopril for the treatment of hypertension may experience the following side effects:
Headache (3.8%)
Dizziness (3.5%)
Cough (2.5%) Persons with the ACE I/D genetic polymorphism may be at higher risk for ACE inhibitor-associated cough.
Difficulty swallowing or breathing (signs of angioedema), allergic reaction (anaphylaxis)
Hyperkalemia (2.2% in adult clinical trials)
Fatigue (1% or more)
Diarrhea (1% or more)
Some severe skin reactions have been reported rarely, including toxic epidermal necrolysis and Stevens–Johnson syndrome; causal relationship has not been established.People taking lisinopril for the treatment of myocardial infarction may experience the following side effects:
Hypotension (5.3%)
Kidney dysfunction (1.3%)People taking lisinopril for the treatment of heart failure may experience the following side effects:
Hypotension (3.8%)
Dizziness (12% at low dose – 19% at high dose)
Chest pain (2.1%)
Fainting (5–7%)
Hyperkalemia (3.5% at low dose – 6.4% at high dose)
Difficulty swallowing or breathing (signs of angioedema), allergic reaction (anaphylaxis)
Fatigue (1% or more)
Diarrhea (1% or more)
Some severe skin reactions have been reported rarely, including toxic epidermal necrolysis and Stevens–Johnson syndrome; a causal relationship has not been established.
Agranulocytosis
Overdose
In one reported overdose, the half-life of lisinopril was prolonged to 14.9 hours. The case report of the event estimates that the individual consumed between 420 and 500 mg of lisinopril and survived. In cases of overdosage, it can be removed from circulation by dialysis.
Interactions
Dental care
ACE-inhibitors like lisinopril are considered to be generally safe for people undergoing routine dental care, though the use of lisinopril prior to dental surgery is more controversial, with some dentists recommending discontinuation the morning of the procedure. People may present to dental care suspicious of an infected tooth, but the swelling around the mouth may be due to lisinopril-induced angioedema, prompting emergency and medical referral.
Pharmacology
Lisinopril is the lysine-analog of enalapril. Unlike other ACE inhibitors, it is not a prodrug, is not metabolized by the liver, and is excreted unchanged in the urine.
Mechanism of action
Lisinopril is an ACE inhibitor, meaning it blocks the actions of angiotensin-converting enzyme (ACE) in the renin–angiotensin–aldosterone system (RAAS), preventing angiotensin I from being converted to angiotensin II. Angiotensin II is a potent direct vasoconstrictor and a stimulator of aldosterone release. Reduction in the amount of angiotensin II results in relaxation of the arterioles. Reduction in the amount of angiotensin II also reduces the release of aldosterone from the adrenal cortex, which allows the kidney to excrete sodium along with water into the urine, and increases retention of potassium ions. Specifically, this process occurs in the peritubular capillaries of the kidneys in response to a change in Starling forces. The inhibition of the RAAS system causes an overall decrease in blood pressure.
Pharmacokinetics
Absorption
Following oral administration of lisinopril, peak serum concentrations of lisinopril occur within about seven hours, although there was a trend to a small delay in time taken to reach peak serum concentrations in acute myocardial infarction patients. Declining serum concentrations exhibit a prolonged terminal phase, which does not contribute to drug accumulation. This terminal phase probably represents saturable binding to ACE and is not proportional to dose. Lisinopril does not appear to be bound to other serum proteins. Lisinopril does not undergo metabolism and absorbed drug is excreted unchanged entirely in the urine. Based on urinary recovery, the mean extent of absorption of lisinopril is approximately 25%, with large interpatient variability (6 to 60%) at all doses tested (5 to 80 mg). Lisinopril absorption is not affected by the presence of food in the gastrointestinal tract.Studies in rats indicate that lisinopril crosses the blood-brain barrier poorly. Multiple doses of lisinopril in rats do not result in accumulation in any tissues.
Usual bioavailability of ~25% (reduced to 16% in people with New York Heart Association Functional Classification (NYHA) Class II–IV heart failure). Its time to peak concentration is 7 hours. The peak effect of lisinopril is about 4 to 8 hours after administration. Food does not affect its absorption.
Distribution
Lisinopril does not bind to proteins in the blood. It does not distribute as well in people with NYHA Class II–IV heart failure.
Metabolism
Lisinopril is the only water-soluble member of the ACE inhibitor class, with no metabolism by the liver.
Elimination
Lisinopril leaves the body completely unchanged in the urine. The half-life of lisinopril is 12 hours, and is increased in people with kidney problems. While the plasma half-life of lisinopril has been estimated between 12 and 13 hours, the elimination half-life is much longer, at around 30 hours. The full duration of action is between 24 and 30 hours.
Chemistry
Pure lisinopril powder is white to off white in color. Lisinopril is soluble in water (approximately 13 mg/L at room temperature), less soluble in methanol, and virtually insoluble in ethanol.
History
Captopril, the first ACE inhibitor, is a functional and structural analog of a peptide derived from the venom of the jararaca, a Brazilian pit viper (Bothrops jararaca). Enalapril is a derivative, designed by scientists at Merck to overcome the rash and bad taste caused by captopril.: 12–13
Enalapril is actually a prodrug; the active metabolite is enalaprilat.The di-acid metabolite of enalapril, enalaprilat, and its lysine analogue lisinopril are potent inhibitors of angiotensin converting enzyme (ACE); they do not contain sulphydryl groups. Both drugs can be assayed by high pressure liquid chromatography and by radioimmunoassay and plasma ACE inhibition remains stable under normal storage conditions. It is therefore possible to study their pharmacokinetics as well as their pharmacodynamic effects in humans. Enalaprilat and lisinopril as well as ACE activity have been measured in blood taken during the course of two studies of the effects of these drugs on blood pressure and autonomic responsiveness.
Lisinopril is a synthetic peptide derivative of captopril. Scientists at Merck created lisinopril by systematically altering each structural unit of enalaprilat, substituting various amino acids. Adding lysine at one end of the drug turned out to have strong activity and had adequate bioavailability when given orally; analogs of that compound resulted in lisinopril, which takes its name from the discovery with lysine. Merck conducted clinical trials, and the drug was approved for hypertension in 1987 and congestive heart failure in 1993.The discovery posed a problem, since sales of enalapril were strong for Merck, and the company did not want to diminish those sales. Merck ended up entering into an agreement with Zeneca under which Zeneca received the right to co-market lisinopril, and Merck received the exclusive rights to an earlier stage aldose reductase inhibitor drug candidate, a potential treatment for diabetes. Zenecas marketing and brand name, "Zestril", turned out to be stronger than Mercks effort. The drug became a blockbuster for AstraZeneca (formed in 1998), with annual sales in 1999 of $1.2B.The US patents expired in 2002. Since then, lisinopril has been available under many brand names worldwide; some formulations include the diuretic hydrochlorothiazide.
References
Further reading
External links
"Lisinopril". Drug Information Portal. U.S. National Library of Medicine. |
Rituximab | Rituximab, sold under the brand name Rituxan among others, is a monoclonal antibody medication used to treat certain autoimmune diseases and types of cancer. It is used for non-Hodgkin lymphoma, chronic lymphocytic leukemia (in non-geriatric patients), rheumatoid arthritis, granulomatosis with polyangiitis, idiopathic thrombocytopenic purpura, pemphigus vulgaris, myasthenia gravis and Epstein–Barr virus-positive mucocutaneous ulcers. It is given by slow injection into a vein. Biosimilars of Rituxan include Blitzima, Riabni, Ritemvia, Rituenza (F.K.A. Tuxella), Rixathon, Ruxience, and Truxima.Common side effects which often occur within two hours of the medication being given include rash, itchiness, low blood pressure, and shortness of breath. Infections are also common.Severe side effects include reactivation of hepatitis B in those previously infected, progressive multifocal leukoencephalopathy, toxic epidermal necrolysis, and death. It is unclear if use during pregnancy is safe for the developing fetus or newborn baby, but it is not proven harmful.
Rituximab is a chimeric monoclonal antibody against the protein CD20, which is primarily found on the surface of immune system B cells. When it binds to this protein it triggers cell death.Rituximab was approved for medical use in 1997. It is on the World Health Organizations List of Essential Medicines.
Medical uses
Rituximab is a chimeric monoclonal antibody targeted against CD20 which is a surface antigen present on B cells. Therefore, it acts by depleting normal as well as pathogenic B cells while sparing plasma cells and hematopoietic stem cells as they do not express the CD20 surface antigen.In the United States, rituximab is indicated to treat:
non-Hodgkin lymphoma (NHL)
chronic lymphocytic leukemia (CLL)
rheumatoid arthritis having inadequate response to one or more TNF inhibitors
vasculitis such as granulomatosis with polyangiitis and microscopic polyangiitis
moderate to severe pemphigus vulgaris
in combination with chemotherapy for children (≥6 months to <18 years) with previously untreated, advanced stage, CD20-positive diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma (BL), Burkitt-like lymphoma (BLL), or mature B-cell acute leukemia (B-AL).
Blood cancers
Rituximab is used to treat cancers of the white blood system such as leukemias and lymphomas, including non-Hodgkins lymphoma, chronic lymphocytic leukemia, and nodular lymphocyte predominant Hodgkins lymphoma. This also includes Waldenströms macroglobulinemia, a type of NHL. Rituximab in combination with hyaluronidase human, sold under the brand names MabThera SC and Rituxan Hycela, is used to treat follicular lymphoma, diffuse large B-cell lymphoma, and chronic lymphocytic leukemia. It is used in combination with fludarabine and cyclophosphamide to treat previously untreated and previously treated CD20-positive chronic lymphocytic leukemia.
Autoimmune diseases
Rituximab has been shown to be an effective rheumatoid arthritis treatment in three randomised controlled trials and is now licensed for use in refractory rheumatoid disease. In the United States, it has been FDA-approved for use in combination with methotrexate (MTX) for reducing signs and symptoms in adult patients with moderately to severely active rheumatoid arthritis (RA) who have had an inadequate response to one or more anti-TNF-alpha therapy. In the European Union, the license is slightly more restrictive: it is licensed for use in combination with MTX in patients with severe active RA who have had an inadequate response to one or more anti-TNF therapy.There is some evidence for efficacy, but not necessarily safety, in a range of other autoimmune diseases, and rituximab is widely used off-label to treat difficult cases of multiple sclerosis, systemic lupus erythematosus, chronic inflammatory demyelinating polyneuropathy and autoimmune anemias. The most dangerous, although among the most rare, side effect is progressive multifocal leukoencephalopathy (PML) infection, which is usually fatal; however only a very small number of cases have been recorded occurring in autoimmune diseases.Other autoimmune diseases that have been treated with rituximab include autoimmune hemolytic anemia, pure red cell aplasia, thrombotic thrombocytopenic purpura (TTP), idiopathic thrombocytopenic purpura (ITP), Evans syndrome, vasculitis (e.g., granulomatosis with polyangiitis), bullous skin disorders (for example pemphigus, pemphigoid—with very encouraging results of approximately 85% rapid recovery in pemphigus, according to a 2006 study), type 1 diabetes mellitus, Sjögren syndrome, anti-NMDA receptor encephalitis and Devics disease, Graves ophthalmopathy, autoimmune pancreatitis, Opsoclonus myoclonus syndrome (OMS), and IgG4-related disease. There is some evidence that it is ineffective in treating IgA-mediated autoimmune diseases.
Adverse events
Serious adverse events, which can cause death and disability, include:
Severe infusion reaction
Cardiac arrest
Cytokine release syndrome
Tumor lysis syndrome, causing acute kidney injury
Infections
Hepatitis B reactivation
Other viral infections
Progressive multifocal leukoencephalopathy (PML) caused by JC virus reactivation
Invasive fungal infections
Immune toxicity, with depletion of B cells in 70% to 80% of lymphoma patients
Pulmonary toxicity
Bowel obstruction and perforationTwo patients with systemic lupus erythematosus died of progressive multifocal leukoencephalopathy (PML) after being treated with rituximab. PML is caused by activation of JC virus, a common virus in the brain which is usually latent. Reactivation of the JC virus usually results in death or severe brain damage.At least one patient with rheumatoid arthritis developed PML after treatment with rituximab.Rituximab has been reported as a possible cofactor in a chronic hepatitis E infection in a person with lymphoma. Hepatitis E infection is normally an acute infection, suggesting the drug in combination with lymphoma may have weakened the bodys immune response to the virus.A major concern with continuous rituximab treatment is the difficulty to induce a proper vaccine response. This was brought into focus during the COVID-19 pandemic, where persons with multiple sclerosis and rituximab treatment had higher risk of severe COVID-19. In persons with rituximab treatment for multiple sclerosis, 9 of 10 patients with B cell counts of 40/µL or more developed protective levels of antibodies after vaccination with tozinameran.
Mechanisms of action
The antibody binds to the cell surface protein CD20. CD20 is widely expressed on B cells, from early pre-B cells to later in differentiation, but it is absent on terminally differentiated plasma cells. Although the function of CD20 is unknown, it may play a role in Ca2+ influx across plasma membranes, maintaining intracellular Ca2+ concentration and allowing activation of B cells.
Rituximab is relatively ineffective in elimination of cells with low CD20 cell-surface levels. It tends to stick to one side of B cells, where CD20 is, forming a cap and drawing proteins over to that side. The presence of the cap changes the effectiveness of natural killer (NK) cells in destroying these B cells. When an NK cell latched onto the cap, it had an 80% success rate at killing the cell. In contrast, when the B cell lacked this asymmetric protein cluster, it was killed only 40% of the time.The following effects have been found:
The Fc portion of rituximab mediates antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC).
Rituximab has a general regulatory effect on the cell cycle.
Preferential elimination of malignant B cells with high CD20 levels and high BCR signaling propensity, especially in chronic lymphocytic leukemia (CLL).
It increases MHC II and adhesion molecules LFA-1 and LFA-3 (lymphocyte function-associated antigen).
It elicits shedding of CD23.
It downregulates the B cell receptor.
It induces apoptosis of CD20+ cells.
Rituximab also induces a release of some chronic lymphocytic leukemia cells from immune niches, which might make them more sensitive to chemotherapy used in combination with an anti-CD20 antibody.The combined effect results in the elimination of B cells (including the cancerous ones) from the body, allowing a new population of healthy B cells to develop from lymphoid stem cells. Standard treatment protocols of the lead compound rituximab result in rapid (within 3-7 days) and profound (≥90%) depletion of pre-B and mature B cells with full recovery taking as long as 12 months; serum immunoglobulin concentrations may be depleted for 5 to 12 months and may require substitution. Rituximab also leads to a reduced function of B cells as antigen presenting cells and, by increasing immature and transitional B cells, to a dysfunction of CD4+ T cells and abnormal cytotoxic T-cell-specific responses.Rituximab binds to amino acids 170–173 and 182–185 on CD20, which are physically close to each other as a result of a disulfide bond between amino acids 167 and 183.Rituximab is co-marketed by Biogen and Genentech in the U.S., by Hoffmann-La Roche in Canada and the European Union, Chugai Pharmaceuticals, Zenyaku Kogyo in Japan and AryoGen in Iran.
History
Rituximab was developed by IDEC Pharmaceuticals under the name IDEC-C2B8. The U.S. patent for the drug was issued in 1998 and expired in 2015.Based on its safety and effectiveness in clinical trials, rituximab was approved by the U.S. Food and Drug Administration in 1997 to treat B-cell non-Hodgkin lymphomas resistant to other chemotherapy regimens. Rituximab, in combination with CHOP chemotherapy, is superior to CHOP alone in the treatment of diffuse large B-cell lymphoma and many other B-cell lymphomas. In 2010, it was approved by the European Commission for maintenance treatment after initial treatment of follicular lymphoma.It is on the World Health Organizations List of Essential Medicines.In 2014, Genentech reclassified rituxan as a specialty drug, a class of drugs that are only available through specialty distributors in the US. Because wholesalers discounts and rebates no longer apply, hospitals would pay more.Originally available for intravenous injection (e.g. over 2.5 hrs), in 2016, it gained EU approval in a formulation for subcutaneous injection for B-cell CLL/lymphoma (CLL).
Society and culture
Economics
Patents on the drug expired in Europe in February 2013, and in the US in September 2016. By November 2018, several biosimilars had been approved in the US, India, the European Union, Switzerland, Japan and Australia. The US FDA approved Truxima (rituximab-abbs) in 2018, Ruxience (rituximab-pvvr) in 2019 and Riabni (rituximab-arrx) in 2020. The latter is about $3600 per 500 mg, wholesale, list.
Research
Chronic fatigue syndrome
Rituximab did not improve symptoms in patients with chronic fatigue syndrome in a trial published in 2019. 22% of participants had serious events. This potential use was investigated after improvements in chronic fatigue syndrome was seen in two cancer patients treated with rituximab.
Intrathecal
For CNS diseases, rituximab could be administered intrathecally and this possibility is under study.
Other anti-CD20 monoclonals
The efficacy and success of rituximab has led to some other anti-CD20 monoclonal antibodies being developed:
ocrelizumab, humanized (90%-95% human) B cell-depleting agent.
ofatumumab (HuMax-CD20) a fully human B cell-depleting agent.
Third-generation anti-CD20s such as obinutuzumab have a glycoengineered Fc fragment (Fc) with enhanced binding to Fc gamma receptors, which increase ADCC (antibody-dependent cellular cytotoxicity). This strategy for enhancing a monoclonal antibodys ability to induce ADCC takes advantage of the fact that the displayed Fc glycan controls the antibodys affinity for Fc receptors.
References
External links
"Rituximab". Drug Information Portal. U.S. National Library of Medicine.
"Discovery – Development of Rituximab". National Cancer Institute. 7 March 2014. |
Teprotumumab | Teprotumumab, sold under the brand name Tepezza, is a medication used to treat adults with thyroid eye disease, a rare condition where the muscles and fatty tissues behind the eye become inflamed, causing the eyes to bulge outwards.The most common side effects are muscle spasm, nausea, hair loss, diarrhea, fatigue, high blood sugar, hearing loss, dry skin, altered sense of taste and headache. Teprotumumab should not be used if pregnant, and women of child-bearing potential should have their pregnancy status verified prior to beginning treatment and should be counseled on pregnancy prevention during treatment and for six months following the last dose.It is a human monoclonal antibody developed by Genmab and Roche for tumour treatment but was later researched by River Vision Development Corporation and Horizon Therapeutics to be used for ophthalmic uses. It binds to IGF-1R.Teprotumumab was approved for use in the United States in January 2020. The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication.
Medical use
In a multicenter randomized trial in patients with active Graves ophthalmopathy teprotumumab was more effective than placebo. In February 2019, Horizon announced results from a Phase III confirmatory trial evaluating teprotumumab for the treatment of active thyroid eye disease (TED). The study met its primary endpoint, showing more patients treated with teprotumumab compared with placebo had a meaningful improvement in proptosis, or bulging of the eye: 82.9 percent of teprotumumab patients compared to 9.5 percent of placebo patients achieved the primary endpoint of a 2 mm or more reduction in proptosis (p<0.001). Proptosis is the main cause of morbidity in TED. All secondary endpoints were also met and the safety profile was consistent with the Phase II study of teprotumumab in TED. On 10 July 2019, Horizon submitted a Biologics License Application (BLA) to the FDA for teprotumumab for the treatment of active thyroid eye disease (TED). Horizon requested priority review for the application - if so granted (FDA has a 60-day review period to decide) it would result in a max. 6 month review process.
History
Teprotumumab-trbw was approved for use in the United States in January 2020, for the treatment of adults with thyroid eye disease.Teprotumumab was first investigated for the treatment of solid and hematologic tumors, including breast cancer, Hodgkins and non-Hodgkins lymphoma, non-small cell lung cancer and sarcoma. Although results of Phase I and early Phase II trials showed promise, research for these indications were discontinued in 2009, by Roche. Phase II trials still in progress were allowed to complete, as the development was halted due to business prioritization rather than safety concerns.
Teprotumumab was subsequently licensed to River Vision Development Corporation in 2012, for research in the treatment of ophthalmic conditions. Horizon Pharma (now Horizon Therapeutics, from hereon Horizon) acquired RVDC in 2017, and will continue clinical trials. It is in Phase III trials for Graves ophthalmopathy (also known as thyroid eye disease (TED)) and Phase I for diabetic macular edema. It was granted Breakthrough Therapy, Orphan Drug Status and Fast Track designations by the FDA for Graves ophthalmopathy.Teprotumumab-trbw was approved based on the results of two clinical trials (Trial 1/ NCT01868997 and Trial 2/ NCT03298867) of 170 subjects with active thyroid eye disease who were randomized to either receive teprotumumab-trbw or a placebo. Of the subjects who were administered Tepezza, 71% in Study 1 and 83% in Study 2 demonstrated a greater than two millimeter reduction in proptosis (eye protrusion) as compared to 20% and 10% of subjects who received placebo, respectively. The trials were conducted at 28 sites in Europe and United States.The U.S. Food and Drug Administration (FDA) granted the application for teprotumumab-trbw fast track designation, breakthrough therapy designation, priority review designation, and orphan drug designation. The FDA granted the approval of Tepezza to Horizon Therapeutics Ireland DAC.
References
External links
"Teprotumumab". Drug Information Portal. U.S. National Library of Medicine. |
Ropinirole | Ropinirole, sold under the brand name Requip among others, is a medication used to treat Parkinsons disease (PD) and restless legs syndrome (RLS). In PD the dose needs to be adjusted to the effect and treatment should not be suddenly stopped. It is taken by mouth. It is approved in the US and UK for inducing emesis (vomiting) in dogs who have ingested toxins or non-sharp foreign material.
Common side effects include sleepiness, vomiting, and dizziness. Serious side effects may include pathological gambling, low blood pressure with standing and hallucinations. Use in pregnancy and breastfeeding is of unclear safety. It is a dopamine agonist and works by triggering dopamine D2 receptors.It was approved for medical use in the United States in 1997. It is available as a generic medication. In 2019, it was the 144th most commonly prescribed medication in the United States, with more than 4 million prescriptions. In June 2020 it was approved for veterinary medical use in dogs in the US and UK.
Medical uses
Ropinirole is prescribed for mainly Parkinsons disease, RLS and extrapyramidal symptoms. It can also reduce the side effects caused by selective serotonin reuptake inhibitors, including Parkinsonism syndrome as well as sexual dysfunction and erectile dysfunction caused by either SSRIs or antipsychotics.
Dosage
Ropinirole is available in various preparations, ranging from a 0.25 mg tablet to a 5 mg tablet. The primary reason is dose titration.
For Parkinsons disease, the maximum recommended dose is 24 mg per day, taken in three separate doses spread throughout the day. The maximum dose recommendations of ropinirole for subjects with end stage renal disease (ESRD) should be reduced by 25% compared with those recommended for subjects with normal renal function. A 25% dose reduction represents a more straightforward dosage regimen in terms of available tablet strength, compared with a 30% dose reduction.For RLS, the maximum recommended dose is 4 mg per day, taken 1 to 3 hours before bedtime. A 52-week open label study had a mean dosage of 1.90 mg, once daily 1 to 3 hours before bedtime.
Side effects
Ropinirole can cause nausea, dizziness, hallucinations, orthostatic hypotension, and sudden sleep attacks during the daytime. Unusual side effects specific to D3 agonists such as ropinirole and pramipexole can include hypersexuality, punding and compulsive gambling, even in patients without a history of these behaviours.Ropinirole is also known to cause an effect known as "augmentation" when used to treat restless legs syndrome, where over time treatment with dopamine agonists will cause RLS symptoms to become more severe. This usually leads to constant dosage increases in an attempt to offset the symptom progression. Symptoms will return to the level of severity they were experienced at before treatment was initiated if the drug is stopped; however, both ropinirole and pramipexole are known to cause painful withdrawal effects when treatment is stopped and the process of taking a patient who has been using the medication long-term off of these drugs is often very difficult and generally should be supervised by a medical professional.
Pharmacology
Ropinirole acts as a D2, D3, and D4 dopamine receptor agonist with highest affinity for D3, which are mostly found in the limbic areas. It is weakly active at the 5-HT2, and α2 receptors and is said to have virtually no affinity for the 5-HT1, GABA, mAChRs, α1, and β-adrenoreceptors.Ropinirole is metabolized primarily by cytochrome P450 CYP1A2 to form two metabolites; SK&F-104557 and SK&F-89124, both of which are renally excreted, and at doses higher than clinical, is also metabolized by CYP3A4. At doses greater than 24 mg, CYP2D6 may be inhibited, although this has been tested only in vitro.
Society and culture
It is manufactured by GlaxoSmithKline (GSK), Mylan Pharmaceuticals, Cipla, Dr. Reddys Laboratories and Sun Pharmaceutical. The discovery of the drugs utility in RLS has been used as an example of successful drug repurposing.
Lawsuits
In November 2012, GlaxoSmithKline was ordered by a Rennes appeals court to pay Frenchman Didier Jambart 197,000 euros ($255,824); Jambart had taken ropinirole from 2003 to 2010 and exhibited risky hypersexual behavior and gambled excessively until stopping the medication.
References
External links
"Ropinirole". Drug Information Portal. U.S. National Library of Medicine.
"Ropinirole hydrochloride". Drug Information Portal. U.S. National Library of Medicine. |
Videx | Videx, Inc. is a Corvallis, Oregon manufacturer of computer hardware such as access control products and data collection terminals. Its initial success came with the first release of the $345 Videoterm (80 column) display card in March 1980 and the $149 shift and custom keyboard mapping Enhancer II terminal card in November 1981, both for Apple II computers. Later, in 1984, it released its $379 UltraTerm expansion card boasting high-definition 96-pixel characters and up to 128 × 32 character display. These products became obsolete when Apple released the Apple IIe with most of the 80-column card hardware built-in - only a much simpler and cheaper RAM card was then required.
Videx also produced software, including Desktop Calendar for the Apple Lisa.
References
External links
Official website |
Magnesium oxide | Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions held together by ionic bonding. Magnesium hydroxide forms in the presence of water (MgO + H2O → Mg(OH)2), but it can be reversed by heating it to remove moisture.
Magnesium oxide was historically known as magnesia alba (literally, the white mineral from Magnesia), to differentiate it from magnesia negra, a black mineral containing what is now known as manganese.
Related oxides
While "magnesium oxide" normally refers to MgO, magnesium peroxide MgO2 is also known as a compound. According to evolutionary crystal structure prediction, MgO2 is thermodynamically stable at pressures above 116 GPa (gigapascals), and a semiconducting suboxide Mg3O2 is thermodynamically stable above 500 GPa. Because of its stability, MgO is used as a model system for investigating vibrational properties of crystals.
Electric properties
Pure MgO is not conductive and has a high resistance to electric current at room temperature. The pure powder of MgO has a relative permettivity inbetween 3.2 to 9.9
k
{\displaystyle k}
with an approximate dielectric loss of tan(δ) > 2.16x103 at 1kHz.
Production
Magnesium oxide is produced by the calcination of magnesium carbonate or magnesium hydroxide. The latter is obtained by the treatment of magnesium chloride MgCl2 solutions, typically seawater, with limewater or milk of lime.
Mg2+ + Ca(OH)2 → Mg(OH)2 + Ca2+Calcining at different temperatures produces magnesium oxide of different reactivity. High temperatures 1500 – 2000 °C diminish the available surface area and produces dead-burned (often called dead burnt) magnesia, an unreactive form used as a refractory. Calcining temperatures 1000 – 1500 °C produce hard-burned magnesia, which has limited reactivity and calcining at lower temperature, (700–1000 °C) produces light-burned magnesia, a reactive form, also known as caustic calcined magnesia. Although some decomposition of the carbonate to oxide occurs at temperatures below 700 °C, the resulting materials appears to reabsorb carbon dioxide from the air.
Applications
Heating elements
MgO is prized as a refractory material, i.e. a solid that is physically and chemically stable at high temperatures. It has two useful attributes: high thermal conductivity and low electrical conductivity. Filling the spiral Calrod range top heating elements on kitchen electric stoves is a major use. "By far the largest consumer of magnesia worldwide is the refractory industry, which consumed about 56% of the magnesia in the United States in 2004, the remaining 44% being used in agricultural, chemical, construction, environmental, and other industrial applications." MgO is used as a basic refractory material for crucibles.
Fireproofing
It is a principal fireproofing ingredient in construction materials. As a construction material, magnesium oxide wallboards have several attractive characteristics: fire resistance, termite resistance, moisture resistance, mold and mildew resistance, and strength.
Gas Mantles
Most Gas Mantles utilize Magnesium Oxide. Early Iterations such as the Clamond basket used only this. Later versions use ~60% Magnesium oxide, with other components such as Lanthanum oxide or Yttrium oxide making up the rest. Another exception would be Thoriated gas mantles.
Niche uses
MgO is one of the components in Portland cement in dry process plants.
Magnesium oxide is used extensively in the soil and groundwater remediation, wastewater treatment, drinking water treatment, air emissions treatment, and waste treatment industries for its acid buffering capacity and related effectiveness in stabilizing dissolved heavy metal species.Many heavy metals species, such as lead and cadmium are most soluble in water at acidic pH (below 6) as well as high pH (above 11). Solubility of metals affects bioavailability of the species and mobility soil and groundwater systems. Most metal species are toxic to humans at certain concentrations, therefore it is imperative to minimize metal bioavailability and mobility.
Granular MgO is often blended into metals-contaminated soil or waste material, which is also commonly of a low pH (acidic), in order to drive the pH into the 8–10 range where most metals are at their lowest solubilities (basic). Metal-hydroxide complexes have a tendency to precipitate out of aqueous solution in the pH range of 8–10. MgO is widely regarded as the most effective metals stabilization compound when compared to Portland cement, lime, kiln dust products, power generation waste products, and various proprietary products due to MgOs superior buffering capacity, cost effectiveness, and ease/safety of handling.
Most, if not all products that are marketed as metals stabilization technologies create very high pH conditions in aquifers whereas MgO creates an ideal aquifer condition with a pH of 8–10. Additionally, magnesium, an essential element to most biological systems, is provided to soil and groundwater microbial populations during MgO-assisted metals remediation as an added benefit.
Medical
Magnesium oxide is used for relief of heartburn and dyspepsia, as an antacid, magnesium supplement, and as a short-term laxative. It is also used to improve symptoms of indigestion. Side effects of magnesium oxide may include nausea and cramping. In quantities sufficient to obtain a laxative effect, side effects of long-term use include enteroliths resulting in bowel obstruction.
Other
As a food additive, it is used as an anticaking agent. It is known to the US Food and Drug Administration for cacao products; canned peas; and frozen dessert. It has an E number of E530.
It was historically used as a reference white color in colorimetry, owing to its good diffusing and reflectivity properties. It may be smoked onto the surface of an opaque material to form an integrating sphere.
It is used extensively as an electrical insulator in tubular construction heating elements. There are several mesh sizes available and most commonly used ones are 40 and 80 mesh per the American Foundry Society. The extensive use is due to its high dielectric strength and average thermal conductivity. MgO is usually crushed and compacted with minimal airgaps or voids. The electrical heating industry also experimented with aluminium oxide, but it is not used anymore.
As a reagent in the installation of the carboxybenzyl (Cbz) group using benzyl chloroformate in EtOAc for the N-protection of amines and amides.
It is also used as an insulator in heat-resistant electrical cable.
MgO doping has been shown to effectively inhibit grain growth in ceramics and improve their fracture toughness by transforming the mechanism of crack growth at nanoscale.
Pressed MgO is used as an optical material. It is transparent from 0.3 to 7 μm. The refractive index is 1.72 at 1 μm and the Abbe number is 53.58. It is sometimes known by the Eastman Kodak trademarked name Irtran-5, although this designation is obsolete. Crystalline pure MgO is available commercially and has a small use in infrared optics.
MgO is packed in bags around transuranic waste in the disposal cells (panels) at the Waste Isolation Pilot Plant, as a CO2 getter to minimize the complexation of uranium and other actinides by carbonate ions and so to limit the solubility of radionuclides. The use of MgO is preferred to this of CaO as the resulting hydration product (Mg(OH)2) is less soluble and releases less hydration heat. Another advantage is to impose a lower pH value of ~ 10.5 in case of accidental water ingress in the dry salt layers while the more soluble Ca(OH)2 would create a higher pH of 12.5 (strongly alkaline conditions). The Mg2+ cation being the second most abundant cation in seawater and in rocksalt, the potential release of magnesium ions dissolving in brines intruding the deep geological repository is also expected to minimize the geochemical perturbations.
MgO has an important place as a commercial plant fertilizer and as animal feed.
An aerosolized solution of MgO is used in library science and collections management for the deacidification of at-risk paper items. In this process, the alkalinity of MgO (and similar compounds) neutralizes the relatively high acidity characteristic of low-quality paper, thus slowing the rate of deterioration.
MgO is also used as a protective coating in plasma displays.
Magnesium oxide is used as an oxide barrier in spin-tunneling devices. Owing to the crystalline structure of its thin films, which can be deposited by magnetron sputtering, for example, it shows characteristics superior to those of the commonly used amorphous Al2O3. In particular, spin polarization of about 85% has been achieved with MgO versus 40–60 % with aluminium oxide. The value of tunnel magnetoresistance is also significantly higher for MgO (600% at room temperature and 1,100 % at 4.2 K) than Al2O3 (ca. 70% at room temperature).
Precautions
Inhalation of magnesium oxide fumes can cause metal fume fever.
See also
Calcium oxide
Barium oxide
Magnesium sulfide
Reactive magnesia
Notes
References
External links
Data page at UCL
Ceramic data page at NIST
NIOSH Pocket Guide to Chemical Hazards at CDC |
Isoflurane | Isoflurane, sold under the brand name Forane among others, is a general anesthetic. It can be used to start or maintain anesthesia; however, other medications are often used to start anesthesia rather than isoflurane, due to airway irritation with isoflurane. Isoflurane is given via inhalation.Side effects of isoflurane include a decreased ability to breathe (respiratory depression), low blood pressure, and an irregular heartbeat. Serious side effects can include malignant hyperthermia or high blood potassium. It should not be used in patients with a history of malignant hyperthermia in either themselves or their family members. It is unknown if its use during pregnancy is safe for the fetus, but use during a cesarean section appears to be safe. Isoflurane is a halogenated ether.Isoflurane was approved for medical use in the United States in 1979. It is on the World Health Organizations List of Essential Medicines.
Medical uses
Isoflurane is always administered in conjunction with air or pure oxygen. Often, nitrous oxide is also used. Although its physical properties imply that anaesthesia can be induced more rapidly than with halothane, its pungency can irritate the respiratory system, negating any possible advantage conferred by its physical properties. It is used in general anesthesia in tandem with or alternatively to other anesthetic drugs, such as thiopentone or propofol.
Adverse effects
Animal studies have raised safety concerns of certain general anesthetics, in particular ketamine and isoflurane, in young children. The risk of neurodegeneration was increased in combination of these agents with nitrous oxide and benzodiazepines such as midazolam. Whether these concerns occur in humans is unclear.
Elderly
Biophysical studies using NMR spectroscopy has provided molecular details of how inhaled anesthetics interact with three amino acid residues (G29, A30 and I31) of amyloid beta peptide and induce aggregation. This area is important as "some of the commonly used inhaled anesthetics may cause brain damage that accelerates the onset of Alzheimers disease".
Physical properties
It is administered as a racemic mixture of (R)- and (S)-optical isomers. Isoflurane has a melting point of 48 - 48.5°Celsius (118 - 119°Fahrenheit) and a boiling point of 48.5 - 49 °C (119 - 120 °F). It is non-combustible but can give off irritable and toxic fumes when exposed to flame.
Mechanism of action
Similar to many general anesthetics, the exact mechanism of the action has not been clearly delineated. Isoflurane reduces pain sensitivity (analgesia) and relaxes muscles. Isoflurane likely binds to GABA, glutamate and glycine receptors, but has different effects on each receptor. Isoflurane acts as a positive allosteric modulator of the GABAA receptor in electrophysiology studies of neurons and recombinant receptors. It potentiates glycine receptor activity, which decreases motor function. It inhibits receptor activity in the NMDA glutamate receptor subtypes. Isoflurane inhibits conduction in activated potassium channels. Isoflurane also affects intracellular molecules. It inhibits plasma membrane calcium ATPases (PMCAs) which affects membrane fluidity by hindering the flow of Ca2+ (calcium ions) out across the membrane, this in turn affects neuron depolarization. It binds to the D subunit of ATP synthase and NADH dehydrogenase.
General anaesthesia with isoflurane reduces plasma endocannabinoid AEA concentrations, and this could be a consequence of stress reduction after loss of consciousness.
History
Together with enflurane and halothane, Isoflurane began to replace the flammable ethers used in the pioneer days of surgery; this shift began in the 1940s to the 1950s. Its name comes from being a structural isomer of enflurane, hence they have the same empirical formula.
Environment
The average lifetime of isoflurane in the atmosphere is 3.2 years, its global warming potential is 510 and the yearly emissions add up to 880 tons.
Veterinary use
Isoflurane is frequently used for veterinary anaesthesia.
References
External links
"Isoflurane". Drug Information Portal. U.S. National Library of Medicine.
U.S. Patent 3,535,388 - 1-chloro-2,2,2-trifluoroethyl difluoromethyl ether
U.S. Patent 3,535,425 - 1-chloro-2,2,2-trifluoroethyl difluoromethyl ether as an anesthetic agent |
Chlordiazepoxide | Chlordiazepoxide, trade name Librium among others, is a sedative and hypnotic medication of the benzodiazepine class; it is used to treat anxiety, insomnia and symptoms of withdrawal from alcohol and other drugs.
Chlordiazepoxide has a medium to long half-life but its active metabolite has a very long half-life. The drug has amnesic, anticonvulsant, anxiolytic, hypnotic, sedative and skeletal muscle relaxant properties.Chlordiazepoxide was patented in 1958 and approved for medical use in 1960. It was the first benzodiazepine to be synthesized and the discovery of chlordiazepoxide was by pure chance. Chlordiazepoxide and other benzodiazepines were initially accepted with widespread public approval but were followed with widespread public disapproval and recommendations for more restrictive medical guidelines for its use.
Medical uses
Chlordiazepoxide is indicated for the short-term (2–4 weeks) treatment of anxiety that is severe and disabling or subjecting the person to unacceptable distress. It is also indicated as a treatment for the management of acute alcohol withdrawal syndrome.It can sometimes be prescribed to ease symptoms of irritable bowel syndrome combined with clidinium bromide as a fixed dose medication, Librax.
Contraindications
Use of chlordiazepoxide should be avoided in individuals with the following conditions:
Myasthenia gravis
Acute intoxication with alcohol, narcotics, or other psychoactive substances
Ataxia
Severe hypoventilation
Acute narrow-angle glaucoma
Severe liver deficiencies (hepatitis and liver cirrhosis decrease elimination by a factor of 2)
Severe sleep apnea
Hypersensitivity or allergy to any drug in the benzodiazepine classChlordiazepoxide is generally considered an inappropriate benzodiazepine for the elderly due to its long elimination half-life and the risks of accumulation. Benzodiazepines require special precaution if used in the elderly, pregnancy, children, alcohol- or drug-dependent individuals and individuals with comorbid psychiatric disorders.
Pregnancy
The research into the safety of benzodiazepines during pregnancy is limited and it is recommended that use of benzodiazepines during pregnancy should be based on whether the benefits outweigh the risks. If chlordiazepoxide is used during pregnancy the risks can be reduced via using the lowest effective dose and for the shortest time possible. Benzodiazepines should generally be avoided during the first trimester of pregnancy. Chlordiazepoxide and diazepam are considered to be among the safer benzodiazepines to use during pregnancy in comparison to other benzodiazepines. Possible adverse effects from benzodiazepine use during pregnancy include, abortion, malformation, intrauterine growth retardation, functional deficits, carcinogenesis and mutagenesis. Caution is also advised during breast feeding as chlordiazepoxide passes into breast milk.
Adverse effects
Sedative drugs and sleeping pills, including chlordiazepoxide, have been associated with an increased risk of death. The studies had many limitations: possibly tending to overestimate risk, such as possible confounding by indication with other risk factors; confusing hypnotics with drugs having other indications;
Common side-effects of chlordiazepoxide include:
Confusion
Constipation
Drowsiness
Fainting
Altered sex drive
Liver problems
Lack of muscle coordination
Minor menstrual irregularities
Nausea
Skin rash or eruptions
Swelling due to fluid retention
Yellow eyes and skinChlordiazepoxide in laboratory mice studies impairs latent learning. Benzodiazepines impair learning and memory via their action on benzodiazepine receptors, which causes a dysfunction in the cholinergic neuronal system in mice. It was later found that scopolamine impairment in learning was caused by an increase in benzodiazepine/GABA activity (and that benzodiazepines were not associated with the cholinergic system). In tests of various benzodiazepine compounds, chlordiazepoxide was found to cause the most profound reduction in the turnover of 5HT (serotonin) in rats. Serotonin is closely involved in regulating mood and may be one of the causes of feelings of depression in rats using chlordiazepoxide or other benzodiazepines.
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.
Tolerance and dependence
Tolerance
Chronic use of benzodiazepines, such as chlordiazepoxide, leads to the development of tolerance, with a decrease in number of benzodiazepine binding sites in mouse forebrain. The Committee of Review of Medicines, who carried out an extensive review of benzodiazepines including chlordiazepoxide, found—and were in agreement with the Institute of Medicine (USA) and the conclusions of a study carried out by the White House Office of Drug Policy and the National Institute on Drug Abuse (USA)—that there was little evidence that long-term use of benzodiazepines were beneficial in the treatment of insomnia due to the development of tolerance. Benzodiazepines tended to lose their sleep-promoting properties within 3–14 days of continuous use, and in the treatment of anxiety the committee found that there was little convincing evidence that benzodiazepines retained efficacy in the treatment of anxiety after 4 months continuous use due to the development of tolerance.
Dependence
Chlordiazepoxide can cause physical dependence and what is known as the benzodiazepine withdrawal syndrome. Withdrawal from chlordiazepoxide or other benzodiazepines often leads to withdrawal symptoms that are similar to those seen with alcohol and barbiturates. 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 at standard dosages and also after short-term use. Benzodiazepine treatment should be discontinued as soon as possible through a slow and gradual dose-reduction regime.Chlordiazepoxide taken during pregnancy can cause a postnatal benzodiazepine withdrawal syndrome.
Overdose
An individual who has consumed excess chlordiazepoxide may display some of the following symptoms:
Somnolence (difficulty staying awake)
Mental confusion
Hypotension
Hypoventilation
Impaired motor functions
Impaired reflexes
Impaired coordination
Impaired balance
Dizziness
Muscle weakness
ComaChlordiazepoxide is a drug that is very frequently involved in drug intoxication, including overdose. Chlordiazepoxide overdose is considered a medical emergency and, in general, requires the immediate attention of medical personnel. The antidote for an overdose of chlordiazepoxide (or any other benzodiazepine) is flumazenil. Flumazenil should be given with caution as it may precipitate severe withdrawal symptoms in benzodiazepine-dependent individuals.
Pharmacology
Chlordiazepoxide acts on benzodiazepine allosteric sites that are part of the GABAA receptor/ion-channel complex and this results in an increased binding of the inhibitory neurotransmitter GABA to the GABAA receptor thereby producing inhibitory effects on the central nervous system and body similar to the effects of other benzodiazepines. Chlordiazepoxide is anticonvulsant.
There is preferential storage of chlordiazepoxide in some organs including the heart of the neonate. Absorption by any administered route and the risk of accumulation is significantly increased in the neonate. The withdrawal of chlordiazepoxide during pregnancy and breast feeding is recommended, as chlordiazepoxide rapidly crosses the placenta and also is excreted in breast milk. Chlordiazepoxide also decreases prolactin release in rats. Benzodiazepines act via micromolar benzodiazepine binding sites as Ca2+ channel blockers and significantly inhibit depolarization-sensitive Calcium uptake in animal nerve terminal preparations. Chlordiazepoxide inhibits acetylcholine release in mouse hippocampal synaptosomes in vivo. This has been found by measuring sodium-dependent high affinity choline uptake in vitro after pretreatment of the mice in vivo with chlordiazepoxide. This may play a role in chlordiazepoxides anticonvulsant properties.
Pharmacokinetics
Chlordiazepoxide is a long-acting benzodiazepine drug. The half-life of Chlordiazepoxide is 5 – 30 hours but has an active benzodiazepine metabolite (desmethyldiazepam), which has a half-life of 36 – 200 hours. The half-life of chlordiazepoxide increases significantly in the elderly, which may result in prolonged action as well as accumulation of the drug during repeated administration. Delayed body clearance of the long half-life active metabolite also occurs in those over 60 years of age, which further prolongs the effects of the drugs with additional accumulation after repeated dosing.Despite its name, chlordiazepoxide is not an epoxide; they are formed from different roots.
History
Chlordiazepoxide (initially called methaminodiazepoxide) was the first benzodiazepine to be synthesized in the mid-1950s. The synthesis was derived from work on a class of dyes, quinazolone-3-oxides. It was discovered by accident when in 1957 tests revealed that the compound had hypnotic, anxiolytic, and muscle relaxant effects. "The story of the chemical development of Librium and Valium was told by Sternbach. The serendipity involved in the invention of this class of compounds was matched by the trials and errors of the pharmacologists in the discovery of the tranquilizing activity of the benzodiazepines. The discovery of Librium in 1957 was due largely to the dedicated work and observational ability of a gifted technician, Beryl Kappell. For some seven years she had been screening compounds by simple animal tests for muscle relaxant activity..." Three years later chlordiazepoxide was marketed as a therapeutic benzodiazepine medication under the brand name Librium. Following chlordiazepoxide, in 1963 diazepam hit the market under the brand name Valium—and was followed by many further benzodiazepine compounds over the subsequent years and decades.In 1959 it was used by over 2,000 physicians and more than 20,000 patients. It was described as "chemically and clinically different from any of the tranquilizers, psychic energizers or other psychotherapeutic drugs now available." During studies, chlordiazepoxide induced muscle relaxation and a quieting effect on laboratory animals like mice, rats, cats, and dogs. Fear and aggression were eliminated in much smaller doses than those necessary to produce hypnosis. Chlordiazepoxide is similar to phenobarbital in its anticonvulsant properties. However, it lacks the hypnotic effects of barbiturates. Animal tests were conducted in the Boston Zoo and the San Diego Zoo. Forty-two hospital patients admitted for acute and chronic alcoholism, and various psychoses and neuroses were treated with chlordiazepoxide. In a majority of the patients, anxiety, tension, and motor excitement were "effectively reduced." The most positive results were observed among alcoholic patients. It was reported that ulcers and dermatologic problems, both of which involved emotional factors, were reduced by chlordiazepoxide.In 1963, approval for use was given to diazepam (Valium), a "simplified" version of chlordiazepoxide, primarily to counteract anxiety symptoms. Sleep-related problems were treated with nitrazepam (Mogadon), which was introduced in 1972, temazepam (Restoril), which was introduced in 1979, and flurazepam (Dalmane), which was introduced in 1975.
Recreational use
In 1963, Carl F. Essig of the Addiction Research Center of the National Institute of Mental Health stated that meprobamate, glutethimide, ethinamate, ethchlorvynol, methyprylon and chlordiazepoxide were drugs whose usefulness “can hardly be questioned.” However, Essig labeled these “newer products” as “drugs of addiction,” like barbiturates, whose habit-forming qualities were more widely known. He mentioned a 90-day study of chlordiazepoxide, which concluded that the automobile accident rate among 68 users was 10 times higher than normal. Participants daily dosage ranged from 5 to 100 milligrams.Chlordiazepoxide is a drug of potential misuse and is frequently detected in urine samples of drug users who have not been prescribed the drug.
Legal status
Internationally, chlordiazepoxide is a Schedule IV controlled drug under the Convention on Psychotropic Substances.
Toxicity
Animal
Laboratory tests assessing the toxicity of chlordiazepoxide, nitrazepam and diazepam on mice spermatozoa found that chlordiazepoxide produced toxicities in sperm including abnormalities involving both the shape and size of the sperm head. Nitrazepam, however, caused more profound abnormalities than chlordiazepoxide.
Availability
Chlordiazepoxide is available in various dosage forms, alone or in combination with other drugs, worldwide. In combination with Clidinium as NORMAXIN-CC and in combination with dicyclomine as NORMAXIN for IBS, and with the anti-depressant Amitriptyline as Limbitrol.
See also
Alcohol withdrawal syndrome
Effects of long-term benzodiazepine use
Benzodiazepine withdrawal syndrome
Benzodiazepine dependence
Benzodiazepine
References
External links
Rx-List.com - Chlordiazepoxide
Inchem.org - Chlordiazepoxide
U.S. National Library of Medicine: Drug Information Portal - Chlordiazepoxide |
Rifabutin | Rifabutin (Rfb) is an antibiotic used to treat tuberculosis and prevent and treat Mycobacterium avium complex. It is typically only used in those who cannot tolerate rifampin such as people with HIV/AIDS on antiretrovirals. For active tuberculosis it is used with other antimycobacterial medications. For latent tuberculosis it may be used by itself when the exposure was with drug-resistant TB.Common side effects include abdominal pain, nausea, rash, headache, and low blood neutrophil levels. Other side effects include muscles pains and uveitis. , especially when hitting Bartonella and Babesia colonies in the capillaries of the ciliary body in the eye anterior chamber. While no harms have been found during pregnancy it has not been well studied in this population. Rifabutin is in the rifamycin family of medications. It works by blocking RNA production in bacteria.Rifabutin was approved for medical use in the United States in 1992. It is on the World Health Organizations List of Essential Medicines.
Medical uses
Rifabutin is now recommended as first-line treatment for tuberculosis (TB), but rifampicin was used more widely because of its cheaper cost. However, due to the expiration of patents, prices are now similar.
Rifabutin is also used in the treatment of Mycobacterium avium complex disease, a bacterial infection most commonly encountered in people with late-stage AIDS. Its has fewer drug interactions than rifampicin, therefore people with HIV/AIDS on HAART are typically prescribed rifabutin instead of rifampicin for the treatment of TB.
Rifabutin is well-tolerated in people with HIV-related TB, but new findings suggest that those with low CD4+ cell counts have a higher risk of treatment failure or relapse due to acquired rifamycin resistance. Since patients co-infected with TB and HIV are likely to be treated for TB first, when the CD4+ cell population is depressed at the time TB treatment begins, doctors and patients should be aware of the possibility for rifamycin resistance to develop.Rifamycins, including rifabutin, are useful in the treatment of Chlamydophila pneumoniae (Cpn) infection.
Rifabutin is being tested in clinical trials for treating Crohns disease as part of the anti-MAP therapy. In a Phase III study administering sub-therapeutic doses of rifabutin in combination therapy to patients not identified with MAP infections, it was associated with significant short term benefits.Rifabutin is also being investigated for the treatment of infections caused by the Gram-negative bacillus Acinetobacter baumannii, which has shown promise in animal studies.
History
Scientists at the Italian drug company Achifar discovered rifabutin in 1975. (Eventually Archifar became part of Farmitalia Carlo Erba, a unit of the conglomerate Montedison which was subsequently bought by Pharmacia) This companys Adria Laboratories subsidiary filed for Food and Drug Administration (FDA) approval of rifabutin under the brand name Mycobutin in the early 1990s and the drug gained FDA approval in December 1992.Rifabutin is primarily bactericidal antibiotic drug used to treat tuberculosis. Its effect on bacteria is based on the DNA-dependent RNA polymerase blocking drug rifamycin S, a semi-synthetic derivative. It is effective, for example, in highly resistant mycobacteria, Gram-positive bacteria (and some are effective against Gram-negative bacteria), but also against Mycobacterium tuberculosis, M. leprae, and M. avium intracellulare.
References
External links
"Rifabutin". Drug Information Portal. U.S. National Library of Medicine. |
Pasireotide | Pasireotide, sold under the brand name Signifor, is an orphan drug approved in the United States and the European Union for the treatment of Cushings disease in patients who fail or are ineligible for surgical therapy. It was developed by Novartis. Pasireotide is a somatostatin analog with a 40-fold increased affinity to somatostatin receptor 5 compared to other somatostatin analogs.
The most common side effects include hyperglycaemia (high blood sugar levels), diabetes, diarrhoea, abdominal pain (stomach ache), nausea (feeling sick), cholelithiasis (gallstones), injection site reactions, and tiredness.Pasireotide was approved for Cushings disease by the European Medicines Agency (EMA) in April 2012 and by the U.S. Food and Drug Administration (FDA) in December 2012.Pasireotide LAR (the long-acting-release formulation) was approved by the FDA for treatment of acromegaly in December 2014, and had been approved for this indication by the EMA in September 2014.
References
External links
"Pasireotide". Drug Information Portal. U.S. National Library of Medicine. |
Tolterodine | Tolterodine, sold under the brand name Detrol among others, is a medication used to treat frequent urination, urinary incontinence, or urinary urgency. Effects are seen within an hour. It is taken by mouth.Common side effects include headache, dry mouth, constipation, and dizziness. Serious side effects may include angioedema, urinary retention, and QT prolongation. Use in pregnancy and breastfeeding are of unclear safety. It works by blocking muscarinic receptors in the bladder thus decreasing bladder contractions.Tolterodine was approved for medical use in 1998. It is available as a generic medication. In 2019, it was the 292nd most commonly prescribed medication in the United States, with more than 1 million prescriptions.
Medical uses
Detrusor overactivity (DO, contraction of the muscular bladder wall) is the most common form of urinary incontinence (UI) in older adults. It is characterized by uninhibited bladder contractions causing an uncontrollable urge to void. Urinary frequency, urge incontinence and nocturnal incontinence occur. Abnormal bladder contractions that coincide with the urge to void can be measured by urodynamic studies. Treatment is bladder retraining, pelvic floor therapy or with drugs that inhibit bladder contractions such as oxybutynin and tolterodine.
Side effects
Known side effects:
Dry mouth
Decreased gastric motility (upset stomach)
Headache
Constipation
Dry eyes
Sleepiness
Urinary retentionThe following reactions have been reported in people who have taken tolterodine since it has become available:
Allergic reactions including swelling
Rapid heartbeat or abnormal heartbeat
Accumulation of fluid in the arms and legs
HallucinationsTolterodine is not recommended for use in people with myasthenia gravis and angle closure glaucoma.
Pharmacology
Tolterodine acts on M2 and M3 subtypes of muscarinic receptors whereas older antimuscarinic treatments for overactive bladder act more specifically on M3 receptors.Tolterodine, although it acts on all types of receptors, has fewer side effects than oxybutynin (M3 and M1 selective, but more so in the parotid than in the bladder) as tolterodine targets the bladder more than other areas of the body.
Society and culture
Brand names
It is marketed by Pfizer in Canada and the United States under the brand name Detrol. In Egypt it is also found under the trade names Tolterodine by Sabaa and Incont L.A. by Adwia.
References
External links
"Tolterodine". Drug Information Portal. U.S. National Library of Medicine. |
Milnacipran | Milnacipran (trade names Ixel, Savella, Dalcipran, Toledomin) is a serotonin–norepinephrine reuptake inhibitor (SNRI) used in the clinical treatment of fibromyalgia. It is not approved for the clinical treatment of major depressive disorder in the US, but it is in other countries.
Medical uses
Depression
In a pooled analysis of 7 comparative trials with imipramine, milnacipran and imipramine were shown to have comparable efficacy while milnacipran was significantly better tolerated. A pooled analysis of studies comparing milnacipran and SSRIs concluded a superior efficacy for milnacipran with similar tolerability for milnacipran and SSRIs. A more recent meta-analysis of 6 studies involving more than 1,000 patients showed no distinction between milnacipran and SSRIs in efficacy or discontinuation rates, including discontinuation for side effects or lack of efficacy. A meta-analysis of a total of 16 randomized controlled trials with more than 2200 patients concluded that there were no statistically significant differences in efficacy, acceptability and tolerability when comparing milnacipran with other antidepressant agents. However, compared with TCAs, significantly fewer patients taking milnacipran dropped out due to adverse events. As with other antidepressants, 1 to 3 weeks may elapse before significant antidepressant action becomes clinically evident.
Fibromyalgia
During its development for fibromyalgia, milnacipran was evaluated utilizing a composite responder approach. To be considered as a responder for the composite ‘treatment of fibromyalgia’ endpoint, each patient had to show concurrent and clinically meaningful improvements in pain, physical function, and global impression of disease status. A systematic review in 2015 showed moderate relief for a minority of people with fibromyalgia. Milnacipran was associated with increased adverse events when discontinuing use of the drug.
Social anxiety
There is some evidence that milnacipran may be effective for social anxiety.
Contraindications
Administration of milnacipran should be avoided in individuals with the following:
Known hypersensitivity to milnacipran (absolute contraindication)
Patients under 15 years of age (no sufficient clinical data)
Concomitant treatment with irreversible MAO inhibitors (e.g. tranylcypromine (Parnate), phenelzine (Nardil), >10 mg selegiline) or digitalis glycosides is an absolute contraindication.Administration of milnacipran should be done with caution in individuals with the following:
Concomitant treatment with parenteral epinephrine, norepinephrine, with clonidine, reversible MAO-A Inhibitors (such as moclobemide, toloxatone) or 5-HT1D-agonists (e.g. triptan migraine drugs)
Advanced renal disease (decreased dosage required)
Hypertrophy of the prostate gland (possibly urination hesitancy induced), with hypertension and heart disease (tachycardia may be a problem) as well as with open angle glaucoma.Milnacipran should not be used during pregnancy because it may cross the placenta barrier and no clinical data exists on harmful effects in humans and animal studies. Milnacipran is contraindicated during lactation because it is excreted in the milk, and it is not known if it is harmful to the newborn.
Side effects
The most frequently occurring adverse reactions (≥ 5% and greater than placebo) were nausea, headache, constipation, dizziness, insomnia, hot flush, hyperhydrosis, vomiting, palpitations, heart rate increase, dry mouth, and hypertension [FDA Savella prescribing information]. Milnacipran can have a significant impact on sexual functions, including both a decrease in sexual desire and ability. Milnacipran can cause pain of the testicles in men. The incidence of cardiovascular and anticholinergic side effects was significantly lower compared to TCAs as a controlled study with over 3,300 patients revealed. Elevation of liver enzymes without signs of symptomatic liver disease has been infrequent. Mood swing to mania has also been seen and dictates termination of treatment. In psychotic patients emergence of delirium has been noticed. Milnacipran has a low incidence of sedation but improves sleep (both duration and quality) in depressed patients. In agitated patients or those with suicidal thoughts additive sedative/anxiolytic treatment is usually indicated.
Interactions
MAOIs — hyperserotonergia (serotonin syndrome), potentially lethal hypertensive crisis
5-HT1 receptor agonists — coronary vasoconstriction with risk of angina pectoris and myocardial infarction
Epinephrine, norepinephrine (also in local anesthesia) — hypertensive crisis and/or possible cardiac arrhythmia
Clonidine — antihypertensive action of clonidine may be antagonized
Digitalis — hemodynamic actions increased
Triptans — there have been rare postmarketing reports of hyperserotonergia (serotonin syndrome). If concomitant treatment of milnacipran with a triptan is clinically warranted, careful observation of patient is advised when starting or increasing dosages.
Alcohol — no interactions known; however, because milnacipran can cause mild elevation of liver enzymes, caution is recommended; the FDA advises against the concomitant use of alcohol and milnacipran
Pharmacology
Pharmacodynamics
Milnacipran inhibits the reuptake of serotonin and norepinephrine in an approximately 1:3 ratio, respectively. Milnacipran exerts no significant actions on H1, α1, D1, D2, and mACh receptors, nor on benzodiazepine and opioid binding sites.Recently, levomilnacipran, the levorotatory enantiomer of milnacipran, has been found to act as an inhibitor of beta-site amyloid precursor protein cleaving enzyme-1 (BACE-1), which is responsible for β-amyloid plaque formation, and hence may be a potentially useful drug in the treatment of Alzheimers disease. Other BACE-1 inhibitors, such as CTS-21166 (ASP1720), MK-8931, and AZD3293 were in clinical trials for the treatment of Alzheimers disease, but in both cases clinical trials were halted due to a lack of positive evidence of a favorable benefit to risk ratio and both were considered unlikely to return satisfactory results.
Pharmacokinetics
Milnacipran is well absorbed after oral dosing and has a bioavailability of 85%. Meals do not have an influence on the rapidity and extent of absorption. Peak plasma concentrations are reached 2 hours after oral dosing. The elimination half-life of 8 hours is not increased by liver impairment and old age, but by significant renal disease. Milnacipran is conjugated to the inactive glucuronide and excreted in the urine as unchanged drug and conjugate. Only traces of active metabolites are found.
History
Milnacipran was first approved for the treatment of major depressive episodes in France in December 1996. It is currently marketed (as Ixel) for this indication in over 45 countries worldwide including several European countries such as Austria, Bulgaria, Finland, France, Portugal, and Russia. It is also available in Japan (as Toledomin) and Mexico (as Dalcipran). Cypress Bioscience bought the exclusive rights for approval and marketing of the drug for any purpose in the United States and Canada in 2003 from the manufacturer Laboratoires Pierre Fabre.
In January 2009 the U.S. Food and Drug Administration (FDA) approved milnacipran (under the brand name Savella) only for the treatment of fibromyalgia, making it the third medication approved for this purpose in the United States. In July and November 2009, the European Medicines Agency refused marketing authorization for a milnacipran product (under the brand name Impulsor) for the treatment of fibromylagia.
References
External links
"Milnacipran". Drug Information Portal. U.S. National Library of Medicine.
"Milnacipran hydrochloride". Drug Information Portal. U.S. National Library of Medicine. |
Nepafenac | Nepafenac, sold under the brand name Nevanac among others, is a nonsteroidal anti-inflammatory drug (NSAID), usually sold as a prescription eye drop 0.1% solution (Nevanac) or 0.3% solution (Ilevro). It is used to treat pain and inflammation associated with cataract surgery. Nepafenac is a prodrug of amfenac, an inhibitor of COX-1 and COX-2 activity.
Medical uses
Nepafenac is indicated for use in the treatment of pain and inflammation following cataract surgery.In the European Union nepafenac is also indicated for the reduction in the risk of postoperative macular edema associated with cataract surgery in people with diabetes.
Pharmacology
Mechanism of action
Nepafenac is an NSAID, thought to be a prodrug of amfenac after conversion by ocular tissue hydrolases after penetration via the cornea. Amfenac, like other NSAIDs, is thought to inhibit cyclooxygenase action.
Adverse events
Side effects include headache; runny nose; pain or pressure in the face; nausea; vomiting; and dry, itchy, sticky eyes. Serious side effects include red or bloody eyes; foreign body sensation in the eye; sensitivity to light; decreased visual acuity; seeing specks or spots; teary eyes; or eye discharge or crusting.
Regulatory
Nevanac
On February 25, 2005, Alcon filed a New Drug Application (NDA) with the U.S. Food and Drug Administration (FDA) for Nevanac 0.1%. Results from the two trials referenced in the NDA (Phase 2/3 study C-02-53; Phase 3 study C-03-32) have not been published. Study C-02-53 consisted of 228 patients across 10 centers in the United States. Study C-03-32 consisted of 522 patients across 22 centers in the United States. The efficacy results presented were confirmed in a study published in 2007.Nevanac was approved by the FDA on August 19, 2005, with application number 021–862.
Ilevro
An NDA for Ilevro was filed on December 15, 2011. In a one-month study, no new toxicities arose in the new formulation of nepafenac. Safety and efficacy information was derived from the previous Nevanac application. In June 2010, a confirmatory study began (Study C09055) consisting of over 2000 patients from 49 US sites and 37 European sites. A second phase 3 trial (Study C11003) was conducted in a population of 1,342 patients at 37 sites across the United States which failed to demonstrate superiority over Nevanac in an altered dosing regimen.Ilevro was approved by the FDA on October 16, 2012, with application number 203–491.
Commercialization
Both Nevanac and Ilevro are manufactured and sold by Alcon, Inc. Alcon is currently a division of Novartis International AG, which is primarily based out of Switzerland. Alcon, Inc. also holds locations in both Switzerland and the United States. The company has gone through several name changes, from Alcon Laboratories, Inc. to Alcon Universal, Ltd., to Alcon, Inc.Nevanac entered the market in 2005 as a product of Alcon, at the time a subsidiary of Nestlé. On April 6, 2008, Novartis agreed to purchase approximately 74 million shares of Alcon from Nestlé at $143.18 per share. On January 4, 2010, Novartis agreed to purchase all remaining shares of Alcon from Nestlé, totalling 156 million shares or 77% of the shares in the company. At the time of the purchase, a proposal for a merger under Swiss merger law was given to the Alcon board of directors. The merger was agreed upon on December 15, 2010, making Alcon "the second largest division within Novartis." The merger was completed on April 8, 2011.Ilevro was launched by Alcon on January 21, 2013. In 2014 and 2015, net sales by Alcon grew, contributed to in part by the increased volume in sales of Ilevro. That financial year, Novartis reported $18 billion in total financial debt. That figure has grown steadily since. In 2016, Novartis reported a total debt of $23.8 billion, up from the $21.9 billion reported in 2015 and the $20.4 billion reported in 2014. As of May 2017, Novartis is estimated to be worth $193.2 billion.On January 27, 2016, Alcon was moved to become a branch of the Innovative Medicines Division at Novartis. Early in 2016, Alcon formed agreements with both TrueVision and PowerVision, and acquired Transcend Medical. As of January 2017, Novartis is weighing options for Alcon in the business structure.
Commercial risks
Alcon faced declining growth in 2016, having faced challenges in development and marketing of new products.
Marketing
Novartis maintains a detailing unit geared toward health professionals consisting of over 3,000 employees within the United States and an additional 21,000 worldwide. Novartis is also seeking to expand direct-to-consumer advertising and entrance into specialty product markets. Novartis also notes the influence of position and preference on US Centers for Medicare & Medicaid formularies in expanding their market value.Nepafenac, Nevanac, and Ilevro are all absent from the 2016 Annual Report issued from Novartis.
Intellectual property
There are currently seven U.S. patents filed that are directly associated with the modernized formulations of nepafenac, all stemming from Novartis. There are three patents associated with Nevanac that are still active and four associated with Ilevro. The earliest patent related to the modern formulations of nepafenac was approved on June 11, 2002, after being filed in 1999, by Bahram Asgharian. A patent was filed by Warren Wong, associated with Alcon, Inc. based out of Fort Worth, Texas, on December 2, 2005, for aqueous suspensions of nepafenac. Another patent for a nepafenac-based drug was filed on May 8, 2006, by Geoffrey Owen, Amy Brooks, and Gustav Graff. A patent was filed by Masood A. Chowhan and Huagang Chen on February 9, 2007, and approved on May 24, 2011, followed closely by a patent filed by Warren Wong on September 23, 2010, and approved on December 6, 2011. Masood A. Chowhan, Malay Ghosh, Bahram Asgharian, and Wesley Wehsin Han filed another patent on December 1, 2010, and approved on December 30, 2014. The most recent patent was filed by Masood A. Chowhan, Malay Ghosh, Bahram Asgharian, and Wesley Weshin Han on November 12, 2014, and approved on May 30, 2017. These patents are in effect until dates ranging between July 17, 2018, and March 31, 2032.Novartis also maintains patents on nepafenac in 26 countries outside the United States.
References
External links
"Nepafenac". Drug Information Portal. U.S. National Library of Medicine. |
Esterified estrogens | Esterified estrogens (EEs), sold under the brand names Estratab and Menest among others, is an estrogen medication which is used hormone therapy for menopausal symptoms and low sex hormone levels in women, to treat breast cancer in both women and men, and to treat prostate cancer in men. It is formulated alone or in combination with methyltestosterone. It is taken by mouth.Side effects of EEs include nausea, breast tension, edema, and breakthrough bleeding among others. It is an estrogen, or an agonist of the estrogen receptors, the biological target of estrogens like estradiol. EEs are a prodrug mainly of estradiol and to a lesser extent of equilin.EEs were introduced for medical use by 1970. They are available in only a few countries, such as Chile and the United States. They have also been marketed in Argentina and Switzerland in the past.
Medical uses
EEs are used in hormone therapy for menopausal symptoms, female hypogonadism, ovariectomy, and primary ovarian failure and in the treatment of breast cancer and prostate cancer.
Available forms
EEs are available in the form of 0.3 mg, 0.625 mg, 1.25 mg, and 2.5 mg oral tablets. Estratest is a combination formulation of 1.25 mg EEs with 2.5 mg methyltestosterone.
Side effects
Pharmacology
EEs consist primarily of sodium estrone sulfate and sodium equilin sulfate, and are very similar to conjugated estrogens (CEEs, conjugated equine estrogens; brand name Premarin). However, EEs and CEEs differ in the sources of their contents and in the percentages of their constituents; CEEs consist of approximately 53% sodium estrone sulfate and 25% sodium equilin sulfate, while EEs contain about 75 to 85% sodium estrone sulfate and 6 to 11% sodium equilin sulfate. EEs have been found to produce similar serum levels of estrone and estradiol relative to CEEs, although with higher levels of estrone and lower levels of equilin. One study found that the risk of venous thrombosis may be less with EEs relative to CEEs.
Chemistry
EEs contain synthetic, plant-derived estrogens and are manufactured from soybeans and yams.
History
EEs were introduced for medical use by 1970.
Society and culture
Generic names
Estrogens, esterified is the generic name of the drug and its USP. It is also known as esterified estrogens.
Brand names
EEs are marketed under a variety of brand names including Amnestrogen, Estragyn, Estratab, Evex, Femibel, Femogen, Menest, Neo Estrone Tab, and Oestro-Feminal alone, and, in combination with methyltestosterone, under the brand names Covaryx, Delitan, Eemt, Essian, Estratest, Feminova-T, Menogen, and Syntest.
Availability
EEs are or have been marketed in Argentina, Chile, Switzerland, and the United States. Both EEs and the combination of EEs and methyltestosterone are listed as being marketed only in Chile and the United States as of present.
See also
Esterified estrogens/methyltestosterone
Estrogenic substances
Conjugated estriol
List of combined sex-hormonal preparations
== References == |
Anavip | ANAVIP is the trade name of a snake antivenin indicated for the management of adult and pediatric patients with North American rattlesnake envenomation. As defined by the FDA, the proper name is crotalidae immune F(ab)2 (equine). It is manufactured by Instituto Bioclon for Rare Disease Therapeutics in the United States.
ANAVIP is a divalent fragment antigen-binding protein, F(ab)2, derived from the blood of horses immunized with the venom of the snakes Bothrops asper and Crotalus durissus. The product is produced by pepsin digestion of horse blood plasma then purified resulting in a preparation containing >85% F(ab)2.
== References == |
Hydrochlorothiazide/triamterene | Hydrochlorothiazide/triamterene, also known as co-triamterzide, is a fixed-dose combination medication of hydrochlorothiazide and triamterene. It is used to treat high blood pressure and edema (swelling). Specifically it is used in those who develop low blood potassium (hypokalemia) when on only hydrochlorothiazide. It is taken by mouth.Side effects may include nausea, trouble sleeping, dizziness, feeling light headed with standing, kidney problems, allergies, and muscle cramps. Other serious side effects may include high blood potassium. Use in pregnancy and breastfeeding is not generally recommended. Use in those with significant kidney problems is not recommended. It decreases blood pressure mainly by hydrochlorothiazide while triamterene decreases the amount of potassium lost.The combination was approved for medical use in the United States in 1965. In 2019, it was the 115th most commonly prescribed medication in the United States, with more than 5 million prescriptions.
References
External links
"Hydrochlorothiazide mixture with triamterene". Drug Information Portal. U.S. National Library of Medicine. |
Cetirizine/pseudoephedrine | Cetirizine/pseudoephedrine (Zyrtec-D) is an antihistamine and decongestant formulation. It is a fixed-dose combination drug containing cetirizine hydrochloride and pseudoephedrine hydrochloride for symptoms related to seasonal allergic rhinitis.
== References == |
Ella | Ella may refer to:
Ella (name), most often a feminine given name, but also used as a surname
Places
United States
Ella, Kentucky, an unincorporated community
Ella, Oregon, an unincorporated community
Ella, Pennsylvania, an unincorporated community
Ella, Wisconsin, an unincorporated community
Lake Ella, Tallahassee, Florida
Greenland
Ella Island, an uninhabited island of the Greenland Sea, Greenland
Sri Lanka
Ella, Sri Lanka, a town in Uva, Sri Lanka
Arts and entertainment
Music
Ella (Ella Fitzgerald album), 1969
Ella (Juan Gabriel album), 1980
Ella (Malaysian singer) (born 1966)
"Ella" (Jack de Nijs song), by André Moss, Jack De Nijs, 1973
"Ella", song by Raphael (singer) L. Favio, 1969
"Ella" (José Alfredo Jiménez song)
"Ella", song by The Way (band) J. Hill, R. Hill, 1972
"Ella", song by Bebe from Pafuera Telarañas, 2004
"Ella" (Tan Biónica song), by Argentine group Tan Biónica, 2010
Other
Ella (2016), documentary film about Australian dancer Ella Havelka
Ella Martinez, a protagonist in the Maximum Ride fantasy novel series
Ella (novel), by Uri Geller
the title character of Ella the Elephant, a Canadian animated preschool series
Other uses
ELLA (programming language), hardware design language
435 Ella, a Main belt asteroid
Tropical Storm Ella (disambiguation), several tropical storms
USS Ella, various United States Navy ships
Ella, trade name in the US of ulipristal acetate, an emergency contraceptive
See also
All pages with titles beginning with Ella
"Ella, elle la", a 1987 song by France Gall
Several settlements near Kingston upon Hull, Yorkshire, England, United Kingdom:
East Ella
Kirk Ella
West Ella
Elah (disambiguation)
Aelle (disambiguation) |
Granisetron | Granisetron is a serotonin 5-HT3 receptor antagonist used as an antiemetic to treat nausea and vomiting following chemotherapy and radiotherapy. Its main effect is to reduce the activity of the vagus nerve, which is a nerve that activates the vomiting center in the medulla oblongata. It does not have much effect on vomiting due to motion sickness. This drug does not have any effect on dopamine receptors or muscarinic receptors.
Granisetron was developed by chemists working at the British drug company Beecham around 1985 and is available as a generic. It is produced by Roche Laboratories under the trade name Kytril. The drug was approved in the United Kingdom in 1991 and in United States in 1994 by the FDA.
A granisetron transdermal patch with the trade name Sancuso was approved by the US FDA on September 12, 2008. Sancuso is manufactured by 3M Drug Delivery Systems for Kyowa Kirin, Inc.
It was patented in 1985 and approved for medical use in 1991. It is on the World Health Organizations List of Essential Medicines.
Medical uses
Chemotherapy
It may be used for chemotherapy-induced nausea and vomiting and appears to work about the same as ondansetron. The most common side-effects of chemotherapy treatment are nausea, vomiting and diarrhea. This is one type of drug that a doctor can prescribe to prevent, lessen, or relieve discomfort.
Post operative
A number of medications including granisetron appear to be effective in controlling post-operative nausea and vomiting (PONV). It is unclear if it is more or less effective than other agents such as droperidol, metoclopramide, or ondansetron.
Gastroparesis
The granisetron patch (Sancuso) has been studied for use in gastroparesis, though it is not FDA approved for this indication.
Other
Is a possible therapy for nausea and vomiting due to acute or chronic medical illness or acute gastroenteritis
Treatment of cyclic vomiting syndrome although there are no formal trials to confirm efficacy.
Adverse effects
Granisetron is a well-tolerated drug with few side effects. Headache, dizziness, and constipation are the most commonly reported side effects associated with its use. There have been no significant drug interactions reported with this drugs use. It is broken down by the livers cytochrome P450 system and it has little effect on the metabolism of other drugs broken down by this system.
Extended release
An extended release injectable version of granisetron, known as Sustol is also available in the United States as of 2016. The long acting form is used for the treatment of both acute and delayed CINV in moderately emetogenic chemotherapy and anthrocycline and/or cyclophosphamide (AC) highly emetogenic regimens. In its review, the FDA did not grant the broad HEC label to the drug citing the focus on AC regimens, primarily breast-cancer, and lack of data.
References
== Further reading == |
Apris | Apri (āprī) in Sanskrit means "conciliation, propitiation" and refers to special invocations spoken previous to the offering of oblations in an animal sacrifice. Some scholars have proposed however, that these hymns were originally meant for a family ritual centered around Agni, which was then later connected to the animal sacrifice.
Aprisuktas
Of the ten Aprisuktas mentioned in Gargya Narayanas commentary, I.13 and I.142 both invoke the Narāśaṁsa and Tanūnapāt manifestations of Agni, I.188, III.4, IX.5 and X.110 invoke only the Tanūnapāt manifestation and II.3, V.5, VII.2 and X.70 invoke only the Narāśaṁsa manifestation.
References
āprī in: Monier-Williams A Sanskrit Dictionary, 1899.
R. Fick, "Gotra" in: ed. Hastings, Encyclopaedia of Religion and Ethics vol. 6, 1999, p. 355
Samir Nath, "Gotra-system" in: Dictionary Of Vedanta, 2002, p. 153. |
Insulin glulisine | Insulin glulisine is a rapid-acting modified form of medical insulin that differs from human insulin in that the amino acid asparagine at position B3 is replaced by lysine and the lysine in position B29 is replaced by glutamic acid. It was developed by Sanofi-Aventis and approved for marketing by the FDA in 2004; it is sold under the trade name Apidra. When injected subcutaneously, it appears in the blood earlier than human insulin. When used as a meal time insulin, the dose is to be administered within 15 minutes before or 20 minutes after starting a meal. Intravenous injections may also be used for extreme hyperglycemia, but must be performed under the supervision of a medical professional.The most common side effects include hypoglycaemia (low blood glucose levels).
Medical uses
Insulin glulisine is indicated for the treatment of diabetes mellitus.
References
External links
"Insulin glulisine". Drug Information Portal. U.S. National Library of Medicine. |
Plazomicin | Plazomicin, sold under the brand name Zemdri, is an aminoglycoside antibiotic used to treat complicated urinary tract infections. As of 2019 it is recommended only for those in whom alternatives are not an option. It is given by injection into a vein.Common side effects include kidney problems, diarrhea, nausea, and blood pressure changes. Other severe side effects include hearing loss, Clostridium difficile-associated diarrhea, anaphylaxis, and muscle weakness. Use during pregnancy may harm the baby. Plazomicin works by decreasing the ability of bacteria to make protein.Plazomicin was approved for medical use in the United States in 2018. It is on the World Health Organizations List of Essential Medicines.
Medical uses
Plazomicin is approved by the U.S. Food and Drug Administration (FDA) for adults with complicated urinary tract infections, including pyelonephritis, caused by Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, or Enterobacter cloacae, in patients who have limited or no alternative treatment options. Zemdri is an intravenous infusion, administered once daily. The FDA declined approval for treating bloodstream infections due to lack of demonstrated effectiveness. The lack of demonstrated effectiveness was not so much about the antibiotic itself being ineffective so much as the low enrollment rate for the study. Studies using mouse models however, showed a high survival rate.Plazomicin has been reported to demonstrate in vitro synergistic activity when combined with daptomycin or ceftobiprole versus methicillin-resistant Staphylococcus aureus, vancomycin-resistant S. aureus and against Pseudomonas aeruginosa when combined with cefepime, doripenem, imipenem or piperacillin/tazobactam. It also demonstrates potent in vitro activity versus carbapenem-resistant Acinetobacter baumannii. Plazomicin was found to be noninferior to meropenem.
History
The drug was developed by the biotech company Achaogen. In 2012, the U.S. Food and Drug Administration granted fast track designation for the development and regulatory review of plazomicin. The FDA approved plazomicin for adults with complicated UTIs and limited or no alternative treatment options in 2018. Achaogen was unable to find a robust market for the drug, and declared bankruptcy a few months later. A generic version is manufactured by Cipla USA.
Synthesis
It is derived from sisomicin by appending a hydroxy-aminobutyric acid substituent at position 1 and a hydroxyethyl substituent at position 6. The latter makes it impervious to acetylation (deactivation) by Aminoglycoside Acetyltransferase 6-N- Type Ib (AAC(6)-Ib), the most prevalent AAC enzyme.
Names
Plazomicin is the international nonproprietary name (INN).
References
Further reading
"FDA Briefing Information for the May 2, 2018 Meeting of the Antimicrobial Drugs Advisory Committee" (PDF). U.S. Food and Drug Administration. 2 May 2018. Retrieved 14 September 2019.
"Achaogen Briefing Information for the May 2, 2018 Meeting of the Antimicrobial Drugs Advisory Committee" (PDF). U.S. Food and Drug Administration. 2 May 2018. Retrieved 14 September 2019.
"Errata to the Achaogen Briefing Information for the May 2, 2018 Meeting of the Antimicrobial Drugs Advisory Committee" (PDF). U.S. Food and Drug Administration. 2 May 2018. Retrieved 14 September 2019.
External links
"Plazomicin". Drug Information Portal. U.S. National Library of Medicine.
"Plazomicin sulfate". Drug Information Portal. U.S. National Library of Medicine. |
Naltrexone | Naltrexone, sold under the brand name Revia among others, is a medication primarily used to manage alcohol or opioid use disorder by reducing cravings and feelings of euphoria associated with substance use disorder. It has also been found to be effective in the treatment of other addictions and may be used for them off-label. An opioid-dependent person should not receive naltrexone before detoxification. It is taken by mouth or by injection into a muscle. Effects begin within 30 minutes. A decreased desire for opioids may take a few weeks to occur.Side effects may include trouble sleeping, anxiety, nausea, and headaches. In those still on opioids, opioid withdrawal may occur. Use is not recommended in people with liver failure. It is unclear if use is safe during pregnancy. Naltrexone is an opioid antagonist and works by blocking the effects of opioids, including both opioid drugs as well as opioids naturally produced in the brain.
Naltrexone was first made in 1965 and was approved for medical use in the United States in 1984. Naltrexone, as naltrexone/bupropion (brand name Contrave), is also used to treat obesity.
Medical uses
Alcohol use disorder
Naltrexone has been best studied as a treatment for alcoholism. Naltrexone has been shown to decrease the quantity and frequency of ethanol consumption. It does not appear to change the percentage of people drinking. Its overall benefit has been described as "modest".Acamprosate may work better than naltrexone for eliminating alcohol abuse, while naltrexone may decrease the desire for alcohol to a greater extent.The Sinclair method is a method involving opiate antagonists such as naltrexone to treat alcoholism. The person takes the medication once, about an hour before consuming alcohol, to curb the urge to drink. The opioid antagonist is thought to block the positive reinforcement effects of alcohol and may assist the person to stop or reduce their drinking.
Opioid use
Long-acting injectable naltrexone is an opioid receptor antagonist, blocking the effects of heroin and other opioids, and decreases heroin use compared to a placebo. Unlike methadone and buprenorphine, it is not a controlled medication. It may decrease cravings for opioids after a number of weeks, and decreases the risk of overdose, at least during the time period that naltrexone is still active, though concern about risk of overdose for those stopping treatment remains. It is given once per month and has better compliance and effect for opioid use than the oral formulation.A drawback of injectable naltrexone as compared to methadone and buprenorphine is the requirement for a period of opioid abstinence before starting the medication, as the injection can otherwise cause sudden and intense opioid withdrawal. This "hurdle" is responsible for worse patient uptake with long-acting injectable naltrexone as compared with buprenorphine. Among patients able to successfully initiate injectable naltrexone, long-term rates were similar Another concern is that while methadone and buprenorphine patients maintain high drug tolerance in the event of return to street drug use, naltrexone allows tolerance to fade, leading to risk of overdose in people who relapse and thus higher mortality. Guidelines from the World Health Organization cite evidence of superiority in reducing mortality and retaining patients in care with opioid agonists (methadone or buprenorphine), concluding that most patients should be advised to use agonists rather than antagonists like naltrexone.A 2011 review found insufficient evidence to determine the effect of naltrexone taken by mouth in opioid dependence. While some do well with this formulation, it must be taken daily, and a person whose cravings become overwhelming can obtain opioid intoxication simply by skipping a dose. Due to this issue, the usefulness of oral naltrexone in opioid use disorders is limited by the low retention in treatment. Naltrexone by mouth remains an ideal treatment for a small number of people with opioid use, usually those with a stable social situation and motivation. With additional contingency management support, naltrexone may be effective in a broader population.
Others
Naltrexone is not useful for quitting smoking. Naltrexone has also been under investigation for reducing behavioral addictions such as gambling or kleptomania as well as compulsive sexual behaviors in both offenders and non-offenders (e.g. compulsive porn viewing and masturbation). The results were promising. In one study, the majority of sexual offenders reported a strong reduction in sexual urges and fantasies which reverted to baseline once the medication was discontinued. Case reports have also shown cessation of gambling and other compulsive behaviors, for as long as the medication was taken.
Available forms
Naltrexone is available and most commonly used in the form of an oral tablet (50 mg). Vivitrol, a naltrexone formulation for depot injection containing 380 mg of the medication per vial, is also available. Additionally, naltrexone subcutaneous implants that are surgically implanted are available. While these are manufactured in Australia, they are not authorized for use within Australia, but only for export. By 2009, naltrexone implants showed superior efficacy in the treatment of heroin dependence when compared to the oral form.When taken at much smaller doses, a regimen known as Low Dose Naltrexone (LDN), naltrexone may reduce pain and help to address neurological symptoms. Some patients report that LDN helps reduce their symptoms of ME/CFS, multiple sclerosis (MS), fibromyalgia (FMS), or autoimmune disease. Although its mechanism of action is unclear, some have speculated that it may act as an anti-inflammatory. LDN is also being considered as a potential treatment for Long COVID.
Contraindications
Naltrexone should not be used by persons with acute hepatitis or liver failure, or those with recent opioid use (typically 7–10 days).
Side effects
The most common side effects reported with naltrexone are gastrointestinal complaints such as diarrhea and abdominal cramping. These adverse effects are analogous to the symptoms of opioid withdrawal, as the μ-opioid receptor blockade will increase gastrointestinal motility.
The side effects of naltrexone by incidence are as follows:
Greater than 10%: difficulty sleeping, anxiety, nervousness, abdominal pain/cramps, nausea and/or vomiting, low energy, joint/muscle pain, and headache.
Less than 10%: loss of appetite, diarrhea, constipation, thirstiness, increased energy, feeling down, irritability, dizziness, skin rash, delayed ejaculation, erectile dysfunction, and chills.
A variety of other adverse events have also been reported with less than 1% incidence.
Opioid withdrawal
Naltrexone should not be started until several (typically 7–10) days of abstinence from opioids have been achieved. This is due to the risk of acute opioid withdrawal if naltrexone is taken, as naltrexone will displace most opioids from their receptors. The time of abstinence may be shorter than 7 days, depending on the half-life of the specific opioid taken. Some physicians use a naloxone challenge to determine whether an individual has any opioids remaining. The challenge involves giving a test dose of naloxone and monitoring for opioid withdrawal. If withdrawal occurs, naltrexone should not be started.
Aversive effects
Whether naltrexone causes dysphoria, depression, anhedonia, or other aversive effects as side effects has been studied and reviewed. In early studies in normal and opioid-abstinent individuals, acute and short-term administration of naltrexone was reported to produce a variety of aversive effects including fatigue, loss of energy, sleepiness, mild dysphoria, depression, lightheadedness, faintness, mental confusion, nausea, gastrointestinal disturbances, sweating, and occasional feelings of unreality. However, these studies were small, often uncontrolled, and used subjective means of assessing side effects. Most subsequent longer-term studies of naltrexone for indications like alcohol or opioid dependence have not reported dysphoria or depression with naltrexone in most individuals. According to one source:
Naltrexone itself produces little or no psychoactive effect in normal research volunteers even at high doses, which is remarkable given that the endogenous opioid system is important in normal hedonic functioning. Because endogenous opioids are involved in the brain reward system, it would be reasonable to hypothesize that naltrexone might produce anhedonic or dysphoric effects. Although some evidence from small, early trials suggested that patients with a history of opiate dependence might be susceptible to dysphoric effects in response to naltrexone (Crowley et al. 1985; Hollister et al. 1981), reports of such effects have been inconsistent. Most large clinical studies of recovering opioid-dependent individuals have not found naltrexone to have an adverse effect on mood (Greenstein et al. 1984; Malcolm et al. 1987; Miotto et al. 2002; Shufman et al. 1994). Some studies have actually found improvements in mood during the course of treatment with naltrexone (Miotto et al. 1997; Rawlins and Randall 1976).Based on available evidence, naltrexone seems to have minimal untoward effects in the aforementioned areas, at least with long-term therapy,. It has been suggested that differences in findings between acute and longer-term studies of naltrexone treatment might be related to altered function in the opioid system with chronic administration of naltrexone. For example, marked upregulation of opioid receptors and hyper-sensitivity to opioids have been observed with naltrexone in preclinical studies. Another possibility is that the central opioid system may have low endogenous functionality in most individuals, becoming active only in the presence of exogenously administered opioid receptor agonists or with stimulation by endogenous opioids induced by pain or stress. A third possibility is that normal individuals may experience different side effects with naltrexone than people with addictive disease such as alcohol or opioid dependence, who may have altered opioid tone or responsiveness. It is notable in this regard that most studies of naltrexone have been in people with substance dependence.Naltrexone may also initially produce opioid withdrawal-like symptoms in a small subset of people not dependent on opioids:
The side-effect profile [of naltrexone], at least on the recommended dose of 50 mg per day, is generally benign, although 5 to 10 percent of detoxified opioid addicts experience immediate, intolerable levels of withdrawal-like effects including agitation, anxiety, insomnia, light-headedness, sweating, dysphoria, and nausea. Most patients on naltrexone experience few or no symptoms after the first 1 to 2 weeks of treatment; for a substantial minority (20 to 30 percent) protracted discomfort is experienced.Persisting affective distress related to naltrexone may account for individuals taking the drug who drop out of treatment.Naltrexone has been reported to reduce feelings of social connection. Studies on whether naltrexone can decrease the pleasurable effects of listening to music are conflicting. Besides humans, naltrexone has been found to produce aversive effects in rodents as assessed by conditioned place aversion.
Liver damage
Naltrexone has been reported to cause liver damage when given at doses higher than recommended. It carries an FDA boxed warning for this rare side effect. Due to these reports, some physicians may check liver function tests prior to starting naltrexone, and periodically thereafter. Concerns for liver toxicity initially arose from a study of nonaddicted obese patients receiving 300 mg of naltrexone. Subsequent studies have suggested limited or no toxicity in other patient populations and at typical recommended doses such as 50 to 100 mg/day.
Overdose
No toxic effects have been observed with naltrexone in doses of up to 800 mg/day in clinical studies. The largest reported overdose of naltrexone, which was 1,500 mg in a female patient and was equivalent to an entire bottle of medication (30 × 50 mg tablets), was uneventful. No deaths are known to have occurred with naltrexone overdose.
Pharmacology
Pharmacodynamics
Opioid receptor blockade
Naltrexone and its active metabolite 6β-naltrexol are competitive antagonists of the opioid receptors. Naltrexone is specifically an antagonist preferentially of the μ-opioid receptor (MOR), to a lesser extent of the κ-opioid receptor (KOR), and to a much lesser extent of the δ-opioid receptor (DOR). However, naltrexone is not actually a silent antagonist of these receptors but instead acts as a weak partial agonist, with Emax values of 14 to 29% at the MOR, 16 to 39% at the KOR, and 14 to 25% at the DOR in different studies. In accordance with its partial agonism, although naltrexone is described as a pure opioid receptor antagonist, it has shown some evidence of weak opioid effects in clinical and preclinical studies.By itself, naltrexone acts as an antagonist or weak partial agonist of the opioid receptors. In combination with agonists of the MOR such as morphine however, naltrexone appears to become an inverse agonist of the MOR. Conversely, naltrexone remains a neutral antagonist (or weak partial agonist) of the KOR and DOR. In contrast to naltrexone, 6β-naltrexol is purely a neutral antagonist of the opioid receptors. The MOR inverse agonism of naltrexone when it is co-present with MOR agonists may in part underlie its ability to precipitate withdrawal in opioid-dependent individuals. This may be due to suppression of basal MOR signaling via inverse agonism.Occupancy of the opioid receptors in the brain by naltrexone has been studied using positron emission tomography (PET). Naltrexone at a dose of 50 mg/day has been found to occupy approximately 90 to 95% of brain MORs and 20 to 35% of brain DORs. Naltrexone at a dose of 100 mg/day has been found to achieve 87% and 92% brain occupancy of the KOR in different studies. Per simulation, a lower dose of naltrexone of 25 mg/day might be expected to achieve around 60% brain occupancy of the KOR but still close to 90% occupancy of the MOR. In a study of the duration of MOR blockade with naltrexone, the drug with a single 50 mg dose showed 91% blockade of brain [11C]carfentanil (a selective MOR ligand) binding at 48 hours (2 days), 80% blockade at 72 hours (3 days), 46% blockade at 120 hours (5 days), and 30% blockade at 168 hours (7 days). The half-time of brain MOR blockade by naltrexone in this study was 72 to 108 hours (3.0 to 4.5 days). Based on these findings, doses of naltrexone of even less than 50 mg/day would be expected to achieve virtually complete brain MOR occupancy. Blockade of brain MORs with naltrexone is much longer-lasting than with other opioid antagonists like naloxone (half-time of ~1.7 hours intranasally) or nalmefene (half-time of ~29 hours).The half-life of occupancy of the brain MOR and duration of clinical effect of naltrexone are much longer than suggested by its plasma elimination half-life. A single 50 mg oral dose of naltrexone has been found to block brain MORs and opioid effects for at least 48 to 72 hours. The half-time of brain MOR blockade by naltrexone (72–108 hours) is much longer than the fast plasma clearance component of naltrexone and 6β-naltrexol (~4–12 hours) but was reported to correspond well to the longer terminal phase of plasma naltrexone clearance (96 hours). As an alternative possibility, the prolonged brain MOR occupancy by opioid antagonists like naltrexone and nalmefene may be due to slow dissociation from MORs consequent to their very high MOR affinity (<1.0 nM).Naltrexone blocks the effects of MOR agonists like morphine, heroin, and hydromorphone in humans via its MOR antagonism. Following a single 100 mg dose of naltrexone, the subjective and objective effects of heroin were blocked by 90% at 24 hours, with blockade then decreasing up to 72 hours. Similarly, 20 to 200 mg naltrexone dose-dependently antagonized the effects of heroin for up to 72 hours. Naltrexone also blocks the effects of KOR agonists like salvinorin A, pentazocine, and butorphanol in humans via its KOR antagonism. In addition to opioids, naltrexone has been found to block or reduce the rewarding and other effects of other euphoriant drugs including alcohol, nicotine, and amphetamines.The opioid receptors are involved in neuroendocrine regulation. MOR agonists produce increases in levels of prolactin and decreases in levels of luteinizing hormone (LH) and testosterone. Doses of naltrexone of 25 to 150 mg/day have been found to produce significant increases in levels of β-endorphin, cortisol, and LH, equivocal changes in levels of prolactin and testosterone, and no significant changes in levels of adrenocorticotrophic hormone (ACTH) or follicle-stimulating hormone (FSH). Naltrexone influences the hypothalamic–pituitary–adrenal axis (HPA axis) probably through interference with opioid receptor signaling by endorphins.Blockade of MORs is thought to be the mechanism of action of naltrexone in the management of opioid dependence—it reversibly blocks or attenuates the effects of opioids. It is also thought to be involved in the effectiveness of naltrexone in alcohol dependence by reducing the euphoric effects of alcohol. The role of KOR modulation by naltrexone in its effectiveness for alcohol dependence is unclear but this action may also be involved based on theory and animal studies.
Other activities
In addition to the opioid receptors, naltrexone binds to and acts as an antagonist of the opioid growth factor receptor (OGFR) and toll-like receptor 4 (TLR4) and interacts with high- and low-affinity binding sites in filamin-A (FLNA). It is said that very low doses of naltrexone (<0.001–1 mg/day) interact with FLNA, low doses (1 to 5 mg/day) produce TLR4 antagonism, and standard clinical doses (50 to 100 mg/day) exert opioid receptor and OGFR antagonism. The interactions of naltrexone with FLNA and TLR4 are claimed to be involved in the therapeutic effects of low-dose naltrexone.
Pharmacokinetics
The absorption of naltrexone with oral administration is rapid and nearly complete (96%). The bioavailability of naltrexone with oral administration is 5 to 60% due to extensive first-pass metabolism. Peak concentrations of naltrexone are 19 to 44 μg/L after a single 100 mg oral dose and time to peak concentrations of naltrexone and 6β-naltrexol (metabolite) is within 1 hour. Linear increases in circulating naltrexone and 6β-naltrexol concentrations occur over an oral dose range of 50 to 200 mg. Naltrexone does not appear to be accumulated with repeated once-daily oral administration and there is no change in time to peak concentrations with repeated administration.The plasma protein binding of naltrexone is about 20% over a naltrexone concentration range of 0.1 to 500 μg/L. Its apparent volume of distribution at 100 mg orally is 16.1 L/kg after a single dose and 14.2 L/kg with repeated doses.Naltrexone is metabolized in the liver mainly by dihydrodiol dehydrogenases into 6β-naltrexol (6β-hydroxynaltrexone). Levels of 6β-naltrexol are 10- to 30-fold higher than those of naltrexone with oral administration due to extensive first-pass metabolism. Conversely, 6β-naltrexol exposure is only about 2-fold higher than that of naltrexone with intramuscular injection of naltrexone in microspheres (brand name Vivitrol). 6β-Naltrexol is an opioid receptor antagonist similarly to naltrexone and shows a comparable binding profile to the opioid receptors. However, 6β-naltrexol is peripherally selective and crosses into the brain much less readily than does naltrexone. In any case, 6β-naltrexol does still show some central activity and may contribute significantly to the central actions of oral naltrexone. Other metabolites of naltrexone include 2-hydroxy-3-methoxy-6β-naltrexol and 2-hydroxy-3-methoxynaltrexone. Following their formation, the metabolites of naltrexone are further metabolized by conjugation with glucuronic acid to form glucuronides. Naltrexone is not metabolized by the cytochrome P450 system and has low potential for drug interactions.The elimination of naltrexone is biexponential and rapid over the first 24 hours followed by a third extremely slow decline after 24 hours. The fast elimination half-lives of naltrexone and its metabolite 6β-naltrexol are about 4 hours and 13 hours, respectively. In Contrave oral tablets, which also contain bupropion and are described as extended-release, the half-life of naltrexone is 5 hours. The slow terminal-phase elimination half-life of naltrexone is approximately 96 hours. As microspheres of naltrexone by intramuscular injection (Vivitrol), the elimination half-lives of naltrexone and 6β-naltrexol are both 5 to 10 days. Whereas oral naltrexone is administered daily, naltrexone in microspheres by intramuscular injection is suitable for administration once every 4 weeks or once per month.Naltrexone and its metabolites are excreted in urine.
Pharmacogenetics
Tentative evidence suggests that family history and presence of the Asn40Asp polymorphism predicts naltrexone being effective.
Chemistry
Naltrexone, also known as N-cyclopropylmethylnoroxymorphone, is a derivative of oxymorphone (14-hydroxydihydromorphinone). It is specifically the derivative of oxymorphone in which the tertiary amine methyl substituent is replaced with methylcyclopropane.
Analogues
The closely related medication, methylnaltrexone (N-methylnaltrexone), is used to treat opioid-induced constipation, but does not treat addiction as it does not cross the blood–brain barrier. Nalmefene (6-desoxy-6-methylenenaltrexone) is similar to naltrexone and is used for the same purposes as naltrexone. Naltrexone should not be confused with naloxone (N-allylnoroxymorphone), which is used in emergency cases of opioid overdose. Other opioid antagonists related to naltrexone include 6β-naltrexol (6β-hydroxynaltrexone), samidorphan (3-carboxamido-4-hydroxynaltrexone), β-funaltrexamine (naltrexone fumarate methyl ester), nalodeine (N-allylnorcodeine), nalorphine (N-allylnormorphine), and nalbuphine (N-cyclobutylmethyl-14-hydroxydihydronormorphine).
History
Naltrexone was first synthesized in 1963 by Metossian at Endo Laboratories, a small pharmaceutical company in New York City. It was characterized by Blumberg, Dayton, and Wolf in 1965 and was found to be an orally active, long-acting, and very potent opioid antagonist. The drug showed advantages over earlier opioid antagonists such as cyclazocine, nalorphine, and naloxone, including its oral activity, a long duration of action allowing for once-daily administration, and a lack of dysphoria, and was selected for further development. It was patented by Endo Laboratories in 1967 under the developmental code name EN-1639A and Endo Laboratories was acquired by DuPont in 1969. Clinical trials for opioid dependence began in 1973, and a developmental collaboration of DuPont with the National Institute on Drug Abuse for this indication started the next year in 1974. The drug was approved by the FDA for the oral treatment of opioid dependence in 1984, with the brand name Trexan, and for the oral treatment of alcohol dependence in 1995, when the brand name was changed by DuPont to Revia. A depot formulation for intramuscular injection was approved by the FDA under the brand name Vivitrol for alcohol dependence in 2006 and opioid dependence in 2010.
Society and culture
Generic names
Naltrexone is the generic name of the drug and its INN, USAN, BAN, DCF, and DCIT, while naltrexone hydrochloride is its USP and BANM.
Brand names
Naltrexone is or has been sold under a variety of brand names, including Adepend, Antaxone, Celupan, Depade, Nalorex, Narcoral, Nemexin, Nodict, Revia, Trexan, Vivitrex, and Vivitrol. It is also marketed in combination with bupropion (naltrexone/bupropion) as Contrave, and was marketed with morphine (morphine/naltrexone) as Embeda. A combination of naltrexone with buprenorphine (buprenorphine/naltrexone) has been developed, but has not been marketed.
Controversies
The FDA authorized use of injectable naltrexone (Vivitrol) for opioid addiction using a single study that was led by Evgeny Krupitsky at Bekhterev Research Psychoneurological Institute, St Petersburg State Pavlov Medical University, St Petersburg, Russia, a country where opioid agonists such as methadone and buprenorphine are not available. The study was a "double-blind, placebo-controlled, randomized", 24-week trial running "from July 3, 2008, through October 5, 2009" with "250 patients with opioid dependence disorder" at "13 clinical sites in Russia" on the use of injectable naltrexone (XR-NTX) for opioid dependence. The study was funded by the Boston-based biotech Alkermes firm which produces and markets naltrexone in the United States. Critics charged that the study violated ethical guidelines, since it compared the formulation of naltrexone not to the best available, evidence-based treatment (methadone or buprenorphine), but to a placebo. Further, the trial did not follow patients who dropped out of the trial to evaluate subsequent risk of fatal overdose, a major health concern. Subsequent trials in Norway and the US did compare injectable naltrexone to buprenorphine and found them to be similar in outcomes for patients willing to undergo the withdrawal symptoms required prior to naltrexone administration. Nearly 30% of patients in the US trial did not complete induction. In real world settings, a review of more than 40,000 patient records found that while methadone and buprenorphine reduced risk of fatal overdose, naltrexone administration showed no greater effect on overdose or subsequent emergency care than counseling alone.Despite these findings, naltrexones manufacturer and some health authorities have promoted the medicine as superior to methadone and buprenorphine since it is not an opioid and does not induce dependence. The manufacturer has also marketed directly to law enforcement and criminal justice |
Naltrexone | officials, spending millions of dollars on lobbying and providing thousands of free doses to jails and prisons. The technique has been successful, with the criminal justice system in 43 states now incorporating long-acting naltrexone. Many do this through Vivitrol courts that offer only this option, leading some to characterize this as "an offer that cannot be refused." The companys marketing techiques have led to a Congressional investigation, and warning from the FDA about failure to adequately state risks of fatal overdose to patients receiving the medicine.In May 2017, United States Secretary of Health and Human Services Tom Price praised [Vivitrol] as the future of opioid addiction treatment after visiting the companys plant in Ohio. His remarks set off sharp criticism with almost 700 experts in the field of substance use submitting a letter to Price cautioning him about Vivitrols "marketing tactics" and warning him that his comments "ignore widely accepted science". The experts pointed out that Vivitrols competitors, buprenorphine and methadone, are "less expensive", "more widely used", and have been "rigorously studied". Price had claimed that buprenorphine and methadone were "simply substitute[s]" for "illicit drugs" whereas according to the letter, "the substantial body of research evidence supporting these treatments is summarized in guidance from within your own agency, including the Substance Abuse and Mental Health Services Administration, the US Surgeon General, the National Institute on Drug Abuse, and the Centers for Disease Control and Prevention. Buprenorphine and methadone have been demonstrated to be highly effective in managing the core symptoms of opioid use disorder, reducing the risk of relapse and fatal overdose, and encouraging long-term recovery."
Film
One Little Pill was a 2014 documentary film about use of naltrexone to treat alcohol use disorder.
Research
Depersonalization
Naltrexone is sometimes used in the treatment of dissociative symptoms such as depersonalization and derealization. Some studies suggest it might help. Other small, preliminary studies have also shown benefit. Blockade of the KOR by naltrexone and naloxone is thought to be responsible for their effectiveness in ameliorating depersonalization and derealization. Since these drugs are less efficacious in blocking the KOR relative to the MOR, higher doses than typically used seem to be necessary.
Low-dose
"Low-dose naltrexone" (LDN) describes the off-label use of naltrexone at low doses for diseases not related to chemical dependency or intoxication, such as multiple sclerosis. Evidence for recommending such use is lacking. This treatment has received attention on the Internet.
Self-injury
One study suggests that self-injurious behaviors present in persons with developmental disabilities (including autism) can sometimes be remedied with naltrexone.
In these cases, the self-injury is believed to be done to release beta-endorphin, which binds to the same receptors as heroin and morphine. If the "rush" generated by self-injury is removed, the behavior may stop.
Behavioral disorders
Some indications exist that naltrexone might be beneficial in the treatment of impulse-control disorders such as kleptomania, compulsive gambling, or trichotillomania (compulsive hair pulling), but evidence of its effectiveness for gambling is conflicting. A 2008 case study reported successful use of naltrexone in suppressing and treating an internet pornography addiction.
Interferon alpha
Naltrexone is effective in suppressing the cytokine-mediated adverse neuropsychiatric effects of interferon alpha therapy.
Critical addiction studies
Some historians and sociologists have suggested that the meanings and uses attributed to anti-craving medicine, such as naltrexone, is context-dependent. Studies have suggested the use of naltrexone in drug courts or healthcare rehabs is a form of "post-social control," or "post-disciplinary control," whereby control strategies for managing offenders and addicts shift from imprisonment and supervision toward more direct control over biological processes.
Sexual addiction
Small studies have shown a reduction of sexual addiction and problematic sexual behaviours from naltrexone.
References
External links
"Naltrexone". Drug Information Portal. U.S. National Library of Medicine. |
Tramadol/paracetamol | Tramadol/paracetamol, also known as tramadol/acetaminophen and sold under the brand name Ultracet, is a fixed-dose combination medication used for the treatment of moderate to severe pain. It contains tramadol hydrochloride and paracetamol. It is taken by mouth.
References
External links
"Acetaminophen mixture with tramadol". Drug Information Portal. U.S. National Library of Medicine. |
Bleomycin | Bleomycin is a medication used to treat cancer. This includes Hodgkins lymphoma, non-Hodgkins lymphoma, testicular cancer, ovarian cancer, and cervical cancer among others. Typically used with other cancer medications, it can be given intravenously, by injection into a muscle or under the skin. It may also be administered inside the chest to help prevent the recurrence of a fluid around the lung due to cancer; however talc is better for this.Common side effects include fever, weight loss, vomiting, and rash. A severe type of anaphylaxis may occur. It may also cause inflammation of the lungs that can result in lung scarring. Chest X-rays every couple of weeks are recommended to check for this. Bleomycin may cause harm to the baby if used during pregnancy. It is believed to primarily work by preventing the synthesis of DNA.Bleomycin was discovered in 1962. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. It is made by the bacterium Streptomyces verticillus.
Medical uses
Cancer
Bleomycin is mostly used to treat cancer. This includes testicular cancer, ovarian cancer, and Hodgkins disease, and less commonly non-Hodgkins disease. It can be given intravenously, by intramuscular injection, or under the skin.
Other uses
It may also be put inside the chest to help prevent the recurrence of a pleural effusion due to cancer. However, for scarring down the pleura, talc appears to be the better option.While potentially effective against bacterial infections, its toxicity prevents its use for this purpose. It has been studied in the treatment of warts but is of unclear benefit.
Side effects
The most common side effects are flu-like symptoms and include fever, rash, dermatographism, hyperpigmentation, alopecia (hair loss), chills, and Raynauds phenomenon (discoloration of fingers and toes). The most serious complication of bleomycin, occurring upon increasing dosage, is pulmonary fibrosis and impaired lung function. It has been suggested that bleomycin induces sensitivity to oxygen toxicity and recent studies support the role of the proinflammatory cytokines IL-18 and IL-1beta in the mechanism of bleomycin-induced lung injury. Any previous treatment with bleomycin should therefore always be disclosed to the anaesthetist prior to undergoing a procedure requiring general anaesthesia. Due to the oxygen sensitive nature of bleomycin, and the theorised increased likelihood of developing pulmonary fibrosis following supplemental oxygen therapy, it has been questioned whether patients should take part in scuba diving following treatment with the drug. Bleomycin has also been found to disrupt the sense of taste.
Lifetime cumulative dose
Bleomycin should not exceed a lifetime cumulative dose greater than 400 units. Pulmonary toxicities, most commonly presenting as pulmonary fibrosis, are associated with doses of bleomycin greater than 400 units.
Mechanism of action
Bleomycin, a non-heme iron protein, acts by induction of DNA strand breaks. Some studies suggest bleomycin also inhibits incorporation of thymidine into DNA strands. DNA cleavage by bleomycin depends on oxygen and metal ions, at least in vitro. The exact mechanism of DNA strand scission is unresolved, but it has been suggested that bleomycin chelates metal ions (primarily iron), producing a pseudoenzyme that reacts with oxygen to produce superoxide and hydroxide free radicals that cleave DNA. An alternative hypothesis states that bleomycin may bind at specific sites in the DNA strand and induce scission by abstracting the hydrogen atom from the base, resulting in strand cleavage as the base undergoes a Criegee-type rearrangement, or forms an alkali-labile lesion. In addition, these complexes also mediate lipid peroxidation and oxidation of other cellular molecules. Therefore, bleomycin is used in combination with doxorubicin in Hodgkins lymphoma, as they have additive and complementary effects on the DNA, since doxorubicin acts by intercalating between DNA strands, and also acts on topoisomerase II enzyme thus relaxing the topoisomerase complexes.
Biosynthesis
Bleomycin is a nonribosomal peptide that is a hybrid peptide-polyketide natural product. The peptide/polyketide/peptide backbone of the bleomycin aglycon is assembled by the bleomycin megasynthetase, which is made of both nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) modules. Nonribosomal peptides and polyketides are synthesized from amino acids and short carboxylic acids by NRPSs and PKSs, respectively. These NRPSs and PKSs use similar strategies for the assembly of these two distinct classes of natural products. Both NRPs and type I PKSs are organized into modules. The structural variations of the resulting peptide and polyketide products are determined by the number and order of modules on each NRPS and PKS protein.
The biosynthesis of the bleomycin aglycon can be visualized in three stages:
NRPS-mediated formation of P-3A from Ser, Asn, His, and Ala
PKS-mediated elongation of P-3A by malonyl CoA and AdoMet to yield P-4
NRPS-mediated elongation of P-4 by Thr to P-5 that is further elongated by β-Ala, Cys, and Cys to get P-6m.On the basis of the bleomycin structure and the deduced functions of individual NRPS and PKS domains and modules, a linear model for the bleomycin megasynthetase-templated assembly of the bleomycin peptide/polyketide/peptide aglycon was proposed from nine amino acids and one acetate.
Biosynthesis of bleomycin is completed by glycosylation of the aglycones. Bleomycin naturally occurring-analogues have two to three sugar molecules, and DNA cleavage activities of these analogues have been assessed, primarily by the plasmid relaxation and break light assays.
History
Bleomycin was first discovered in 1962 when the Japanese scientist Hamao Umezawa found anticancer activity while screening culture filtrates of Streptomyces verticillus. Umezawa published his discovery in 1966. The drug was launched in Japan by Nippon Kayaku in 1969. In the US, bleomycin gained FDA approval in July 1973. It was initially marketed in the US by the Bristol-Myers Squibb precursor, Bristol Laboratories, under the brand name Blenoxane.
Research
Bleomycin is used in research to induce pulmonary fibrosis in mice.
See also
Flagellate pigmentation from bleomycin
Pingyangmycin (Bleomycin A5)
References
Further reading
External links
"Bleomycin". Drug Information Portal. U.S. National Library of Medicine.
"Bleomycin". European Medicines Agency (EMA). |
Ismo | Ismo may refer to:
-ism in Spanish, Portuguese, Esperanto and Italian
Ismo, a brand name for isosorbide mononitrate
Ismo Leikola, Finnish comedian |
Silodosin | Silodosin (known by the trade names Silosoft in India, Urief in Japan, Rapaflo in North America, and Silodyx or Niksol in the European Union) is a medication for the symptomatic treatment of benign prostatic hyperplasia (BPH). It acts as an α1-adrenoceptor antagonist with high uroselectivity (selectivity for the prostate).
Medical uses
Silodosin is used for the treatment of BPH in adult men.
Contraindications
According to European labels, silodosin has no contraindications apart from known hypersensitivity. Another source names recurring urinary retention, recurring urinary infections, uncontrolled macrohematuria, bladder stones, hydronephrosis, combination with other α1-antagonists or dopamine agonists, and severe renal or hepatic impairment as contraindications. According to the FDA, silodosin is contraindicated with paxlovid, a drug used in treating COVID-19 ( https://www.fda.gov/media/155050/download ).
Side effects
The most common adverse effect is loss of seminal emission. This seems to be caused by silodosins high selectivity for α1A receptors.Other common adverse effects (in more than 1% of patients) are dizziness, orthostatic hypotension, diarrhoea, and clogged nose. Less common (0.1–1%) are tachycardia (fast heartbeat), dry mouth, nausea, skin reactions, and erectile dysfunction. Hypersensitivity reactions occur in fewer than 0.01% of patients. There have been reports about intraoperative floppy iris syndrome during cataract extractions. These side effects are similar to those of other α1 antagonists.
Interactions
Combining silodosin with strong inhibitors of the liver enzyme CYP3A4, such as ketoconazole, significantly increases its concentrations in the blood plasma and its area under the curve (AUC). Less potent CYP3A4 inhibitors such as diltiazem have a less pronounced effect on this parameters, which is not considered clinically significant. Inhibitors and inducers of the enzyme UGT2B7, alcohol dehydrogenases, and aldehyde dehydrogenases, as well as the transporter P-glycoprotein (P-gp), may also influence silodosin concentrations in the body. Digoxin, which is transported by P-gp, is not affected by silodosin; this means that silodosin does not significantly inhibit or induce P-gp.No relevant interactions with antihypertensive drugs or with PDE5 inhibitors have been found in studies; although combination with other α1-antagonists is not well studied.
Pharmacology
Mechanism of action
Silodosin has high affinity for the α1A adrenergic receptor in the prostate, the bladder, and the prostatic urethra. By this mechanism it relaxes the smooth muscle in these organs, easing urinary flow and other symptoms of BPH.
Pharmacokinetics
The absolute bioavailability after oral intake is 32%. Food has little effect on the AUC. When in the bloodstream, 96,6% of the substance are bound to blood plasma proteins. Its main metabolite is silodosin glucuronide, which inhibits the α1A receptor with 1/8 of the affinity of the parent substance. 91% of the glucuronide are bound to plasma proteins. The enzyme mainly responsible for the formation of the glucuronide is UGT2B7. Other enzymes involved in the metabolism are alcohol dehydrogenases, aldehyde dehydrogenases and CYP3A4.Silodosin is almost completely excreted in the form of metabolites; 33.5% via the urine and 54.9% via the feces. The biological half-life of silodosin is 11 hours on average, and that of the glucuronide is 18 hours or 24 hours. (Sources are contradictory on this.)
History
Silodosin received its first marketing approval in Japan in May 2006, under the brand name Urief, which is jointly marketed by Kissei Pharmaceutical and Daiichi Sankyo.
Kissei licensed the US, Canadian, and Mexican rights for silodosin to Watson Pharmaceuticals (now Allergan) in 2004. AbbVie absorbed Allergan in 2019. The United States Food and Drug Administration and Health Canada approved silodosin under the brand name Rapaflo on 9 October 2008 and 11 January 2011, respectively.
Society and culture
Brand names
Other brand names include Urorec (European Union, Australia, Russia), Niksol (Croatia), Silorel (Jamaica),
SiloSoft Sildoo, Silodal Silofast (India), Thrupas (South Korea), and Flopadex (Egypt).
Research
As α1A adrenoceptor antagonists are being investigated as a means to male birth control due to their ability to inhibit ejaculation but not orgasm, a trial with 15 male volunteers was conducted. While silodosin was completely efficacious in preventing the release of semen in all subjects, 12 out of the 15 patients reported mild discomfort upon orgasm. The men also reported the psychosexual side effect of being strongly dissatisfied by their lack of ejaculation.
References
External links
"Silodosin". Drug Information Portal. U.S. National Library of Medicine. |
Becaplermin | Becaplermin (brand name Regranex) is a cicatrizant, available as a topical gel. Regranex is a human platelet-derived growth factor indicated along with good wound care for the treatment of lower extremity diabetic neuropathic ulcers. It is also known as "platelet-derived growth factor BB".
Medical uses
The drug is used for the treatment of diabetic foot ulcers. Studies of becaplermin showed that when used with good wound care, complete healing significantly increased and the ulcers healed on average 6 weeks faster. Pharmacoeconomic studies reinforce the cost effectiveness of becaplermin as an adjunct to good wound care.The amount of becaplermin to be applied will vary depending upon the size of the ulcer area. Becaplermin should be stored in the refrigerator.
Analysis of healing human wounds showed that PDGF-BB induces fibroblast proliferation and differentiation and was found to increase healing in patients with decreased healing capacity, such as people living with diabetes.
Contraindications
Becaplermin must not be used at the site of a skin cancer.
Adverse effects
The most common side effects in clinical studies were erythematous rashes.A boxed warning has been added to the safety label to describe an increase rate of death from cancer when three or more tubes are used.
Regranex should be used with caution in patients with known malignancy.
See also
Nepidermin
References
External links
Regranex website |
Sertaconazole | Sertaconazole, sold under the brand name Ertaczo among others, is an antifungal medication of the Benzothiophene class. It is available as a cream to treat skin infections such as athletes foot.
It is also available in a vaginal tablet form. The most popular of these is Gyno-Dermofix.
Medical uses
In randomized, double-blind, multicentre trials of 3 to 6 weeks duration (n=127-383), a significantly greater number of patients with tinea of the glabrous skin and tinea pedis receiving a topical 2% sertaconazole cream once or twice daily achieved a successful mycological cure compared with recipients of a placebo cream.
Side effects
Side effects were rarely reported with sertaconazole therapy, but may include contact dermatitis, burning on application site and skin dryness.
Pharmacology
Pharmacodynamics
Sertaconazole has several known mechanisms of action. It is considered fungistatic, fungicidal, antibacterial, antiinflammatory, antitrichomonal, and antipruritic.Like other imidazole antifungals, sertaconazole blocks the synthesis of ergosterol by inhibiting the 14α-demethylase enzyme. Ergosterol is a critical component of the fungal cell membrane. Inhibition of ergosterol synthesis prevents fungal cells from multiplying and impairs hyphae growth.
Chemically, sertaconazole contains a benzothiophene ring which makes it unique from other imidazole antifungals. A benzothiophene ring is a sulfur analogue of the indole ring found in the amino acid tryptophan. Tryptophan is found in the fungal membrane in addition to lipids such as ergosterol. The benzothiophene ring in sertaconazole mimics tryptophan and increases the drugs ability to form pores in the fungal cell membrane. If the cell membrane is made sufficiently leaky by these pores the fungal cell will die from loss of ATP and other effects which can include calcium disregulation. These pores are believed to open at about 10 minutes following topical application of sertaconazole. One hour following topical application, approximately 90% of fungal cells die from lack of energy (due to ATP loss) and general loss of homeostasis. Sertaconazole is thought to be the only Benzothiophene antifungal with this mechanism of action.
Sertaconazole has also antiinflammatory and antipruritic action. It inhibits the release of proinflammatory cytokines from activated immune cells. It has been shown that sertaconazole activates the p38/COX2/PGE2 pathway. PGE2 can have a variety of important effects in the body including activation of the bodys fever response.
Sertaconazole also has antibacterial action. It is hypothesized that the mechanism of action again involves sertaconazoles ability to form pores by mimicking tryptophan.
It has also been shown that sertaconazole can kill Trichomonas vaginalis in vitro. The exact mechanism of action is as yet unknown.
Sertaconazole also appears to inhibit the dimorphic transformation of Candida albicans into pathogenic fungi.
The following fungal organisms, among others, are known to be susceptible to sertaconazole:
Candida albicans
Epidermophyton floccosum
Trichophyton mentagrophytes
Trichophyton rubrum
Chemistry
Sertaconazole contains a stereocenter and consists of two enantiomers. The pharmaceutical drug is a racemate, an equal mixture of the (R)- and (S)-forms.
References
External links
"Sertaconazole". Drug Information Portal. U.S. National Library of Medicine.
"Sertaconazole nitrate". Drug Information Portal. U.S. National Library of Medicine. |
Melphalan flufenamide | Melphalan flufenamide, sold under the brand name Pepaxto, is an anticancer medication used to treat multiple myeloma.The most common adverse reactions include fatigue, nausea, diarrhea, pyrexia and respiratory tract infection.Melphalan flufenamide is a peptidase enhanced cytotoxic (PEnC) that exerts a targeted delivery of melphalan in cells with high expression of aminopeptidases, such as aminopeptidase N, which has been described as over-expressed in human malignancies. Aminopeptidase N plays a functional role in malignant angiogenesis.Melphalan flufenamide was approved for medical use in the United States in February 2021.
Medical uses
Melphalan flufenamide is indicated in combination with dexamethasone for the treatment of adults with relapsed or refractory multiple myeloma, with relapsed or refractory multiple myeloma who have received at least four prior lines of therapy and whose disease is refractory to at least one proteasome inhibitor, one immunomodulatory agent, and one CD-38 directed monoclonal antibody.
Metabolism
Melphalan flufenamide is metabolized by aminopeptidase hydrolysis and by spontaneous hydrolysis on N-mustard. Its biological half-life is 10 minutes in vitro.
Origin and development
Melphalan flufenamide is a peptidase enhanced cytotoxic (PEnC) with a targeted delivery within tumor cells of melphalan, a widely used classical chemotherapeutic belonging to a group of alkylating agents developed more than 50 years ago. Substantial clinical experience has been accumulated about melphalan since then. Numerous derivatives of melphalan, designed to increase the activity or selectivity, have been developed and investigated in vitro or in animal models. Melphalan flufenamide was synthesized, partly due to previous experience of an alkylating peptide cocktail named Peptichemio and its anti-tumor activity is being investigated.
Pharmacology
Compared to melphalan, melphalan flufenamide exhibits significantly higher in vitro and in vivo activity in several models of human cancer.
A preclinical study, performed at Dana–Farber Cancer Institute, demonstrated that melphalan flufenamide induced apoptosis in multiple myeloma cell lines, even those resistant to conventional treatment (including melphalan). In vivo effects in xenografted animals were also observed, and the results confirmed by M Chesi and co-workers – in a unique genetically engineered mouse model of multiple myeloma – are believed to be predictive of clinical efficacy.
Structure
Chemically, the drug is best described as the ethyl ester of a dipeptide consisting of melphalan and the amino acid derivative para-fluoro-L-phenylalanine.
Pharmacokinetics
Pharmacokinetic analysis of plasma samples showed a rapid formation of melphalan; concentrations generally exceeded those of melphalan flufenamide during ongoing infusion. Melphalan flufenamide rapidly disappeared from plasma after infusion, while melphalan typically peaked a few minutes after the end of infusion. This suggests that melphalan flufenamide is rapidly and widely distributed to extravasal tissues, in which melphalan is formed and thereafter redistributed to plasma.This rapid disappearance from plasma is likely due to hydrolytic enzymes.
The Zn(2+) dependent ectopeptidase (also known as alanine aminopeptidase), degrades proteins and peptides with a N-terminal neutral amino acid. Aminopeptidase N is frequently overexpressed in tumors and has been associated with the growth of different human cancers suggesting it as a suitable target for anti-cancerous therapy.
Adverse effects
In a human Phase 1 trial, no dose-limiting toxicities (DLTs) were observed at lower doses. At doses above 50 mg, reversible neutropenias and thrombocytopenias were observed, and particularly evident in heavily pretreated patients. These side-effects are shared by most chemotherapies, including alkylating agents in general.
Drug interactions
No drug interaction studies have been reported. Several in vitro studies indicate that melphalan flufenamide may be successfully combined with standard chemotherapy or targeted agents.
Therapeutic efficacy
In a Phase 1/2 trial, in solid tumor patients refractory to standard therapy, response evaluation showed disease stabilization in a majority of patients. In relapsed and refractory multiple-myeloma (RRMM) patients, promising activity was seen in heavily pre-treated RRMM patients where conventional therapies had failed; the median Progression-Free Survival was 9.4 months and the Duration of Response was 9.6 months. An overall response rate of 41% and a clinical benefit rate of 56% were also shown, with similar results seen across patient populations regardless of their refractory status.
Hematologic toxicity was common, but manageable with cycle prolongations, dose modifications and supportive therapy, and non-hematologic treatment-related adverse events were infrequent.
History
Efficacy was evaluated in HORIZON (NCT02963493), a multicenter, single-arm trial. Eligible patients were required to have relapsed refractory multiple myeloma. Patients received melphalan flufenamide 40 mg intravenously on day 1 and dexamethasone 40 mg orally (20 mg for patients ≥75 years of age) on day 1, 8, 15 and 22 of each 28-day cycle until disease progression or unacceptable toxicity. Efficacy was evaluated in a subpopulation of 97 patients who received four or more prior lines of therapy and were refractory to at least one proteasome inhibitor, one immunomodulatory agent, and a CD38-directed antibody.The application for melphalan flufenamide was granted priority review and orphan drug designations.
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 authorisation for the medicinal product Pepaxti, intended for the treatment of multiple myeloma. The applicant for this medicinal product is Oncopeptides AB.
Names
Melphalan flufenamide is the international nonproprietary name (INN).
References
External links
"Melphalan flufenamide". Drug Information Portal. U.S. National Library of Medicine.
Clinical trial number NCT02963493 for "A Study of Melphalan Flufenamide (Melflufen) in Combination With Dexamethasone in Relapsed Refractory Multiple Myeloma Patients (HORIZON)" at ClinicalTrials.gov
"FDA alerts patients and health care professionals about clinical trial results showing an increased risk of death associated with Pepaxto (melphalan flufenamide)". U.S. Food and Drug Administration (FDA). 23 August 2021. |
Bimatoprost | Bimatoprost, sold under the brand name Lumigan among others, is a medication used to treat high pressure inside the eye including glaucoma. Specifically it is used for open angle glaucoma when other agents are not sufficient. It may also be used to increase the size of the eyelashes. It is used as an eye drop and effects generally occur within four hours.Common side effects include red eyes, dry eyes, change in color of the eyes, blurry vision, and cataracts. Use during pregnancy or breastfeeding is generally not recommended. It is a prostaglandin analog and works by increasing the outflow of aqueous fluid from the eyes.Bimatoprost was approved for medical use in the United States in 2001. It is available as a generic medication. In 2018, it was the 274th most commonly prescribed medication in the United States, with more than 2 million prescriptions.
Uses
Medical
Bimatoprost is used for the treatment of open-angle glaucoma and ocular hypertension in adults, either alone or in combination with a beta blocker, typically timolol.Studies have shown bimatoprost to be more effective than timolol in reduction of intraocular pressure (IOP) and at least as effective as the prostaglandin analogs latanoprost and travoprost in reducing IOP.
Cosmetic
Bimatoprost may be used to treat small or underdeveloped eyelashes. The medical term for this is treatment of hypotrichosis; however, the U.S. Food and Drug Administration (FDA) approval is for purely cosmetic purposes (see Prostaglandin F receptor#Clinical significance).
Side effects
Side effects are similar to other prostaglandin analogs applied to the eye. The most common one is conjunctival hyperemia, which occurs in more than 10% of patients. Other effects include blurred vision, eye and eyelid redness, eye burning or other discomfort, and permanent darkening of the iris to brown. Occasional adverse effects (in less than 1% of patients) are headache and nausea.Some side effects are specific to the cosmetic formulation, which is applied to the skin at the base of the eyelash rather than instilled into the eye. These include infection if the one-time applicators are reused, and darkening of the eyelid or of the area beneath the eye. Research suggests that wiping the eye with an absorbent pad after the administration of eye drops can result in shorter eyelashes and a lesser chance of hyperpigmentation in the eyelid, compared to not wiping off excess fluid.
Interactions
No interaction studies with this substance have been performed. Interactions with systemic (for example, oral) drugs are considered unlikely because bimatoprost does not reach relevant concentrations in the bloodstream. Bimatoprost does not negatively interact with timolol eye drops.
Pharmacology
Mechanism of action
Bimatoprost is a structural analog of prostaglandin F2α (PGF2α). Like other PGF2α analogs such as travoprost, latanoprost and tafluprost, it increases the outflow of aqueous fluid from the eye and lowers intraocular pressure. However, in contrast to these it does not act on the prostaglandin F receptor, nor on any other known prostaglandin receptor. It is thought that bimatoprost mimics the human bodys own prostamides (which are chemically similar), a class of substances related to prostaglandins, but with an unknown mechanism of action. No prostamide receptor has been identified as of 2015; the search is ongoing. As of 2019 it was thought that bimatoprost worked via the trabecular meshwork and uveoscleral pathways.
Pharmacokinetics
Bimatoprost is well absorbed through the cornea. It starts lowering intraocular pressure after four hours, lasting for at least 24 hours. A low percentage enters the bloodstream. In the blood plasma, peak concentrations are reached after 10 minutes, then drop below the detection limit of 25 pg/ml after 1.5 hours. The substance does not accumulate in the body.Plasma protein binding is 88%. Bimatoprost is metabolized by oxidation, N-deethylation and glucuronidation, forming a variety of metabolites. Biological half-life was measured to be 45 minutes after intravenous infusion. 67% are eliminated via the kidney, and 25% via the feces.
References
Further reading
"Prostaglandin Analogues for Ophthalmic Use: A Review of the Comparative Clinical Effectiveness and Cost-Effectiveness". CADTH Rapid Response Reports. July 2015. PMID 26985536.
External links
"Bimatoprost". Drug Information Portal. U.S. National Library of Medicine. |
Furosemide | Furosemide is a loop diuretic medication used to treat fluid build-up due to heart failure, liver scarring, or kidney disease. It may also be used for the treatment of high blood pressure. It can be taken by injection into a vein or by mouth. When taken by mouth, it typically begins working within an hour, while intravenously, it typically begins working within five minutes.Common side effects include feeling lightheaded with standing, ringing in the ears, and sensitivity to light. Potentially serious side effects include electrolyte abnormalities, low blood pressure, and hearing loss. Blood tests are recommended regularly for those on treatment. Furosemide is a type of loop diuretic that works by decreasing the reabsorption of sodium by the kidneys. Common side effects of furosemide injection include hypokalemia (low potassium level), hypotension (low blood pressure), and dizziness.Furosemide was patented in 1959 and approved for medical use in 1964. It is on the World Health Organizations List of Essential Medicines. In the United States, it is available as a generic medication. In 2020, it was the nineteenth most commonly prescribed medication in the United States, with more than 26 million prescriptions. In 2020/21 it was the twentieth most prescribed medication in England. It is on the World Anti-Doping Agencys banned drug list due to concerns that it may mask other drugs. It has also been used in race horses for the treatment and prevention of exercise-induced pulmonary hemorrhage.
Medical uses
Furosemide is primarily used for the treatment of edema, but also in some cases of hypertension (where there is also kidney or heart impairment). It is often viewed as a first-line agent in most people with edema caused by congestive heart failure because of its anti-vasoconstrictor and diuretic effects. Compared with furosemide, however, torasemide (aka "torsemide") has been demonstrated to show improvements to heart failure symptoms, possibly lowering the rates of rehospitalisation associated with heart failure, with no difference in risk of death. Torsemide may also be safer than furosemide.Furosemide is also used for liver cirrhosis, kidney impairment, nephrotic syndrome, in adjunct therapy for swelling of the brain or lungs where rapid diuresis is required (IV injection), and in the management of severe hypercalcemia in combination with adequate rehydration.
Kidney disease
In chronic kidney diseases with hypoalbuminemia, furosemide is used along with albumin to increase diuresis. It is also used along with albumin in nephrotic syndrome to reduce edema.
Other information
Furosemide is mainly excreted by tubular secretion in the kidney. In kidney impairment, clearance is reduced, increasing the risk of adverse effects. Lower initial doses are recommended in older patients (to minimize side-effects) and high doses may be needed in kidney failure. It can also cause kidney damage; this is mainly by loss of excessive fluid (i.e., dehydration), and is usually reversible.Furosemide acts within 1 hour of oral administration (after IV injection, the peak effect is within 30 minutes). Diuresis is usually complete within 6–8 hours of oral administration, but there is significant variation between individuals.
Adverse effects
Furosemide also can lead to gout caused by hyperuricemia. Hyperglycemia is also a common side effect.
The tendency, as for all loop diuretics, to cause low serum potassium concentration (hypokalemia) has given rise to combination products, either with potassium or with the potassium-sparing diuretic amiloride (Co-amilofruse). Other electrolyte abnormalities that can result from furosemide use include hyponatremia, hypochloremia, hypomagnesemia, and hypocalcemia.In the treatment of heart failure, many studies have shown that the long-term use of furosemide can cause varying degrees of thiamine deficiency, so thiamine supplementation is also suggested.Furosemide is a known ototoxic agent generally causing transient hearing loss but can be permanent. Reported cases of furosemide induced hearing loss appeared to be associated with rapid intravenous administration, high dosages, concomitant renal disease and coadministration with other ototoxic medication. However, a recently reported longitudinal study showed that participants treated with loop diuretics over 10 years were 40% more likely to develop hearing loss and 33% more likely of progressive hearing loss compared to participants who did not use loop diuretics. This suggests the long-term consequences of loop diuretics on hearing could be a more significant than previously thought and further research is required in this area.
Other precautions include: nephrotoxicity, sulfonamide (sulfa) allergy, and increases free thyroid hormone effects with large doses.
Interactions
Furosemide has potential interactions with these medications:
Aspirin and other salicylates
Other diuretics (e.g. ethacrynic acid, hydrochlorothiazide)
Synergistic effects with other antihypertensives (e.g. doxazosin)
SucralfatePotentially hazardous interactions with other drugs:
Analgesics: increased risk of kidney damage (nephrotoxicity) with nonsteroidal anti-inflammatory drugs; antagonism of diuretic effect with NSAIDs
Antiarrhythmics: a risk of cardiac toxicity exists with antiarrhythmics if hypokalemia occurs; the effects of lidocaine and mexiletine are antagonized.
Antibacterials: increased risk of ototoxicity with aminoglycosides, polymyxins and vancomycin; avoid concomitant use with lymecycline
Antidepressants: increased risk of hypokalemia with reboxetine; enhanced hypotensive effect with MAOIs; increased risk of postural hypotension with tricyclic antidepressants
Antiepileptics: increased risk of hyponatremia with carbamazepine
Antifungals: increased risk of hypokalemia with amphotericin
Antihypertensives: enhanced hypotensive effect; increased risk of first dose hypotensive effect with alpha-blockers; increased risk of ventricular arrhythmias with sotalol if hypokalemia occurs
Antipsychotics: increased risk of ventricular arrhythmias with amisulpride, sertindole, or pimozide (avoid with pimozide) if hypokalemia occurs; enhanced hypotensive effect with phenothiazines
Atomoxetine: hypokalemia increases risk of ventricular arrhythmias
Cardiac glycosides: increased toxicity if hypokalemia occurs
Cyclosporine: variable reports of increased nephrotoxicity, ototoxicity and hepatotoxicity
Lithium: risk of toxicity.
Mechanism of action
Furosemide, like other loop diuretics, acts by inhibiting the luminal Na-K-Cl cotransporter in the thick ascending limb of the loop of Henle, by binding to the chloride transport channel, thus causing more sodium, chloride, and potassium to remain in the urine.The action on the distal tubules is independent of any inhibitory effect on carbonic anhydrase or aldosterone; it also abolishes the corticomedullary osmotic gradient and blocks negative, as well as positive, free water clearance. Because of the large NaCl absorptive capacity of the loop of Henle, diuresis is not limited by development of acidosis, as it is with the carbonic anhydrase inhibitors.
Additionally, furosemide is a noncompetitive subtype-specific blocker of GABA-A receptors. Furosemide has been reported to reversibly antagonize GABA-evoked currents of α6β2γ2 receptors at μM concentrations, but not α1β2γ2 receptors. During development, the α6β2γ2 receptor increases in expression in cerebellar granule neurons, corresponding to increased sensitivity to furosemide.
Pharmacokinetics
Molecular weight (daltons) 330.7
% Bioavailability 47-70%
Bioavailability with end-stage renal disease 43 - 46%
% Protein binding 91–99
Volume of distribution (L/kg) 0.07 – 0.2Volume of distribution may be higher in patients with cirrhosis or nephrotic syndrome
Excretion
% Excreted in urine (% of total dose) 60 - 90
% Excreted unchanged in urine (% of total dose) 53.1 - 58.8
% Excreted in feces (% of total dose) 7 - 9
% Excreted in bile (% of total dose) 6 - 9
Approximately 10% is metabolized by the liver in healthy individuals, but this percentage may be greater in individuals with severe kidney failure
Renal clearance (mL/min/kg) 2.0
Elimination half-life (hrs) 2Prolonged in congestive heart failure (mean 3.4 hrs)
Prolonged in severe kidney failure (4 - 6 hrs) and anephric patients (1.5-9 hrs)
Time to peak concentration (hrs)
Intravenous administration 0.3
Oral solution 0.83
Oral tablet 1.45The pharmacokinetics of furosemide are apparently not significantly altered by food.No direct relationship has been found between furosemide concentration in the plasma and furosemide efficacy. Efficacy depends upon the concentration of furosemide in urine.
Names
Furosemide is the INN and BAN. The previous BAN was frusemide.
Brand names under which furosemide is marketed include: Aisemide, Apo-Furosemide, Beronald, Desdemin, Discoid, Diural, Diurapid, Dryptal, Durafurid, Edemid, Errolon, Eutensin, Flusapex, Frudix, Frusemide, Frusetic, Frusid, Fulsix, Fuluvamide, Furesis, Furix, Furo-Puren, Furon, Furosedon, Fusid.frusone, Hydro-rapid, Impugan, Katlex, Lasilix, Lasix, Lodix, Lowpston, Macasirool, Mirfat, Nicorol, Odemase, Oedemex, Profemin, Rosemide, Rusyde, Salix, Seguril, Teva-Furosemide, Trofurit, Uremide, and Urex.
Veterinary uses
The diuretic effects are put to use most commonly in horses to prevent bleeding during a race. Sometime in the early 1970s, furosemides ability to prevent, or at least greatly reduce, the incidence of bleeding (exercise-induced pulmonary hemorrhage) by horses during races was discovered accidentally. In the United States of America, pursuant to the racing rules of most states, horses that bleed from the nostrils three times are permanently barred from racing. Clinical trials followed, and by decades end, racing commissions in some states in the USA began legalizing its use on race horses. In 1995, New York became the last state in the United States to approve such use, after years of refusing to consider doing so. Some states allow its use for all racehorses; some allow it only for confirmed "bleeders". Its use for this purpose is still prohibited in many other countries.
Furosemide is also used in horses for pulmonary edema, congestive heart failure (in combination with other drugs), and allergic reactions. Although it increases circulation to the kidneys, it does not help kidney function, and is not recommended for kidney disease.It is also used to treat congestive heart failure (pulmonary edema, pleural effusion, and/or ascites) in cats and dogs. It can also be used in an attempt to promote urine production in anuric or oliguric acute kidney failure.
Horses
Furosemide is injected either intramuscularly or intravenously, usually 0.5-1.0 mg/kg twice/day, although less before a horse is raced. As with many diuretics, it can cause dehydration and electrolyte imbalance, including loss of potassium, calcium, sodium, and magnesium. Excessive use of furosemide will most likely lead to a metabolic alkalosis due to hypochloremia and hypokalemia. The drug should, therefore, not be used in horses that are dehydrated or experiencing kidney failure. It should be used with caution in horses with liver problems or electrolyte abnormalities. Overdose may lead to dehydration, change in drinking patterns and urination, seizures, gastrointestinal problems, kidney damage, lethargy, collapse, and coma.
Furosemide should be used with caution when combined with corticosteroids (as this increases the risk of electrolyte imbalance), aminoglycoside antibiotics (increases risk of kidney or ear damage), and trimethoprim sulfa (causes decreased platelet count). It may also cause interactions with anesthetics, so its use should be related to the veterinarian if the animal is going into surgery, and it decreases the kidneys ability to excrete aspirin, so dosages will need to be adjusted if combined with that drug.
Furosemide may increase the risk of digoxin toxicity due to hypokalemia.
The drug is best not used during pregnancy or in a lactating mare, as it has been shown to be passed through the placenta and milk in studies with other species. It should not be used in horses with pituitary pars intermedia dysfunction (Cushings).
Furosemide is detectable in urine 36–72 hours following injection. Its use is restricted by most equestrian organizations.
In April 2019, it was announced that Lasix would be banned from use at US racetracks within 24 hours of a horse racing starting in 2021.
References
Further reading
Aventis Pharma (1998). Lasix Approved Product Information. Lane Cove: Aventis Pharma Pty Ltd.
Barbara Forney (2007). Understanding Equine Medications, Revised Edition (Horse Health Care Library). Eclipse Press. ISBN 978-1-58150-151-3.
External links
"Furosemide". Drug Information Portal. U.S. National Library of Medicine.
"Furosemide Injection". MedlinePlus.
Lasix and horse bleeding |
Ethinylestradiol/norethisterone acetate | Ethinylestradiol/norethisterone acetate (EE/NETA), or ethinylestradiol/norethindrone acetate, is a combination of ethinylestradiol (EE) and norethisterone acetate (NETA) which is used as birth control and menopausal hormone therapy. EE is an estrogen, while norethisterone acetate (NETA) is a progestin. It is taken by mouth. Some preparations of EE/NETA used in birth control additionally contain an iron supplement in the form of ferrous fumarate.In 2019, it was the 42nd most commonly prescribed medication in the United States, with more than 16 million prescriptions.
Society and culture
Brand names
Brand names of EE/NETA include Anovlar, Blisovi, Cumorit, Estrostep, FemHRT, Fyavolv, Gildess, Junel, Larin, Leribane, Loestrin, Lo Loestrin (Lo Lo), Mibelas, Microgestin, Minastrin, Norlestrin, Primodos, Taytulla, and Tri-Legest, among others.In addition, the combination is sold in the United States under the brand name FemHRT for use in menopausal hormone therapy.
See also
Estradiol/norethisterone acetate
Oral contraceptive formulations
List of combined sex-hormonal preparations
Nand Peeters
References
External links
"Ethinyl estradiol mixture with norethindrone acetate". Drug Information Portal. U.S. National Library of Medicine. |
Benzyl alcohol | Benzyl alcohol is an aromatic alcohol with the formula C6H5CH2OH. The benzyl group is often abbreviated "Bn" (not to be confused with "Bz" which is used for benzoyl), thus benzyl alcohol is denoted as BnOH. Benzyl alcohol is a colorless liquid with a mild pleasant aromatic odor. It is a useful solvent due to its polarity, low toxicity, and low vapor pressure. Benzyl alcohol has moderate solubility in water (4 g/100 mL) and is miscible in alcohols and diethyl ether. The anion produced by deprotonation of the alcohol group is known as benzylate or benzyloxide.
Natural occurrences
Benzyl alcohol is produced naturally by many plants and is commonly found in fruits and teas. It is also found in a variety of essential oils including jasmine, hyacinth and ylang-ylang. It is also found in castoreum from the castor sacs of beavers. Benzyl esters also occur naturally.
Preparation
Benzyl alcohol is produced industrially from toluene via benzyl chloride, which is hydrolyzed:
C6H5CH2Cl + H2O → C6H5CH2OH + HClAnother route entails hydrogenation of benzaldehyde, a by-product of the oxidation of toluene to benzoic acid.For laboratory use, Grignard reaction of phenylmagnesium bromide (C6H5MgBr) with formaldehyde and the Cannizzaro reaction of benzaldehyde also give benzyl alcohol. The latter also gives benzoic acid, an example of an organic disproportionation reaction.
Reactions
Like most alcohols, it reacts with carboxylic acids to form esters. In organic synthesis, benzyl esters are popular protecting groups because they can be removed by mild hydrogenolysis.Benzyl alcohol reacts with acrylonitrile to give N-benzylacrylamide. This is an example of a Ritter reaction:
C6H5CH2OH + NCCHCH2 → C6H5CH2N(H)C(O)CHCH2
Applications
Benzyl alcohol is used as a general solvent for inks, waxes, shellacs, paints, lacquers, and epoxy resin coatings. Thus it can be used in paint strippers, especially when combined with compatible viscosity enhancers to encourage the mixture to cling to painted surfaces.It is a precursor to a variety of esters and ethers, used in the soap, perfume, and flavor industries.
E.g. benzyl benzoate, benzyl salicylate, benzyl cinnamate, dibenzyl ether, benzyl butyl phthalate.
It can be used as a local anesthetic, especially with epinephrine.As a dye solvent, it enhances the process of dying wool, nylon, and leather.
Use in health care
Benzyl alcohol is used as a bacteriostatic preservative at low concentration in intravenous medications, cosmetics, and topical drugs. Some caution is necessary if a high percent of Benzyl alcohol is used as benzaldehyde arises from benzyl alcohol when used as preservative in an injectable formulation solution.
Benzyl alcohol, sold under the brand name Ulesfia, was approved by the U.S. Food and Drug Administration (FDA) in 2009, as a 5% solution for the treatment of head lice in people 6 months of age and older. It affects the louses spiracles, preventing them from closing. These then become clogged with water or mineral oil or other matter and cause the insect to die from asphyxiation.Benzyl alcohol is used effectively for treating lice infestations as the active ingredient in lotion shampoo with 5% benzyl alcohol.
Contact dermatitis
Benzyl alcohol is an ingredient used in the manufacture of soaps, topical creams, skin lotions, shampoos, and facial cleansers and is popular due to its anti-bacterial and anti-fungal properties. It is a common ingredient in a variety of
household products and can cause severe allergic contact dermatitis in a significant percentage of the population.
Safety
Benzyl alcohol has low acute toxicity with an LD50 of 1.2 g/kg in rats. It oxidizes rapidly in healthy individuals to benzoic acid, conjugated with glycine in the liver, and excreted as hippuric acid. Very high concentrations can result in toxic effects including respiratory failure, vasodilation, hypotension, convulsions, and paralysis.
Benzyl alcohol is toxic to neonates and is associated with the gasping syndrome.Benzyl alcohol is severely toxic and highly irritating to the eye. Pure benzyl alcohol produces corneal necrosis.Benzyl alcohol is not considered to be a carcinogen, and no data are available regarding teratogenic or reproductive effects.
References
External links
International Chemical Safety Card 0833
"Benzyl alcohol". Drug Information Portal. U.S. National Library of Medicine. |
Intal | Intal may refer to:
Intal, a brand name for the pharmaceutical drug cromoglicic acid
Intal language, an international auxiliary language
JC Intal, a Filipino professional basketball player |
Estradiol acetate | Estradiol acetate (EA), sold under the brand names Femtrace, Femring, and Menoring, is an estrogen medication which is used in hormone therapy for the treatment of menopausal symptoms in women. It is taken by mouth once daily or given as a vaginal ring once every three months.Side effects of estradiol acetate include breast tenderness, breast enlargement, nausea, headache, and fluid retention. Estradiol acetate is an estrogen and hence is an agonist of the estrogen receptor, the biological target of estrogens like estradiol. It is an estrogen ester and a prodrug of estradiol in the body. Because of this, it is considered to be a natural and bioidentical form of estrogen.Estradiol acetate was introduced for medical use in 2001. It is available in the United States and the United Kingdom. The formulation for use by mouth has been discontinued in the United States.
Medical uses
Estradiol acetate is used as a component of menopausal hormone therapy to treat and prevent menopausal symptoms such as hot flashes and osteoporosis in women.The Womens Health Initiative studies report increased health risks for menopausal women when using unopposed estrogens. Estrogens with or without progestins should be prescribed at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman.
Available forms
Estradiol acetate comes in the form of 0.45, 0.9, and 1.8 mg oral tablets (Femtrace) and in the form of 12.4 or 24.8 mg vaginal rings that release 50 or 100 μg/day estradiol for 3 months (Femring, Menoring). However, the Femtrace product was discontinued in the United States.
Contraindications
Contraindications of estrogens include coagulation problems, cardiovascular diseases, liver disease, and certain hormone-sensitive cancers such as breast cancer and endometrial cancer, among others.
Side effects
The side effects of estradiol acetate are the same as those of estradiol. Examples of such side effects include breast tenderness and enlargement, nausea, bloating, edema, headache, and melasma.
Overdose
Symptoms of estrogen overdosage may include nausea, vomiting, bloating, increased weight, water retention, breast tenderness, vaginal discharge, heavy legs, and leg cramps. These side effects can be diminished by reducing the estrogen dosage.
Interactions
Inhibitors and inducers of cytochrome P450 may influence the metabolism of estradiol and by extension circulating estradiol levels.
Pharmacology
Pharmacodynamics
Estradiol acetate is an estradiol ester, or a prodrug of estradiol. As such, it is an estrogen, or an agonist of the estrogen receptors. Estradiol acetate is of about 15% higher molecular weight than estradiol due to the presence of its C3 acetate ester. Because estradiol acetate is a prodrug of estradiol, it is considered to be a natural and bioidentical form of estrogen.
Pharmacokinetics
Estradiol acetate is converted into estradiol in the body.
Chemistry
Estradiol acetate is a synthetic estrane steroid and the C3 acetate ester of estradiol. It is also known as estradiol 3-acetate or as estra-1,3,5(10)-triene-3,17β-diol 3-acetate. Another common ester of estradiol in use for oral administration is estradiol valerate, which is a C17β ester of estradiol.The experimental octanol/water partition coefficient (logP) of estradiol acetate is 4.2.
History
Estradiol acetate is relatively recent to the market, having been first approved in a vaginal ring formulation as Menoring in the United Kingdom in 2001, followed by a vaginal ring formulation as Femring in the United States in 2002, and finally as an oral preparation as Femtrace in the United States in 2004.
Society and culture
Generic names
Estradiol acetate is the generic name of the drug and its USAN.
Brand names
Estradiol acetate is marketed under the brand names Femtrace, Femring, and Menoring.
Availability
Estradiol acetate is available in the United States and the United Kingdom.
== References == |
Ixabepilone | Ixabepilone (INN; also known as azaepothilone B, codenamed BMS-247550) is a pharmaceutical drug developed by Bristol-Myers Squibb as a chemotherapeutic medication for cancer.
History
Ixabepilone is a semi-synthetic analog of epothilone B, a natural chemical compound produced by Sorangium cellulosum. Epothilone B itself could not be developed as a pharmaceutical drug because of poor metabolic stability and pharmacokinetics. Ixabepilone was designed through medicinal chemistry to improve upon these properties.
Pharmacology
Much like Taxol, Ixabepilone acts to stabilize microtubules.
It is highly potent, capable of damaging cancer cells in very low concentrations, and retains activity in cases where tumor cells are insensitive to taxane type drugs.
Approval
On October 16, 2007, the U.S. Food and Drug Administration approved ixabepilone for the treatment of aggressive metastatic or locally advanced breast cancer no longer responding to currently available chemotherapies. In November 2008, the EMEA has refused a marketing authorisation for Ixabepilone.Ixabepilone is administered through injection, and is marketed under the trade name Ixempra.
Clinical uses
Ixabepilone, in combination with capecitabine, has demonstrated effectiveness in the treatment of metastatic or locally advanced breast cancer in patients after failure of an anthracycline and a taxane.It has been investigated for use in treatment of non-Hodgkins lymphoma.
In pancreatic cancer phase two trial it showed some promising results (used alone). Combination therapy trials are ongoing.
References
External links
Ixempra product website
Ixempra prescribing information |
Lurbinectedin | Lurbinectedin, sold under the brand name Zepzelca, is a medication used for the treatment of small cell lung cancer.The most common side effects include leukopenia, lymphopenia, fatigue, anemia, neutropenia, increased creatinine, increased alanine aminotransferase, increased glucose, thrombocytopenia, nausea, decreased appetite, musculoskeletal pain, decreased albumin, constipation, dyspnea, decreased sodium, increased aspartate aminotransferase, vomiting, cough, decreased magnesium and diarrhea.Lurbinectedin is a synthetic tetrahydropyrrolo [4,3,2-de]quinolin-8(1H)-one alkaloid analogue with potential antineoplastic activity. Lurbinectedin covalently binds to residues lying in the minor groove of DNA, which may result in delayed progression through S phase, cell cycle arrest in the G2/M phase and cell death.Lurbinectedin was approved for medical use in the United States in June 2020.
Medical uses
Lurbinectedin is indicated for the treatment of adults with metastatic small cell lung cancer (SCLC) with disease progression on or after platinum-based chemotherapy.
Structure
Lurbinectedin is structurally similar to trabectedin, although the tetrahydroisoquinoline present in trabectedin is replaced with a tetrahydro β-carboline which enables lurbinectedin to exhibit increased antitumor activity compared with trabectedin.
Synthesis
Synthesis of lurbinectedin starts from small, common starting materials that require twenty-six individual steps to produce the drug with overall yield of 1.6%.
Mechanism of action
According to PharmaMar, lurbinectedin inhibits the active transcription of the encoding genes. This has two consequences. It promotes tumor cell death and normalizes the tumor microenvironment. Active transcription is the process by which there are specific signal where information contained in the DNA sequence is transferred to an RNA molecule. This activity depends on the activity of an enzyme called RNA polymerase II. Lurbinectedin inhibits transcription through a very precise mechanism. Firstly, lurbinectedin binds to specific DNA sequences. It is at these precise spots that slides down the DNA to produce RNA polymerase II that is blocked and degraded by lurbinectedin. Lurbinectedin also has important role in tumor microenvironment. The tumor cells act upon macrophages to avoid them from behaving like an activator of the immune system. Macrophages can contribute to tumor growth and progression by promoting tumor cell proliferation and invasion, fostering tumor angiogenesis and suppressing antitumor immune cells. Attracted to oxygen-starved (hypoxic) and necrotic tumor cells they promote chronic inflammation. So, not only that macrophages inhibit immune system avoiding the destruction of tumor cells, but they also create tumor tissue that allows tumor growth. However, macrophages associated with tumors are cells that are addicted to the transcription process. Lurbinectedin acts specifically on the macrophages associated with tumors in two ways: firstly, by inhibiting the transcription of macrophages that leads to cell death and secondly, inhibiting the production of tumor growth factors. In this way, lurbinectedin normalizes the tumor microenvironment.
History
Lurbinectedin was approved for medical use in the United States in June 2020.Efficacy was demonstrated in the PM1183-B-005-14 trial (Study B-005; NCT02454972), a multicenter open-label, multi-cohort study enrolling 105 participants with metastatic SCLC who had disease progression on or after platinum-based chemotherapy. Participants received lurbinectedin 3.2 mg/m2 by intravenous infusion every 21 days until disease progression or unacceptable toxicity. The trial was conducted at 26 sites in the United States, Great Britain, Belgium, France, Italy, Spain and Czech Republic.The U.S. Food and Drug Administration (FDA) granted the application for lurbinectedin priority review and orphan drug designations and granted the approval of Zepzelca to Pharma Mar S.A.
Research
Clinical Trials
Lurbinectedin can be used as monotherapy in the treatment of SCLC. Lurbinectedin monotherapy demonstrated the following clinical results in relapsed extensive stage SCLC:
For sensitive disease (chemotherapy-free interval of ≥ 90 days) overall response rate (ORR) was 46.6% with 79.3% disease control rate and median overall survival (OS) being increased to 15.2 months.
For resistant disease (chemotherapy-free interval of < 90 days) overall response rate (ORR) was 21.3% with 46.8% disease control rate and 5.1 months median overall survival (OS).Lurbinectedin is also being investigated in combination with doxorubicin as second-line therapy in a randomized Phase III trial. While overall survival in this trial is not yet known, response rates at second line were
91.7% in sensitive disease with median progression-free survival of 5.8 months, and
33.3% in resistant disease with median progression-free of 3.5 months.Lurbinectedin is available in the U.S. under Expanded Access Program (EAP).
References
External links
"Lurbinectedin". Drug Information Portal. U.S. National Library of Medicine.
"Lurbinectedin". NCI Dictionary of Cancer Terms. National Cancer Institute.
Clinical trial number NCT02454972 for "Clinical Trial of Lurbinectedin (PM01183) in Selected Advanced Solid Tumors" at ClinicalTrials.gov |
Maprotiline | Maprotiline, sold under the brand name Ludiomil among others, is a tetracyclic antidepressant (TeCA) that is used in the treatment of depression. It may alternatively be classified as a tricyclic antidepressant (TCA), specifically a secondary amine. In terms of its chemistry and pharmacology, maprotiline is closely related to other secondary amine TCAs like nortriptyline and protriptyline, and has similar effects to them.
Medical uses
Maprotiline is used in the treatment of depression, such as depression associated with agitation or anxiety and has similar efficacy to the antidepressant drug moclobemide.
Treatment of depression of all forms and severities (endogenous, psychotic, involutional, and neurotic) especially for depression associated with agitation or anxiety
Panic disorder
Neuropathic pain
Treatment of the depressive phase in bipolar depression
For the symptomatic relief of anxiety, tension or insomniaThe use of maprotiline in the treatment of enuresis in pediatric patients has so far not been systematically explored and its use is not recommended. Safety and effectiveness in the pediatric population in general have not been established. Anyone considering the use of maprotiline in a child or adolescent must balance the potential risks with the clinical need. In general, lower dosages are recommended for patients over 60 years of age. Dosages of 50 mg to 75 mg daily are usually satisfactory as maintenance therapy for elderly patients who do not tolerate higher amounts.
Available forms
Coated Tablets, 10 mg, 25 mg, 50 mg, and 75 mg
Injectable concentrate, 25 mg
Contraindications
Maprotiline may worsen psychotic conditions like schizophrenia and should be given with caution. The antipsychotic treatment should be continued. Patients with bipolar affective disorder should not receive antidepressants whilst in a manic phase, as antidepressants can worsen mania.
Absolute
Hypersensitivity to maprotiline or to other TCAs and TeCAs
Hypertrophy of the prostate gland with urine hesitancy
Closed angle glaucoma
Special caution needed
Concomitant treatment with a MAO inhibitor
Serious impairment of liver and kidney function
Epilepsy and other conditions that lower the seizure threshold (active brain tumors, alcohol withdrawal, other medications)
Serious cardiovascular conditions (arrhythmias, heart insufficience, state after myocardial infarction etc.)
Treatment of patients under age 18
Suicidal patients
Same as other antidepressants, maprotiline increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents and young adults in short-term studies of major depressive disorder (MDD) and other psychiatric disorders. Anyone considering the use of maprotiline or any other antidepressant in a child, adolescent, or young adult must balance this risk with the clinical need. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction in risk with antidepressants compared to placebo in adults aged 65 and older. Depression and certain other psychiatric disorders are themselves associated with increases in the risk of suicide. Patients of all ages who are started on antidepressant therapy should be monitored appropriately and observed closely for clinical worsening, suicidality, or unusual changes in behavior. Families and caregivers should be advised of the need for close observation and communication with the prescriber. Maprotiline is not approved for use in pediatric patients.
Pregnancy and lactation
Reproduction studies have been performed in female laboratory rabbits, mice, and rats at doses up to 1.3, 7, and 9 times the maximum daily human dose respectively and have revealed no evidence of impaired fertility or harm to the fetus due to maprotiline. There are, however, no adequate and well controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.
Maprotiline is excreted in breast milk. At steady-state, the concentrations in milk correspond closely to the concentrations in whole blood. Caution should be exercised when maprotiline hydrochloride is administered to a nursing woman.
Side effects
The side-effect profile is comparable to other TCAs and TeCAS and many of the following are due to anticholinergic (which are less prominent than those of most TCAs) and antihistamine effects. Most often seen are:
Dizziness
Drowsiness
Somnolence
Fatigue
Dry mouth (and complications of long-term uncontrolled dry mouth such as dental caries)
Constipation
Vertigo
Nausea (rare, incidence of ~2%) and vomiting
Increased appetite and weight gain
Orthostatic hypotension, hypertension, sinus tachycardia, heart-block, arrhythmias and other cardiac effects
Sexual dysfunction in men: impotence, priapism, delayed ejaculation, anejaculation, decreased libido
Sexual dysfunction in women: decreased libido, vaginal dryness, painful sexual intercourse, anorgasmia
Allergic skin reactions such as rash or urticaria (more often than with other antidepressants). Rarely, severe skin reactions such as erythema multiforme can occur.
Photosensitivity
Agitation, confusion
Induction of hypomania or mania in patients with underlying bipolar affective disorder
Psychotic symptoms
Tremor
Extrapyramidal symptoms
Headache
Seizures (at high doses)
Rare haematological complications: leukopenia and agranulocytosis (dangerous fall in white blood cells)
Fever
Urinary retentionMaprotiline causes a strong initial sedation (first 2 to 3 weeks of therapy) and is therefore indicated to treat agitated patients or those with suicidal risks. It causes anticholinergic side effects (dry mouth, constipation, confusion, tachycardia) with a lower incidence than amitriptyline. Originally, the manufacturer claimed that maprotiline is better tolerated than other TCAs and TeCAs. However, seizures, leukopenia and skin reactions occur more often with maprotiline than with comparable drugs like amitriptyline.
Maprotiline has no known potential for abuse and psychological dependence.
Withdrawal
Withdrawal symptoms frequently seen when treatment with maprotiline is stopped abruptly (agitation, anxiety, insomnia, sometimes activation of mania or rebound depression) are not indicative of addiction and can be avoided by reducing the daily dose of maprotiline gradually by approximately 25% each week. If treatment has to be stopped at once due to medical reasons, the use of a benzodiazepine (e.g. lorazepam, clonazepam, or alprazolam) for a maximum of 4 weeks as needed will usually suppress withdrawal symptoms.
Interactions
Maprotiline has a wide range of possible interactions. Some are typical for TCAs and TeCAs, others are caused by specific metabolic effects (e.g. high plasma-protein-binding) of maprotiline:
Irreversible MAO-inhibitors: agitation, delirium, coma, hyperpyrexia (high fever), seizures and severe changes in blood pressure. Treatment-resistant and hospitalized patients may be treated concomitantly with an MAO-inhibitor, if they are closely monitored and if the initial dose of the MAO-Inhibitor is low.Increased drug actions:
Other antidepressants, barbiturates, narcotics, sedating antihistamines, anticonvulsive drugs, alcohol - resulting in increased central depression
Anticholinergics (antiparkinsonian agents, TCAs and TeCAs) - resulting in increased anticholinergic action (dry mouth, constipation etc.)
Sympathomimetics (also those used in local anesthetics like noradrenaline) : sympathomimetic effects increased (increased blood pressure, pulse rate, paleness of skin etc.)
Nitrates and antihypertensives (e.g. beta-blockers) - increased antihypertensive action with pronounced fall in blood pressureDecreased drug actions:
Guanethidine, Reserpine, Guanfacine : antihypertensive effects decreased
Clonidine : antihypertensive effects decreased and risk of (massive) rebound hypertension.Other types of interaction:
Drugs, which induce certain enzymes in the liver, e.g. barbiturates, phenytoin, carbamazepine and oral anticonceptive drugs, enhance the elimination of maprotiline and decrease its antidepressant effects. Additionally the blood-concentrations of phenytoin or carbamazepine may be increased, leading to a higher incidents of side effects.
The concomitant use of maprotiline and neuroleptics can lead to increased maprotiline blood-levels and to seizures. Combining maprotiline and thioridazine could induce severe arrhythmias.
Additionally, increased blood-levels of Maprotiline are possible, if certain beta-blocking agents (e.g. Propranolol) are given concomitantly.
Maprotiline may amplify the actions of coumarin-type anticoagulants (e.g. warfarin, phenprocoumon). The plasma-prothrombin-activity must be assessed closely in order to avoid overt bleedings.
Maprotiline can increase the actions of oral antidiabetic drugs (sulfonylureas) and Insulin. Diabetic patients should have regular assessments of their blood-glucose-levels.
The concomitant application with fluoxetine or fluvoxamine may lead to significantly increased plasma-levels of maprotiline with a high incidence of maprotiline side effects. Due to the long half-lives of fluoxetine and fluvoxamine this effect may persist.
Pharmacology
Pharmacodynamics
Maprotiline exhibits strong effects as a norepinephrine reuptake inhibitor with only weak actions the reuptake of serotonin and dopamine. It is also a strong antagonist of the H1 receptor, a moderate antagonist of the 5-HT2 and α1-adrenergic receptors, and a weak antagonist of the D2 and muscarinic acetylcholine receptors. Maprotiline has also more recently been identified as a potent antagonist of the 5-HT7 receptor, with this action potentially playing an important role in its antidepressant effectiveness. The drug is a strong antihistamine, but unlike most TCAs, has minimal anticholinergic effects.The pharmacological profile of maprotiline explains its antidepressant, sedative, anxiolytic, and sympathomimetic activities. In accordance to the pharmacological characteristics it is used in the treatment of depression, such as depression associated with agitation or anxiety. Additionally, it shows strong antagonism against reserpine-induced effects in animal studies, as do the other classical antidepressants. Although maprotiline behaves in most regards as a first-generation antidepressant it is commonly referred to as second-generation antidepressant.
The postulated mechanism of maprotiline is that it acts primarily by potentiation of central adrenergic synapses by blocking reuptake of norepinephrine at nerve endings. This pharmacological action is thought to be primarily responsible for the drugs antidepressant and anxiolytic effects. It is a strong norepinephrine reuptake inhibitor with only weak effects on serotonin and dopamine reuptake. At higher doses however, maprotiline increases serotonergic transmission and increases the level of serotonin available.
Pharmacokinetics
After oral use absorption is good. It binds to plasma proteins 80–90%. Maximal plasma concentration is reached 6 hours after use. The mean time to peak is 12 hours. The terminal half-life of averages 51 hours.
Chemistry
Maprotiline is a tetracyclic compound and is grouped with the TeCAs. Its chemical name is N-methyl-9,10-ethanoanthracen-9(10H)-propylamine. The drug has a dibenzobicyclo[2.2.2]octadiene (9,10-dihydro-9,10-ethanoanthracene) ring system; that is, a tricyclic anthracene ring system with an ethylene bridge across the central ring. This results in it having a unique three-dimensional central ring (a bicyclo[2.2.2]octane or 1,4-endoethylenecyclohexane ring) and being a tetracyclic rather than a tricyclic compound. However, it could also or alternatively be considered to be a tricyclic and hence a TCA. In addition to its heterocyclic ring system, maprotiline has an alkylamine side chain attached similarly to other TCAs (but notably unlike other TeCAs). In terms of the side chain, it is a secondary amine, and its chemical structure, aside from the ethylene link in the central ring, is similar to that of secondary amine TCAs like nortriptyline and protriptyline. In accordance, the pharmacology of maprotiline is very similar to that of secondary amine TCAs.Maprotiline is very similar in structure to the anxiolytic, sedative, and muscle relaxant drug benzoctamine (Tacitin). The only structural difference between the two compounds is in the length of their side chain. However, this modification results in considerable differences in their pharmacological and therapeutic effects.
History
Maprotiline was developed by Ciba (now operated by Novartis). It was patented in 1966 and was first described in the literature in 1969. The drug was introduced for medical use in 1974. Generics are now widely available. It was introduced after most of the other TCAs but was the first TeCA to be developed and marketed, with the TeCAs mianserin and amoxapine following shortly thereafter and mirtazapine being introduced later on.
Society and culture
Generic names
Maprotiline is the English and French generic name of the drug and its INN, USAN, BAN, and DCF, while maprotiline hydrochloride is its USAN, USP, BANM and JAN. Its generic name in Spanish and Italian and its DCIT are maprotilina, in German is maprotilin, and in Latin is maprotilinum. The methanesulfonate (mesylate) salt is known unofficially as maprotiline methanesulfonate.
Brand names
Maprotiline is marketed throughout the world mainly under the brand name Ludiomil. It is also available under a variety of other brand names including Deprilept, Maprolu, and Psymion among others.
== References == |
Crisaborole | Crisaborole, sold under the brand name Eucrisa among others, is a nonsteroidal topical medication used for the treatment of mild-to-moderate atopic dermatitis (eczema) in adults and children.The most common side effects are reactions at the application site (including burning or stinging).Crisaborole is a phosphodiesterase 4 (PDE-4) inhibitor, although its specific mechanism of action in atopic dermatitis is not known.
Side effects
At the site of application, crisaborole may cause burning or stinging. Rarely, there may be an allergic reaction.
Medical uses
In the US, crisaborole is indicated for topical treatment of mild to moderate atopic dermatitis in people three months of age and older.In the EU, crisaborole was authorized for treatment of mild to moderate atopic dermatitis in people two years of age and older with ≤ 40% body surface area (BSA) affected.
Pharmacology
Pharmacodynamics
Crisaborole is a phosphodiesterase-4 inhibitor, mainly acting on phosphodiesterase 4B (PDE4B), which causes inflammation. Chemically, crisaborole is a phenoxybenzoxaborole. Inhibition of PDE4B appears to suppress the release of tumor necrosis factor alpha (TNFα), interleukin-12 (IL-12), IL-23 and other cytokines, proteins believed to be involved in the immune response and inflammation.People with atopic dermatitis produce high levels of proteins called cytokines, which can cause the inflammation of the skin seen in dermatitis. Crisaborole blocks the release of certain cytokines involved in the inflammation process such as tumor necrosis factor alpha, interleukins (IL‑2, IL-4, IL-5), and interferon gamma. By blocking their release, crisaborole is expected to ease the inflammation and therefore relieve symptoms of the disease.
Chemistry
Crisaborole (chemical name: 4-[(1-hydroxy-1,3-dihydro-2,1-benzoxaborol-5-yl)oxy]benzonitrile) is a member of the class of benzoxaboroles characterized by the presence of a boronic acid hemiester with a phenolic ether and a nitrile. Crisaborole crystallizes into two polymorphs that differ in the conformation of the oxaborole ring. A cocrystal with 4,4-bipyridine has been prepared and studied by X-ray crystallography.
History
Crisaborole was developed by Anacor Pharmaceuticals for the topical treatment of psoriasis. During preclinical and clinical development, crisaborole was called AN2728 and PF-06930164. The drug was assumed to be potential $2bn-a-year blockbuster, when Pfizer acquired Anacor Pharmaceuticals. However, the drug was commercially not successful, reaching only US$147 million in sales in 2018, and US$138 million in sales in 2019.Crisaborole was approved for use in the United States in December 2016 and for use in Canada in June 2018.The safety and efficacy of crisaborole were established in two placebo-controlled trials with a total of 1,522 participants ranging in age from two years of age to 79 years of age, with mild to moderate atopic dermatitis. In both trials participants received treatment with either crisaborole or placebo twice daily for 28 days. Neither the participants nor the health care providers knew which treatment was being given until after the trials were completed. Overall, participants receiving crisaborole achieved greater response with clear or almost clear skin after 28 days of treatment. The trials were conducted in the US.Crisaborole, approved for the treatment of mild to moderate atopic dermatitis in the European Union, has been rapidly withdrawn from the European market (March 2020 - February 2022).
See also
Tavaborole – a structurally related topical antifungal developed by Anacor
References
External links
"Crisaborole". Drug Information Portal. U.S. National Library of Medicine. |
Mogamulizumab | Mogamulizumab, sold under the brand name Poteligeo, is a humanized, afucosylated monoclonal antibody targeting CC chemokine receptor 4 (CCR4). The U.S. Food and Drug Administration (FDA) approved it in August 2018 for treatment of relapsed or refractory mycosis fungoides and Sézary disease. It was approved in Japan in 2012, for the treatment of relapsed or refractory CCR4+ adult T-cell leukemia/lymphoma (ATCLL) and in 2014, for relapsed or refractory CCR4+ cutaneous T cell lymphoma (CTCL). The latter approval was based on study with 28 subjects.The precursor to mogamulizumab was a mouse anti-human CCR4 IgG1 mAb (KM2160), that was made in 1996 in a collaboration between Kouji Matsushima of University of Tokyo and Kyowa Hakko Kirin. Kyowa humanized it, and expressed the humanized gene in a CHO cell line in which FUT8 had been knocked out, which produced antibodies with no fucose in the Fc region. This is thought to enhance its antibody-dependent cell-mediated cytotoxicity. It was first tested in humans in 2007.Kyowa licensed rights for use outside of cancer to Amgen in 2008, for $100 million up front and $420 million in biodollars. Amgen ran a Phase I study to explore its use in asthma. Amgen terminated the agreement in 2014.As of 2014, there were reports that mogamulizimab can cause serious skin rashes and some cases of Stevens–Johnson syndrome.In 2017, the US FDA granted it a priority review for CTCL. Full approval was granted in August 2018. The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication.
Research
Mogamulizumab is being explored as a treatment for HTLV-1–Associated Myelopathy. An early Phase 1-2a study showed decreased in proviral loads, as well as inflammatory markers in the CSF. 79% of the patients showed reduction in spasticity and 32% showed decrease in motor disability.
References
External links
"Mogamulizumab". Drug Information Portal. U.S. National Library of Medicine.
"Mogamulizumab-kpkc". National Cancer Institute. 30 August 2018.
"Mogamulizumab-kpkc". NCI Drug Dictionary. National Cancer Institute. |
Arylsulfatase B | Arylsulfatase B (N-acetylgalactosamine-4-sulfatase, chondroitinsulfatase, chondroitinase, acetylgalactosamine 4-sulfatase, N-acetylgalactosamine 4-sulfate sulfohydrolase, EC 3.1.6.12) is an enzyme associated with mucopolysaccharidosis VI (Maroteaux–Lamy syndrome).
Arylsulfatase B is among a group of arylsulfatase enzymes present in the lysosomes of the liver, pancreas, and kidneys of animals. The purpose of the enzyme is to hydrolyze sulfates in the body. ARSB does this by breaking down glycosaminoglycans (GAGs), which are large sugar molecules in the body. ARSB targets two GAGs in particular: dermatan sulfate and chondroitin sulfate.Over 130 mutations to ARSB have been found, each leading to a deficiency in the body. In most cases, the mutation occurs on a single nucleotide in the sequence. An arylsulfatase B deficiency can lead to an accumulation of GAGs in lysosomes, which in turn can lead to mucopolysaccharidosis VI.
Used as a pharmaceutical drug, the enzyme is known under the International Nonproprietary Name galsulfase and is sold under the brand name Naglazyme. Galsulfase was approved for medical use in the United States in May 2005 and in European Union in January 2006. Galsulfase is indicated for long-term enzyme-replacement therapy in people with a confirmed diagnosis of mucopolysaccharidosis VI (MPS VI; N-acetylgalactosamine-4-sulfatase deficiency; Maroteaux-Lamy syndrome).
Structure
The primary structure of Escherichia coli arylsulfatase B contains a primary sequence of 502 amino acids. Its secondary structure is quite complex, containing numerous alpha helices (20 total containing 138 residues) and beta sheets (21 strands total containing 87 residues). The functional enzyme is believed to be a homo tetramer. Due to the complexity of arylsulfatase Bs secondary structure, many hydrophobic and hydrophilic regions are present, as demonstrated by the Kyte-Doolittle hydropathy plot:
Medical uses
Galsulfase is used to treat adults and children who have mucopolysaccharidosis VI (MPS VI or Maroteaux-Lamy syndrome). This disease is caused by the lack of an enzyme called N-acetylgalactosamine 4-sulfatase, which is needed to break down substances in the body called glycosaminoglycans (GAGs). If the enzyme is not present, GAGs cannot be broken down and they build up in the cells. This causes the signs of the disease, the most noticeable being a short body, a large head and difficulty moving about. The disease is usually diagnosed in infants between one and five years of age. Galsulfase has been shown to improve walking and stair-climbing capacity.The most common adverse reactions (≥10%) are: rash, pain, urticaria, pyrexia, pruritus, chills, headache, nausea, vomiting, abdominal pain and dyspnea. The most common adverse reactions requiring interventions are infusion-related reactions.Galsulfase (N-acetylgalactosamine-4-sulfatase, recombinant human) was granted orphan drug designation by both the European Commission and the U.S. Food and Drug Administration (FDA).
Role in cystic fibrosis
Expression and activity of ARSB were found to be related to the function of cystic fibrosis transmembrane conductance regulator (CFTR), the membrane channel deficient in cystic fibrosis. Measurements in cystic fibrosis cell line IB3 and its derivative cell line C38, which has a functional CFTR, showed increased ARSB activity and expression in the C38 line. CFTR potentiator VRT-532 increased ARSB expression and activity in cystic fibrosis cells to the level in the normal bronchial epithelial cells.
Role in malignancy
ARSB has been studied in a variety of cancers. Cultured normal mammary epithelial and myoepithelial cells had significantly higher ARSB activity than cultured malignant mammary cells. Immunohistochemistry in the colon showed decreased membrane ARSB staining in colon cancer compared to normal colon, as well as in higher grade malignancies. ARSB activity was lower in malignant than normal prostate tissue, and immunostaining of prostate tissue microarrays showed not only decreasing ARSB staining in prostate cancer tissue of a higher Gleason score, but also lower staining in patients with recurrent compared to non-recurrent cancer. ARSB staining was a greater predictor of recurrence than Prostate-specific antigen (PSA) test, indicating possible future role of ARSB as a prognostic biomarker of prostate cancer. Further evidence of ARSB as a tumor suppressor was determined by molecular studies in cell cultures where ARSB was silenced by siRNA. The studies showed that decrease of ARSB leads to increase in free galectin-3, which attaches more strongly to less sulfated chondroitin 4-sulfate. Galectin-3 then acts on transcription factors AP-1 to increase expression of chondroitin sulfate proteoglycan versican and SP-1 to increase expression of WNT9A. Another mechanism by which reduced ARSB is associated with carcinogenesis is through increased binding of SHP2 to more sulfated chondroitin 4-sulfate, which leads to increased phosphorylation of p38 and MITF with subsequently increased expression of GPNMB.
Role in metabolism
Reduced sulfate availability due to impaired activity of ARSB has been linked to increased aerobic glycolysis, as shown by an increase in NADH and NADPH, reduced oxygen consumption, increased extracellular acidification and serum lactate, and a decline in mitochondrial membrane potential in ARSB-silenced cells and ARSB-null mouse tissues.
Extra-lysosomal localization
Although primarily a lysosomal enzyme, ARSB was also found to localize at the cell membrane of hepatocytes, sinusoidal endothelial cells, and Kupffer cells in the liver, as well as in the apical membranes of normal and malignant colonic and prostatic epithelial cells, by immunohistochemistry and immunofluorescence studies. Membrane immunostaining in the colon and prostate was lower in malignant than in normal tissue and also was lower in higher grade malignancies. ARSB activity assay in the membrane and cytosol fractions of cultured bronchial epithelial cells showed that the activity was several-fold greater in the membrane fraction.
See also
Aryl
Sulfatase
References
Further reading
Brunelli MJ, Atallah ÁN, da Silva EM (September 2021). "Enzyme replacement therapy with galsulfase for mucopolysaccharidosis type VI". Cochrane Database Syst Rev. 2021 (9): CD009806. doi:10.1002/14651858.CD009806.pub3. PMC 8447860. PMID 34533215.
"Galsulfase (Naglazyme)". Common Drug Review. Ottawa (ON): Canadian Agency for Drugs and Technologies in Health (CADTH). November 2016. PMID 28121110.
Ferreira CR, Gahl WA (May 2017). "Lysosomal storage diseases". Transl Sci Rare Dis. 2 (1–2): 1–71. doi:10.3233/TRD-160005. PMC 5685203. PMID 29152458.
External links
Medical Dictionary, Arylsulfatase B function.
Protein Data Base (PDB), Arylsulfatase structure.
Genetics Home Reference, Arylsulfatase B function.
Overview of all the structural information available in the PDB for UniProt: P15848 (Arylsulfatase B) at the PDBe-KB.
"Galsulfase". Drug Information Portal. U.S. National Library of Medicine.
Galsulfase at the US National Library of Medicine Medical Subject Headings (MeSH) |
Etelcalcetide | Etelcalcetide (formerly velcalcetide, trade name Parsabiv) is a calcimimetic drug for the treatment of secondary hyperparathyroidism in patients undergoing hemodialysis. It is administered intravenously at the end of each dialysis session. Etelcalcetide functions by binding to and activating the calcium-sensing receptor in the parathyroid gland. Parsabiv is currently owned by Amgen and Ono Pharmaceuticals in Japan.
Medical uses
Etelcalcetide is used for the treatment of secondary hyperparathyroidism in people with chronic kidney disease (CKD) on hemodialysis. Hyperparathyroidism is the condition of elevated parathyroid hormone (PTH) levels and is often observed in people with CKD.
Pharmacodynamics
Mechanism of action
Etelcalcetide functions by binding to and activating the calcium-sensing receptor (CaSR) in the parathyroid gland as an allosteric activator, resulting in PTH reduction and suppression.
Pharmacokinetics
Etelcalcetide functions in a first order elimination, with a half life of 19 hours.No interaction studies in humans were conducted. Studies in vitro showed no affinity of etelcalcetide to cytochrome P450 enzymes or common transport proteins. Therefore, no relevant pharmacokinetic interactions are expected.
Side effects
Common side effects (in more than 10% of people) are nausea, vomiting, diarrhoea, muscle spasms, and hypocalcaemia (too low blood calcium levels). In clinical studies, the latter side effect was usually mild to moderate and without symptoms. An increase of the QT interval of more than 60 ms was detected in 1.2% of people receiving etelcalcetide.Due to the lower iPTH levels achieved by the use of this drug, it is possible that adynamic bone disease could occur at levels "below 100 pg/mL"
Contraindications
The drug is contraindicated in people with blood serum calcium levels below the norm.
Chemistry
The substance is a peptide consisting mostly of D-amino acids instead of the common L-amino acids. More specifically, it is the disulfide of N-acetyl-D-cysteinyl-D-alanyl-D-arginyl-D-arginyl-D-arginyl-D-alanyl-D-argininamide with L-cysteine.
History
Originally, Etelcalcetide was being developed by KAI Pharmaceuticals. After positive Phase II trials, Amgen acquired KAI for $315 Million.In 2011, KAI entered into agreement with Ono Pharmaceutical for production of Etelcalcetide in Japan, the deal being worth ¥1 Billion.On 25 August 2015 Amgen Inc. announced its submission of a new drug application to the Food and Drug Administration for etelcalcetide. The European Medicines Agency approved the drug in November 2016.In February 2017, the FDA approved Parsabiv for the treatment of secondary hyperparathyroidism.
Research
Phase II trials found that Etelcalcetide was able to lower PTH levels in one cohort by -49% vs a 29% increase in the placebo group. In another Phase II study "89% of patients experienced a C30% reduction in PTH and 56% achieved a PTH level of B300 pg/mL."In 2017, two Phase III trials found that using etelcalcetide showed greater symptom reduction compared to placebo. Etelcalcetide was also able to lower PTH levels below 300pg/mL more often.Phase I Pediatric studies are planned for the US and UK for etelcalcetide.
References
Further reading
HSRIC Fact sheet 2014 Archived 2016-03-04 at the Wayback Machine |
Timolol | Timolol is a beta blocker medication used either by mouth or as eye drops. As eye drops it is used to treat increased pressure inside the eye such as in ocular hypertension and glaucoma. By mouth it is used for high blood pressure, chest pain due to insufficient blood flow to the heart, to prevent further complications after a heart attack, and to prevent migraines.Common side effects with the drops is irritation of the eye. Common side effects by mouth include tiredness, slow heart beat, itchiness, and shortness of breath. Other side effects include masking the symptoms of low blood sugar in those with diabetes. Use is not recommended in those with asthma, uncompensated heart failure, or COPD. It is unclear if use during pregnancy is safe for the baby. Timolol is a non-selective beta blocker.Timolol was patented in 1968, and came into medical use in 1978. It is on the World Health Organizations List of Essential Medicines. Timolol is available as a generic medication. In 2019, it was the 160th most commonly prescribed medication in the United States, with more than 3 million prescriptions.
Medical uses
By mouth
In its by mouth or oral form, it is used:
to treat high blood pressure
to prevent heart attacks
to prevent migraine headachesThe combination of timolol and the alpha-1 blocker prazosin has sedative effects.
Eye drops
In its eye drop form it is used to treat open-angle and, occasionally, secondary glaucoma. The mechanism of action of timolol is probably the reduction of the formation of aqueous humor in the ciliary body in the eye. It was the first beta blocker approved for topical use in treatment of glaucoma in the United States (1978). When used by itself, it depresses intraocular pressure (IOP) 18–34% below baseline within first few treatments. However, there are short-term escape and long-term drift effects in some people. That is, tolerance develops. It may reduce the extent of the diurnal IOP curve up to 50%. The IOP is higher during sleep. Efficacy of timolol in lowering IOP during the sleep period may be limited. It is a 5–10× more potent β-blocker than propranolol. Timolol is light-sensitive; it is usually preserved with 0.01% benzalkonium chloride (BAC), but also comes BAC-free. It can also be used in combination with pilocarpine, carbonic anhydrase inhibitors or prostaglandin analogs.A Cochrane review compared the effect of timolol versus brimonidine in slowing the progression of open angle glaucoma in adults but found insufficient evidence to come to conclusions.
On the skin
In its gel form it is used on the skin to treat infantile hemangiomas.
Contraindications
The medication should not be taken by individuals with:
An allergy to timolol or any other beta-blockers
Asthma or severe chronic obstructive bronchitis
A slow heart rate (bradycardia), or a heart block
Heart failure
Side effects
The most serious possible side effects include cardiac arrhythmias and severe bronchospasms. Timolol can also lead to fainting, congestive heart failure, depression, confusion, worsening of Raynauds syndrome and impotence.Side effects when given in the eye include: burning sensation, eye redness, superficial punctate keratopathy, corneal numbness.
Formulations
It is available in tablet and liquid formulations.For ophthalmic use, timolol is also available combined:
with carbonic anhydrase inhibitors:
timolol and brinzolamide
timolol and dorzolamide
with α2 agonists:
timolol and brimonidine
with prostaglandin analogs:
timolol and latanoprost
timolol and travoprost
Brand names
Timolol is marketed under many trade names worldwide. Timolol eye drops are marketed under the brand name Istalol among others.
References
External links
"Timolol". Drug Information Portal. U.S. National Library of Medicine.
"Timolol Ophthalmic". Drug Information Portal. U.S. National Library of Medicine.
"Timolol maleate". Drug Information Portal. U.S. National Library of Medicine.
"Timolol Ophthalmic". MedlinePlus. |
Mupirocin | Mupirocin, sold under the brand name Bactroban among others, is a topical antibiotic useful against superficial skin infections such as impetigo or folliculitis. It may also be used to get rid of methicillin-resistant S. aureus (MRSA) when present in the nose without symptoms. Due to concerns of developing resistance, use for greater than ten days is not recommended. It is used as a cream or ointment applied to the skin.Common side effects include itchiness and rash at the site of application, headache, and nausea. Long term use may result in increased growth of fungi. Use during pregnancy and breastfeeding appears to be safe. Mupirocin is in the carboxylic acid class of medications. It works by blocking a bacterias ability to make protein, which usually results in bacterial death.Mupirocin was initially isolated in 1971 from Pseudomonas fluorescens. It is on the World Health Organizations List of Essential Medicines. In 2019, it was the 190th most commonly prescribed medication in the United States, with more than 3 million prescriptions.
Medical uses
Mupirocin is used as a topical treatment for bacterial skin infections, for example, furuncle, impetigo, open wounds, which are typically due to infection by Staphylococcus aureus or Streptococcus pyogenes. It is also useful in the treatment of superficial methicillin-resistant Staphylococcus aureus (MRSA) infections. Mupirocin is inactive for most anaerobic bacteria, mycobacteria, mycoplasma, chlamydia, yeast and fungi.Intranasal mupirocin before surgery is effective for prevention of post-operative wound infection with Staphylcoccus aureus and preventative intranasal or catheter-site treatment is effective for reducing the risk of catheter site infection in persons treated with chronic peritoneal dialysis.
Resistance
Shortly after the clinical use of mupirocin began, strains of Staphylococcus aureus that were resistant to mupirocin emerged, with nares clearance rates of less than 30% success. Two distinct populations of mupirocin-resistant S. aureus were isolated. One strain possessed low-level resistance, MuL, (MIC = 8–256 mg/L) and another possessed high-level resistance, MuH, (MIC > 256 mg/L). Resistance in the MuL strains is probably due to mutations in the organisms wild-type isoleucyl-tRNA synthetase. In E. coli IleRS, a single amino acid mutation was shown to alter mupirocin resistance. MuH is linked to the acquisition of a separate Ile synthetase gene, MupA. Mupirocin is not a viable antibiotic against MuH strains. Other antibiotic agents, such as azelaic acid, nitrofurazone, silver sulfadiazine, and ramoplanin have been shown to be effective against MuH strains.Most strains of Cutibacterium acnes, a causative agent in the skin disease acne vulgaris, are naturally resistant to mupirocin.The mechanism of action of mupirocin differs from other clinical antibiotics, rendering cross-resistance to other antibiotics unlikely. However, the MupA gene may co-transfer with other antibacterial resistance genes. This has been observed already with resistance genes for triclosan, tetracycline, and trimethoprim. It may also result in overgrowth of non-susceptible organisms.
Mechanism of action
Pseudomonic acid inhibits isoleucine tRNA synthetase in bacteria, leading to depletion of isoleucyl-tRNA and accumulation of the corresponding uncharged tRNA. Depletion of isoleucyl-tRNA results in inhibition of protein synthesis. The uncharged form of the tRNA binds to the aminoacyl-tRNA binding site of ribosomes, triggering the formation of (p)ppGpp, which in turn inhibits RNA synthesis. The combined inhibition of protein synthesis and RNA synthesis results in bacteriostasis. This mechanism of action is shared with furanomycin, an analog of isoleucine.
Biosynthesis
Mupirocin is a mixture of several pseudomonic acids, with pseudomonic acid A (PA-A) constituting greater than 90% of the mixture. Also present in mupirocin are pseudomonic acid B with an additional hydroxyl group at C8, pseudomonic acid C with a double bond between C10 and C11, instead of the epoxide of PA-A, and pseudomonic acid D with a double bond at C4` and C5` in the 9-hydroxy-nonanoic acid portion of mupirocin.
Biosynthesis of pseudomonic acid A
The 74 kb mupirocin gene cluster contains six multi-domain enzymes and twenty-six other peptides (Table 1). Four large multi-domain type I polyketide synthase (PKS) proteins are encoded, as well as several single function enzymes with sequence similarity to type II PKSs. Therefore, it is believed that mupirocin is constructed by a mixed type I and type II PKS system. The mupirocin cluster exhibits an atypical acyltransferase (AT) organization, in that there are only two AT domains, and both are found on the same protein, MmpC. These AT domains are the only domains present on MmpC, while the other three type I PKS proteins contain no AT domains. The mupirocin pathway also contains several tandem acyl carrier protein doublets or triplets. This may be an adaptation to increase the throughput rate or to bind multiple substrates simultaneously.Pseudomonic acid A is the product of an esterification between the 17C polyketide monic acid and the 9C fatty acid 9-hydroxy-nonanoic acid. The possibility that the entire molecule is assembled as a single polyketide with a Baeyer-Villiger oxidation inserting an oxygen into the carbon backbone has been ruled out because C1 of monic acid and C9 of 9-hydroxy-nonanoic acid are both derived from C1 of acetate.
Monic acid biosynthesis
Biosynthesis of the 17C monic acid unit begins on MmpD (Figure 1). One of the AT domains from MmpC may transfer an activated acetyl group from acetyl-Coenzyme A (CoA) to the first ACP domain. The chain is extended by malonyl-CoA, followed by a SAM-dependent methylation at C12 (see Figure 2 for PA-A numbering) and reduction of the B-keto group to an alcohol. The dehydration (DH) domain in module 1 is predicted to be non-functional due to a mutation in the conserved active site region. Module 2 adds another two carbons by the malonyl-CoA extender unit, followed by ketoreduction (KR) and dehydration. Module three adds a malonyl-CoA extender unit, followed by SAM-dependent methylation at C8, ketoreduction, and dehydration. Module 4 extends the molecule with a malonyl-CoA unit followed by ketoreduction.
Assembly of monic acid is continued by the transfer of the 12C product of MmpD to MmpA. Two more rounds of extension with malonyl-CoA units are achieved by module 5 and 6. Module 5 also contains a KR domain.
Post-PKS tailoring
The keto group at C3 is replaced with a methyl group in a multi-step reaction (Figure 3). MupG begins by decarboxylating a malonyl-ACP. The alpha carbon of the resulting acetyl-ACP is linked to C3 of the polyketide chain by MupH. This intermediate is dehydrated and decarboxylated by MupJ and MupK, respectively.The formation of the pyran ring requires many enzyme-mediated steps (Figure 4). The double bond between C8 and C9 is proposed to migrate to between C8 and C16. Gene knockout experiments of mupO, mupU, mupV, and macpE have eliminated PA-A production. PA-B production is not removed by these knockouts, demonstrating that PA-B is not created by hydroxylating PA-A. A knockout of mupW eliminated the pyran ring, identifying MupW as being involved in ring formation. It is not known whether this occurs before or after the esterification of monic acid to 9-hydroxy-nonanoic acid.
The epoxide of PA-A at C10-11 is believed to be inserted after pyran formation by a cytochrome P450 such as MupO. A gene knockout of mupO abolished PA-A production but PA-B, which also contains the C10-C11 epoxide, remained. This indicates that MupO is either not involved or is not essential for this epoxidation step.
9-Hydroxy-nonanoic acid biosynthesis
The nine-carbon fatty acid 9-hydroxy-nonanoic acid (9-HN) is derived as a separate compound and later esterified to monic acid to form pseudomonic acid. 13C labeled acetate feeding has shown that C1-C6 are constructed with acetate in the canonical fashion of fatty acid synthesis. C7 shows only C1 labeling of acetate, while C8 and C9 show a reversed pattern of 13C labeled acetate. It is speculated that C7-C9 arises from a 3-hydroxypropionate starter unit, which is extended three times with malonyl-CoA and fully reduced to yield 9-HN. It has also been suggested that 9-HN is initiated by 3-hydroxy-3-methylglutaric acid (HMG). This latter theory was not supported by feeding of [3-14C] or [3,6-13C2]-HMG.It is proposed that MmpB to catalyzes the synthesis of 9-HN (Figure 5). MmpB contains a KS, KR, DH, 3 ACPs, and a thioesterase (TE) domain. It does not contain an enoyl reductase (ER) domain, which would be required for the complete reduction to the nine-carbon fatty acid. MupE is a single-domain protein that shows sequence similarity to known ER domains and may complete the reaction. It also remains possible that 9-hydroxy-nonanoic acid is derived partially or entirely from outside of the mupirocin cluster.
References
External links
"Mupirocin". Drug Information Portal. U.S. National Library of Medicine. |
Haloperidol | Haloperidol, sold under the brand name Haldol among others, is a typical antipsychotic medication. Haloperidol is used in the treatment of schizophrenia, tics in Tourette syndrome, mania in bipolar disorder, delirium, agitation, acute psychosis, and hallucinations from alcohol withdrawal. It may be used by mouth or injection into a muscle or a vein. Haloperidol typically works within 30 to 60 minutes. A long-acting formulation may be used as an injection every four weeks by people with schizophrenia or related illnesses, who either forget or refuse to take the medication by mouth.Haloperidol may result in a movement disorder known as tardive dyskinesia which may be permanent. Neuroleptic malignant syndrome and QT interval prolongation may occur. In older people with psychosis due to dementia it results in an increased risk of death. When taken during pregnancy it may result in problems in the infant. It should not be used by people with Parkinsons disease.Haloperidol was discovered in 1958 by Paul Janssen, prepared as part of a structure-activity relationship investigation into analogs of pethidine (meperidine). It is on the World Health Organizations List of Essential Medicines. It is the most commonly used typical antipsychotic. In 2017, it was the 296th most commonly prescribed medication in the United States, with more than one million prescriptions.
Medical uses
Haloperidol is used in the control of the symptoms of:
Acute psychosis, such as drug-induced psychosis caused by, amphetamines, ketamine, and phencyclidine, and psychosis associated with high fever or metabolic disease. Some evidence, however, has found haloperidol to worsen psychosis due to psilocybin.
Adjunctive treatment of alcohol and opioid withdrawal
Agitation and confusion associated with cerebral sclerosis
Alcohol-induced psychosis
Hallucinations in alcohol withdrawal
Hyperactive delirium (to control the agitation component of delirium)
Hyperactivity, aggression
Otherwise uncontrollable, severe behavioral disorders in children and adolescents
Schizophrenia
Therapeutic trial in personality disorders, such as borderline personality disorder
Treatment of intractable hiccups
Treatment of neurological disorders, such as tic disorders such as Tourette syndrome, and chorea
Treatment of severe nausea and emesis in postoperative and palliative care, especially for palliating adverse effects of radiation therapy and chemotherapy in oncology. Also used as a first line antiemetic for acute Cannabis Hyperemesis Syndrome.Haloperidol was considered indispensable for treating psychiatric emergency situations, although the newer atypical drugs have gained a greater role in a number of situations as outlined in a series of consensus reviews published between 2001 and 2005.In a 2013 comparison of 15 antipsychotics in schizophrenia, haloperidol demonstrated standard effectiveness. It was 13–16% more effective than ziprasidone, chlorpromazine, and asenapine, approximately as effective as quetiapine and aripiprazole, and 10% less effective than paliperidone. A 2013 systematic review compared haloperidol to placebo in schizophrenia:
Pregnancy and lactation
Data from animal experiments indicate haloperidol is not teratogenic, but is embryotoxic in high doses. In humans, no controlled studies exist. Reports in pregnant women revealed possible damage to the fetus, although most of the women were exposed to multiple drugs during pregnancy. In addition, reports indicate neonates exposed to antipsychotic drugs are at risk for extrapyramidal and/or withdrawal symptoms following delivery, such as agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, and feeding disorder. Following accepted general principles, haloperidol should be given during pregnancy only if the benefit to the mother clearly outweighs the potential fetal risk.Haloperidol is excreted in breast milk. A few studies have examined the impact of haloperidol exposure on breastfed infants and in most cases, there were no adverse effects on infant growth and development.
Other considerations
During long-term treatment of chronic psychiatric disorders, the daily dose should be reduced to the lowest level needed for maintenance of remission. Sometimes, it may be indicated to terminate haloperidol treatment gradually. In addition, during long-term use, routine monitoring including measurement of BMI, blood pressure, fasting blood sugar, and lipids, is recommended due to the risk of side effects.Other forms of therapy (psychotherapy, occupational therapy/ergotherapy, or social rehabilitation) should be instituted properly.
PET imaging studies have suggested low doses are preferable. Clinical response was associated with at least 65% occupancy of D2 receptors, while greater than 72% was likely to cause hyperprolactinaemia and over 78% associated with extrapyramidal side effects. Doses of haloperidol greater than 5 mg increased the risk of side effects without improving efficacy. Patients responded with doses under even 2 mg in first-episode psychosis. For maintenance treatment of schizophrenia, an international consensus conference recommended a reduction dosage by about 20% every 6 months until a minimal maintenance dose is established.
Depot forms are also available; these are injected deeply intramuscularly at regular intervals. The depot forms are not suitable for initial treatment, but are suitable for patients who have demonstrated inconsistency with oral dosages.The decanoate ester of haloperidol (haloperidol decanoate, trade names Haldol decanoate, Halomonth, Neoperidole) has a much longer duration of action, so is often used in people known to be noncompliant with oral medication. A dose is given by intramuscular injection once every two to four weeks. The IUPAC name of haloperidol decanoate is [4-(4-chlorophenyl)-1-[4-(4-fluorophenyl)-4-oxobutyl]piperidin-4-yl] decanoate.
Topical formulations of haloperidol should not be used as treatment for nausea because research does not indicate this therapy is more effective than alternatives.
Adverse effects
Sources for the following lists of adverse effects:As haloperidol is a high-potency typical antipsychotic, it tends to produce significant extrapyramidal side effects. According to a 2013 meta-analysis of the comparative efficacy and tolerability of 15 antipsychotic drugs it was the most prone of the 15 for causing extrapyramidal side effects.With more than 6 months of use 14 percent of users gain weight. Haloperidol may be neurotoxic.Common (>1% incidence)
Extrapyramidal side effects including:
Akathisia (motor restlessness)
Dystonia (continuous spasms and muscle contractions)
Muscle rigidity
Parkinsonism (characteristic symptoms such as rigidity)
Hypotension
Anticholinergic side effects such as: (These adverse effects are less common than with lower-potency typical antipsychotics, such as chlorpromazine and thioridazine.)
Blurred vision
Constipation
Dry mouth
Somnolence (which is not a particularly prominent side effect, as is supported by the results of the aforementioned meta-analysis.)Unknown frequency
Anemia
Headache
Increased respiratory rate
Orthostatic hypotension
Prolonged QT interval
Visual disturbancesRare (<1% incidence)
Contraindications
Pre-existing coma, acute stroke
Severe intoxication with alcohol or other central depressant drugs
Known allergy against haloperidol or other butyrophenones or other drug ingredients
Known heart disease, when combined will tend towards cardiac arrest
Special cautions
A multiple-year study suggested this drug and other neuroleptic antipsychotic drugs commonly given to people with Alzheimers with mild behavioral problems often make their condition worse and its withdrawal was even beneficial for some cognitive and functional measures.
Elderly patients with dementia-related psychosis: analysis of 17 trials showed the risk of death in this group of patients was 1.6 to 1.7 times that of placebo-treated patients. Most of the causes of death were either cardiovascular or infectious in nature. It is not clear to what extent this observation is attributed to antipsychotic drugs rather than the characteristics of the patients. The drug bears a boxed warning about this risk.
Impaired liver function, as haloperidol is metabolized and eliminated mainly by the liver
In patients with hyperthyroidism, the action of haloperidol is intensified and side effects are more likely.
IV injections: risk of hypotension or orthostatic collapse
Patients at special risk for the development of QT prolongation (hypokalemia, concomitant use of other drugs causing QT prolongation)
Patients with a history of leukopenia: a complete blood count should be monitored frequently during the first few months of therapy and discontinuation of the drug should be considered at the first sign of a clinically significant decline in white blood cells.
Pre-existing Parkinsons disease or dementia with Lewy bodies
Interactions
Amiodarone: Q-Tc interval prolongation (potentially dangerous change in heart rhythm).
Amphetamine and methylphenidate: counteracts increased action of norepinephrine and dopamine in patients with narcolepsy or ADD/ADHD
Epinephrine: action antagonized, paradoxical decrease in blood pressure may result
Guanethidine: antihypertensive action antagonized
Levodopa: decreased action of levodopa
Lithium: rare cases of the following symptoms have been noted: encephalopathy, early and late extrapyramidal side effects, other neurologic symptoms, and coma.
Methyldopa: increased risk of extrapyramidal side effects and other unwanted central effects
Other central depressants (alcohol, tranquilizers, narcotics): actions and side effects of these drugs (sedation, respiratory depression) are increased. In particular, the doses of concomitantly used opioids for chronic pain can be reduced by 50%.
Other drugs metabolized by the CYP3A4 enzyme system: inducers such as carbamazepine, phenobarbital, and rifampicin decrease plasma levels and inhibitors such as quinidine, buspirone, and fluoxetine increase plasma levels
Tricyclic antidepressants: metabolism and elimination of tricyclics significantly decreased, increased toxicity noted (anticholinergic and cardiovascular side effects, lowering of seizure threshold)
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.
Overdose
Symptoms
Symptoms are usually due to side effects. Most often encountered are:
Anticholinergic side effects (dry mouth, constipation, paralytic ileus, difficulties in urinating, decreased perspiration)
Coma in severe cases, accompanied by respiratory depression and massive hypotension, shock
Hypotension or hypertension
Rarely, serious ventricular arrhythmia (torsades de pointes), with or without prolonged QT-time
Sedation
Severe extrapyramidal side effects with muscle rigidity and tremors, akathisia, etc.
Treatment
Treatment is mostly symptomatic and involves intensive care with stabilization of vital functions. In early detected cases of oral overdose, induction of emesis, gastric lavage, and the use of activated charcoal can be tried. In the case of a severe overdose, antidotes such as bromocriptine or ropinirole may be used to treat the extrapyramidal effects caused by haloperidol, acting as dopamine receptor agonists. ECG and vital signs should be monitored especially for QT prolongation and severe arrhythmias should be treated with antiarrhythmic measures.
Prognosis
An overdose of haloperidol can be fatal, but in general the prognosis after overdose is good, provided the person has survived the initial phase.
Pharmacology
Haloperidol is a typical butyrophenone type antipsychotic that exhibits high affinity dopamine D2 receptor antagonism and slow receptor dissociation kinetics. It has effects similar to the phenothiazines. The drug binds preferentially to D2 and α1 receptors at low dose (ED50 = 0.13 and 0.42 mg/kg, respectively), and 5-HT2 receptors at a higher dose (ED50 = 2.6 mg/kg). Given that antagonism of D2 receptors is more beneficial on the positive symptoms of schizophrenia and antagonism of 5-HT2 receptors on the negative symptoms, this characteristic underlies haloperidols greater effect on delusions, hallucinations and other manifestations of psychosis. Haloperidols negligible affinity for histamine H1 receptors and muscarinic M1 acetylcholine receptors yields an antipsychotic with a lower incidence of sedation, weight gain, and orthostatic hypotension though having higher rates of treatment emergent extrapyramidal symptoms.
Haloperidol acts on these receptors: (Ki)
D1 (silent antagonist) – Unknown efficiency
D5 (silent antagonist) – Unknown efficiency
D2 (inverse agonist) – 0.7 nM
D3 (inverse agonist) – 0.2 nM
D4 (inverse agonist) – 5–9 nM
σ1 (irreversible inactivation by haloperidol metabolite HPP+) – 3 nM
σ2 (agonist): 54 nM
5HT1A receptor agonist – 1927 nM
5HT2A (silent antagonist) – 53 nM
5HT2C (silent antagonist) – 10,000 nM
5HT6 (silent antagonist) – 3666 nM
5HT7 (irreversible silent antagonist) – 377.2 nM
H1 (silent antagonist) – 1,800 nM
M1 (silent antagonist) – 10,000 nM
α1A (silent antagonist) – 12 nM
α2A (silent antagonist) – 1130 nM
α2B (silent antagonist) – 480 nM
α2C (silent antagonist) – 550 nM
NR1/NR2B subunit containing NMDA receptor (antagonist; ifenprodil site): IC50 – 2,000 nM
Pharmacokinetics
By mouth
The bioavailability of oral haloperidol ranges from 60 to 70%. However, there is a wide variance in reported mean Tmax and T1/2 in different studies, ranging from 1.7 to 6.1 hours and 14.5 to 36.7 hours respectively.
Intramuscular injections
The drug is well and rapidly absorbed with a high bioavailability when injected intramuscularly. The Tmax is 20 minutes in healthy individuals and 33.8 minutes in patients with schizophrenia. The mean T1/2 is 20.7 hours. The decanoate injectable formulation is for intramuscular administration only and is not intended to be used intravenously. The plasma concentrations of haloperidol decanoate reach a peak at about six days after the injection, falling thereafter, with an approximate half-life of three weeks.
Intravenous injections
The bioavailability is 100% in intravenous (IV) injection, and the very rapid onset of action is seen within seconds. The T1/2 is 14.1 to 26.2 hours. The apparent volume of distribution is between 9.5 and 21.7 L/kg. The duration of action is four to six hours.
Therapeutic concentrations
Plasma levels of five to 15 micrograms per liter are typically seen for therapeutic response (Ulrich S, et al. Clin Pharmacokinet. 1998). The determination of plasma levels is rarely used to calculate dose adjustments but can be useful to check compliance.
The concentration of haloperidol in brain tissue is about 20-fold higher compared to blood levels. It is slowly eliminated from brain tissue, which may explain the slow disappearance of side effects when the medication is stopped.
Distribution and metabolism
Haloperidol is heavily protein bound in human plasma, with a free fraction of only 7.5 to 11.6%. It is also extensively metabolized in the liver with only about 1% of the administered dose excreted unchanged in the urine. The greatest proportion of the hepatic clearance is by glucuronidation, followed by reduction and CYP-mediated oxidation, primarily by CYP3A4.
History
Haloperidol was discovered by Paul Janssen. It was developed in 1958 at the Belgian company Janssen Pharmaceutica and submitted to the first of clinical trials in Belgium later that year.Haloperidol was approved by the U.S. Food and Drug Administration (FDA) on 12 April 1967; it was later marketed in the U.S. and other countries under the brand name Haldol by McNeil Laboratories.
Society and culture
Cost
Haloperidol is relatively inexpensive, being up to 100 fold less expensive than newer antipsychotics.
Brand names
Haloperidol is the INN, BAN, USAN, AAN approved name.
It is sold under the tradenames Aloperidin, Bioperidolo, Brotopon, Dozic, Duraperidol (Germany), Einalon S, Eukystol, Haldol (common tradename in the US and UK), Halol, Halosten, Keselan, Linton, Peluces, Serenace and Sigaperidol.
Veterinary use
Haloperidol is also used on many different kinds of animals for nonselective tranquilization and diminishing behavioral arousal, in veterinary and other settings including captivity management.
References
External links
"Haloperidol". Drug Information Portal. U.S. National Library of Medicine. |
Vigabatrin | Vigabatrin, brand name Sabril, is a medication used to treat epilepsy. It became available as a generic medication in 2019.It works by inhibiting the breakdown of γ-aminobutyric acid (GABA). It is also known as γ-vinyl-GABA, and is a structural analogue of GABA, but does not bind to GABA receptors.
Medical uses
Epilepsy
In Canada, vigabatrin is approved for use as an adjunctive treatment (with other drugs) in treatment resistant epilepsy, complex partial seizures, secondary generalized seizures, and for monotherapy use in infantile spasms in West syndrome.As of 2003, vigabatrin is approved in Mexico for the treatment of epilepsy that is not satisfactorily controlled by conventional therapy (adjunctive or monotherapy) or in recently diagnosed patients who have not tried other agents (monotherapy).Vigabatrin is also indicated for monotherapy use in secondarily generalized tonic-clonic seizures, partial seizures, and in infantile spasms due to West syndrome.On August 21, 2009, Lundbeck announced that the U.S. Food and Drug Administration had granted two New Drug Application approvals for vigabatrin. The drug is indicated as monotherapy for pediatric patients one month to two years of age with infantile spasms for whom the potential benefits outweigh the potential risk of vision loss, and as adjunctive (add-on) therapy for adult patients with refractory complex partial seizures (CPS) who have inadequately responded to several alternative treatments and for whom the potential benefits outweigh the risk of vision loss.In 1994, Feucht and Brantner-Inthaler reported that vigabatrin reduced seizures by 50-100% in 85% of children with Lennox-Gastaut syndrome who had poor results with sodium valproate.
Others
Vigabatrin reduced cholecystokinin tetrapeptide-induced symptoms of panic disorder, in addition to elevated cortisol and ACTH levels, in healthy volunteers.Vigabatrin is also used to treat seizures in succinic semialdehyde dehydrogenase deficiency (SSADHD), which is an inborn GABA metabolism defect that causes intellectual disability, hypotonia, seizures, speech disturbance, and ataxia through the accumulation of γ-Hydroxybutyric acid (GHB). Vigabatrin helps lower GHB levels through GABA transaminase inhibition. However, this is in the brain only; it has no effect on peripheral GABA transaminase, so the GHB keeps building up and eventually reaches the brain.
Adverse effects
Central nervous system
Sleepiness (12.5%), headache (3.8%), dizziness (3.8%), nervousness (2.7%), depression (2.5%), memory disturbances (2.3%), diplopia (2.2%), aggression (2.0%), ataxia (1.9%), vertigo (1.9%), hyperactivity (1.8%), vision loss (1.6%) (See below), confusion (1.4%), insomnia (1.3%), impaired concentration (1.2%), personality issues (1.1%). Out of 299 children, 33 (11%) became hyperactive.Some patients develop psychosis during the course of vigabatrin therapy, which is more common in adults than in children. This can happen even in patients with no prior history of psychosis. Other rare CNS side effects include anxiety, emotional lability, irritability, tremor, abnormal gait, and speech disorder.
Gastrointestinal
Abdominal pain (1.6%), constipation (1.4%), vomiting (1.4%), and nausea (1.4%). Dyspepsia and increased appetite occurred in less than 1% of subjects in clinical trials.
Body as a whole
Fatigue (9.2%), weight gain (5.0%), asthenia (1.1%).
Teratogenicity
A teratology study conducted in rabbits found that a dose of 150 mg/kg/day caused cleft palate in 2% of pups and a dose of 200 mg/kg/day caused it in 9%. This may be due to a decrease in methionine levels, according to a study published in March 2001. In 2005, a study conducted at the University of Catania was published stating that rats whose mothers had consumed 250–1000 mg/kg/day had poorer performance in the water maze and open-field tasks, rats in the 750-mg group were underweight at birth and did not catch up to the control group, and rats in the 1000 mg group did not survive pregnancy.There is no controlled teratology data in humans to date.
Sensory
In 2003, vigabatrin was shown by Frisén and Malmgren to cause irreversible diffuse atrophy of the retinal nerve fiber layer in a retrospective study of 25 patients. This has the most effect on the outer area (as opposed to the macular, or central area) of the retina.
Visual field defects had been reported as early as 1997 by Tom Eke and others, in the UK. Some authors, including Comaish et al. believe that visual field loss and electrophysiological changes may be demonstrable in up to 50% of Vigabatrin users.
The retinal toxicity of vigabatrin can be attributed to a taurine depletion.Due to safety issues, the Vigabatrin REMS Program is required by the FDA to ensure informed decisions before initiating and to ensure appropriate use of this drug.
Interactions
A study published in 2002 found that vigabatrin causes a statistically significant increase in plasma clearance of carbamazepine.In 1984, Drs Rimmer and Richens at the University of Wales reported that administering vigabatrin with phenytoin lowered the serum phenytoin concentration in patients with treatment-resistant epilepsy. Five years later, the same two scientists reported a fall in concentration of phenytoin of 23% within five weeks in a paper describing their failed attempt at elucidating the mechanism behind this interaction.
Pharmacology
Vigabatrin is an irreversible mechanism-based inhibitor of gamma-aminobutyric acid aminotransferase (GABA-AT), the enzyme responsible for the catabolism of GABA. Inhibition of GABA-AT results in increased levels of GABA in the brain. Vigabatrin is a racemic compound, and its [S]-enantiomer is pharmacologically active.,
Pharmacokinetics
With most drugs, elimination half-life is a useful predictor of dosing schedules and the time needed to reach steady state concentrations. In the case of vigabatrin, however, it has been found that the half-life of biologic activity is far longer than the elimination half-life.For vigabatrin, there is no range of target concentrations because researchers found no difference between the serum concentration levels of responders and those of non-responders. Instead, the duration of action is believed to be more a function of the GABA-T resynthesis rate; levels of GABA-T do not usually return to their normal state until six days after stopping the medication.
History
Vigabatrin was developed in the 1980s with the specific goal of increasing GABA concentrations in the brain in order to stop an epileptic seizure. To do this, the drug was designed to irreversibly inhibit the GABA transaminase, which degrades the GABA substrate. Although the drug was approved for treatment in the United Kingdom in 1989, the authorized use of Vigabatrin by US Food and Drug Administration was delayed twice in the United States before 2009. It was delayed in 1983 because animal trials produced intramyelinic edema, however, the effects were not apparent in human trials so the drug design continued. In 1997, the trials were temporarily suspended because it was linked to peripheral visual field defects in humans.
Society and culture
Brand Names
Vigabatrin is sold as Sabril in Canada, Mexico,
and the United Kingdom. The brand name in Denmark is Sabrilex. Sabril was approved in the United States on August 21, 2009 and is marketed in the U.S. by Lundbeck Inc., which acquired Ovation Pharmaceuticals, the U.S. sponsor in March 2009.
Generic equivalents
On January 16, 2019, the Food and Drug Administration approved the first generic version of Sabril (vigabatrin) in the United States.
References
External links
"Vigabatrin". Drug Information Portal. U.S. National Library of Medicine. |
Fluvoxamine | Fluvoxamine, sold under the brand name Luvox among others, is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. It is primarily used to treat major depressive disorder and obsessive–compulsive disorder (OCD), but is also used to treat anxiety disorders such as panic disorder, social anxiety disorder, and post-traumatic stress disorder.Fluvoxamines side-effect profile is very similar to other SSRIs: constipation, gastrointestinal problems, headache, anxiety, irritation, sexual problems, dry mouth, sleep problems and a risk of suicide at the start of treatment by lifting the psychomotor inhibition, but these effects appear to be significantly weaker than with other SSRIs (except gastrointestinal side-effects). The tolerance profile is superior in some respects to other SSRIs, particularly with respect to cardiovascular complications, despite its age.It is on the World Health Organizations List of Essential Medicines.
Medical uses
In many countries (e.g., Australia, the UK, and Russia) it is commonly used for major depressive disorder. Fluvoxamine is also approved in the United States for OCD, and social anxiety disorder. In Japan it is also approved to treat OCD, social anxiety disorder and MDD. Fluvoxamine is indicated for children and adolescents with OCD. The drug works long-term, and retains its therapeutic efficacy for at least one year. It has also been found to possess some analgesic properties in line with other SSRIs and tricyclic antidepressants.There is tentative evidence that fluvoxamine is effective for social phobia in adults. Fluvoxamine is also effective for GAD, social anxiety disorder, panic disorder and separation anxiety disorder in children and adolescents. There is tentative evidence that fluvoxamine may help some people with negative symptoms of chronic schizophrenia.
Adverse effects
Gastrointestinal side effects are more common in those receiving fluvoxamine than with other SSRIs. Otherwise, fluvoxamines side-effect profile is very similar to other SSRIs.
Common (1–10% incidence) adverse effects
Uncommon (0.1–1% incidence) adverse effects
Rare (0.01–0.1% incidence) adverse effects
Unknown frequency adverse effects
Interactions
Fluvoxamine inhibits the following cytochrome P450 enzymes:
CYP1A2 (strongly) which metabolizes agomelatine, amitriptyline, caffeine, clomipramine, clozapine, duloxetine, haloperidol, imipramine, phenacetin, tacrine, tamoxifen, theophylline, olanzapine, etc.
CYP3A4 (moderately) which metabolizes alprazolam, aripiprazole, clozapine, haloperidol, quetiapine, pimozide, ziprasidone, etc.
CYP2D6 (weakly) which metabolizes aripiprazole, chlorpromazine, clozapine, codeine, fluoxetine, haloperidol, olanzapine, oxycodone, paroxetine, perphenazine, pethidine, risperidone, sertraline, thioridazine, zuclopenthixol, etc.
CYP2C9 (moderately) which metabolizes nonsteroidal anti-inflammatory drugs, phenytoin, sulfonylureas, etc.
CYP2C19 (strongly) which metabolizes clonazepam, diazepam, phenytoin, etc.
CYP2B6 (weakly) which metabolizes bupropion, cyclophosphamide, sertraline, tamoxifen, valproate, etc.By so doing, fluvoxamine can increase serum concentration of the substrates of these enzymes.The plasma levels of oxidatively metabolized benzodiazepines (e.g., triazolam, midazolam, alprazolam and diazepam) are likely to be increased when co-administered with fluvoxamine. However the clearance of benzodiazepines metabolized by glucuronidation (e.g., lorazepam, oxazepam, temazepam) is unlikely to be affected by fluvoxamine. It appears that benzodiazepines metabolized by nitro-reduction (clonazepam, nitrazepam) are unlikely to be affected by fluvoxamine. Using fluvoxamine and alprazolam together can increase alprazolam plasma concentrations. If alprazolam is coadministered with fluvoxamine, the initial alprazolam dose should be reduced to the lowest effective dose.Fluvoxamine and ramelteon coadministration is not indicated.Fluvoxamine has been observed to increase serum concentrations of mirtazapine, which is mainly metabolized by CYP1A2, CYP2D6, and CYP3A4, by three- to four-fold in humans. Caution and adjustment of dosage as necessary are warranted when combining fluvoxamine and mirtazapine.Fluvoxamine seriously affects the pharmacokinetics of tizanidine and increases the intensity and duration of its effects. Because of the potentially hazardous consequences, the concomitant use of tizanidine with fluvoxamine, or other potent inhibitors of CYP1A2, should be avoided.
Pharmacology
Fluvoxamine is a potent selective serotonin reuptake inhibitor with around 100-fold affinity for the serotonin transporter over the norepinephrine transporter. It has negligible affinity for the dopamine transporter or any other site, with the sole exception of the σ1 receptor. It behaves as a potent agonist at this receptor and has the highest affinity (36 nM) of any SSRI for doing so. This may contribute to its antidepressant and anxiolytic effects and may also afford it some efficacy in treating the cognitive symptoms of depression. Unlike some other SSRI, fluvoxamines metabolites are pharmacologically neutral.
History
Fluvoxamine was developed by Kali-Duphar, part of Solvay Pharmaceuticals, Belgium, now Abbott Laboratories, and introduced as Floxyfral in Switzerland in 1983. It was approved by the U.S. Food and Drug Administration (FDA) in 1994, and introduced as Luvox in the US. In India, it is available, among several other brands, as Uvox by Abbott. It was one of the first SSRI antidepressants to be launched, and is prescribed in many countries to patients with major depression. It was the first SSRI, a non-TCA drug, approved by the U.S. FDA specifically for the treatment of OCD. At the end of 1995, more than ten million patients worldwide had been treated with fluvoxamine. Fluvoxamine was the first SSRI to be registered for the treatment of obsessive compulsive disorder in children by the FDA in 1997. In Japan, fluvoxamine was the first SSRI to be approved for the treatment of depression in 1999 and was later in 2005 the first drug to be approved for the treatment of social anxiety disorder. Fluvoxamine was the first SSRI approved for clinical use in the United Kingdom.
Society and culture
Manufacturers include BayPharma, Synthon, and Teva, among others.
Research
COVID-19
There is tentative evidence fluvoxamine might be useful for reducing COVID-19 disease severity if given as an early treatment. In Canada, Ontarios COVID-19 Advisory had approved it for usage if other preferred treatments were unavailable.In May 2022, based on a review of available scientific evidence, the U.S. Food and Drug Administration (FDA) refused to issue an emergency use authorization covering the use of fluvoxamine to treat COVID-19, saying that, at the time, the data was not sufficient to conclude that fluvoxamine may be effective in treating non-hospitalized people with COVID-19 to prevent serious illness or hospitalization. The agency stated that study results suggest that further clinical trials may be warranted.
Environment
Fluvoxamine is a common finding in waters near human settlement. Christensen et al. 2007 finds it is "very toxic to aquatic organisms" by European Union standards.
References
External links
"Fluvoxamine". Drug Information Portal. U.S. National Library of Medicine. |
Pethidine | Pethidine, also known as meperidine and sold under the brand name Demerol among others, is a synthetic opioid pain medication of the phenylpiperidine class. Synthesized in 1938 as a potential anticholinergic agent by the German chemist Otto Eisleb, its analgesic properties were first recognized by Otto Schaumann while working for IG Farben, Germany. Pethidine is the prototype of a large family of analgesics including the pethidine 4-phenylpiperidines (piminodine, anileridine and others), the prodines (alphaprodine, MPPP, etc.), bemidones (ketobemidone, etc.) and others more distant, including diphenoxylate and analogues.Pethidine is indicated for the treatment of moderate to severe pain, and is delivered as a hydrochloride salt in tablets, as a syrup, or by intramuscular, subcutaneous, or intravenous injection. For much of the 20th century, pethidine was the opioid of choice for many physicians; in 1975, 60% of doctors prescribed it for acute pain and 22% for chronic severe pain.It was patented in 1937 and approved for medical use in 1943. Compared with morphine, pethidine was thought to be safer, carry a lower risk of addiction, and to be superior in treating the pain associated with biliary spasm or renal colic due to its putative anticholinergic effects. These were later discovered to be inaccurate assumptions, as it carries an equal risk of addiction, possesses no advantageous effects on biliary spasm or renal colic compared to other opioids, and due to its toxic metabolite, norpethidine, it is more toxic than other opioids—especially during long-term use. The norpethidine metabolite was found to have serotonergic effects, so pethidine could, unlike most opioids, contribute to serotonin syndrome.
Medical uses
Pethidine is the most widely used opioid in labour and delivery but has fallen out of favour in some countries such as the United States in favour of other opioids, due to its potential drug interactions (especially with serotonergics) and its neurotoxic metabolite, norpethidine. It is still commonly used in the United Kingdom and New Zealand, and was the preferred opioid in the United Kingdom for use during labour, but has been superseded somewhat by diamorphine and other strong semi-synthetic opioids (e.g. hydromorphone) to avoid serotonin interactions since the mid-2000s. Pethidine is the preferred painkiller for diverticulitis, because it decreases intestinal intraluminal pressure.Before 2003 it was on the World Health Organizations List of Essential Medicines, the most effective and safe medicines needed in a health system.
Adverse effects
The adverse effects of pethidine administration are primarily those of the opioids as a class: nausea, vomiting, dizziness, diaphoresis, urinary retention, and constipation. Due to moderate stimulant effects mediated by dopamine and norepinephrine, sedation is less likely compared to other opioids. Unlike other opioids, it does not cause miosis because of its anticholinergic properties. Overdose can cause muscle flaccidity, respiratory depression, obtundation, psychosis, cold and clammy skin, hypotension, and coma. A narcotic antagonist such as naloxone is indicated to reverse respiratory depression and other effects of pethidine. Serotonin syndrome has occurred in patients receiving concurrent antidepressant therapy with selective serotonin reuptake inhibitors (SSRIs) or monoamine oxidase inhibitors, or other medication types (see Interactions below). Convulsive seizures sometimes observed in patients receiving parenteral pethidine on a chronic basis have been attributed to accumulation in plasma of the metabolite norpethidine (normeperidine). Fatalities have occurred following either oral or intravenous pethidine overdose.
Interactions
Pethidine has serious interactions that can be dangerous with monoamine oxidase inhibitors (e.g., furazolidone, isocarboxazid, moclobemide, phenelzine, procarbazine, selegiline, tranylcypromine). Such patients may suffer agitation, delirium, headache, convulsions, and/or hyperthermia. Fatal interactions have been reported including the death of Libby Zion. Seizures may develop when tramadol is given intravenously following, or with, pethidine. It can interact as well with SSRIs and other antidepressants, antiparkinson agents, migraine therapy, stimulants and other agents causing serotonin syndrome. It is thought to be caused by an increase in cerebral serotonin concentrations. It is probable that pethidine can also interact with a number of other medications, including muscle relaxants, benzodiazepines, and ethanol.
Mechanism of action
Like morphine, pethidine exerts its analgesic effects by acting as an agonist at the μ-opioid receptor.Pethidine is often employed in the treatment of postanesthetic shivering. The pharmacologic mechanism of this antishivering effect is not fully understood, but it may involve the stimulation of κ-opioid receptors.Pethidine has structural similarities to atropine and other tropane alkaloids and may have some of their effects and side effects. In addition to these opioidergic and anticholinergic effects, it has local anesthetic activity related to its interactions with sodium ion channels.
Pethidines apparent in vitro efficacy as an antispasmodic agent is due to its local anesthetic effects. It does not have antispasmodic effects in vivo. Pethidine also has stimulant effects mediated by its inhibition of the dopamine transporter (DAT) and norepinephrine transporter (NET). Because of its DAT inhibitory action, pethidine will substitute for cocaine in animals trained to discriminate cocaine from saline.Several analogs of pethidine such as 4-fluoropethidine have been synthesized that are potent inhibitors of the reuptake of the monoamine neurotransmitters dopamine and norepinephrine via DAT and NET. It has also been associated with cases of serotonin syndrome, suggesting some interaction with serotonergic neurons, but the relationship has not been definitively demonstrated.It is more lipid-soluble than morphine, resulting in a faster onset of action. Its duration of clinical effect is 120–150 minutes, although it is typically administered at 4– to 6-hour intervals. Pethidine has been shown to be less effective than morphine, diamorphine, or hydromorphone at easing severe pain, or pain associated with movement or coughing.Like other opioid drugs, pethidine has the potential to cause physical dependence or addiction. It may be more likely to be abused than other prescription opioids, perhaps because of its rapid onset of action. A study which compared 75 mg pethidine administered via intravenous injection (IV) and 100 mg administered orally (PO) to 10 mg oxycodone (IV) and 10 mg (PO), 10 mg morphine (IV) and 20 mg (PO), 2 mg hydromorphone (IV) and 4 mg (PO), and placebo (C) in the subjects self-reported subjective effects such as drug-liking (how many of the subjects enjoyed or not, the experience; if yes, what was the most enjoyable part and why?, etc.) and how eagerly did subject want to re-experience it, and after IV doses were administered, pethidine 75 mg second-highest rates of drug-liking, after morphine 10 mg. Descriptive adjectives for morphine by subjects were: “more sedating”, “more relaxing” and in comparison to the others, many subjects described that the experience was “more intense”. Pethidine followed, then hydromorphone, oxycodone and last was placebo. Upon oral administration, preference went from (greatest>least): oxycodone 10 mg>morphine 20 mg>hydromorphone 4 mg>pethidine 100 mg>placebo. The especially severe side effects unique to pethidine among opioids—serotonin syndrome, seizures, delirium, dysphoria, tremor—are primarily or entirely due to the action of its metabolite, norpethidine.
Pharmacokinetics
Pethidine is quickly hydrolysed in the liver to pethidinic acid and is also demethylated to norpethidine, which has half the analgesic activity of pethidine but a longer elimination half-life (8–12 hours); accumulating with regular administration, or in kidney failure. Norpethidine is toxic and has convulsant and hallucinogenic effects. The toxic effects mediated by the metabolites cannot be countered with opioid receptor antagonists such as naloxone or naltrexone, and are probably primarily due to norpethidines anticholinergic activity probably due to its structural similarity to atropine, though its pharmacology has not been thoroughly explored. The neurotoxicity of pethidines metabolites is a unique feature of pethidine compared to other opioids. Pethidines metabolites are further conjugated with glucuronic acid and excreted into the urine.
Recreational use
Trends
In data from the U.S. Drug Abuse Warning Network, mentions of hazardous or harmful use of pethidine declined between 1997 and 2002, in contrast to increases for fentanyl, hydromorphone, morphine, and oxycodone. The number of dosage units of pethidine reported lost or stolen in the U.S. increased 16.2% between 2000 and 2003, from 32,447 to 37,687.This article uses the terms "hazardous use", "harmful use", and "dependence" in accordance with Lexicon of alcohol and drug terms, published by the World Health Organization (WHO) in 1994. In WHO usage, the first two terms replace the term "abuse" and the third term replaces the term "addiction".
Synthesis
Pethidine can be produced in a two-step synthesis. The first step is reaction of benzyl cyanide and chlormethine in the presence of sodium amide to form a piperidine ring. The nitrile is then converted to an ester.
Control
Pethidine is in Schedule II of the Controlled Substances Act 1970 of the United States as a Narcotic with ACSCN 9230 with a 6250 kilo aggregate manufacturing quota as of 2014. The free base conversion ratio for salts includes 0.87 for the hydrochloride and 0.84 for the hydrobromide. The A, B, and C intermediates in production of pethidine are also controlled, with ACSCN being 9232 for A (with a 6 gram quota) and 9233 being B (quota of 11 grams) and 9234 being C (6 gram quota). It is listed under the Single Convention for the Control of Narcotic Substances 1961 and is controlled in most countries in the same fashion as is morphine.
Society and culture
In Raymond Chandlers novel The Long Goodbye (1953), in response to "How is Mrs. Wade?", police Lieutenant Bernie Ohls answers, "Too relaxed. She must have grabbed some pills. Theres a dozen kinds up there -- even demerol. Thats bad stuff."
Harold Shipman once got addicted to pethidine.Danish writer Tove Ditlevsen suffered a lifelong addiction to pethidine since her husband, a dodgy doctor, had injected her a dose as a painkiller.Pethidine is referenced by its brand name Demerol in the song "Morphine" by singer Michael Jackson on his 1997 album Blood on the Dance Floor: HIStory in the Mix. Pethidine was one of several prescription drugs which Michael Jackson was addicted to at the time and the singer describes this in the lyrics of the song with phrases such as "Relax/This wont hurt you" and "Yesterday you had his trust/Today hes taking twice as much".Pethidine is referenced in the television show Broadchurch, season 2, episode 3, as it was given to the character Beth after she has her baby.
In the 1987 Malayalam movie, Amrutham Gamaya, Mohanlals character, Dr. P.K. Haridas injects pethidine in himself and gets addicted to it.
A doctor in the TV show Call the Midwife becomes addicted to pethidine.In William Gibsons book Neuromancer, one of the characters say "A mixture of cocaine and meperidine, yes." The Armenian went back to the conversation he was having with the Sanyo. "Demerol, they used to call that," said the Finn.South Carolina-based modern rock group Crossfade mentions Demerol in the lyrics of their 2004 song, "Dead Skin".
In the episode "The Fight" of the TV show Parks and Recreation, some characters become intoxicated on a mixed drink called Snake Juice. The character Ann (Rashida Jones), who is a nurse, asks, "What the hell is in Snake Juice? Demerol?"
In David Foster Wallaces book Infinite Jest, one of the main characters, Don Gately, is a Demerol addict in recovery.
See also
Libby Zion Law (a case involving phenelzine and pethidine)
== References == |
Flumazenil | Flumazenil (also known as flumazepil, code name Ro 15-1788) is a selective GABAA receptor antagonist administered via injection, otic insertion, or intranasally. Therapeutically, it acts as both an antagonist and antidote to benzodiazepines (particularly in cases of overdose), through competitive inhibition.
It was first characterized in 1981, and was first marketed in 1987 by Hoffmann-La Roche under the trade name Anexate. However, it did not receive FDA approval until December 20, 1991. The developer lost its exclusive patent rights in 2008; so at present, generic formulations of this drug are available. Intravenous flumazenil is primarily used to treat benzodiazepine overdoses and to help reverse anesthesia. Administration of flumazenil by sublingual lozenge and topical cream has also been tested.
Medical uses
Flumazenil benefits patients who become excessively drowsy after use of benzodiazepines for either diagnostic or therapeutic procedures.The drug has been used as an antidote in the treatment of benzodiazepine overdoses. It reverses the effects of benzodiazepines by competitive inhibition at the benzodiazepine (BZ) recognition site on the GABA/benzodiazepine receptor complex. There are many complications that must be taken into consideration when used in the acute care setting. These include lowered seizure threshold, agitation, and anxiousness. Flumazenils short half-life requires multiple doses. Because of the potential risks of withdrawal symptoms and the drugs short half-life, patients must be carefully monitorered to prevent recurrence of overdose symptoms or adverse side effects.
Flumazenil is also sometimes used after surgery to reverse the sedative effects of benzodiazepines. This is similar to naloxones application to reverse the effect of opiates and opioids following surgery. Administration of the drug requires careful monitoring by an anesthesiologist due to potential side effects and serious risks associated with over-administeration. Likewise, post-surgical monitoring is also necessary because flumazenil can mask the apparent metabolization ("wearing off") of the drug after removal of patient life-support and monitoring equipment.
Flumazenil has been effectively used to treat overdoses of non-benzodiazepine hypnotics, such as zolpidem, zaleplon and zopiclone (also known as "Z-drugs").It may also be effective in reducing excessive daytime sleepiness while improving vigilance in primary hypersomnias, such as idiopathic hypersomnia.The drug has also been used in hepatic encephalopathy. It may have beneficial short‐term effects in people with cirrhosis, but there is no evidence for long-term benefits.The onset of action is rapid, and effects are usually seen within one to two minutes. The peak effect is seen at six to ten minutes. The recommended dose for adults is 200 μg every 1–2 minutes until the effect is seen, up to a maximum of 3 mg per hour. It is available as a clear, colourless solution for intravenous injection, containing 500 μg in 5 mL.
Many benzodiazepines (including midazolam) have longer half-lives than flumazenil. Therefore, in cases of overdose, repeat doses of flumazenil may be required to prevent recurrent symptoms once the initial dose of flumazenil wears off.
It is hepatically metabolised to inactive compounds which are excreted in the urine. Individuals who are physically dependent on benzodiazepines may experience benzodiazepine withdrawal symptoms, including seizure, upon rapid administration of flumazenil.
It is not recommended for routine use in those with a decreased level of consciousness.In terms of drug enforcement initiatives, diversion control programs and required post-marketing surveillance of adverse events, orders for flumazenil may trigger a prescription audit to the search for benzodiazepine misuse and for clinically significant adverse reactions related to their use.
PET radioligand
Radiolabeled with the radioactive isotope carbon-11, flumazenil may be used as a radioligand in neuroimaging with positron emission tomography to visualize the distribution of GABAA receptors in the human brain.
Treatment for benzodiazepine dependence & tolerance
Epileptic patients who have become tolerant to the anti-seizure effects of the benzodiazepine clonazepam became seizure-free for several days after treatment with 1.5 mg of flumazenil. Similarly, patients who were dependent on high doses of benzodiazepines (median dosage 333 mg diazepam-equivalent) were able to be stabilised on a low dose of clonazepam after 7–8 days of treatment with flumazenil.Flumazenil has been tested against placebo in benzo-dependent subjects. Results showed that typical benzodiazepine withdrawal effects were reversed with few to no symptoms. Flumazenil was also shown to produce significantly fewer withdrawal symptoms than saline in a randomized, placebo-controlled study with benzodiazepine-dependent subjects. Additionally, relapse rates were much lower during subsequent follow-up.In vitro studies of tissue cultured cell lines have shown that chronic treatment with flumazenil enhanced the benzodiazepine binding site where such receptors have become more numerous and uncoupling/down-regulation of GABAA has been reversed. After long-term exposure to benzodiazepines, GABAA receptors become down-regulated and uncoupled. Growth of new receptors and recoupling after prolonged flumazenil exposure has also been observed. It is thought this may be due to increased synthesis of receptor proteins.Flumazenil was found to be more effective than placebo in reducing feelings of hostility and aggression in patients who had been free of benzodiazepines for 4–266 weeks. This may suggest a role for flumazenil in treating protracted benzodiazepine withdrawal symptoms.
Low-dose, slow subcutaneous flumazenil administration is a safe procedure for patients withdrawing from long-term, high-dose benzodiazepine dependency. It has a low risk of seizures even amongst those who have experienced convulsions when previously attempting benzodiazepine withdrawal.In Italy, the gold standard for treatment of high-dose benzodiazepine dependency is 8–10 days of low-dose, slowly infused flumazenil. One addiction treatment centre in Italy has used flumazenil to treat over 300 patients who were dependent on high doses of benzodiazepines (up to 70 times higher than conventionally prescribed) with physicians being among the clinics most common patients.
Clinical pharmacology
Flumazenil, an imidazobenzodiazepine derivative, antagonizes the actions of benzodiazepines on the central nervous system. Flumazenil competitively inhibits the activity at the benzodiazepine recognition site on the GABA/benzodiazepine receptor complex. It also exhibits weak partial agonism of GABAA receptor complexes that contain α6-type monomers; the clinical relevance of this is unknown.Flumazenil does not antagonize all of the central nervous system effects of drugs affecting GABA-ergic neurons by means other than the benzodiazepine receptor (including ethanol, barbiturates, and most anesthetics) and does not reverse the effects of opioids. It will however antagonize the action of non-benzodiazepine z-drugs, such as zolpidem and zopiclone, because they act via the benzodiazepine site of the GABA receptor - it has been used to successfully treat z-drug overdose.
Pharmacodynamics
Intravenous flumazenil has been shown to antagonize sedation, impairment of recall, psychomotor impairment and ventilatory depression produced by benzodiazepines in healthy human volunteers.
The duration and degree of reversal of sedative benzodiazepine effects are related to the dose and plasma concentrations of flumazenil.
Availability
Flumazenil is sold under a wide variety of brand names worldwide like Anexate, Lanexat, Mazicon, Romazicon. In India it is manufactured by Roche Bangladesh Pharmaceuticals and USAN Pharmaceuticals.
See also
Benzodiazepine overdose
Benzodiazepine
Bretazenil
Imidazenil
Ro15-4513
GABAA receptor negative allosteric modulators
References
Other
Romazicon product information, Roche USA
External links
Media related to Flumazenil at Wikimedia Commons
Flumazenil drug label/data at Daily Med from U.S. National Library of Medicine, National Institutes of Health. |
Clomipramine | Clomipramine, sold under the brand name Anafranil among others, is a tricyclic antidepressant (TCA). It is used for the treatment of obsessive–compulsive disorder, panic disorder, major depressive disorder, and chronic pain. It may increase the risk of suicide in those under the age of 25. It is taken by mouth. It has also been used to treat premature ejaculation.Common side effects include dry mouth, constipation, loss of appetite, sleepiness, weight gain, sexual dysfunction, and trouble urinating. Serious side effects include an increased risk of suicidal behavior in those under the age of 25, seizures, mania, and liver problems. If stopped suddenly a withdrawal syndrome may occur with headaches, sweating, and dizziness. It is unclear if it is safe for use in pregnancy. Its mechanism of action is not entirely clear but is believed to involve increased levels of serotonin.Clomipramine was discovered in 1964 by the Swiss drug manufacturer Ciba-Geigy. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication.
Medical uses
Clomipramine has a number of uses in medicine including in the treatment of:
Obsessive–compulsive disorder (OCD) which is its only U.S. FDA-labeled indication. Other regulatory agencies (such as the TGA of Australia and the MHRA of the UK) have also approved clomipramine for this indication.
Major depressive disorder (MDD) a popular off-label use in the US. It is approved by the Australian TGA and the United Kingdom MHRA for this indication. Some have suggested the possible superior efficacy of clomipramine compared to other antidepressants in the treatment of MDD, although at the current time the evidence is insufficient to adequately substantiate this claim.
Panic disorder with or without agoraphobia.
Body dysmorphic disorder
Cataplexy associated with narcolepsy. Which is a TGA and MHRA-labeled indication for clomipramine.
Premature ejaculation
Depersonalization disorder
Chronic pain with or without organic disease, particularly headache of the tension type.
Sleep paralysis, with or without narcolepsy
Enuresis (involuntary urinating in sleep) in children. The effect may not be sustained following treatment, and alarm therapy may be more effective in both the short-term and the long-term. Combining a tricyclic (such as clomipramine) with anticholinergic medication, may be more effective for treating enuresis than the tricyclic alone.
TrichotillomaniaIn a meta-analysis of various trials involving fluoxetine (Prozac), fluvoxamine (Luvox), and sertraline (Zoloft) to test their relative efficacies in treating OCD, clomipramine was found to be the most effective.
Contraindications
Contraindications include:
Known hypersensitivity to clomipramine, or any of the excipients or cross-sensitivity to tricyclic antidepressants of the dibenzazepine group
Recent myocardial infarction
Any degree of heart block or other cardiac arrhythmias
Mania
Severe liver disease
Narrow angle glaucoma
Urinary retention
It must not be given in combination or within 3 weeks before or after treatment with a monoamine oxidase inhibitor. (Moclobemide included, however clomipramine can be initiated sooner at 48 hours following discontinuation of moclobemide.)
Pregnancy and lactation
Clomipramine use during pregnancy is associated with congenital heart defects in the newborn. It is also associated with reversible withdrawal effects in the newborn. Clomipramine is also distributed in breast milk and hence nursing while taking clomipramine is advised against.
Side effects
Clomipramine has been associated with the following side effects:Very common (>10% frequency):
Common (1–10% frequency):
Uncommon (0.1–1% frequency):
Convulsions
Ataxia
Arrhythmias
Elevated blood pressure
Activation of psychotic symptomsVery rare (<0.01% frequency):
Conduction disorder (e.g. widening of QRS complex, prolonged QT interval, PR/PQ interval changes, bundle-branch block, torsade de pointes, particularly in patients with hypokalaemia)
Withdrawal
Withdrawal symptoms may occur during gradual or particularly abrupt withdrawal of tricyclic antidepressant drugs. Possible symptoms include: nausea, vomiting, abdominal pain, diarrhea, insomnia, headache, nervousness, anxiety, dizziness and worsening of psychiatric status. Differentiating between the return of the original psychiatric disorder and clomipramine withdrawal symptoms is important. Clomipramine withdrawal can be severe. Withdrawal symptoms can also occur in neonates when clomipramine is used during pregnancy. A major mechanism of withdrawal from tricyclic antidepressants is believed to be due to a rebound effect of excessive cholinergic activity due to neuroadaptations as a result of chronic inhibition of cholinergic receptors by tricyclic antidepressants. Restarting the antidepressant and slow tapering is the treatment of choice for tricyclic antidepressant withdrawal. Some withdrawal symptoms may respond to anticholinergics, such as atropine or benztropine mesylate.
Overdose
Clomipramine overdose usually presents with the following symptoms:
There is no specific antidote for overdose and all treatment is purely supportive and symptomatic. Treatment with activated charcoal may be used to limit absorption in cases of oral overdose. Anyone suspected of overdosing on clomipramine should be hospitalised and kept under close surveillance for at least 72 hours. Clomipramine has been reported as being less toxic in overdose than most other TCAs in one meta-analysis but this may well be due to the circumstances surrounding most overdoses as clomipramine is more frequently used to treat conditions for which the rate of suicide is not particularly high such as OCD. In another meta-analysis, however, clomipramine was associated with a significant degree of toxicity in overdose.
Interactions
Clomipramine may interact with a number of different medications, including the monoamine oxidase inhibitors which include isocarboxazid, moclobemide, phenelzine, selegiline and tranylcypromine, antiarrhythmic agents (due to the effects of TCAs like clomipramine on cardiac conduction. There is also a potential pharmacokinetic interaction with quinidine due to the fact that clomipramine is metabolised by CYP2D6 in vivo), diuretics (due to the potential for hypokalaemia (low blood potassium) to develop which increases the risk for QT interval prolongation and torsades de pointes), the selective serotonin reuptake inhibitors (SSRIs; due to both potential additive serotonergic effects leading to serotonin syndrome and the potential for a pharmacokinetic interaction with the SSRIs that inhibit CYP2D6 [e.g. fluoxetine and paroxetine]) and serotonergic agents such as triptans, other tricyclic antidepressants, tramadol, etc. (due to the potential for serotonin syndrome). Its use is also advised against in those concurrently on CYP2D6 inhibitors due to the potential for increased plasma levels of clomipramine and the resulting potential for CNS and cardiotoxicity.
Pharmacology
Pharmacodynamics
Clomipramine is a reuptake inhibitor of serotonin and norepinephrine, or a serotonin–norepinephrine reuptake inhibitor (SNRI); that is, it blocks the reuptake of these neurotransmitters back into neurons by preventing them from interacting with their transporters, thereby increasing their extracellular concentrations in the synaptic cleft and resulting in increased serotonergic and noradrenergic neurotransmission. In addition, clomipramine also has antiadrenergic, antihistamine, antiserotonergic, antidopaminergic, and anticholinergic activities. It is specifically an antagonist of the α1-adrenergic receptor, the histamine H1 receptor, the serotonin 5-HT2A, 5-HT2C, 5-HT3, 5-HT6, and 5-HT7 receptors, the dopamine D1, D2, and D3 receptors, and the muscarinic acetylcholine receptors (M1–M5). Like other TCAs, clomipramine weakly blocks voltage-dependent sodium channels as well.Although clomipramine shows around 100- to 200-fold preference in affinity for the serotonin transporter (SERT) over the norepinephrine transporter (NET), its major active metabolite, desmethylclomipramine (norclomipramine), binds to the NET with very high affinity (Ki = 0.32 nM) and with dramatically reduced affinity for the SERT (Ki = 31.6 nM). Moreover, desmethylclomipramine circulates at concentrations that are approximately twice those of clomipramine. In accordance, occupancy of both the SERT and the NET has been shown with clomipramine administration in positron emission tomography studies with humans and non-human primates. As such, clomipramine is in fact a fairly balanced SNRI rather than only a serotonin reuptake inhibitor (SRI).The antidepressant effects of clomipramine are thought to be due to reuptake inhibition of serotonin and norepinephrine, while serotonin reuptake inhibition only is thought to be responsible for the effectiveness of clomipramine in the treatment of OCD. Conversely, antagonism of the H1, α1-adrenergic, and muscarinic acetylcholine receptors is thought to contribute to its side effects. Blockade of the H1 receptor is specifically responsible for the antihistamine effects of clomipramine and side effects like sedation and somnolence (sleepiness). Antagonism of the α1-adrenergic receptor is thought to cause orthostatic hypotension and dizziness. Inhibition of muscarinic acetylcholine receptors is responsible for the anticholinergic side effects of clomipramine like dry mouth, constipation, urinary retention, blurred vision, and cognitive/memory impairment. In overdose, sodium channel blockade in the brain is believed to cause the coma and seizures associated with TCAs while blockade of sodium channels in the heart is considered to cause cardiac arrhythmias, cardiac arrest, and death. On the other hand, sodium channel blockade is also thought to contribute to the analgesic effects of TCAs, for instance in the treatment of neuropathic pain.The exceptionally strong serotonin reuptake inhibition of clomipramine likely precludes the possibility of its antagonism of serotonin receptors (which it binds to with more than 100-fold lower affinity than the SERT) resulting in a net decrease in signaling by these receptors. In accordance, while serotonin receptor antagonists like cyproheptadine and chlorpromazine are effective as antidotes against serotonin syndrome, clomipramine is nonetheless capable of inducing this syndrome. In fact, while all TCAs are SRIs and serotonin receptor antagonists to varying extents, the only TCAs that are associated with serotonin syndrome are clomipramine and to a lesser extent its dechlorinated analogue imipramine, which are the two most potent SRIs of the TCAs (and in relation to this have the highest ratios of serotonin reuptake inhibition to serotonin receptor antagonism). As such, whereas other TCAs can be combined with monoamine oxidase inhibitors (with caution due to the risk of hypertensive crisis from NET inhibition; sometimes done in treatment-resistant depressives), clomipramine cannot be due to the risk of serotonin syndrome and death. Unlike the case of its serotonin receptor antagonism, orthostatic hypotension is a common side effect of clomipramine, suggesting that its blockade of the α1-adrenergic receptor is strong enough to overcome the stimulatory effects on the α1-adrenergic receptor of its NET inhibition.
Serotonergic activity
Clomipramine is a very strong SRI. Its affinity for the SERT was reported in one study using human tissues to be 0.14 nM, which is considerably higher than that of other TCAs. For example, the TCAs with the next highest affinities for the SERT in the study were imipramine, amitriptyline, and dosulepin (dothiepin), with Ki values of 1.4 nM, 4.3 nM, and 8.3 nM, respectively. In addition, clomipramine has a terminal half-life that is around twice as long as that of amitriptyline and imipramine. In spite of these differences however, clomipramine is used clinically at the same usual dosages as other serotonergic TCAs (100–200 mg/day). It achieves typical circulating concentrations that are similar in range to those of other TCAs but with an upper limit that is around twice that of amitriptyline and imipramine. For these reasons, clomipramine is the most potent SRI among the TCAs and is far stronger as an SRI than other TCAs at typical clinical dosages. In addition, clomipramine is more potent as an SRI than any selective serotonin reuptake inhibitors (SSRIs), it is more potent than paroxetine, which is the strongest SSRI.A positron emission tomography study found that a single low dose of 10 mg clomipramine to healthy volunteers resulted in 81.1% occupancy of the SERT, which was comparable to the 84.9% SERT occupancy by 50 mg fluvoxamine. In the study, single doses of 5 to 50 mg clomipramine resulted in 67.2 to 94.0% SERT occupancy while single doses of 12.5 to 50 mg fluvoxamine resulted in 28.4 to 84.9% SERT occupancy. Chronic treatment with higher doses was able to achieve up to 100.0% SERT occupancy with clomipramine and up to 93.6% SERT occupancy with fluvoxamine. Other studies have found 83% SERT occupancy with 20 mg/day paroxetine and 77% SERT occupancy with 20 mg/day citalopram. These results indicate that very low doses of clomipramine are able to substantially occupy the SERT and that clomipramine achieves higher occupancy of the SERT than SSRIs at comparable doses. Moreover, clomipramine may be able to achieve more complete occupancy of the SERT at high doses, at least relative to fluvoxamine.If the ratios of the 80% SERT occupancy dosage and the approved clinical dosage range are calculated and compared for SSRIs, SNRIs, and clomipramine, it can be deduced that clomipramine is by far the strongest SRI used medically. The lowest approved dosage of clomipramine can be estimated to be roughly comparable in SERT occupancy to the maximum approved dosages of the strongest SSRIs and SNRIs. Because their mechanism of action was originally not known and dose-ranging studies were never conducted, first-generation antipsychotics were dramatically overdosed in patients. It has been suggested that the same may have been true for clomipramine and other TCAs.
Obsessive–compulsive disorder
Clomipramine was the first drug that was investigated for and found to be effective in the treatment of OCD. In addition, it was the first drug to be approved by the FDA in the United States for the treatment of OCD. The effectiveness of clomipramine in the treatment of OCD is far greater than that of other TCAs, which are comparatively weak SRIs; a meta-analysis found pre- versus post-treatment effect sizes of 1.55 for clomipramine relative to a range of 0.67 for imipramine and 0.11 for desipramine. In contrast to other TCAs, studies have found that clomipramine and SSRIs, which are more potent SRIs, have similar effectiveness in the treatment of OCD. However, multiple meta-analyses have found that clomipramine nonetheless retains a significant effectiveness advantage relative to SSRIs; in the same meta-analysis mentioned previously, the effect sizes of SSRIs in the treatment of OCD ranged from 0.81 for fluoxetine to 1.36 for sertraline (relative to 1.55 for clomipramine). However, the effectiveness advantage for clomipramine has not been apparent in head-to-head comparisons of clomipramine versus SSRIs for OCD. The differences in effectiveness findings could be due to differences in methodologies across non-head-to-head studies.Relatively high doses of SSRIs are needed for effectiveness in the treatment of OCD. Studies have found that high dosages of SSRIs above the normally recommended maximums are significantly more effective in OCD treatment than lower dosages (e.g., 250 to 400 mg/day sertraline versus 200 mg/day sertraline). In addition, the combination of clomipramine and SSRIs has also been found to be significantly more effective in alleviating OCD symptoms, and clomipramine is commonly used to augment SSRIs for this reason. Studies have found that intravenous clomipramine, which is associated with very high circulating concentrations of the drug and a much higher ratio of clomipramine to its metabolite desmethylclomipramine, is more effective than oral clomipramine in the treatment of OCD. There is a case report of complete remission from OCD for approximately one month following a massive overdose of fluoxetine, an SSRI with a uniquely long duration of action. Taken together, stronger serotonin reuptake inhibition has consistently been associated with greater alleviation of OCD symptoms, and since clomipramine, at the clinical dosages in which it is employed, is effectively the strongest SRI used medically (see table above), this may underlie its unique effectiveness in the treatment of OCD.
In addition to serotonin reuptake inhibition, clomipramine is also a mild but clinically significant antagonist of the dopamine D1, D2, and D3 receptors at high concentrations. Addition of antipsychotics, which are potent dopamine receptor antagonists, to SSRIs, has been found to significantly augment their effectiveness in the treatment of OCD. As such, besides strong serotonin reuptake inhibition, clomipramine at high doses might also block dopamine receptors to treat OCD symptoms, and this could additionally or alternatively be involved in its possible effectiveness advantage over SSRIs.Although clomipramine is probably more effective in the treatment of OCD compared to SSRIs, it is greatly inferior to them in terms of tolerability and safety due to its lack of selectivity for the SERT and promiscuous pharmacological activity. In addition, clomipramine has high toxicity in overdose and can potentially result in death, whereas death rarely, if ever, occurs with overdose of SSRIs. It is for these reasons that clomipramine, in spite of potentially superior effectiveness to SSRIs, is now rarely used as a first-line agent in the treatment of OCD, with SSRIs being used as first-line therapies instead and clomipramine generally being reserved for more severe cases and as a second-line agent.
Pharmacokinetics
The oral bioavailability of clomipramine is approximately 50%. Peak plasma concentrations occur around 2–6 hours (with an average of 4.7 hours) after taking clomipramine orally and are in the range of 56–154 ng/mL (178–489 nmol/L). Steady-state concentrations of clomipramine are around 134–532 ng/mL (426–1,690 nmol/L), with an average of 218 ng/mL (692 nmol/L), and are reached after 7 to 14 days of repeated dosing. Steady-state concentrations of the active metabolite, desmethylclomipramine, are around 230–550 ng/mL (730–1,750 nmol/L). The volume of distribution (Vd) of clomipramine is approximately 17 L/kg. It binds approximately 97–98% to plasma proteins, primarily to albumin. Clomipramine is metabolized in the liver mainly by CYP2D6. It has a terminal half-life of 32 hours, and its N-desmethyl metabolite, desmethylclomipramine, has a terminal half-life of approximately 69 hours. Clomipramine is mostly excreted in urine (60%) and feces (32%).
Chemistry
Clomipramine is a tricyclic compound, specifically a dibenzazepine, and possesses three rings fused together with a side chain attached in its chemical structure. Other dibenzazepine TCAs include imipramine, desipramine, and trimipramine. Clomipramine is a derivative of imipramine with a chlorine atom added to one of its rings and is also known as 3-chloroimipramine. It is a tertiary amine TCA, with its side chain-demethylated metabolite desmethylclomipramine being a secondary amine. Other tertiary amine TCAs include amitriptyline, imipramine, dosulepin (dothiepin), doxepin, and trimipramine. The chemical name of clomipramine is 3-(3-chloro-10,11-dihydro-5H-dibenzo[b,f]azepin-5-yl)-N,N-dimethylpropan-1-amine and its free base form has a chemical formula of C19H23ClN2 with a molecular weight of 314.857 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 303-49-1 and of the hydrochloride is 17321-77-6.
History
Clomipramine was developed by Geigy as a chlorinated derivative of Imipramine. It was first referenced in the literature in 1961 and was patented in 1963. The drug was first approved for medical use in Europe in the treatment of depression in 1970, and was the last of the major TCAs to be marketed. In fact, clomipramine was initially considered to be a "me-too drug" by the FDA, and in relation to this, was declined licensing for depression in the United States. As such, to this day, clomipramine remains the only TCA that is available in the United States that is not approved for the treatment of depression, in spite of the fact that it is a highly effective antidepressant. Clomipramine was eventually approved in the United States for the treatment of OCD in 1989 and became available in 1990. It was the first drug to be investigated and found effective in the treatment of OCD. The first reports of benefits in OCD were in 1967, and the first double-blind, placebo-controlled clinical trial of clomipramine for OCD was conducted in 1976, with more rigorous clinical studies that solidified its effectiveness conducted in the 1980s. It remained the "gold standard" for the treatment of OCD for many years until the introduction of the SSRIs, which have since largely superseded it due to greatly improved tolerability and safety (although notably not effectiveness). Clomipramine is the only TCA that has been shown to be effective in the treatment of OCD and that is approved by the FDA for the treatment of OCD; the other TCAs failed clinical trials for this indication, likely due to insufficient serotonergic activity.
Society and culture
Generic names
Clomipramine is the English and French generic name of the drug and its INN, BAN, and DCF, while clomipramine hydrochloride is its USAN, USP, BANM, and JAN. Clomipramina is its generic name in Spanish, Portuguese and Italian and its DCIT, while clomipramin is its generic name in German and clomipraminum is its generic name in Latin.
Brand names
Clomipramine is marketed throughout the world mainly under the brand names Anafranil and Clomicalm for use in humans and animals, respectively.
Veterinary uses
In the U.S., clomipramine is only licensed to treat separation anxiety in dogs for which it is sold under the brand name Clomicalm. It has proven effective in the treatment of obsessive–compulsive disorders in cats and dogs. In dogs, it has also demonstrated similar efficacy to fluoxetine in treating tail chasing. In dogs some evidence suggests its efficacy in treating noise phobia.Clomipramine has also demonstrated efficacy in treating urine spraying in cats. Various studies have been done on the effects of clomipramine on cats to reduce urine spraying/marking behavior. It has been shown to be able to reduce this behavior by up to 75% in a trial period of four weeks.
References
External links
"Clomipramine". Drug Information Portal. U.S. National Library of Medicine. |
Vismodegib | Vismodegib (trade name Erivedge ERR-i-vej) is a drug for the treatment of basal-cell carcinoma (BCC). The approval of vismodegib on January 30, 2012, represents the first Hedgehog signaling pathway targeting agent to gain U.S. Food and Drug Administration (FDA) approval. The drug is also undergoing clinical trials for metastatic colorectal cancer, small-cell lung cancer, advanced stomach cancer, pancreatic cancer, medulloblastoma and chondrosarcoma as of June 2011. The drug was developed by the biotechnology/pharmaceutical company Genentech.
Indication
Vismodegib is indicated for patients with basal-cell carcinoma (BCC) which has metastasized to other parts of the body, relapsed after surgery, or cannot be treated with surgery or radiation.
Mechanism of action
The substance acts as a cyclopamine-competitive antagonist of the smoothened receptor (SMO) which is part of the Hedgehog signaling pathway. SMO inhibition causes the transcription factors GLI1 and GLI2 to remain inactive, which prevents the expression of tumor mediating genes within the hedgehog pathway. This pathway is pathogenetically relevant in more than 90% of basal-cell carcinomas.
Side effects
In clinical trials, common side effects included gastrointestinal disorders (nausea, vomiting, diarrhoea, constipation), muscle spasms, fatigue, hair loss, and dysgeusia (distortion of the sense of taste). The effects were mostly mild to moderate.
Development
Vismodegib has undergone several promising phase I and phase II clinical trials for its use in treating medulloblastoma.
See also
Cyclopamine, a naturally occurring SMO antagonist
References
Further reading
Efficacy and Safety of Vismodegib
External links
"Vismodegib". Drug Information Portal. U.S. National Library of Medicine.
Food and Drug Administration (FDA) approved vismodegib |
Mitomycin C | Mitomycin C is a mitomycin that is used as a chemotherapeutic agent by virtue of its antitumour activity.
Medical uses
It is given intravenously to treat upper gastro-intestinal cancers (e.g. esophageal carcinoma), anal cancers, and breast cancers, as well as by bladder instillation for superficial bladder tumours.
Mitomycin C has also been used topically rather than intravenously in several areas. The first is cancers, particularly bladder cancers and intraperitoneal tumours. It is now well known that a single instillation of this agent within 6 hours of bladder tumor resection can prevent recurrence. The second is in eye surgery where mitomycin C 0.02% is applied topically to prevent scarring during glaucoma filtering surgery and to prevent haze after PRK or LASIK; mitomycin C has also been shown to reduce fibrosis in strabismus surgery. The third is in esophageal and tracheal stenosis where application of mitomycin C onto the mucosa immediately following dilatation will decrease re-stenosis by decreasing the production of fibroblasts and scar tissue.
In April 2020, mitomycin gel, sold under the brand name Jelmyto, was approved in the United States for the treatment of low-grade upper tract urothelial cancer (UTUC). Urothelial cancer is a cancer of the lining of the urinary system.Mitomycin is also used as a chemotherapeutic agent in glaucoma surgery.
Contraindications
Pregnant women should not take mitomycin gel because it may cause harm to a developing fetus or newborn baby.
Side effects
It causes delayed bone marrow toxicity and therefore it is usually administered at 6-weekly intervals. Prolonged use may result in permanent bone-marrow damage. It may also cause lung fibrosis and renal damage.
Anticancer treatments with chemotherapeutic agents often impair brain cell function leading to memory loss and cognitive dysfunction. In order to understand the basis of these impairments, mice were treated with mitomycin C, a chemotherapeutic agent, and cells of the prefrontal cortex were examined. This treatment resulted in an increase of the oxidative DNA damage 8-oxo-dG, a decrease in the enzyme OGG1 that ordinarily repairs such damage and epigenetic alterations. These alterations at the DNA level may explain, at least in part, the impairments of cognitive function after chemotherapy.Common side effects are ureteric obstruction (narrowing or blockage of the ureter that may lead to excess fluid in the kidney due to a backup of urine), flank pain (pain occurring on the side of the body), urinary tract infection, hematuria (blood in the urine), renal dysfunction (inability of the kidney to function in its designed capacity), fatigue, nausea, abdominal pain, dysuria (painful or difficult urination) and vomiting.
Pharmacology
Mitomycin C is a potent DNA crosslinker. A single crosslink per genome has shown to be effective in killing bacteria. This is accomplished by reductive activation of mitomycin to form a mitosene, which reacts successively via N-alkylation of two DNA bases. Both alkylations are sequence specific for a guanine nucleoside in the sequence 5-CpG-3.Mitomycin gel is an alkylating drug, meaning it inhibits the transcription of DNA into RNA, stopping protein synthesis and taking away the cancer cells ability to multiply.
History
Mitomycin was discovered in the 1950s by Japanese scientists in cultures of the microorganism Streptomyces caespitosus.It was approved based on the results of the OLYMPUS (NCT02793128) multicenter trial involving 71 subjects with low-grade UTUC. These subjects had never undergone treatment (treatment-naïve) or had recurrent low-grade non-invasive UTUC with at least one measurable papillary tumor (a tumor shaped like a small mushroom with its stem attached to the inner lining of an organ) located above the ureteropelvic junction. Subjects received mitomycin gel once a week (mitomycin gel 4 mg per mL instillations via ureteral catheter or nephrostomy tube) for six weeks and, if assessed as a complete response (complete disappearance of the papillary tumor), monthly for up to eleven additional months. Efficacy of mitomycin gel was evaluated using urine cytology (a test to look for abnormal cells in a subjectss urine), ureteroscopy (an examination of the upper urinary tract) and biopsy (if warranted) three months following the initiation of therapy.The primary endpoint was complete response at three months following initiation of therapy. A complete response was found in 41 of the 71 subjects (58%) following six treatments of mitomycin gel administered weekly. Durability of the effect of mitomycin gel in subjects with a complete response was also evaluated using urine cytology, ureteroscopy and biopsy (if warranted) every three months for a year following the initiation of therapy. Nineteen subjects (46%) who achieved a complete response continued to have a complete response at the twelve-month mark.The US Food and Drug Administration (FDA) granted the application for mitomycin gel priority review along with breakthrough therapy, fast track, and orphan drug designations. The FDA granted approval of Jelmyto to UroGen Pharma, Inc.
Research
Potential bis-alkylating heterocyclic quinones were synthetised in order to explore their antitumoral activities by bioreductive alkylation.In the bacterium Legionella pneumophila, mitomycin C induces competence, a condition necessary for the process of natural transformation that transfers DNA and promotes recombination between cells. Exposure of the fruitfly Drosophila melanogaster to mitomycin C increases recombination during meiosis, a key stage of the sexual cycle. It has been suggested that during sexual process in prokaryotes (transformation) and eukaryotes (meiosis) DNA cross-links and other damages introduced by mitomycin C may be removed by recombinational repair.
See also
Aziridine
References
External links
"Mitomycin". Drug Information Portal. U.S. National Library of Medicine.
Clinical trial number NCT02793128 for "The OLYMPUS Study - Optimized DeLivery of Mitomycin for Primary UTUC Study (Olympus)" at ClinicalTrials.gov |
Ertugliflozin | Ertugliflozin, sold under the brand name Steglatro, is a medication for the treatment of type 2 diabetes.The most common side effects include fungal infections of the vagina and other infections of the female reproductive system.Ertugliflozin is a sodium/glucose cotransporter 2 (SGLT2) inhibitor and is in the class of drugs known as gliflozins.In the United States, it was approved by the Food and Drug Administration for use as a monotherapy and as a fixed dose combination with either sitagliptin or with metformin. In the European Union, it was approved in March 2018, for use as a monotherapy or combination therapy. In September 2020, The New England Journal of Medicine reported that ertugliflozin was shown to be essentially non-inferior to placebo.A combination with metformin is marketed as Segluromet and a combination with sitagliptin is marketed as Steglujan.
Medical uses
Steglatro is indicated for the treatment of adults with insufficiently controlled type 2 diabetes as an adjunct to diet and exercise as monotherapy when metformin is considered inappropriate due to intolerance or contraindications or in addition to other medicinal products for the treatment of diabetes.
Contraindications
Under the US approval, ertugliflozin is contraindicated for patients with severe kidney failure, end-stage renal disease, and dialysis. The European Union approval does not list any contraindications apart from hypersensitivity to the drug, which is standard for all drug approvals.
Adverse effects
Adverse effects in studies that were significantly more common under ertugliflozin than under placebo included mycosis of the genitals in both men and women, vaginal itch, increased urination, thirst, hypoglycaemia (low blood sugar), and weight loss under the higher dosing scheme. A rare but life-threatening side effect of gliflozins is ketoacidosis; it occurred in three patients (0.1%) in ertugliflozin studies.To lessen the risk of developing ketoacidosis (a serious condition in which the body produces high levels of blood acids called ketones) after surgery, the FDA has approved changes to the prescribing information for SGLT2 inhibitor diabetes medicines to recommend they be stopped temporarily before scheduled surgery. Ertugliflozin should be stopped at least four days before scheduled surgery.Symptoms of ketoacidosis include nausea, vomiting, abdominal pain, tiredness, and trouble breathing.
Overdose
Up to sixfold clinical doses over two weeks, or 20-fold single doses, are tolerated by patients without any toxic effects.
Interactions
As with many diabetes drugs, combining ertugliflozin with insulin or insulin secretagogues (such as sulfonylureas) may result in an increased risk for low blood sugar. Combination with diuretics may result in a higher risk for dehydration and low blood pressure. No clinically relevant pharmacokinetic interactions have been found in studies.
Pharmacology
Mechanism of action
Pharmacokinetics
After oral intake, ertugliflozin is practically completely absorbed from the gut and undergoes no relevant first-pass effect. Highest blood plasma concentrations are reached after one hour. When in circulation, 93.6% of the substance are bound to plasma proteins. Ertugliflocin is metabolised mainly to glucuronides by the enzymes UGT1A9 and UGT2B7. Cytochrome P450 enzymes play only a minor role in its metabolism.The elimination half-life is estimated to be 17 hours. 40.9% are eliminated via the feces (33.8% in unchanged form and 7.1% as metabolites) and 50.2% via the urine (1.5% unchanged and 48.7% as metabolites). The high proportion of unchanged substance in the feces is probably due to hydrolysis of the metabolites back to the parent substance.
Society and culture
Legal status
Ertugliflozin, ertugliflozin/metformin, and ertugliflozin/sitagliptin were approved for medical use in the United States in December 2019, and in the European Union in March 2018.
References
External links
"Ertugliflozin". Drug Information Portal. U.S. National Library of Medicine. |
Trazodone | Trazodone, sold under many brand names, is an antidepressant medication. It is used to treat major depressive disorder, anxiety disorders, and difficulties with sleep. The medication is taken orally.Common side-effects include dry mouth, feeling faint, vomiting, and headache. More serious side effects may include suicide, mania, irregular heart rate, and pathologically prolonged erections. It is unclear if use during pregnancy or breastfeeding is safe. It is a phenylpiperazine compound of the serotonin antagonist and reuptake inhibitor (SARI) class. Trazodone also has sedating effects.Trazodone was approved for medical use in the United States in 1981. It is available as a generic medication. In 2020, it was the 21st most commonly prescribed medication in the United States, with more than 26 million prescriptions.
Medical uses
Depression
The primary use of trazodone is the treatment of unipolar major depression with or without anxiety. Data from open and double-blind trials suggest the antidepressant efficacy of trazodone is comparable to that of amitriptyline, doxepin, and mianserin. Also, trazodone showed anxiolytic properties, low cardiotoxicity, and relatively mild side effects.Because trazodone has minimal anticholinergic activity, it was especially welcomed as a treatment for geriatric patients with depression when it first became available. Three double-blind studies reported trazodone has antidepressant efficacy similar to that of other antidepressants in geriatric patients. However, a side effect of trazodone, orthostatic hypotension, which may cause dizziness and increase the risk of falling, can have devastating consequences for elderly patients; thus, this side effect, along with sedation, often makes trazodone less acceptable for this population, compared with newer compounds that share its lack of anticholinergic activity but not the rest of its side-effect profile. Still, trazodone is often helpful for geriatric patients with depression who have severe agitation and insomnia.Trazodone is usually used at a dosage of 150 to 300 mg/day for the treatment of depression. Lower doses have also been used to augment other antidepressants, or when initiating therapy. Higher doses up to 600 mg/day have been used in more severe cases of depression, for instance in hospitalized patients. Trazodone is usually administered multiple times per day, but once-daily administration may be similarly effective.
Anxiety disorders
Trazodone is often used in the treatment of anxiety disorders such as generalized anxiety disorder, panic disorder, post-traumatic stress disorder (PTSD), and obsessive–compulsive disorder (OCD). However, use of trazodone in anxiety disorders is off-label and evidence of its effectiveness for these indications is variable and limited. Benefits for OCD appear to be mild. Besides anxiety, trazodone has been used to treat sleep disturbances and nightmares in PTSD. Trazodone is often used as an alternative to benzodiazepines in the treatment of anxiety disorders.
Insomnia
Low-dose trazodone is used off-label in the treatment of insomnia and is considered to be effective and safe for this indication. It may also be used to treat antidepressant-related insomnia. Trazodone was the second-most prescribed agent for insomnia in the early 2000s, though most studies of trazodone for treatment of sleep disturbances have been in depressed individuals.Systematic reviews and meta-analyses published in the late 2010s, including a Cochrane review, found low-dose trazodone to be an effective medication for short-term treatment of insomnia both in depressed and non-depressed people. Trazodone slightly improves subjective sleep quality (SMD = –0.34 to –0.41) and reduces number of nighttime awakenings (MD = –0.31, SMD = –0.51). Conversely, it does not appear to affect sleep onset, total sleep time, time awake after sleep onset, or sleep efficiency. It appears to increase deep sleep, in contrast to certain other hypnotics. The quality of evidence of trazodone for short-term treatment of insomnia was rated as low to moderate. There is no evidence available at present to inform long-term use of trazodone in the treatment of insomnia.The benefits of trazodone for insomnia must be weighed against potential adverse effects such as morning grogginess, daytime sleepiness, cognitive and motor impairment, and postural hypotension, among others. Quality safety data on use of trazodone as a sleep aid are currently lacking.Trazodone is used at low doses in the range of 25 to 150 mg/day for insomnia. Higher doses of 200 to 600 mg/day have also been studied.The American Academy of Sleep Medicines 2017 clinical practice guidelines recommended against the use of trazodone in the treatment of insomnia due to inadequate evidence and due to harms potentially outweighing benefits.
Combination with other antidepressants
Trazodone is often used in combination with other antidepressants such as selective serotonin reuptake inhibitors in order to augment their antidepressant and anxiolytic effects and to reduce side effects such as sexual dysfunction, anxiety, and insomnia.
Available forms
Trazodone is provided as the hydrochloride salt and is available in the form of 50 mg, 100 mg, 150 mg, and 300 mg oral tablets.An extended-release oral tablet formulation at doses of 150 mg and 300 mg is also available.
Side effects
Because of its lack of anticholinergic side effects, trazodone is especially useful in situations in which antimuscarinic effects are particularly problematic (e.g., in patients with benign prostatic hyperplasia, closed-angle glaucoma, or severe constipation). Trazodones propensity to cause sedation is a dual-edged sword. For many patients, the relief from agitation, anxiety, and insomnia can be rapid; for other patients, including those individuals with considerable psychomotor retardation and feelings of low energy, therapeutic doses of trazodone may not be tolerable because of sedation. Trazodone elicits orthostatic hypotension in some people, probably as a consequence of α1-adrenergic receptor blockade. The unmasking of bipolar disorder may occur with trazodone and other antidepressants.Precautions for trazodone include known hypersensitivity to trazodone and under 18 years and combined with other antidepressant medications, it may increase the possibility of suicidal thoughts or actions.While trazodone is not a true member of the SSRI class of antidepressants, it does still share many properties of SSRIs, especially the possibility of discontinuation syndrome if the medication is stopped too quickly. Care must, therefore, be taken when coming off the medication, usually by a gradual process of tapering down the dose over a period of time.
Suicide
Antidepressants may increase the risk of suicidal thoughts and behaviors in children and young adults. Close monitoring for emergence of suicidal thoughts and behaviors is thus recommended.
Sedation
Since trazodone may impair the mental and/or physical abilities required for performance of potentially hazardous tasks, such as operating an automobile or machinery, the patient should be cautioned not to engage in such activities while impaired. Compared to the reversible MAOI antidepressant drug moclobemide, more impairment of vigilance occurs with trazodone. Trazodone has been found to impair driving ability.
Cardiac
Case reports have noted cardiac arrhythmias emerging in relation to trazodone treatment, both in patients with pre-existing mitral valve prolapse and in patients with negative personal and family histories of cardiac disease.QT prolongation has been reported with trazodone therapy. Arrhythmia identified include isolated PVCs, ventricular couplets, and in two patients short episodes (three to four beats) of ventricular tachycardia. Several post-marketing reports have been made of arrhythmia in trazodone-treated patients who have pre-existing cardiac disease and in some patients who did not have pre-existing cardiac disease. Until the results of prospective studies are available, patients with pre-existing cardiac disease should be closely monitored, particularly for cardiac arrhythmias. Trazodone is not recommended for use during the initial recovery phase of myocardial infarction. Concomitant administration of drugs that prolong the QT interval or that are inhibitors of CYP3A4 may increase the risk of cardiac arrhythmia.
Priapism
A relatively rare side effect associated with trazodone is priapism, likely due to its antagonism at α-adrenergic receptors. More than 200 cases have been reported, and the manufacturer estimated that the incidence of any abnormal erectile function is about one in 6,000 male patients treated with trazodone. The risk for this side effect appears to be greatest during the first month of treatment at low dosages (i.e. <150 mg/day). Early recognition of any abnormal erectile function is important, including prolonged or inappropriate erections, and should prompt discontinuation of trazodone treatment. Spontaneous orgasms have also been reported with trazodone in men.Clinical reports have described trazodone-associated psychosexual side effects in women as well, including increased libido, priapism of the clitoris, and spontaneous orgasms.
Others
Rare cases of liver toxicity have been observed, possibly due to the formation of reactive metabolites.Elevated prolactin concentrations have been observed in people taking trazodone. They appear to be increased by around 1.5- to 2-fold.Studies on trazodone and cognitive function are mixed, with some finding improvement, others finding no change, and some finding impairment.Trazodone does not seem to worsen periodic limb movements during sleep.Trazodone is associated with increased risk of falls in older adults. It has also been associated with increased risk of hip fractures in older adults.
Pregnancy and lactation
Sufficient data in humans are lacking. Use should be justified by the severity of the condition to be treated.
Overdose
There are reported cases of high doses of trazodone precipitating serotonin syndrome. There are also reports of patients taking multiple SSRIs with trazodone and precipitating serotonin syndrome.Trazodone appears to be relatively safer than TCAs, MAOIs, and a few of the other second-generation antidepressants in overdose situations, especially when it is the only agent taken. Fatalities are rare, and uneventful recoveries have been reported after ingestion of doses as high as 6,000–9,200 mg. In one report, 9 of 294 cases of overdose were fatal, and all nine patients had also taken other central nervous system (CNS) depressants. When trazodone overdoses occur, clinicians should carefully monitor for low blood pressure, a potentially serious toxic effect. In a report of a fatal trazodone overdose, torsades de pointes and complete atrioventricular block developed, along with subsequent multiple organ failure, with a trazodone plasma concentration of 25.4 mg/L on admission.
Interactions
Trazodone is metabolized by several liver enzymes, including CYP3A4, CYP2D6, and CYP1A2. Its active metabolite meta-chlorophenylpiperazine (mCPP) is known to be formed by CYP3A4 and metabolized by CYP2D6. Inhibition or induction of the aforementioned enzymes by various other substances may alter the metabolism of trazodone and/or mCPP, leading to increased and/or decreased blood concentrations. The enzymes in question are known to be inhibited and induced by many medications, herbs, and foods, and as such, trazodone may interact with these substances. Potent CYP3A4 inhibitors such as clarithromycin, erythromycin, fluvoxamine, grapefruit juice, ketoconazole, and ritonavir may lead to increased concentrations of trazodone and decreased concentrations of mCPP, while CYP3A4 inducers like carbamazepine, enzalutamide, phenytoin, phenobarbital, and St. Johns wort may result in decreased trazodone concentrations and increased mCPP concentrations. CYP2D6 inhibitors may result in increased concentrations of both trazodone and mCPP while CYP2D6 inducers may decrease their concentrations. Examples of potent CYP2D6 inhibitors include bupropion, cannabidiol, duloxetine, fluoxetine, paroxetine, quinidine, and ritonavir, while CYP2D6 inducers include dexamethasone, glutethimide, and haloperidol. CYP1A2 inhibitors may increase trazodone concentrations while CYP1A2 inducers may decrease trazodone concentrations. Examples of potent CYP1A2 inhibitors include ethinylestradiol (found in hormonal birth control), fluoroquinolones (e.g., ciprofloxacin), fluvoxamine, and St. Johns wort, while potent CYP1A2 inducers include phenytoin, rifampin, ritonavir, and tobacco.
A study found that ritonavir, a strong CYP3A4 and CYP2D6 inhibitor and moderate CYP1A2 inducer, increased trazodone peak levels by 1.34-fold, increased area-under-the-curve levels by 2.4-fold, and decreased the clearance of trazodone by 50%. This was associated with adverse effects such as nausea, hypotension, and syncope. Another study found that the strong CYP3A4 inducer carbamazepine reduced concentrations of trazodone by 60 to 74%. The strong CYP2D6 inhibitor thioridazine has been reported to increase concentrations of trazodone by 1.36-fold and concentrations of mCPP by 1.54-fold. On the other hand, CYP2D6 genotype has not been found to predict trazodone or mCPP concentrations with trazodone therapy, although it did correlate with side effects like dizziness and prolonged corrected QT interval.Combination of trazodone with selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), or monoamine oxidase inhibitors has a theoretical risk of serotonin syndrome. However, trazodone has been studied in combination with SSRIs and seemed to be safe in this context. On the other hand, cases of excessive sedation and serotonin syndrome have been reported with the combinations of trazodone and fluoxetine or paroxetine. This may be due to combined potentiation of the serotonin system. However, it may also be related to the fact that fluoxetine and paroxetine are strong inhibitors of CYP2D6 and fluoxetine is additionally a weak or moderate inhibitor of CYP3A4. Accordingly, fluoxetine has been reported to result in increased levels of trazodone and mCPP by 1.31- to 1.65-fold and by 2.97- to 3.39-fold, respectively.Smokers have lower levels of trazodone and higher ratios of mCPP to trazodone. Trazodone levels were 30% lower in smokers and mCPP to trazodone ratio was 1.29-fold higher in smokers, whereas mCPP concentrations were not different between smokers and non-smokers. Smoking is known to induce CYP1A2, and this may be involved in these findings.
Pharmacology
Pharmacodynamics
Trazodone is a mixed agonist and antagonist of various serotonin receptors, antagonist of adrenergic receptors, weak histamine H1 receptor antagonist, and weak serotonin reuptake inhibitor. More specifically, it is an antagonist of 5-HT2A and 5-HT2B receptors, a partial agonist of the 5-HT1A receptor, and an antagonist of the α1- and α2-adrenergic receptors. It is also a ligand of the 5-HT2C receptor with lower affinity than for the 5-HT2A receptor. However, it is unknown whether trazodone acts as a full agonist, partial agonist, or antagonist of the 5-HT2C receptor. Trazodone is a 5-HT1A receptor partial agonist similarly to buspirone and tandospirone but with comparatively greater intrinsic activity. A range of weak affinities (Ki) have been reported for trazodone at the human histamine H1 receptor, including 220 nM, 350 nM, 500 nM, and 1,100 nM.Trazodone has a minor active metabolite known as meta-chlorophenylpiperazine (mCPP), and this metabolite may contribute to some degree to the pharmacological properties of trazodone. In contrast to trazodone, mCPP is an agonist of various serotonin receptors. It has relatively low affinity for α1-adrenergic receptors unlike trazodone, but does high affinity for α2-adrenergic receptors and weak affinity for the H1 receptor. In addition to direct interactions with serotonin receptors, mCPP is a serotonin releasing agent similarly to agents like fenfluramine and MDMA. In contrast to these serotonin releasing agents however, mCPP does not appear to cause long-term serotonin depletion (a property thought to be related to serotonergic neurotoxicity).Trazodones 5-HT2A receptor antagonism and weak serotonin reuptake inhibition form the basis of its common label as an antidepressant of the serotonin antagonist and reuptake inhibitor (SARI) type.
Target occupancy studies
Studies have estimated occupancy of target sites by trazodone based on trazodone concentrations in blood and brain and on the affinities of trazodone for the human targets in question. Roughly half of brain 5-HT2A receptors are blocked by 1 mg of trazodone and essentially all 5-HT2A receptors are saturated at 10 mg of trazodone, but the clinically effective hypnotic doses of trazodone are in the 25–100 mg range. The occupancy of the serotonin transporter (SERT) by trazodone is estimated to be 86% at 100 mg/day and 90% at 150 mg/day. Trazodone may almost completely occupy the 5-HT2A and 5-HT2C receptors at doses of 100 to 150 mg/day. Significant occupancy of a number of other sites may also occur. However, another study estimated much lower occupancy of the SERT and 5-HT2A receptors by trazodone.
Correspondence to clinical effects
Trazodone may act predominantly as a 5-HT2A receptor antagonist to mediate its therapeutic benefits against anxiety and depression. Its inhibitory effects on serotonin reuptake and 5-HT2C receptors are comparatively weak. In relation to these properties, trazodone does not have similar properties to selective serotonin reuptake inhibitors (SSRIs) and is not particularly associated with increased appetite and weight gain—unlike other 5-HT2C antagonists like mirtazapine. Moderate 5-HT1A partial agonism may contribute to trazodones antidepressant and anxiolytic actions to some extent as well.The combined actions of 5-HT2A and 5HT2C receptor antagonism with serotonin reuptake inhibition only occur at moderate to high doses of trazodone. Doses of trazodone lower than those effective for antidepressant action are frequently used for the effective treatment of insomnia. Low doses exploit trazodones potent actions as a 5-HT2A receptor antagonist, and its properties as an antagonist of H1 and α1-adrenergic receptors, but do not adequately exploit its SERT or 5-HT2C inhibition properties, which are weaker. Since insomnia is one of the most frequent residual symptoms of depression after treatment with an SSRI, a hypnotic is often necessary for patients with a major depressive episode. Not only can a hypnotic potentially relieve the insomnia itself, but treating insomnia in patients with major depression may also increase remission rates due to improvement of other symptoms such as loss of energy and depressed mood. Thus, the ability of low doses of trazodone to improve sleep in depressed patients may be an important mechanism whereby trazodone can augment the efficacy of other antidepressants.Trazodones potent α1-adrenergic blockade may cause some side effects like orthostatic hypotension and sedation. Conversely, along with 5-HT2A and H1 receptor antagonism, it may contribute to its efficacy as a hypnotic. Trazodone lacks any affinity for the muscarinic acetylcholine receptors, so does not produce anticholinergic side effects.
mCPP, a non-selective serotonin receptor modulator and serotonin releasing agent, is an active metabolite of trazodone and has been suggested to possibly play a role in its therapeutic benefits. However, research has not supported this hypothesis and mCPP might actually antagonize the efficacy of trazodone as well as produce additional side effects.
Pharmacokinetics
Absorption
Trazodone is well-absorbed after oral administration. Its bioavailability is 65 to 80%. Peak blood levels of trazodone occur 1 to 2 hours after ingestion and peak levels of the metabolite mCPP occur after 2 to 4 hours. Absorption is somewhat delayed and enhanced by food.
Distribution
Trazodone is not sequestered into any tissue. The medication is 89 to 95% protein-bound. The volume of distribution of trazodone is 0.8 to 1.5 L/kg. Trazodone is highly lipophilic.
Metabolism
The metabolic pathways involved in the metabolism are not well-characterized. In any case, the cytochrome P450 enzymes CYP3A4, CYP2D6, and CYP1A2 may all be involved to varying extents. Trazodone is known to be extensively metabolized by the liver via hydroxylation, N-oxidation, and N-dealkylation. Several metabolites of trazodone have been identified, including a dihydrodiol metabolite (via hydroxylation), a metabolite hydroxylated at the para position of the meta-chlorophenyl ring (via CYP2D6), oxotriazolepyridinepropionic acid (TPA) and mCPP (both via N-dealkylation of the piperazinyl nitrogen mediated by CYP3A4), and a metabolite formed by N-oxidation of the piperazinyl nitrogen. CYP1A2, CYP2D6, and CYP3A4 genotypes all do not seem to predict concentrations of trazodone or mCPP. In any case, there are large interindividual variations in the metabolism of trazodone. In addition, poor metabolizers of dextromethorphan, a CYP2D6 substrate, eliminate mCPP more slowly and have higher concentrations of mCPP than do extensive metabolizers.mCPP is formed from trazodone by CYP3A4 and is metabolized via hydroxylation by CYP2D6 (to a para-hydroxylated metabolite). It may contribute to the pharmacological actions of trazodone. mCPP levels are only 10% of those of trazodone during therapy with trazodone, but is nonetheless present at concentrations known to produce psychic and physical effects in humans when mCPP has been administered alone. In any case, the actions of trazodone, such as its serotonin antagonism, might partially overwhelm those of mCPP. As a consequence of the production of mCPP as a metabolite, patients administered trazodone may test positive on EMIT II urine tests for the presence of MDMA ("ecstasy").
Elimination
The elimination of trazodone is biphasic: the first phases half-life (distribution) is 3 to 6 hours, and the following phases half-life (elimination) is 4.1 to 14.6 hours. The elimination half-life of extended-release trazodone is 9.1 to 13.2 hours. The elimination half-life of mCPP is 2.6 to 16.0 hours and is longer than that of trazodone. Metabolites are conjugated to gluconic acid or glutathione and around 70 to 75% of 14C-labelled trazodone was found to be excreted in the urine within 72 hours. The remaining drug and its metabolites are excreted in the faeces via biliary elimination. Less than 1% of the drug is excreted in its unchanged form. After an oral dose of trazodone, it was found to be excreted 20% in the urine as TPA and conjugates, 9% as the dihydrodiol metabolite, and less than 1% as unconjugated mCPP. mCPP is glucuronidated and sulfated similarly to other trazodone metabolites.
Chemistry
Trazodone is a triazolopyridine derivative and a phenylpiperazine that is structurally related to nefazodone and etoperidone, each of which are derivatives of it. Flibanserin is an analogue of trazodone.
History
Trazodone was developed in Italy, in the 1960s, by Angelini Research Laboratories as a second-generation antidepressant. It was developed according to the mental pain hypothesis, which was postulated from studying patients and which proposes that major depression is associated with a decreased pain threshold. In sharp contrast to most other antidepressants available at the time of its development, trazodone showed minimal effects on muscarinic cholinergic receptors. Trazodone was patented and marketed in many countries all over the world. It was approved by the Food and Drug Administration (FDA) in 1981 and was the first non-tricyclic or MAOI antidepressant approved in the US.
Society and culture
Generic names
Trazodone is the generic name of the drug and its INN, BAN, and DCF, while trazodone hydrochloride is its USAN, USP, BANM, and JAN.
Brand names
Trazodone has been marketed under a large number of brand names throughout the world. Major brand names include Desyrel (worldwide), Donaren (Brazil), Molipaxin (Ireland, United Kingdom), Oleptro (United States), Trazorel (Canada), and Trittico (worldwide).
Research
Trazodone may be effective in the treatment of sexual dysfunction, for instance female sexual dysfunction and erectile dysfunction. A 2003 systematic review and meta-analysis found some indication that trazodone may be useful in the treatment of erectile dysfunction. Besides trazodone alone, a combination of trazodone and bupropion (developmental code names and tentative brand names S1P-104, S1P-205, Lorexys, and Orexa) is under development for the treatment of erectile dysfunction and female sexual dysfunction. As of September 2021, it is in phase 2 clinical trials for these indications. It has been in this stage of clinical development since at least February 2015.Trazodone may be useful in the treatment of certain symptoms like sleep disturbances in alcohol withdrawal and recovery. However, reviews have recommended against use of trazodone for alcohol withdrawal due to inadequate evidence. Very limited evidence suggests that trazodone might be useful in the treatment of certain symptoms in cocaine use disorder. Trazodone has been reported to be effective in the treatment of sleep apnea. Cochrane reviews found that trazodone was not effective in the treatment of agitation in dementia. Another Cochrane review found that trazodone might be useful in the treatment of sleep disturbances in dementia. Further systematic reviews have found that trazodone may be effective for behavioral and psychological symptoms in dementias such as frontotemporal dementia and Alzheimers disease.Trazodone has been studied as an adjunctive therapy in the treatment of schizophrenia. It has been reported to decrease negative symptoms without worsening positive symptoms although improvement in negative symptoms was modest. Trazod |
Trazodone | one has also been reported to be effective in treating antipsychotic-related extrapyramidal symptoms such as akathisia. Trazodone has been studied and reported to be effective in the treatment of bulimia, but there is limited evidence to support this use. It might be useful in the treatment of night eating disorder as well. Trazodone might be effective in the treatment of adjustment disorder. It may also be effective in the treatment of bruxism in children and adolescents.Trazodone may be useful in the treatment of certain chronic pain disorders. There is limited but conflicting evidence to support the use of trazodone in the treatment of headaches and migraines in children. Trazodone may be useful in the treatment of fibromyalgia as well as diabetic neuropathy. It may also be useful in the treatment of burning mouth syndrome. A 2004 narrative review claimed that trazodone could be used in the treatment of complex regional pain syndrome. Trazodone may also be effective in the treatment of functional gastrointestinal disorders. It may be effective in the treatment of non-cardiac chest pain as well.Trazodone may be useful in promoting motor recovery after stroke.
Veterinary use
Trazodone has been used to reduce anxiety and stress, to improve sleep, and to produce sedation in dogs and cats in veterinary medicine.
References
External links
"Trazodone". Drug Information Portal. U.S. National Library of Medicine.
"Trazodone hydrochloride". Drug Information Portal. U.S. National Library of Medicine. |
Abacavir/dolutegravir/lamivudine | Abacavir/dolutegravir/lamivudine, sold under the brand name Triumeq among others, is a fixed-dose combination antiretroviral medication for the treatment of HIV/AIDS. It is a combination of three medications with different and complementary mechanisms of action: abacavir (reverse transcriptase inhibitor), dolutegravir (integrase inhibitor) and lamivudine (nucleoside analog reverse transcriptase inhibitor).The medication was developed by ViiV Healthcare and was approved for use in the United States and in the European Union in 2014.Abacavir is a nucleotide reverse transcriptase inhibitor. Specifically, abacavir is a guanosine analogue that interferes with HIV viral RNA-dependent DNA polymerase, ultimately resulting in inhibition of replication of HIV. Dolutegravir inhibits the HIV replication cycle by binding to the integrase active site and inhibiting the strand transfer step of HIV-1 DNA integration. Lamivudine is a cytosine analogue that inhibits HIV reverse transcription by terminating the viral DNA chain.
Medical uses
Abacavir/dolutegravir/lamivudine is indicated for the treatment of HIV/AIDS in adults and adolescents aged 12 years of age and older who weigh at least 40 kilograms (88 lb).
Adverse effects
The following adverse reactions were reported in <2% of patients:
Central nervous system: drowsiness, lethargy, nightmares, sleep disorders, suicidal ideation
Dermatologic: pruritus
Endocrine and metabolic: high levels of triglycerides
Gastrointestinal: abdominal distention, abdominal distress, abdominal pain, lack of appetite, stomach upset, flatulence, gastroesophageal reflux disease, upper abdominal pain, vomiting
Hepatic: hepatitis
Neuromuscular and skeletal: joint pain, muscle inflammation
Kidney: chronic kidney disease
Miscellaneous: feverSee individual agents as well as other combination products for additional information.
Pregnancy
Abacavir/dolutegravir/lamivudine should only be used in pregnancy if the potential benefits outweigh the risks.
Breastfeeding
The US Centers for Disease Control and Prevention (CDC) recommends that HIV-infected mothers do not breastfeed their infants to avoid risking postnatal transmission of HIV. This recommendation is coupled with the potential for serious adverse reactions in nursing infants. Dolutegravir and abacavir were shown to be excreted in the milk of lactating rats. Lamivudine was shown to be excreted in human breast milk.
History
Approval
The patent was filed on April 28, 2006, and expires on October 5, 2027. It was approved for use in the United States and in the European Union in 2014.
Major label changes
In August 2015, the Food and Drug Administration (FDA) sent a bulletin regarding label updates for dolutegravir and Triumeq regarding drug-drug information.Drug interactions was updated to include a statement that in vitro, dolutegravir was not a substrate of OATP1B1 or OATP1B3. Furthermore, information regarding drug interactions with carbamazepine and metformin.Additionally, less common adverse reactions observed in clinical trials was updated to include suicidal ideation, attempt, behavior, or completion in order to be consistent with dolutegravir label.In September 2015, the FDA added a boxed warning of hypersensitivity reactions, lactic acidosis, and severe hepatomegaly in abacavir-containing products regarding HLA-B*507 allele.Boxed warning (9/2015)
Hypersensitivity reactions
Lactic acidosis and severe hepatomegaly with steatosis
Exacerbations of hepatitis BDosage and administration
Dosage recommendation with certain concomitant medications (8/2015)
Not recommended due to lack of dosage adjustment (9/2015)Contraindications (9/2015)
Warnings and precautions, hypersensitivity reactions (9/2015)
Society and culture
Economics
A year supply of abacavir/dolutegravir/lamivudine costs around US$33,000 as it is under patent and not available as a generic.In July 2015, ViiV Healthcare struck a deal with Shanghai-based Desano Pharmaceuticals for a cheaper supply of dolutegravir (Tivicay) with the goal of cutting the cost in China and other developing countries. After approval of dolutegravir (Tivicay) in 2014, it came with a retail cost of $14,000 per year in the United States.
Research
Clinical trials
Efficacy of abacavir/dolutegravir/lamivudine was demonstrated in antiretroviral treatment-naive participants by SINGLE (ING114467), the randomized, controlled trial and other trials in treatment-naive subjects (see dolutegravir).In the SINGLE trial, 414 participants received dolutegravir + abacavir/lamivudine once daily and 419 participants received efavirenz/emtricitabine/tenofovir once daily. dolutegravir + abacavir/lamivudine compared to efavirenz/emtricitabine/tenofovir showed a reduction in viral load of HIV-1 RNA <50 copies/mL in 80% of participants compared to 72% of participants, respectively. Furthermore, in participants with baseline plasma viral load of <100,000 and >100,000 copies/mL, dolutegravir + abacavir/lamivudine compared to efavirenz/emtricitabine/tenofovir showed a reduction to <50 copies/mL in 85% and 71% compared to 73% and 72%, respectively.
Post-marketing experience
In addition to the adverse reactions reported in clinical trials, the following adverse reactions have been reported voluntarily from a population of unknown size. As such, it is not always possible to estimate frequency or establish a causal relationship to drug exposure.Abacavir and/or Lamivudine
Digestive System: stomatitis
Gastrointentional: pancreatitis
General: weakness
Blood and Lymphatic Systems: aplastic anemia, anemia, enlarged lymph nodes, enlarged spleen
Hypersensitivity: sensitization reactions (including anaphylaxis), urticaria
Metabolism and Nutrition Disorders: hyperprolactinemia
Musculoskeletal System: muscle weakness, CPK elevation, rhabdomyolysis
Nervous System: paresthesia, peripheral neuropathy, seizures
Respiratory System: abnormal breath sounds/wheezing
Skin: hair loss, erythema multiforme. Suspected Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) have been reported in participants receiving abacavir primarily in combination with medications that are known to be associated with SJS and TEN, respectively.
Amyotrophic lateral sclerosis
The safety and tolerability of Triumeq was evaluated for amyotrophic lateral sclerosis (ALS) patients as part of the Lighthouse trial, an open-label, phase 2a study, conducted in Australia beginning in late 2016 over 24 weeks. The study premise was human endogenous retroviruses, specifically human endogenous retrovirus K (HERV-K) may be a trigger or cause of ALS. Research has linked HERV-K to ALS based on increased nonspecific reverse transcriptase activity in the cerebrospinal fluid and blood of ALS patients, as well as HERV-K being found in the motor neurons of ALS patients. Triumeq was chosen as all three component drugs have good penetration of the central nervous system, particularly dolutegravir, which has high clearance rates for CNS HIV. The study found a significant decrease in HERV-K DNA in serum among study participants and showed a decrease in the slope of clinical progression based on the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) of roughly 30%. The trial has since progressed to Phase 3.
References
External links
"Abacavir mixture with dolutegravir and lamivudine". Drug Information Portal. U.S. National Library of Medicine. |
Amoxicillin/clavulanic acid | Amoxicillin/clavulanic acid, also known as co-amoxiclav or amox-clav, sold under the brand name Augmentin, among others, is an antibiotic medication used for the treatment of a number of bacterial infections. It is a combination consisting of amoxicillin, a β-lactam antibiotic, and potassium clavulanate, a β-lactamase inhibitor. It is specifically used for otitis media, streptococcal pharyngitis, pneumonia, cellulitis, urinary tract infections, and animal bites. It is taken by mouth or by injection into a vein.Common side effects include diarrhea, vomiting, and allergic reactions. It also increases the risk of yeast infections, headaches, and blood clotting problems. It is not recommended in people with a history of a penicillin allergy. It is relatively safe for use during pregnancy.Amoxicillin/clavulanic acid was approved for medical use in the United States in 1984. It is on the World Health Organizations List of Essential Medicines. The World Health Organization classifies amoxicillin/clavulanic-acid as critically important for human medicine. It is available as a generic medication. In 2019, it was the 93rd most commonly prescribed medication in the United States, with more than 8 million prescriptions.
Medical uses
Amoxicillin/clavulanic acid is widely used to treat or prevent many infections caused by susceptible bacteria, such as:
urinary tract infections
respiratory tract infections
skin and soft tissue infections
sinus infections
tonsillitis
cat scratches
infections caused by the bacterial flora of the mouth, such as:
dental infections
infected animal bites
infected human bites (including uncomplicated "clenched-fist" or "reverse-bite" injuries)It is also used for tuberculosis that is resistant to other treatments. The World health organisation recommends giving amoxicillin-clavulanate along with meropenem as one of the therapeutic options in drug resistant tuberculosis, where clavulanate and not amoxicillin is being relied upon for anti TB activity. However, across the spectrum of dosage of amoxicillin-clavulanate combination, the dose of clavulanate is constant at 125 mg, whereas the dose of amoxicillin varies at 250 mg, 500 mg and 875 mg. Thus the use of low dose amoxicillin-clavulanate in combination with meropenem may be used in part of treatment regime for drug resistant TB and this has been demonstrated in a clinical setting also.This combination results in an antibiotic with an increased spectrum of action and restored efficacy against amoxicillin-resistant bacteria that produce β-lactamase.
Adverse effects
Possible side effects include diarrhea, vomiting, nausea, thrush, and skin rash. These do not usually require medical attention. As with all antimicrobial agents, antibiotic-associated diarrhea due to Clostridium difficile infection—sometimes leading to pseudomembranous colitis—may occur during or after treatment with amoxicillin/clavulanic acid.Rarely, cholestatic jaundice (also referred to as cholestatic hepatitis, a form of liver toxicity) has been associated with amoxicillin/clavulanic acid. The reaction may occur up to several weeks after treatment has stopped, and usually takes weeks to resolve. It is more frequent in men, older people, and those who have taken long courses of treatment; the estimated overall incidence is one in 100,000 exposures. In the United Kingdom, co-amoxiclav carries a warning from the Committee on Safety of Medicines to this effect.As all aminopenicillins, amoxicillin has been associated with Stevens–Johnson syndrome/toxic epidermal necrolysis, although these reactions are very rare.
History
British scientists working at Beecham (now part of GlaxoSmithKline), filed for patent protection for the drug combination in 1977, which was granted in 1982.
It was sold under the brand name Augmentin.
Preparations
Amoxicillin/clavulanic acid is the International Nonproprietary Name (INN) and co-amoxiclav is the British Approved Name (BAN).Many branded products indicate their strengths as the quantity of amoxicillin. Augmentin 250, for example, contains 250 mg of amoxicillin and 125 mg of clavulanic acid.An intravenous preparation has been available in the UK since 1985, but no parenteral preparation is available in the US; the nearest equivalent is ampicillin/sulbactam.Suspensions of amoxicillin/clavulanic acid are available for use in children. They must be refrigerated to maintain effectiveness.
Veterinary use
Amoxicillin/clavulanic acid is used in numerous animals for a variety of conditions:
Dogs: periodontitis, kennel cough
Cats: urinary tract infections, skin and soft tissue infections
Calves: enteritis, navel ill
Cattle: respiratory tract infections, soft tissue infections, metritis, mastitis
Pigs: respiratory tract infections, colibacillosis, mastitis, metritis, agalactiaIn combination with prednisolone, it is used for intramammary infusion for the treatment of mastitis in lactating cows. Trade names include Clavaseptin, Clavamox, and Synulox.Amoxicillin/clavulanic acid is banned from use in domestic-food animals (cattle, swine, etc.) in both the US and Europe; in the UK, Synulox can be used in domestic-food animals as long as a specified withdrawal period is observed.
Bacterial resistance
Bacterial antibiotic resistance is a growing problem in veterinary medicine. Amoxicillin/clavulanic acid is reported to be effective against clinical Klebsiella infections, but is not efficacious against Pseudomonas infections.
References
External links
"Amoxicillin / clavulanic acid". Drug Information Portal. U.S. National Library of Medicine. |
Alpha-galactosidase | α-Galactosidase ( EC 3.2.1.22, α-GAL, α-GAL A; systematic name α-D-galactoside galactohydrolase) is a glycoside hydrolase enzyme that catalyses the following reaction:
Hydrolysis of terminal, non-reducing α-D-galactose residues in α-D-galactosides, including galactose oligosaccharides, galactomannans and galactolipidsIt catalyzes many catabolic processes, including cleavage of glycoproteins, glycolipids, and polysaccharides.
The enzyme is encoded by the GLA gene. Two recombinant forms of human α-galactosidase are called agalsidase α (INN) and agalsidase β (INN). A mold-derived form is the primary ingredient in gas relief supplements.
Function
This enzyme is a homodimeric glycoprotein that hydrolyses the terminal α-galactosyl moieties from glycolipids and glycoproteins. It predominantly hydrolyzes ceramide trihexoside, and it can catalyze the hydrolysis of melibiose into galactose and glucose.
Reaction mechanism
Disease relevance
Fabry disease
Signs and Symptoms
Defects in human α-GAL result in Fabry disease, a rare lysosomal storage disorder and sphingolipidosis that results from a failure to catabolize α-D-galactosyl glycolipid moieties. Characteristic features include episodes of pain in hands and feet (acroparesthesia), dark red spots on skin (angiokeratoma), decreased sweating (hypohidrosis), decreased vision (corneal opacity), gastrointestinal problems, hearing loss, tinnitus, etc.. Complications for this disease can be life-threatening and may include progressive kidney damage, heart attack, and stroke. This disease may have late onset and only affect the heart or kidneys.Fabry disease is an X-linked disease, affecting 1 in 40,000 males. However, unlike other X-linked diseases, this condition also creates significant medical problems for females carrying only 1 copy of the defective GLA gene. These women may experience many classic symptoms of the disorder including cardiac and kidney problems. However, a small number of females carrying only one copy of the mutated GLA gene never shows any symptoms of Fabry disease.
Cause
Mutations to the GLA gene encoding α-GAL may result in complete loss of function of the enzyme. α-GAL is a lysosomal protein responsible for breaking down globotriaosylceramide, a fatty substance stored various types of cardiac and renal cells. When globotriaosylceramide is not properly catabolized, it is accumulated in cells lining blood vessels in the skin, cells in the kidney, heart and nervous system. As a result, signs and symptoms of Fabry disease begin to manifest.
Treatment
There are three treatment options for Fabry disease: recombinant enzyme replacement therapy, pharmacological chaperone therapy, and organ specific treatment.
Recombinant enzyme replacement therapy (RERT)
RERT was approved as a treatment for Fabry disease in the United States in 2003.Two recombinant enzyme replacement therapies are available to functionally compensate for α-galactosidase deficiency. Agalsidase α and β are both recombinant forms of the human α-galactosidase A enzyme and both have the same amino acid sequence as the native enzyme. Agalsidase α and β differ in the structures of their oligosaccharide side chains.In Fabry disease patients, 88% percent of patients develop IgG antibodies towards the injected recombinant enzyme, as it is foreign to their immune system. One suggested approach to solving this problem involves converting the paralogous enzyme α-NAGAL (NAGA) into one that has with α-GAL activity. Because patients still have a functional NAGA gene, their immune system will not produce NAGA antibodies.
Agalsidase α
The pharmaceutical company Shire manufactures agalsidase alfa (INN) under the trade name Replagal as a treatment for Fabry disease, and was granted marketing approval in the EU in 2001. FDA approval was applied for the United States. However, in 2012, Shire withdrew their application for approval in the United States citing that the agency will require additional clinical trials before approval.
Agalsidase β
The pharmaceutical company Genzyme produces synthetic agalsidase β (INN) under the trade name Fabrazyme for treatment of Fabry disease. In 2009, contamination at Genzymes Allston, Massachusetts plant caused a worldwide shortage of Fabrazyme, and supplies were rationed to patients at one-third the recommended dose. Some patients have petitioned to break the companys patent on the drug under the "march-in" provisions of the Bayh–Dole Act.
Pharmacological chaperone therapy
Fabry patients who display neurological symptoms cannot receive RERT because recombinant enzymes cannot normally pass the blood-brain barrier. Thus, a more suitable alternative treatment is used: pharmacological chaperone therapy.
It has been shown that more potent competitive inhibitors of an enzyme can act as a more powerful chemical chaperone for the corresponding mutant enzyme that fails to maintain proper folding and conformation, despite its intact active site. These chemical chaperones bind to the active site of the mutant enzyme, which can help promote proper folding and stabilize the mutant enzyme. Thus, this results in functional mutant enzymes that will not be degraded via the ubiquitin-proteasome pathway.
1-Deoxygalactonojirimycin (DGJ) has been shown to be both a potent competitive inhibitor of α-GAL and an effective chaperone to for Fabry disease, increasing intracellular α-GALs activity by 14-fold.
Modifying blood type group B to group O
α-GAL, known as B-zyme in this context, has also demonstrated its ability to convert human blood group B to human blood group O, which can be transfused to patients of all blood types in the ABO blood group categorization. The current B-zyme used comes from Bacteroides fragilis. The idea of maintaining a blood supply at healthcare facilities with all non-O units converted to O units is achieved using enzyme-converted to group O technology, first developed in 1982.
Advantages
A blood bank with ECO blood demonstrates the following advantages:
Compatible with and transfusable to patients of all blood groups
Reduce the demand for specific ABO blood groups A, B, AB
Reduce cost of maintaining a blood bank inventory in hospitals
Reduce blood transfusion reactions due to human error and ABO incompatibility
Reduce wastage of less needed blood types
Mechanism of Action
Red blood cell (RBC) surfaces are decorated with the glycoproteins and glycolipids that have the same basic sequence with terminal sugar α1‐2‐linked fucose linked to the penultimate galactose. This galactose molecule is called the H antigen. Blood type A, B, AB, and O differ only in the sugar (red molecule in the illustration) linked with the penultimate galactose. For blood type B, this linked sugar is an α-1‐3‐linked galactose. Using α-GAL, this terminal galactose molecule can be removed, converting RBC to type O.
Supplements
α-GAL derived from the mold Aspergillus niger is an active ingredient in products marketed to reduce stomach gas production after eating foods known to cause gas. It is optimally active at 55°C, after which its half-life is 120 minutes.There are scores of supplements containing the enzyme over the counter in the United States and many more world wide. Products with α-galactosidase include:
Beano
CVS BeanAid
Enzymedicas BeanAssist
Gasfix
Bloateez (in India as Cogentrix)
See also
β-galactosidase
Migalastat, a drug targeting α-galactosidase
Classification of α-galactosidases (according to CAZy)
References
Further reading
External links
alpha-Galactosidase at the US National Library of Medicine Medical Subject Headings (MeSH)
Human GLA genome location and GLA gene details page in the UCSC Genome Browser.This article incorporates text from the United States National Library of Medicine, which is in the public domain. |
Methadone | Methadone, sold under the brand names Dolophine and Methadose among others, is a synthetic opioid agonist used for chronic pain and also for opioid dependence. It is used to treat chronic pain, and it is also used to treat addiction to heroin or other opioids. Prescribed for daily use, the medicine relieves cravings and removes withdrawal symptoms. Detoxification using methadone can be accomplished in less than a month, or it may be done gradually over as long as six months. While a single dose has a rapid effect, maximum effect can take up to five days of use. The pain-relieving effects last about six hours after a single dose. After long-term use, in people with normal liver function, effects last 8 to 36 hours. Methadone is usually taken by mouth and rarely by injection into a muscle or vein.Side effects are similar to those of other opioids. These frequently include dizziness, sleepiness, vomiting, and sweating. Serious risks include opioid abuse and respiratory depression. Abnormal heart rhythms may also occur due to a prolonged QT interval. The number of deaths in the United States involving methadone poisoning declined from 4,418 in 2011 to 3,300 in 2015. Risks are greater with higher doses. Methadone is made by chemical synthesis and acts on opioid receptors.Methadone was developed in Germany around 1937 to 1939 by Gustav Ehrhart and Max Bockmühl. It was approved for use as an analgesic in the United States in 1947, and has been used in the treatment of addiction since the 1960s. It is on the World Health Organizations List of Essential Medicines.
Medical uses
Opioid addiction
Methadone is used for the treatment of opioid use disorder.
It may be used as maintenance therapy or in shorter periods for detoxification to manage opioid withdrawal symptoms. Its use for the treatment of addiction is usually strictly regulated. In the US, outpatient treatment programs must be certified by the federal Substance Abuse and Mental Health Services Administration (SAMHSA) and registered by the Drug Enforcement Administration (DEA) in order to prescribe methadone for opioid addiction.
A 2009 Cochrane review found methadone was effective in retaining people in treatment and in the reduction or cessation of heroin use as measured by self-report and urine/hair analysis but did not affect criminal activity or risk of death.Treatment of opioid-dependent persons with methadone follows one of two routes: maintenance or detoxification. Methadone maintenance therapy (MMT) usually takes place in outpatient settings. It is usually prescribed as a single daily dose medication for those who wish to abstain from illicit opioid use. Treatment models for MMT differ. It is not uncommon for treatment recipients to be administered methadone in a specialist clinic, where they are observed for around 15–20 minutes post-dosing, to reduce the risk of diversion of medication.The duration of methadone treatment programs range from a few months to years. Given opioid dependence is characteristically a chronic relapsing/remitting disorder, MMT may be lifelong. The length of time a person remains in treatment depends on a number of factors. While starting doses may be adjusted based on the amount of opioids reportedly used, most clinical guidelines suggest doses start low (e.g. at doses not exceeding 40 mg daily) and are incremented gradually. It has been found that doses of 40 mg per day were sufficient to help control the withdrawal symptoms but not enough to curb the cravings for the drug. Doses of 80 to 100 mg per day have shown higher rates of success in patients and less illicit heroin use during the maintenance therapy. However, higher doses do put a patient more at risk for overdose than a moderately low dose (e.g. 20 mg/day). Methadone maintenance has been shown to reduce the transmission of bloodborne viruses associated with opioid injection, such as hepatitis B and C, and/or HIV. The principal goals of methadone maintenance are to relieve opioid cravings, suppress the abstinence syndrome, and block the euphoric effects associated with opioids.
Chronic methadone dosing will eventually lead to neuroadaptation, characterised by a syndrome of tolerance and withdrawal (dependence). However, when used correctly in treatment, maintenance therapy has been found to be medically safe, non-sedating, and can provide a slow recovery from opioid addiction. Methadone has been widely used for pregnant women addicted to opioids.
Pain
Methadone is used as an analgesic in chronic pain, often in rotation with other opioids. Due to its activity at the NMDA receptor, it may be more effective against neuropathic pain; for the same reason, tolerance to the analgesic effects may be less than that of other opioids.
Adverse effects
Adverse effects of methadone include:
Sedation
Constipation
Flushing
Perspiration
Heat intolerance
Dizziness or fainting
Weakness
Chronic fatigue, sleepiness and exhaustion
Sleep problems such as drowsiness,
Insomnia
Constricted pupils
Dry mouth
Nausea and vomiting
Low blood pressure
Headache
Heart problems such as chest pain or fast/pounding heartbeat
Abnormal heart rhythms
Respiratory problems such as trouble breathing, slow or shallow breathing (hypoventilation), light-headedness, or fainting
weight gain
Memory loss
Itching
Difficulty urinating
Swelling of the hands, arms, feet, and legs
Mood changes, euphoria, disorientation
Blurred vision
Decreased libido, difficulty in reaching orgasm, or impotence
Missed menstrual periods,
Skin rash
Central sleep apnea
Withdrawal symptoms
Physical symptoms
Lightheadedness
Tearing of the eyes
Mydriasis (dilated pupils)
Photophobia (sensitivity to light)
Hyperventilation syndrome (breathing that is too fast/deep)
Runny nose
Yawning
Sneezing
Nausea, vomiting, and diarrhea
Fever
Sweating
Chills
Tremors
Akathisia (restlessness)
Tachycardia (fast heartbeat)
Aches and pains, often in the joints or legs
Elevated pain sensitivity
Blood pressure that is too high (hypertension, may cause a stroke)Cognitive symptoms
Suicidal ideation
Susceptibility to cravings
Depression
Spontaneous orgasm
Prolonged insomnia
Delirium
Auditory hallucinations
Visual hallucinations
Increased perception of odors (olfaction), real or imagined
Marked increase in sex drive
Agitation
Anxiety
Panic disorder
Nervousness
Paranoia
Delusions
Apathy
Anorexia (symptom)Methadone withdrawal symptoms are reported as being significantly more protracted than withdrawal from opioids with shorter half-lives.
When used for opioid maintenance therapy, Methadone is generally administered as an oral liquid. Methadone has been implicated in contributing to significant tooth decay. Methadone causes dry mouth, reducing the protective role of saliva in preventing decay. Other putative mechanisms of methadone-related tooth decay include craving for carbohydrates related to opioids, poor dental care, and general decrease in personal hygiene. These factors, combined with sedation, have been linked to the causation of extensive dental damage.
Black box warning
Methadone has the following US FDA black box warning:
Risk of addiction and abuse
Potentially fatal respiratory depression
Lethal overdose in accidental ingestion
QT prolongation
Neonatal opioid withdrawal syndrome in children of pregnant women
CYP450 drug interactions
Risks when used with benzodiazepines and other CNS depressants, including alcohol.
A certified opioid treatment program is required under federal law (42 CFR 8.12) when dispensing methadone for the treatment of opioid addiction or detoxification.
Overdose
Most people who overdose on methadone show some of the following symptoms:
Miosis (constricted pupils)
Vomiting
Spasms of the stomach and intestines
Hypoventilation (breathing that is too slow/shallow)
Drowsiness, sleepiness, disorientation, sedation, unresponsiveness
Skin that is cool, clammy (damp), and pale
Blue fingernails and lips
Limp muscles, trouble staying awake, nausea
Unconsciousness and comaThe respiratory depression of an overdose can be treated with naloxone. Naloxone is preferred to the newer, longer-acting antagonist naltrexone. Despite methadones much longer duration of action compared to either heroin and other shorter-acting agonists and the need for repeat doses of the antagonist naloxone, it is still used for overdose therapy. As naltrexone has a longer half-life, it is more difficult to titrate. If too large a dose of the opioid antagonist is given to a dependent person, it will result in withdrawal symptoms (possibly severe). When using naloxone, the naloxone will be quickly eliminated and the withdrawal will be short-lived. Doses of naltrexone take longer to be eliminated from the persons system. A common problem in treating methadone overdoses is that, given the short action of naloxone (versus the extremely longer-acting methadone), a dosage of naloxone given to a methadone-overdosed person will initially work to bring the person out of overdose, but once the naloxone wears off, if no further naloxone is administered, the person can go right back into overdose (based upon time and dosage of the methadone ingested).
Tolerance and dependence
As with other opioid medications, tolerance and dependence usually develop with repeated doses. There is some clinical evidence that tolerance to analgesia is less with methadone compared to other opioids; this may be due to its activity at the NMDA receptor. Tolerance to the different physiological effects of methadone varies; tolerance to analgesic properties may or may not develop quickly, but tolerance to euphoria usually develops rapidly, whereas tolerance to constipation, sedation, and respiratory depression develops slowly (if ever). Methadone fills the same opioid receptors in the brain as heroin and other prescription painkillers making it a suitable substitute.
Driving
Methadone treatment may impair driving ability. Drug abusers had significantly more involvement in serious crashes than non-abusers in a study by the University of Queensland. In the study of a group of 220 drug abusers, most of them poly-drug abusers, 17 were involved in crashes killing people, compared with a control group of other people randomly selected having no involvement in fatal crashes. However, there have been multiple studies verifying the ability of methadone maintenance patients to drive. In the UK, persons who are prescribed oral methadone can continue to drive after they have satisfactorily completed an independent medical examination which will include a urine screen for drugs. The license will be issued for 12 months at a time and even then, only following a favourable assessment from their own doctor. Individuals who are prescribed methadone for either IV or IM administration cannot drive in the UK, mainly due to the increased sedation effects that this route of use can cause.
Mortality
In the United States, deaths linked to methadone more than quadrupled in the five-year period between 1999 and 2004. According to the U.S. National Center for Health Statistics, as well as a 2006 series in the Charleston Gazette (West Virginia), medical examiners listed methadone as contributing to 3,849 deaths in 2004. That number was up from 790 in 1999. Approximately 82 percent of those deaths were listed as accidental, and most deaths involved combinations of methadone with other drugs (especially benzodiazepines).
Although deaths from methadone are on the rise, methadone-associated deaths are not being caused primarily by methadone intended for methadone treatment programs, according to a panel of experts convened by the Substance Abuse and Mental Health Services Administration, which released a report titled "Methadone-Associated Mortality, Report of a National Assessment". The consensus report concludes that "although the data remains incomplete, National Assessment meeting participants concurred that methadone tablets or Diskets® distributed through channels other than opioid treatment programs most likely are the central factors in methadone-associated mortality."In 2006, the U.S. Food and Drug Administration issued a caution about methadone, titled "Methadone Use for Pain Control May Result in Death." The FDA also revised the drugs package insert. The change deleted previous information about the usual adult dosage. The Charleston Gazette reported, "The old language about the usual adult dose was potentially deadly, according to pain specialists."
Pharmacology
Methadone acts by binding to the µ-opioid receptor, but also has some affinity for the NMDA receptor, an ionotropic glutamate receptor. Methadone is metabolized by CYP3A4, CYP2B6, CYP2D6, and is a substrate, or in this case target, for the P-glycoprotein efflux protein, a protein which helps pump foreign substances out of cells, in the intestines and brain. The bioavailability and elimination half-life of methadone are subject to substantial interindividual variability. Its main route of administration is oral. Adverse effects include sedation, hypoventilation, constipation and miosis, in addition to tolerance, dependence and withdrawal difficulties. The withdrawal period can be much more prolonged than with other opioids, spanning anywhere from two weeks to several months.
The metabolic half-life of methadone differs from its duration of action. The metabolic half-life is 8 to 59 hours (approximately 24 hours for opioid-tolerant people, and 55 hours in opioid-naive people), as opposed to a half-life of 1 to 5 hours for morphine. The length of the half-life of methadone allows for exhibition of respiratory depressant effects for an extended duration of time in opioid-naive people.
Mechanism of action
Levomethadone (the L enantiomer) is a μ-opioid receptor agonist with higher intrinsic activity than morphine, but lower affinity. Dextromethadone (the S enantiomer) does not affect opioid receptors but binds to the glutamatergic NMDA (N-methyl-D-aspartate) receptor, and acts as an antagonist against glutamate. Methadone has been shown to reduce neuropathic pain in rat models, primarily through NMDA receptor antagonism. Glutamate is the primary excitatory neurotransmitter in the central nervous system. NMDA receptors have a very important role in modulating long-term excitation and memory formation. NMDA antagonists such as dextromethorphan (DXM, a cough suppressant), ketamine (a dissociative anaesthetic), tiletamine (a veterinary anaesthetic) and ibogaine (from the African tree Tabernanthe iboga) are being studied for their role in decreasing the development of tolerance to opioids and as possible for eliminating addiction/tolerance/withdrawal, possibly by disrupting memory circuitry. Acting as an NMDA antagonist may be one mechanism by which methadone decreases craving for opioids and tolerance, and has been proposed as a possible mechanism for its distinguished efficacy regarding the treatment of neuropathic pain. The dextrorotary form (dextromethadone), which acts as an NMDA receptor antagonist and is devoid of opioid activity, has been shown to produce analgesia in experimental models of chronic pain. Methadone also acted as a potent, noncompetitive α3β4 neuronal nicotinic acetylcholine receptor antagonist in rat receptors, expressed in human embryonic kidney cell lines.
Metabolism
Methadone has a slow metabolism and very high fat solubility, making it longer lasting than morphine-based drugs. Methadone has a typical elimination half-life of 15 to 60 hours with a mean of around 22. However, metabolism rates vary greatly between individuals, up to a factor of 100, ranging from as few as 4 hours to as many as 130 hours, or even 190 hours. This variability is apparently due to genetic variability in the production of the associated cytochrome enzymes CYP3A4, CYP2B6 and CYP2D6. Many substances can also induce, inhibit or compete with these enzymes further affecting (sometimes dangerously) methadone half-life. A longer half-life frequently allows for administration only once a day in opioid detoxification and maintenance programs. People who metabolize methadone rapidly, on the other hand, may require twice daily dosing to obtain sufficient symptom alleviation while avoiding excessive peaks and troughs in their blood concentrations and associated effects. This can also allow lower total doses in some such people. The analgesic activity is shorter than the pharmacological half-life; dosing for pain control usually requires multiple doses per day normally dividing daily dosage for administration at 8 hour intervals.The main metabolic pathway involves N-demethylation by CYP3A4 in the liver and intestine to give 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP). This inactive product, as well as the inactive 2-ethyl-5-methyl-3,3-
diphenyl-1-pyrroline (EMDP), produced by a second N-demethylation, are detectable in the urine of those taking methadone.
Methadone and its two main metabolites
Route of administration
The most common route of administration at a methadone clinic is in a racemic oral solution, though in Germany, only the R enantiomer (the L optical isomer) has traditionally been used, as it is responsible for most of the desired opioid effects. The single-isomer form is becoming less common due to the higher production costs.
Methadone is available in traditional pill, sublingual tablet, and two different formulations designed for the person to drink. Drinkable forms include ready-to-dispense liquid (sold in the United States as Methadose), and Diskets® (known on the street as "wafers" or "biscuits") tablets which are dispersible in water for oral administration, used in a similar fashion to Alka-Seltzer. The liquid form is the most common as it allows for smaller dose changes. Methadone is almost as effective when administered orally as by injection. Oral medication is usually preferable because it offers safety, simplicity and represents a step away from injection-based drug abuse in those recovering from addiction. U.S. federal regulations require the oral form in addiction treatment programs. Injecting methadone pills can cause collapsed veins, bruising, swelling, and possibly other harmful effects. Methadone pills often contain talc that, when injected, produces a swarm of tiny solid particles in the blood, causing numerous minor blood clots. These particles cannot be filtered out before injection, and will accumulate in the body over time, especially in the lungs and eyes, producing various complications such as pulmonary hypertension, an irreversible and progressive disease. The formulation sold under the brand name Methadose (flavored liquid suspension for oral dosing, commonly used for maintenance purposes) should not be injected either.Information leaflets included in packs of UK methadone tablets state that the tablets are for oral use only and that use by any other route can cause serious harm. In addition to this warning, additives have now been included in the tablet formulation to make the use of them by the IV route more difficult.
Chemistry
Detection in biological fluids
Methadone and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), are often measured in urine as part of a drug abuse testing program, in plasma or serum to confirm a diagnosis of poisoning in hospitalized victims, or in whole blood to assist in a forensic investigation of a traffic or other criminal violation or a case of sudden death. Methadone usage history is considered in interpreting the results as a chronic user can develop tolerance to doses that would incapacitate an opioid-naïve individual. Chronic users often have high methadone and EDDP baseline values.
Conformation
The protonated form of methadone takes on an extended conformation, while the free base is more compact. In particular, it was found that there is an interaction between the tertiary amine and the carbonyl carbon of the ketone function (R3N ••• >C=O) that limits the molecules conformation freedom, though the distance (291 pm by X-ray) is far too long to represent a true chemical bond. However, it does represent the initial trajectory of attack of an amine on a carbonyl group and was an important piece of experimental evidence for the proposal of the Bürgi–Dunitz angle for carbonyl addition reactions.
History
Methadone was developed in 1937 in Germany by scientists working for I.G. Farbenindustrie AG at the Farbwerke Hoechst who were looking for a synthetic opioid that could be created with readily available precursors, to solve Germanys opium and morphine shortage problem. On 11 September 1941 Bockmühl and Ehrhart filed an application for a patent for a synthetic substance they called Hoechst 10820 or Polamidon (a name still in regular use in Germany) and whose structure had little relation to morphine or other "true opiates” such as diamorphine (HeroinTM), desomorphine (PermonidTM), nicomorphine (VilanTM), codeine, dihydrocodeine, oxymorphone (OpanaTM), hydromorphone (DilaudidTM), oxycodone (OxyContinTM), hydrocodone (DicodidTM), and other closely related opium alkaloid derivatives and analogues. It was brought to market in 1943 and was widely used by the German army during WWII as a substitute for morphine.In the 1930s, pethidine (meperidine) went into production in Germany; however, production of methadone, then being developed under the designation Hoechst 10820, was not carried forward because of side effects discovered in the early research. After the war, all German patents, trade names and research records were requisitioned and expropriated by the Allies. The records on the research work of the I.G. Farbenkonzern at the Farbwerke Hoechst were confiscated by the U.S. Department of Commerce Intelligence, investigated by a Technical Industrial Committee of the U.S. Department of State and then brought to the US. The report published by the committee noted that while methadone itself was potentially addictive, it produced “considerably” less euphoria, sedation, and respiratory depression than morphine at equianalgesic doses and was thus interesting as a commercial drug. The same report also compared methadone to pethidine. German researchers reported that methadone was capable of producing strong morphine-like physical dependence, which is characterized by opioid withdrawal symptoms which are lesser in severity and intensity compared to morphine, but methadone was associated with a considerably prolonged or protracted withdrawal syndrome when compared to morphine. Morphine produced higher rates of self-administration and reinforcing behaviour in both human and animal subjects when compared to both methadone and pethidine. In comparison to equianalgesic doses of pethidine (DemerolTM), methadone was shown to produce less euphoria, but higher rates of constipation, and roughly equal levels of respiratory depression and sedation.In the early 1950s, methadone (most times the racemic HCl salts mixture) was also investigated for use as an antitussive.Isomethadone, noracymethadol, LAAM, and normethadone were first developed in Germany, United Kingdom, Belgium, Austria, Canada, and the United States in the thirty or so years after the 1937 discovery of pethidine, the first synthetic opioid used in medicine. These synthetic opioids have increased length and depth of satiating any opiate cravings and generate very strong analgesic effects due to their long metabolic half-life and strong receptor affinity at the mu-opioid receptor sites. Therefore, they impart much of the satiating and anti-addictive effects of methadone by means of suppressing drug cravings.It was only in 1947 that the drug was given the generic name “methadone” by the Council on Pharmacy and Chemistry of the American Medical Association. Since the patent rights of the I.G. Farbenkonzern and Farbwerke Hoechst were no longer protected, each pharmaceutical company interested in the formula could buy the rights for the commercial production of methadone for just one dollar (MOLL 1990).
Methadone was introduced into the United States in 1947 by Eli Lilly and Company as an analgesic under the trade name Dolophine. An urban myth later arose that Nazi leader Adolf Hitler ordered the manufacture of methadone or that the brand name Dolophine was named after him, probably based on the similarity of “doloph” with “Adolph”. (The pejorative term “adolphine” would appear in the early 1970s.) However, the name “Dolophine” was a contraction of "Dolo” from the Latin word dolor (pain), and finis, the Latin word for “end”. Therefore, Dolophine literally means “pain end”.Methadone was studied as a treatment for opioid addiction at the Addiction Research Center of the Narcotics Farm in Lexington, Kentucky in the 1950s, and by Rockefeller University physicians Robert Dole and Marie Nyswander in the 1960s in New York City. By 1976, methadone clinics had opened in cities including Chicago, New York, and New Haven, with some 38,000 patients treated in New York City alone.
Society and culture
Brand names
Brand names include Dolophine, Symoron, Amidone, Methadose, Physeptone, Metadon, Metadol, Metadol-D, Heptanon and Heptadon among others.
Cost
In the US, generic methadone tablets are inexpensive, with retail prices ranging from $0.25 to $2.50 per defined daily dose. Brand-name methadone tablets may cost much more.
Methadone maintenance clinics in the US may be covered by private insurances, Medicaid, or Medicare. Medicare covers methadone under the prescription drug benefit, Medicare Part D, when it is prescribed for pain, but not when it is used for opioid dependence treatment because it cannot be dispensed in a retail pharmacy for this purpose. In California methadone maintenance treatment is covered under the medical benefit. Patients eligibility for methadone maintenance treatment is most often contingent on them being enrolled in substance abuse counseling. People on methadone maintenance in the US either have to pay cash or if covered by insurance must complete a pre-determined number of hours per month in therapeutic groups or counseling. The United States Department of Veterans Affairs (VA) Alcohol and Drug Dependence Rehabilitation Program offers methadone services to eligible veterans enrolled in the VA health care system.Methadone maintenance treatment (MMT) cost analyses often compare the cost of clinic visits versus the overall societal costs of illicit opioid use. A preliminary cost analysis conducted in 2016 by the US Department of Defense determined that methadone treatment, which includes psychosocial and support services, may cost an average of $126.00 per week or $6,552.00 per year. The average cost for one full year of methadone maintenance treatment is approximately $4,700 per patient, whereas one full year of imprisonment costs approximately $24,000 per person.
Controversy
Methadone substitution as a treatment of opioid addiction has been criticized in the social sciences for its role in the social control of addicts. Such critique centers on the notion that substance addiction is reframed with a disease model. Thus methadone, which mimics the effects of opioids and renders the addict compliant, is labeled as a "treatment" and so achieves the disciplinary objectives of managing the "undesirables". It is suggested that methadone does not function as much to curb addiction as to redirect it and maintain dependency on authorised channels. Several authors apply a Foucauldian analysis to the widespread prescription |
Methadone | of the drug and use in institutions such as prisons, hospitals, and rehabilitation centres.
Regulation
United States and Canada
Methadone is a Schedule I controlled substance in Canada and Schedule II in the United States, with an ACSCN of 9250 and a 2014 annual aggregate manufacturing quota of 31,875 kilos for sale. Methadone intermediate is also controlled, under ACSCN 9226 also under Schedule II, with a quota of 38,875 kilos. In most countries of the world, methadone is similarly restricted. The salts of methadone in use are the hydrobromide (free base conversion ratio 0.793), hydrochloride (0.894), and HCl monohydrate (0.850). Methadone is also regulated internationally as a Schedule I controlled substance under the United Nations Single Convention on Narcotic Drugs of 1961.
Methadone clinics
In the United States, prescription of methadone requires intensive monitoring and must be obtained in-person from an opioid treatment program—colloquially known as a methadone clinic—when prescribed for opioid use disorder (OUD). According to federal laws, methadone cannot be prescribed by a doctor and obtained from a pharmacy in order to treat addiction. Because of its long half-life, methadone is almost invariably prescribed to be taken in a single daily dose. At nearly all methadone clinics in the US, patients must visit a clinic to receive and take their dose under the supervision of a nurse. Both patients who are new to methadone treatment and high-risk patients—such as those who are using drugs and alcohol, including cannabis—must visit the clinic daily. However, some clinics close on national holidays and provide doses to patients to take home.
Take-home or take-away methadone
After 90 days to six months (depending on the clinic), if patients have met the clinics criteria, they are typically eligible for take-home doses of methadone. Therefore, they may be allowed to take anywhere from one to six days to visit the clinic once or twice weekly instead of every day. In accordance with DEA and SAMHSA regulations, patients who use other drugs (including legally obtained cannabis) are not eligible for take-home methadone.In recent years, patients, doctors, nurses, those working in the addiction field, and advocates of many kinds have heavily criticized the extremely tight regulations regarding take-home methadone. Advocates for reforming methadone regulations argue that methadone could be much more effective if it was not necessary for patients to visit clinics daily. Many addicts seeking treatment usually avoid methadone or see it as a last resort, specifically because they do not want to have to go to a clinic every day to receive their medication.
Other countries
In Russia, methadone treatment is illegal. In 2008, Chief Sanitary Inspector of Russia Gennadiy Onishchenko, claimed that Russian health officials are not convinced of the methadones efficacy in treating heroin and/or opioid addicts. Instead of replacement therapy and gradual reduction of illicit drug abuse, Russian doctors encourage immediate cessation and withdrawal. Addicts are generally given sedatives and non-opioid analgesics in order to cope with withdrawal symptoms. Brazilian footballer assistant Robson Oliveira was arrested in 2019 upon arriving in Russia with methadone tablets sold legally in other countries for what was considered drug trafficking under Russian law.As of 2015 China had the largest methadone maintenance treatment program with over 250,000 people in over 650 clinics in 27 provinces.
References
External links
"Methadone". Drug Information Portal. U.S. National Library of Medicine.
Methadone, Substance Abuse and Mental Health Services Administration, U.S. Department of Health and Human Services
Tapering off of methadone maintenance
DE patent 711069, Dr Max Bockmuehl & Dr Gustav Ehrhart, "Verfahren zur Darstellung von basischen Estern", published 1941-09-25, issued 1941-09-25, assigned to IG Farbenindustrie AG |
Crizanlizumab | Crizanlizumab, sold under the brand name Adakveo & Ryverna both by Novartis, is a monoclonal antibody medication that binds to P-selectin. It is a drug used to reduce the frequency of vaso-occlusive crisis in people aged 16 years and older who have sickle cell anemia. Vaso-occlusive crisis is a common and painful complication of sickle cell disease that occurs when blood circulation is obstructed by sickled red blood cells (red cells are usually round and flexible, but sometimes many red cells in a person with sickle cell anemia will become rigid and crescent-shaped due to polymerization of hemoglobin).The result of the Phase II SUSTAIN clinical trial was published in December 2016, and in November 2019, crizanlizumab-tmca was approved in the United States. The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication.
Pathophysiology
P-selectin molecules are present on the surface of activated platelets and vascular endothelial cells and have been linked to sickle cell vaso-occlusive crises.
History
The U.S. Food and Drug Administration (FDA) approved crizanlizumab based on evidence from one clinical trial (Trial 1/NCT01895361) of 132 patients with sickle cell diseases who had a history of vaso-occlusive crisis. The trial was conducted at 60 sites in the United States, Brazil and Jamaica.The FDA granted the application for crizanlizumab-tmca priority review, breakthrough therapy designation, and orphan drug designation. The FDA granted approval of Adakveo to Novartis.
References
External links
"Crizanlizumab". Drug Information Portal. U.S. National Library of Medicine. |
Phentermine/topiramate | Phentermine/topiramate, sold under the brand name Qsymia, is a combination drug of phentermine and topiramate used to treat obesity. It is used together with dietary changes and exercise. If less than 3% weight loss is seen after 3 months it is recommended the medication be stopped. The weight loss is modest. Effects on heart related health problems or death is unclear.Common side effects include tingling, dizziness, trouble sleeping, and constipation. Serious side effects may include suicide, abuse. Use is not recommended during pregnancy. Phentermine is a stimulant and appetite suppressant. Topiramate is an anticonvulsant that has weight loss side effects. The exact mechanism of action for both drugs is unknown.Phentermine/topiramate was approved for medical use in the United States in 2012. Approval was denied in Europe, due to concerns regarding safety.
Medical uses
In clinical trials, people treated with the highest dose of phentermine/topiramate ER in combination with a program of diet and exercise lost 10% to 11% of their body weight compared to 1% to 2% for those who received placebo. In addition, 62% to 70% of subjects receiving the recommended dose or top dose of phentermine/topiramate ER achieved ≥5% weight reduction by week 56 (ITT-LOCF) compared to 17% to 21% of those receiving a placebo.A Cochrane review on the long-term effects of weight-reducing drugs on people with hypertension found that phentermine/topiramate reduced body weight (when compared to orlistat, and naltrexone/bupropion) and also reduced blood pressure.
Adverse effects
In clinical trials, the most common adverse events which occurred at a rate ≥5% and ≥1.5 times placebo included paraesthesia (tingling in fingers/toes), dizziness, altered taste, insomnia, constipation, and dry mouth.In the U.S., the drug label contains warnings for increased heart rate, suicidal behavior and ideation, glaucoma, mood and sleep disorders, creatine elevation, and metabolic acidosis. Some of these warnings are based on historical observations in epilepsy patients taking topiramate. The FDA is requiring the company to perform a post-approval cardiovascular outcomes trial, due in part to the observation of increased heart rate in some people taking the drug in clinical trials.
Pregnancy
Phentermine and topiramate can cause fetal harm. Data from pregnancy registries and epidemiology studies indicate that a fetus exposed to topiramate in the first trimester of pregnancy has an increased risk of oral clefts (cleft lip with or without cleft palate). If a patient becomes pregnant while taking phentermine/topiramate ER, treatment should be discontinued immediately, and the patient should be apprised of the potential hazard to a fetus. Females of reproductive potential should have a negative pregnancy test before starting phentermine/topiramate ER and monthly thereafter during phentermine/topiramate ER therapy. Females of reproductive potential should use effective contraception during phentermine/topiramate ER therapy.
Risk evaluation and mitigation strategy
Phentermine and topiramate was approved with a risk evaluation and mitigation strategy (REMS) program to ensure that benefits of treatment outweigh the risks. Because of the teratogenic risk associated with phentermine/topiramate ER therapy, phentermine/topiramate ER is distributed via certified pharmacies.
Contraindications
Phentermine/topiramate ER is contraindicated in pregnancy, glaucoma, hyperthyroidism, during or within 14 days of taking monoamine oxidase inhibitors, and in patients with hypersensitivity or idiosyncrasy to sympathomimetic amines. Phentermine/topiramate ER can cause an increase in resting heart rate.
History
Phentermine and topiramate was developed by Vivus, a California pharmaceutical company.
In December 2009 VIVUS, Inc. submitted a new drug application (NDA) to the FDA and on March 1, 2010, VIVUS, Inc. announced that the FDA accepted the NDA for review.
In October 2010, the FDA announced its decision to not approve phentermine/topiramate ER in its current form and issued a Complete Response Letter to VIVUS due to lack of long-term data and concerns about side effects including elevated heart rate, major adverse cardiovascular events, and birth defects.The FDA expressed concerns about the potential for phentermine/topiramate ER to cause birth defects and requested that Vivus assess the feasibility of analyzing existing healthcare databases to determine the historical incidence of oral cleft in offspring of women treated with topiramate for migraine prophylaxis (100 mg).In October 2011, VIVUS resubmitted the NDA to the FDA with responses to the issues addressed in the CRL. The FDA accepted the NDA in November 2011.On September 18, 2012, Qsymia became available on the US market.
References
External links
"Phentermine mixture with topiramate". Drug Information Portal. U.S. National Library of Medicine. |
Epinastine | Epinastine (brand names Alesion, Elestat, Purivist, Relestat) is a second-generation antihistamine and mast cell stabilizer that is used in eye drops to treat allergic conjunctivitis. It is produced by Allergan and marketed by Inspire in the United States. It is highly selective for the H1 receptor and does not cross the blood-brain-barrier.It was patented in 1980 and came into medical use in 1994.
References
External links
Official U.S. website of Elestat |
Mometasone | Mometasone, also known as mometasone y 3 s, is a steroid medication used to treat certain skin conditions, hay fever, and asthma. Specifically it is used to prevent rather than treat asthma attacks. It can be applied to the skin, inhaled, or used in the nose. Mometasone furoate, not mometasone, is used in medical products.Common side effects when used for asthma includes asthma and thrush. It is therefore recommended to rinse the mouth after use. Long term use may increase the risk for glaucoma and cataracts. Common side effects when used in the nose includes upper respiratory tract infections and nose bleeds. Common side effects when applied on the skin include acne, skin atrophy, and itchiness. It works by decreasing inflammation.Mometasone furoate was patented in 1981 and came into medical use in 1987. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2017, it was the 197th most commonly prescribed medication in the United States, with more than two million prescriptions.
Medical uses
Mometasone furoate is used in the treatment of inflammatory skin disorders (such as eczema and psoriasis) (topical form), allergic rhinitis (such as hay fever) (topical form), asthma (inhalation form) for patients unresponsive to less potent corticosteroids, and penile phimosis. In terms of steroid strength, it is more potent than hydrocortisone, and less potent than dexamethasone.Some low-quality evidence suggests the use of mometasone for symptomatic improvement in children with adenoid hypertrophy.Mometasone is used to alleviate inflammation and itchiness in skin conditions that respond to treatment with glucocorticoids such as psoriasis and atopic dermatitis.Nasal mometasone is used in adults (including the elderly) and children over two years of age, to diminish the symptoms of hay fever (seasonal allergic rhinitis) and other allergies (perennial rhinitis), including nasal congestion, discharge, pruritus, and sneezing and to treat nasal polyps.It is not useful for the common cold.
Asthma
Mometasone furoate can be used with formoterol for the treatment of asthma, due to its anti-inflammatory properties.
Contraindications
People should not use inhaled mometasone or mometasone nasal spray if:
glaucoma or cataracts
hypersensitivity or allergic to any ingredient in mometasoneThose who are using mometasone nasal or inhaled for a long period of time (e.g. more than three months) should get regular eye exams to check for glaucoma and cataracts and should take precautions to avoid infections such as taking a vitamin D supplement, staying away from those with an infection (chickenpox, measles, colds or flu, COVID-19), washing foods, hand washing and calling a family doctor at the first sign of a severe infection.
People should not use mometasone topical (skin cream) if:
hypersensitive or allergic to any ingredient in the skin creamMometasone furoate is in class C in terms of safety while use during pregnancy. Therefore, its risks to the baby cannot be ruled out. Therefore, the use in pregnancy is not recommended.
Side effects
The nasal spray form of mometasone may cause the following side effects:
headache
Viral upper respiratory infections
sore throat
nose bleeds
cough
muscle and joint painSerious side effects include: Thrush (fungal infection in the nose or throat), slow wound healing, eye problems such as glaucoma or cataracts, weakened immune system (immunodeficiency) which causes an increased susceptibility to infections and adrenal insufficiency.
The inhaled form of mometasone for asthma may cause the following side effects
headache
stuffy or runny nose
dry throat
swelling of nose, throat and sinuses
flu like symptoms
painful menstrual periodsSerious side effects may include: allergic reactions (anaphylaxis), increased risk of osteoporosis, glaucoma and cataracts, thrush in the mouth or throat, growth retardation in children, bronchospasms, adrenal insufficiency and weakened immune system which causes an increased susceptibility to infections.
The topical (skin cream) version may cause:
burning and itching at the application site
acne
changes in skin color
dryness at application site
skin soresThe only serious side effect that is known with mometasone topical is adrenal insufficiency.
Pharmacology
Pharmacodynamics
Mometasone furoate reduces inflammation by causing several effects:
Reversing the activation of inflammatory proteins
Activating the secretion of anti-inflammatory proteins
Stabilizing cell membranes
Decreasing the influx of inflammatory cellsIn addition to the glucocorticoid properties of mometasone furoate, it is a very potent agonist of the progesterone receptor as well as a partial agonist of the mineralocorticoid receptor.
Mechanism of action
Mometasone, like other corticosteroids, possesses anti-inflammatory, antipruritic, and vasoconstrictive properties. For allergies, corticosteroids reduce the allergic reactions in various types of cells (mastocytes and eosinophils) that are responsible for allergic reactions. Mometasone and other corticosteroids circulate in the blood easily, crossing cellular membranes and binding with cytoplasmic receptors, resulting in the transcription and synthesis of proteins. It also inhibits the actions of the enzyme cytochrome P450 2C8 which participates in the activity of monooxygenase.The inflammation is reduced in decreasing the liberation of hydrolase acids of leukocytes, the prevention of the accumulation macrophages in the sites of inflammation, the interference with adhesion of leukocytes to capillary walls, the reduction of the permeability of the capillary membranes and consequently edema, the reduction of complementary components, inhibition of histamine and kinin liberation, and interference with scar tissue formation. The proliferation of fibroblasts and collagen deposits is also reduced. It is believed that the action of corticosteroid anti-inflammatory agents is bound to inhibitive proteins of phospholipase A2, collectively called lipocortins. The lipocortins, in turn, control the biosynthesis of potent mediators of inflammation as the prostaglandins and leukotrienes, inhibiting the liberation of the molecular precursors of arachidonic acid. Intranasal mometasone alleviates symptoms such as rhinorrhea aquosa, nasal congestion, nasal drip, sneezing, and pharyngeal itching. Topical administration applied to skin reduces the inflammation associated with chronic or acute dermatosis.
Although mometasone furoate does not have significant systemic immunomodulatory effects, it can be considered a local immunosuppressive drug because clinical studies have shown reductions (vs. baseline ) in neutrophils (a white blood cell) in the nasal mucosa. It could be also considered an antihistamine along with its glucocorticoid effects because it significantly reduces histamine and eosinophil cationic protein levels.
Pharmacokinetics
Metabolism
Extensive metabolic hepatic metabolism of mometasone furoate to multiple metabolites occurs. No principal metabolites are detectable in plasma. After in vitro incubation, one of the minor metabolites formed is furoate 6β-hydroxymometasone. In human hepatic microsomes, the formation of these metabolites is regulated by CYP3A4.
Mometasone
Mometasone by itself is a synthetic, steroidal glucocorticoid or corticosteroid that was never marketed. The C17α furoate ester of mometasone, is the marketed medication. Mometasone furoate acts as a prodrug of mometasone. In addition to its glucocorticoid activity, mometasone also has very potent progestogenic activity and acts as a partial agonist of the mineralocorticoid receptor.
Society and culture
Brand names
As of 2016 mometasone furoate was available worldwide in formulations for nasal, oral inhalation, and topical administration, for human and for veterinary use, and in combinations with other drugs, under many brand names. It was available as the single active agent in the following brands: Alcom, Altosone, Asmanex, Atozon, Aureox, Belloseta, Bioelementa, Biometasona, Bloctimo, Borgasone, Breso, Broner, Codermo, Cortynase, Cutimom, Cutizone, Cutticom, Dance, Demoson, Dergentil, Derimod, Dermacortine, Dermaten, Dermome, Dermosona, Dermotasone, Dermovel, Desdek, Ecelecort, Ecural, Edelan, Elica, Elisone, Elisox, Elitasone, Elna, Elocan, Elocom, Elocon, Elocortin, Elofute, Elomet, Elomox, Eloskin, Eloson, Elosone, Elovent, Elox, Etacid, Eversone, Eztom, F-Din, Fenisona, Flazcort, Flogocort, Fremomet, Frondava, Fu Mei Song, Fulmeta, Furo, Furoato de Mometasona, Furoderm, Gistan-H, Honmet, Iflacort, Intercon, Ivoxel, Kalmente, Konex, Ladexol, Lisoder, Logren, Loksin, Lomeane, M-Furo, Makiren, Mefurosan, Melocort, Mena, Mesone, Metacortil, Metactiv, Metaflam, Metagra, Metasafe, Metason, Metasone, Metaspray, Metatop, Metaz, Metmin, Metsone, Midermin, Mifusin, Minyear, Mofacort, Mofulex, Mofur, Mofuroate, Molison, Momate, Momax, Momecon, Momecort, Momecutan, Momederm, MomeGalen, Momegen, Momekort, Momelab, Momentum, Momeplus, Momerid, Momeson, Momesone, Momester, Momet, Mometa, Mometagen, Mometason, Mometasona, Mometasona Furoato, Mometasone Furoate, Mometasone Furoate Hydrate, Mometasonfuroaat, Mometasonfuroat, Mometasoni Furoas, Mometasonum, Mometasyn, Mometasyn, Mometax, Mometazon, Mometazona, Mometazona Fuorat, Mometazonfuroat, Mometix-AQ, Momevate, Momexa, Mommex, Mommox, Momtas, Monaliz, Monez, Monovel, Monovo, Mosone, Motaderm, Motaneal, Movesan, Mtaz, Mundoson, Murozo, Myrey, Narinex, Nasamet, Nasehaler, Nasocure, Nasomet, Nasometin, Nasonex, Nassomet, Nazofix, Nazoster, Netonox, Nexomist, Novasone, Ovison, Ovixan, Oximax, Pharmecort, Pluster, Pronasal, Propel, Prospiril, Pydercon, Rinelon, Rinitek, Rino-Val, Rinobudex, Rinonex, Rinosal, Rinosona, Rinoval, Risonel, Sensicort, Septopic, Silkaren, Soneta, Suavicort, Suqi, Synaller, Tabunex, Topcort, Topison, Uniclar, Uniderm, Vizomet, Yperod, Zalconex, and Zynovate.
Combinations
The following combination drugs are available as of 2022:
Mometasone and azelastine as Nasaflex
Mometasone and clotrimazole and gentamicin for veterinary use as Mometamax and Mometavet
Mometasone and clotrimazole and mupirocin as Derma Q
Mometasone and florfenicol and terbinafine for veterinary use as Claro
Mometasone and formoterol as Dulera, Hexaler Bronquial Duo, and Zenhale
Mometasone and fusidic acid as Bactirest-M, Dermotil Fusid, and Momate-F
Mometasone and gentamicin and posaconazole for veterinary use as Mometamax Ultra
Mometasone and hydroquinone and tretinoin as Acnezac-MH
Mometasone and miconazole as Elica M, Elica-M, and Sensicort-F
Mometasone and mupirocin as Sensicort-B
Mometasone and orbifloxacin and posaconazole for veterinary use as Posatex, Posatex voor honden, and Posatex für Hunde
Mometasone and salicylic acid as Cortimax-S, Elicasal, Elocom Plus, Elosalic, Mezo-S, Momate-S, Momesalic, Momtas-S, Monsalic, and Sensicort-S
Mometasone and terbinafine as Cutizone-T, Mezo-T, and MomelomTerbi-Humanity
Mometasone and tiotropium as Tiomom
References
External links
"Mometasone". Drug Information Portal. U.S. National Library of Medicine. |
Ciclosporin | Ciclosporin, also spelled cyclosporine and cyclosporin, is a calcineurin inhibitor, used as an immunosuppressant medication. It is a natural product. It is taken orally or intravenously for rheumatoid arthritis, psoriasis, Crohns disease, nephrotic syndrome, and in organ transplants to prevent rejection. It is also used as eye drops for keratoconjunctivitis sicca (dry eyes).Common side effects include high blood pressure, headache, kidney problems, increased hair growth, and vomiting. Other severe side effects include an increased risk of infection, liver problems, and an increased risk of lymphoma. Blood levels of the medication should be checked to decrease the risk of side effects. Use during pregnancy may result in preterm birth; however, ciclosporin does not appear to cause birth defects.Ciclosporin is believed to work by decreasing the function of lymphocytes. It does this by forming a complex with cyclophilin to block the phosphatase activity of calcineurin, which in turn decreases the production of inflammatory cytokines by T-lymphocytes.Ciclosporin was isolated in 1971 from the fungus Tolypocladium inflatum and came into medical use in 1983. It is on the World Health Organizations List of Essential Medicines. In 2019, it was the 195th most commonly prescribed medication in the United States, with more than 2 million prescriptions that year. It is available as a generic medication.
Medical uses
Ciclosporin is indicated to treat and prevent graft-versus-host disease in bone marrow transplantation and to prevent rejection of kidney, heart, and liver transplants. It is also approved in the US for treating of rheumatoid arthritis and psoriasis, persistent nummular keratitis following adenoviral keratoconjunctivitis, and as eye drops for treating dry eyes caused by Sjögrens syndrome and meibomian gland dysfunction.In addition to these indications, ciclosporin is also used in severe atopic dermatitis, Kimura disease, pyoderma gangrenosum, chronic hives, acute systemic mastocytosis, and posterior or intermediate uveitis with noninfective cause. It is also used, albeit infrequently, in severe rheumatoid arthritis and related diseases.Ciclosporin has also been used in people with acute severe ulcerative colitis and hives that do not respond to treatment with steroids.
Side effects
Side effects of ciclosporin can include gum enlargement, increased hair growth, convulsions, peptic ulcers, pancreatitis, fever, vomiting, diarrhea, confusion, increased cholesterol, trouble breathing, numbness and tingling (particularly of the lips), itchiness, high blood pressure, potassium retention (possibly leading to hyperkalemia), kidney and liver dysfunction, burning sensations at finger tips, and an increased vulnerability to opportunistic fungal and viral infections. Ciclosporin causes hypertension by inducing vasoconstriction in the kidneys and increasing sodium reabsorption. The increase in blood pressure can cause cardiovascular events; it is thus recommended that the lowest effective dose for people requiring long-term treatment be used.Ciclosporin use after a kidney transplantation is associated with increased levels of uric acid in the blood and, in some cases, gout. This is due to the decrease in glomerular filtration rate, which leads to uric acid retention. Use of azathioprine as an alternative has shown to reduce the incidence of gouty arthritis.Ciclosporin is listed as an IARC Group 1 carcinogen (i.e. there is sufficient evidence of carcinogenicity in humans), specifically leading to squamous cell skin cancer and non-Hodgkin lymphoma.
Pharmacology
Mechanism of action
Ciclosporins main effect is to lower the activity of T-cells; it does so by inhibiting calcineurin in the calcineurin–phosphatase pathway and preventing the mitochondrial permeability transition pore from opening. Ciclosporin binds to the cytosolic protein cyclophilin (immunophilin) of lymphocytes, especially of T cells. This cyclosporin—cyclophilin complex inhibits calcineurin, which is normally responsible for activating the transcription of interleukin 2. In T-cells, activation of the T-cell receptor normally increases intracellular calcium, which acts via calmodulin to activate calcineurin. Calcineurin then dephosphorylates the transcription factor NF-AT (nuclear factor of activated T-cells), which moves to the T-cell nucleus and increases the transcription of genes for IL-2 and related cytokines. Ciclosporin, by preventing the dephosphorylation of NF-AT, leads to reduced effector T-cell function; it does not affect cytostatic activity.Ciclosporin also binds to the cyclophilin D protein that constitutes part of the mitochondrial permeability transition pore (MPTP), thus preventing MPTP opening. The MPTP is found in the mitochondrial membrane of cardiac muscle cells. MPTP opening signifies a sudden change in the inner mitochondrial membrane permeability, allowing protons and other ions and solutes of a size up to ~1.5 kDa to go through the inner membrane. This change of permeability is considered a cellular catastrophe, leading to cell death. However, brief mitochondrial permeability transition pore openings play an essential physiological role in maintaining healthy mitochondrial homeostasis.
Pharmacokinetics
Ciclosporin is a cyclic peptide of 11 amino acids; it contains a single D-amino acid, which is rarely encountered in nature. Unlike most peptides, ciclosporin is not synthesized by ribosomes.Ciclosporin is highly metabolized in humans and animals after ingestion. The metabolites, which include cyclosporin B, C, D, E, H, and L, have less than 10% of ciclosporins immunosuppressant activity and are associated with higher kidney toxicity. Individual ciclosporin metabolites have been isolated and characterized but do not appear to be extensively studied.
Biosynthesis
Cyclosporin is synthesized by a nonribosomal peptide synthetase, cyclosporin synthetase. The enzyme contains an adenylation domain, a thiolation domain, a condensation domain, and an N-methyltransferase domain. The adenylation domain is responsible for substrate recognition and activation, whereas the thiolation domain covalently binds the adenylated amino acids to phosphopantetheine, and the condensation domain elongates the peptide chain. Cyclosporin synthetase substrates include L-valine, L-leucine, L-alanine, glycine, 2-aminobutyric acid, 4-methylthreonine, and D-alanine, which is the starting amino acid in the biosynthetic process. With the adenylation domain, cyclosporin synthetase generates the acyl-adenylated amino acids, then covalently binds the amino acid to phosphopantetheine through a thioester linkage. Some of the amino acid substrates become N-methylated by S-adenosyl methionine. The cyclization step releases cyclosporin from the enzyme. Amino acids such as D-Ala and butenyl-methyl-L-threonine (Bmt) indicate cyclosporin synthetase requires the action of other enzymes. The racemization of L-Ala to D-Ala by alanine racemase is pyridoxal phosphate-dependent. The formation of butenyl-methyl-L-threonine is performed by a Bmt polyketide synthase that uses acetate/malonate as its starting material.
Gene cluster
Tolypocladium inflatum, the species currently used for mass production of Cyclosporin, has the biosynthetic genes arranged into a 12-gene cluster. Of these 12 genes, SimA (Q09164) is the cyclosporin synthetase, SimB (CAA02484.1) is the alanine racemase, and SimG (similar to ATQ39432.1) is the polyketide synthase. These genes are associated with an active retrotransposon. Although these sequences are poorly-annotated on GenBank and other databases, 90% similar sequences can be found for the Cyclosporin-producing Beauveria felina (or Amphichorda ~). SimB has two paralogs in the same organism with different but overlapping functions thanks to their low speficity.
History
In 1970, new strains of fungi were isolated from soil samples taken from Norway and from Wisconsin in the US by employees of Sandoz (now Novartis) in Basel, Switzerland. Both strains produced a family of natural products called cyclosporins. Two related components that had antifungal activity were isolated from extracts from these fungi. The Norwegian strain, Tolypocladium inflatum Gams, was later used for the large scale fermentation of ciclosporin.The immunosuppressive effect of the natural product ciclosporin was discovered on January 31, 1972 in a screening test on immune suppression designed and implemented by Hartmann F. Stähelin at Sandoz. The chemical structure of cyclosporin was determined in 1976, also at Sandoz. The success of the drug candidate ciclosporin in preventing organ rejection was shown in kidney transplants by R.Y. Calne and colleagues at the University of Cambridge, and in liver transplants performed by Thomas Starzl at the University of Pittsburgh Hospital. The first patient, on 9 March 1980, was a 28-year-old woman. In the United States, the Food and Drug Administration (FDA) approved ciclosporin for clinical use in 1983.
Society and culture
Name
The natural product was named cyclosporin by the German-speaking scientists who first isolated it and cyclosporine when translated into English. Per International Nonproprietary Name (INN) guidelines for drugs, the y was replaced with i so that the INN for the medication is spelled ciclosporin.Ciclosporin is the INN and the British Approved Name (BAN), while cyclosporine is the United States Adopted Name (USAN) and cyclosporin is a former BAN.
Available forms
Ciclosporin exhibits very poor solubility in water, and, as a consequence, suspension and emulsion forms of the medication have been developed for oral administration and for injection. Ciclosporin was originally brought to market by Sandoz (now Novartis), under the brand name Sandimmune, which is available as soft gelatin capsules, an oral solution, and a formulation for intravenous administration. These are all nonaqueous compositions. A newer microemulsion, orally-administered formulation, Neoral, is available as a solution and as soft gelatin capsules. The Neoral compositions are designed to form microemulsions in contact with water.Generic ciclosporin preparations have been marketed under various trade names, including Cicloral (Sandoz/Hexal), Gengraf (Abbott) and Deximune (Dexcel Pharma). Since 2002, a topical emulsion of ciclosporin for treating inflammation caused by keratoconjunctivitis sicca (dry eye syndrome) has been marketed under the trade name Restasis. Ikervis is a similar formulation with a concentration of 0.1%. Inhaled ciclosporin formulations are in clinical development, and include a solution in propylene glycol and liposome dispersions.
Research
Neuroprotection
Ciclosporin is currently in a phase II/III (adaptive) clinical study in Europe to determine its ability to ameliorate neuronal cellular damage and reperfusion injury (phase III) in traumatic brain injury. This multi-center study is being organized by NeuroVive Pharma and the European Brain Injury Consortium using NeuroVives formulation of ciclosporin called NeuroSTAT (also known by its cardioprotection trade name of CicloMulsion). This formulation uses a lipid emulsion base instead of cremophor and ethanol. NeuroSTAT was compared to Sandimmune in a phase I study and found to be bioequivalent. In this study, NeuroSTAT did not exhibit the anaphylactic and hypersensitivity reactions found in cremophor- and ethanol-based products.Ciclosporin has been investigated as a possible neuroprotective agent in conditions such as traumatic brain injury, and has been shown in animal experiments to reduce brain damage associated with injury. Ciclosporin blocks the formation of the mitochondrial permeability transition pore, which has been found to cause much of the damage associated with head injury and neurodegenerative diseases. Ciclosporins neuroprotective properties were first discovered in the early 1990s when two researchers (Eskil Elmér and Hiroyuki Uchino) were conducting experiments in cell transplantation. An unintended finding was that cyclosporin A was strongly neuroprotective when it crossed the blood–brain barrier. This same process of mitochondrial destruction through the opening of the MPT pore is implicated in making traumatic brain injuries much worse.
Cardiac disease
Ciclosporin has been used experimentally to treat cardiac hypertrophy (an increase in cell volume).
Inappropriate opening of the mitochondrial permeability transition pore (MPTP) manifests in ischemia (blood flow restriction to tissue) and reperfusion injury (damage occurring after ischemia when blood flow returns to tissue), after myocardial infarction (heart attack) and when mutations in mitochondrial DNA polymerase occur. The heart attempts to compensate for disease state by increasing the intracellular Ca2+ to increase the contractility cycling rates. Constitutively high levels of mitochondrial Ca2+ cause inappropriate MPTP opening leading to a decrease in the cardiac range of function, leading to cardiac hypertrophy as an attempt to compensate for the problem.Cyclosporin A has been shown to decrease cardiac hypertrophy by affecting cardiac myocytes in many ways. Cyclosporin A binds to cyclophilin D to block the opening of MPTP, and thus decreases the release of protein cytochrome C, which can cause programmed cell death. CypD is a protein within the MPTP that acts as a gate; binding by cyclosporin A decreases the amount of inappropriate opening of MPTP, which decreases the intramitochondrial Ca2+. Decreasing intramitochondrial Ca2+ allows for reversal of cardiac hypertrophy caused in the original cardiac response. Decreasing the release of cytochrome C caused decreased cell death during injury and disease. Cyclosporin A also inhibits the phosphatase calcineurin pathway (14). Inhibition of this pathway has been shown to decrease myocardial hypertrophy.
Veterinary use
The medication is approved in the United States for the treatment of atopic dermatitis in dogs. Unlike the human form of the medication, the lower doses used in dogs mean the drug acts as an immunomodulator and has fewer side effects than in humans. The benefits of using this product include the reduced need for concurrent therapies to bring the condition under control. It is available as an ophthalmic ointment for dogs called Optimmune, manufactured by Intervet, which is part of Merck. It is also used to treat sebaceous adenitis (immune response against the sebaceous glands), pemphigus foliaceus (autoimmune blistering skin disease), Inflammatory bowel disease, anal furunculosis (anal inflammatory disease), and myasthenia gravis (a neuromuscular disease).
References
External links
Cyclosporine at the US National Library of Medicine Medical Subject Headings (MeSH)
"Cyclosporine". Drug Information Portal. U.S. National Library of Medicine.
ChemSub Online : Cyclosporin A |
Methylprednisolone | Methylprednisolone (Depo-Medrol, Medrol, Solu-Medrol) is a synthetic glucocorticoid, primarily prescribed for its anti-inflammatory and immunosuppressive effects. It is either used at low doses for chronic illnesses or used concomitantly at high doses during acute flares. Methylprednisolone and its derivatives can be administered orally or parenterally.Regardless of route of administration, methylprednisolone integrates systemically as exhibited by its effectiveness to quickly reduce inflammation during acute flares. It is associated with many adverse reactions that require tapering off the drug as soon as the disease is under control. Serious side effects include iatrogenic Cushings Syndrome, hypertension, osteoporosis, diabetes, infection, and skin atrophy.Chemically, methylprednisolone is a synthetic pregnane steroid hormone derived from hydrocortisone and prednisolone. It belongs to a class of synthetic glucocorticoids and more generally, corticosteroids. It acts as a mineralocorticoid and glucocorticoid receptor agonist. In comparison to other exogenous glucocorticoids, methylprednisolone has a higher affinity to glucocorticoid receptors than to mineralocorticoid receptors.
Glucocorticoids name was derived after the discovery of their involvement in regulating carbohydrate metabolism. The cellular functions of glucocorticoids, such as methylprednisolone, are now understood to regulate homeostasis, metabolism, development, cognition, and inflammation. They play a critical role in adapting and responding to environmental, physical and emotional stress.Methylprednisolone was first synthesized and manufactured by The Upjohn Company (now Pfizer) and FDA approved in the United States in October 1957. In 2019, it was the 161st most commonly prescribed medication in the United States, with more than 3 million prescriptions. Methylprednisolone is also on the World Health Organizations List of Essential Medicines for its effects against lymphoid leukemia.
Pharmacodynamics
Methylprednisolone is a synthetic glucocorticoid (GCs) that exhibits pleiotropic effects on a variety of physiological mechanisms. However, they have been prescribed extensively for their effects on inflammation and immunity. The effects of synthetic glucocorticoids, such as methylprednisolone, is dependent on its association with intracellular glucocorticoid receptors (GRs), and to a lesser extent, mineralocorticoid receptors (MRs). GRs are widely distributed in contrast to MRs that show a restricted tissue distribution. By this mechanism, the ligand-bound receptor translocate to the nucleus and modulate gene expression.
Signal transduction
In the absence of endogenous or synthetic GCs, monomeric GRs are located in the cytoplasm and form multiprotein complexes with heat shock proteins (HSPs), immunophilins, and other chaperones such as src, and p23. The GR acts in a ligand-dependent manner, with the complex holding the GR in an inactive form with high specificity for the ligand. When methylprednisolone from the plasma or interstitial fluid diffuses passively across the cell membrane, it binds to the GR inducing a conformational change and GC-GR dimerization. It was previously thought that this conformational change was necessary to dissociate the multiprotein complex to allow the ligand bound receptor to translocate to the nucleus. However, recent studies have indicated that chaperones play a role in nuclear import. The now active methylprednisolone-GR complex can either transduce non-genomic changes in the cytoplasm or translocate to the nucleus and regulate transcriptional activity of target genes by direct, tethering or composite mechanisms.
Genomic signaling
Genomic mechanisms, regardless of which type, elicit responses with a slow onset and a slow dissipation. This is attributed to the duration of mRNA transcription and translation. Glucocorticoids have the ability to regulate roughly 100 to 1000 genes with specificity to cell-type.Three major mechanisms have described how the MP-GR complex alter gene expression by either binding to DNA or transcription modulators. One mechanism of genomic signaling occurs when the MP-GR complex directly binds to DNA sequences called glucocorticoid response elements (GREs). GREs are located in regulatory regions of target genes and mediate their transactivation or transrepression. For example, the activation of lipocortin 1 (ANAX1) negatively interferes with the production of prostaglandins and leukotrienes, known pro-inflammatory signals. Likewise, negative GREs (nGREs) are responsible for repressing genes involved in immune cell activation.
Post transcriptional modifications
Post translational modifications (PTMs) also contribute to methylprednisolone signaling and can produce genomic and non-genomic effects. The GR has contains several sites for phosphorylation, sumoylation, ubiquitination, and acetylation that primarily occurs after intracellular methylprednisolone binding to the GR. PTMs modulate many functions including nuclear translocation, strength and duration of receptor signaling and cofactor interaction. A specific example is the deacetylation by histone deacetylase 2 (HDACe) was necessary for transrepression of NF-κB.
Non-genomic signaling
The mechanisms of non-genomic signaling are distinct from genomic signaling, yet mediate similar pathways and provide therapeutic relevance. These mechanisms are characterized as having a rapid onset (less than 15 minutes), because they do not rely on time-consuming transcription or translation and are not modified by inhibitors of transcription.Methylprednisolone induced non-genomic signaling is classified by three mechanisms: (1) cytoplasmic glucocorticoid receptor (cGR)-mediated non-genomic effects, (2) membrane-bound glucocorticoid receptor (mGR) non-genomic effects, and (3) physiochemical interactions with cellular membranes (non-specific non-genomic effects).Proteins that dissociate from the activated GC-cGR complex, initiate intracellular transcription-independent mechanisms. It is evidence that dissociated SRC is responsible for inhibiting the release of arachidonic acid (AA) from cell membrane phospholipids. AA is required for the synthesis of inflammatory mediators (prostaglandins and leukotrienes) and thus AA inhibition mediates several important pathways such as cellular growth, metabolism and inflammation.Previous studies identified mGRs in lymphoma cells, but it wasnt until 2004 that mGRs were identified in human peripheral mononuclear cells. The prevalence of mGRs ranges per cell type, with the highest concentration in B lymphocytes at up to 12.3%, up to 9.2% in monocytes, and absent from T lymphocytes. Studies have shown a positive correlation between the mGR-positive cells and disease related activity. There are no proven signaling pathways associated with mGR at this time. Some researchers hypothesize that high disease activity activates mGR expression and upon administering methylprednisolone, creates a negative feedback loop by inducing apoptosis.High concentrations of methylprednisolone intercalate in plasma and mitochondrial cellular membranes. This association changes physiochemical properties of the membrane; activating membrane proteins, altering cellular functions and ultimately influencing cation transport through the plasma membrane and stimulating the proton leak across the inner mitochondrial membrane. Hindered oxidative phosphorylation compromises ATP production, a major energy source for cellular energy metabolism and immune function. In vivo studies of Con-A stimulated thymocytes (in rats) and human immune cells that were administered high doses of methylprednisolone has been shown to inhibit respiration in a dose-dependent manner, inhibit plasma calcium and sodium uptake, and increase cytoplasmic calcium concentration. The summative process is as follows: Methylprednisolone intercalates in the plasma membrane, causes physiochemical changes, activates membrane proteins that inhibit plasma calcium and sodium uptake (mimicking an energy deficit state). ATP consumption drops (resembled by inhibited respiration), resulting in protein permeability at the inner mitochondrial membrane and uncoupling of oxidative phosphorylation. Of notable importance, DNA/RNA synthesis was not hindered. The dependency of house keeping cells and immune cells on ATP, results in immunosuppression during ATP deficit. Specific immune functions effected by this process are cytokinesis, migration, phagocytosis, antigen processing and presenting, antibody synthesis, cytotoxicity and regulation.
The HPA axis
The activation of the hypothalamic-pituitary axis (HPA axis) stimulates the production of endogenous glucocorticoids within the adrenal cortex. The HPA axis interprets stimuli (stress, inflammation and circadian cues) and transduces a corresponding physiochemical response. Glucocorticoids released in the blood, serve as a messenger by binding to glucocorticoid receptors in a wide distribution across the body, including the HPA axis itself. Thus, the physiological range of GCs is monitored by the negative feedback loop GCs exert on any portion of the HPA axis. Methylprednisolone structurally and functionally mimics endogenous corticoids and will act upon the HPA axis in a similar fashion.
Pharmacokinetics
Methylprednisolone is approved for oral and parenteral administration. Methylprednisolone (Medrol) for oral administration is available in a tablet formulation in 2 mg, 4 mg, 8 mg, 16 mg or 32 mg strengths. Both methylprednisolone acetate (Depo-Medrol) and methylprednisolone succinate (Solu-Medrol) are approved for intramuscular injection. Depo-Medrol is additionally approved for intralesional, intra-articular, and soft tissue injections. Depo-Medrol is available as sterile aqueous solution in 20 mg/mL, 40 mg/mL, or 80 mg/mL strengths. Solu-Medrol is the only derivative of methylprednisolone that is approved for intravenous infusion, as the sterile powder is soluble in water and can be mixed with a diluent. Strengths vary from 40 mg to 2g.Synthetic glucocorticoids are similar to endogenous steroids in metabolism, but differ in affinity for glucocorticoid and mineralocorticoid receptors, affinity for protein-binding, rate of elimination, and metabolic products.Oral methylprednisolone is readily absorbed from the gastrointestinal tract with a bioavailability of 89.9%. In contrast to endogenous GCs, methylprednisolone does not bind to the glycoprotein transcortin (corticosteroid binding globulin, CBG) but does have moderate protein binding to albumin. Thus, pharmacokinetics of methylprednisolone is linear and show no dose dependency. Patients exhibiting low albumin concentrations are at risk for adverse effects during glucocorticoid therapy. Oral methylprednisolone has a moderate distribution into tissue at 1.38L/kg.Methylprednisolone is primarily eliminated by hepatic metabolism and renal excretion of metabolites; with renal excretion of unchanged methylprednisolone at only 1.3–9.2%. Methylprednisolone can be interconverted with methylprednisone. Hepatic metabolism is mediated by 11 beta-hydroxysteroid dehydrogenases (11[beta]-HSD) and 20-ketosteroid reductases. Methylprednisolone undergoes renal excretion of hydrophilic inactive metabolites, including 20-carboxymelthylprednisolone and 6[beta]-hydroxy-20[alpha]-hydroxymethylprednisolone.
Medical uses
As stated previously, the primary use of methylprednisolone is to suppress inflammatory and immune responses. Methylprednisolone achieves this primarily by regulating the number and function of leukocytes, cytokines and chemokines. Its widespread inflammatory control is conducive in use across multiple disorders regardless of pathology. Methylprednisolone is commonly prescribed as short-term therapy for acute flares, as seen with acute gouty arthritis. It can be prescribed during on-going therapy in lower doses contingent upon monitorization of adverse effects. Dosage strength and formulation are optimized per medical use.
Asthma
In 2001–2002, 11.4% of patients diagnosed with asthma and seen at an outpatient visit were prescribed oral corticosteroids as a long-term control therapy. The National Asthma Education and Prevention Program (NAEPP) indicates systemic methylprednisolone in both short and long term therapies to quickly control and to suppress persistent asthma, respectively. For exacerbations that result in a visit to the Emergency Department (ED), oral methylprednisolone is preferred over intravenous administration, unless there are issues with adherence or vomiting. Oral methylprednisolone is less invasive and studies have shown that equivalent efficacy compared to intravenous methylprednisolone. Dosage above 60–80 mg/day or 2 mg/kg/day is not recommended as it has not been shown to alter pulmonary function, rate of admission, or length of stay in the hospital compared to lower doses. Following ED discharge, it is advised to prescribed a five-day course of methylprednisolone to decrease the probability of relapse or withdrawal symptoms.
Rheumatic diseases
Methylprednisolone is used to treat several rheumatic diseases, such as Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA). Methylprednisolone dosage and administration for these diseases is highly variable due to varied pathophysiology between the diseases and within patients diagnosed with a given disease. In Lupus Nephritis, a common manifestation of SLE, patients are often prescribed methylprednisolone concomitantly with immunosuppressants. Severe manifestations are often treated with Cyclophosphamide or Rituximab and three doses of methylprednisolone IV-pulse treatment (as recommended by ACR guidelines) prior to switching to oral prednisolone and azathioprine for maintenance.Intra-articular corticosteroid injections (IACI) are a second line therapy to relieve joint pain resulting from rheumatoid arthritis. It is most commonly injected into the joints of the knees and shoulders. Although the injection is local, studies have shown systemic absorption as evidenced by beneficial effects on distant joints. In an attempt to minimize HPA suppression, FDA guidelines have restricted IACIs to three per year, with a minimum of 30 days in between injections.
Primary or secondary adrenocortical insufficiency
Methylprednisolone is not typically recommended for primary or secondary adrenocortical insufficiency compared to other corticosteroids which have a higher affinity for mineralocorticoid receptor and salt retaining properties.
Labeled indications
The labeled indications below are categorized by route of administration then by medical discipline.
Oral methylprednisolone
Allergy and Immunology: angioneurotic edema, asthma, urticaria, seasonal or perennial allergic rhinitis, drug hypersensitivity reactions, and serum sickness.
Dermatology: toxic epidermal necrolysis, atopic dermatitis, contact dermatitis, pemphigus, erythema multiforme, Steven-Johnson syndrome, bullous dermatitis herpetiformis, severe seborrheic dermatitis, exfoliative dermatitis, mycosis fungoides, and severe psoriasis.
Endocrinology: congenital adrenal hyperplasia, hypercalcemia associated with cancer, nonsuppurative thyroiditis, and primary or secondary adrenocortical insufficiency.
Gastroenterology: inflammatory bowel disease and ulcerative colitis.
Hematology: acquired (autoimmune) hemolytic anemia, idiopathic thrombocytopenic purpura, secondary thrombocytopenia, erythroblastopenia, leukemia, lymphoma and congenital (erythroid) hypoplastic anemia.
Pulmonary: aspiration pneumonitis, chronic beryllium disease, eosinophilic pneumonia, symptomatic sarcoidosis, and pulmonary tuberculosis in conjunction with antituberculosis chemotherapy.
Nephrology: nephrotic syndrome, idiopathic type or secondary to lupus nephritis.
Neurology: multiple sclerosis.
Ophthalmology: scleritis, retinal vasculitis, uveitis, choroiditis, iritis, iridocyclitis, keratitis, optic neuritis, allergic conjunctivitis, allergic corneal marginal ulcers, herpes zoster ophthalmicus, sympathetic ophthalmia, and chorioretinitis.
Rheumatology: rheumatoid arthritis, rheumatic carditis, acute gouty arthritis, ankylosing spondylitis, dermatomyositis and polymyositis, psoriatic arthritis, systemic lupus erythematosus, acute and subacute bursitis, synovitis of osteoarthritis, post-traumatic osteoarthritis, and epicondylitis.
Miscellaneous: trichinosis with neurologic or myocardial involvement.
Parenteral methylprednisolone
Intra-articular or soft tissue injections: acute gouty arthritis, acute and subacute bursitis, acute tenosynovitis, epicondylitis, and synovitis of osteoarthritis.
Intralesional injections: alopecia areata, discoid lupus erythematosus, keloids, granuloma annulare, lichen planus, lichen simplex chronicus, psoriatic plaques, necrobiosis lipoidica diabeticorum.
Intramuscular injections are prescribed treat many of the same conditions indicated for oral administration. Intramuscular injections are administered as an alternative to oral therapy.
Off-label indications
Some of the off-label indications of methylprednisolone include acute spinal cord injury, acute respiratory distress syndrome, alcoholic hepatitis, hormonal resuscitation in cadaveric organ recovery, and chronic obstructive pulmonary disease.
Available forms
Footnotes:
1Signifies varying strengths of available forms. Is not indicative of frequency nor daily cumulative dose; varies per patient and condition.
2Benzyl alcohol should not to be used on neonates
3Preservative free formulation
Contraindications
Methylprednisolone should not be taken orally by people who have systemic fungal infections, with the exception of Depo-Medrol when administered as an intra-articular injection for localized joint conditions. Methylprednisolone is contraindicated in those with known hypersensitivity to methylprednisolone or its components Steroids should be used with caution in patients with ulcerative colitis, heart disease or hypertension, peptic ulcer, renal insufficiency, osteoporosis, myasthenia gravis, glaucoma, and diabetes. Psychic manifestations may appear while taking methylprednisolone, ranging from euphoria, insomnia, personality changes to depression. Caution is required for patients with predisposed psychoses, as psychotic tendencies may be exacerbated while taking corticosteroids.Solu-Medrol 40 mg dosage contains lactose monohydrate produced from cows milk; It should not be taken by anyone with known hypersensitivity to dairy products or its components. Severe medical events have been associated with epidural administration of Solu-Medrol and Depo-Medrol, including spinal cord infarction, paraplegia, quadriplegia, cortical blindness and stroke. Intramuscular injections should not be administered to those with idiopathic thrombocytopenic purpura. Formulations of Solu-Medrol and Depo-Medrol containing benzyl alcohol are contraindicated for use in premature infants. Exposure of neural tissue to excessive amounts of benzyl alcohol has been associated with toxicity and in rare events has resulted in death.
Adverse reactions
Adverse reactions may overshadow the therapeutic effects of methylprednisolone.
Central nervous system
There is minimal clinical diagnostic criteria to define the psychic adverse effects (PAE) associated with methylprednisolone use in patients with systemic lupus erythematosus (SLE). The prevalence varies from 1.3 to 62% of adult treated patients. The type and severity of neuropsychiatric symptoms also varies significantly between patients, with 33% of patients reporting mild to moderate PAE and 5-10% reporting severe PAE. Methylprednisolone dose and duration have been implicated in PAE development. 20 mg/day of prednisone (16 mg/day of methylprednisolone) is the threshold dosage for PAE development agreed upon by many studies. Short-term pulse IV therapy at high doses is associated with rapid onset of manic and hypomanic symptoms, whereas long term therapy gives rise to depressive symptoms (suicide attempts infrequent). PAE are reversible with treatment reduction or discontinuation.
Metabolic and endocrine
Iatrogenic Cushings Syndrome is a direct complication of glucocorticoid therapy, and the most common cause of exogenous Cushings Syndrome. Clinical features of Cushings Syndrome is inclusive of many adverse effects in glucocorticoid therapy. Traditional symptoms include weight gain, myopathy, osteoporosis, increased risk of infection, hypertension and psychological effect. Fat deposition is centralized on the trunk, in between shoulders ("buffalo hump"), and on the face ("moon face"). Patient education and provider monitoring is the first step in recognizing and diagnosing Iatrogenic Cushings Syndrome. Exogenous glucocorticoids suppress adrenocorticotropic hormone (ATCH) production, which can be verified by AM biochemical analysis. The onset of side effects varies; neuropsychiatric symptoms can arise within a few hours, while osteoporosis would take months to develop.The metabolic effects of taking methylprednisolone involve the continuous breakdown of proteins for gluconeogenesis increase necessity for insulin. This results in hyperlipidemia, weight gain, myopathy that may prompt a patient to cease treatment.
Infections
See: Glucocorticoids § ImmunodeficiencyThe Immunodeficiency section tabulates known pathogens of concern in glucocorticoid induced immunodeficiency.
Musculoskeletal
Osteoporosis is a type of bone disease characterized by a loss of bone density, mass and architecture that leaves a patient susceptible to fractures. The World Health Organization (WHO) defines osteoporosis in caucasian postmenopausal women as a bone mineral density (BMD) and a T-score of -2.5 or less. The prevalence of osteoporosis in patients with SLE varies geographically and some attribute it to BMD and T-score diagnostic appropriateness. British 10.3%, Chinese 21.7%The Canadian Clinical Practice Guidelines and The American College of Rheumatology have switched to using a Z-score as a diagnostic marker for osteoporosis but have failed to find a clinical diagnostic threshold. Additionally, a UK-based study showed that BMD may underrepresent a patient with SLE, as their risk for fractures is 22% higher than the healthy individual.Exogenous corticosteroids induce osteoporosis by increasing bone resorption and reducing bone formation. Bone loss can be pronounced within the first few months of initiating methylprednisolone with a steady decrease with chronic use. Trabecular bone loss in the lumbar spine precedes cortical bone loss in the femoral neck.
Exhaustive list
Allergic: allergic or hypersensitivity reactions, anaphylactoid reaction, anaphylaxis, and urticaria.Cardiovascular: hypertension, congestive heart failure in susceptible patients, premature atherosclerotic disease, arrhythmias, and possible hyperlipidemia.Dermatologic: impaired wound healing, petechiae and ecchymoses, thinning of the skin, facial erythema, and increased sweating.Endocrine: Cushingoid features, growth suppression in children, secondary adrenocortical and pituitary unresponsiveness, menstrual irregularities, decreased carbohydrate intolerance, and latent diabetes mellitus. In patients with diabetes, increased requirements of insulin or oral hypoglycemic agents.Fluid and electrolyte disturbances: sodium retention, fluid retention, potassium loss, hypokalemic alkalosis, or congestive heart failure in susceptible patients.Gastrointestinal: peptic ulcer, pancreatitis, abdominal distention, and ulcerative esophagitis.Metabolic: protein catabolism which causes negative nitrogen balance.Musculoskeletal: muscle weakness, loss of muscle mass, steroid myopathy, osteoporosis, tendon rupture (especially Achilles), vertebral compression fractures, aseptic necrosis of femoral and humeral heads, and pathologic fracture of long bones.Neurological: increased intracranial pressure with papilledema, convulsions, vertigo, and headache.Ophthalmic: posterior sub-capsular cataracts, increased intraocular pressure, glaucoma, and exophthalmos.
Withdrawal
Feedback of the exogenous glucocorticoids at the hypothalamic–pituitary–adrenal (HPA) axis inhibits the secretion of the corticotropin-releasing hormone (CRH) and the adrenocorticotropic hormone (ATCH) at the hypothalamus and pituitary glands, respectively. Prolonged suppression leads to inadequate responses to physical and emotional stresses, such as illness and trauma. Suppression of ATCH may result in adrenal hypoplasia or secondary adrenal gland atrophy within 6 weeks of methylprednisolone therapy, leaving a patient at risk for developing life-threatening adrenal insufficiency crisis. Factors that contribute to the extent of HPA axis suppression include steroid hormone potency (type of compound and route of administration), cumulative dose, duration of treatment and concomitant drug use. Any individual who has taken steroid hormones for 2+ weeks is at risk for developing HPA axis suppression. t Systemic methylprednisolone risk has been marked as moderate within the class of synthetic glucocorticoids.Consult with your physician prior to discontinuing methylprednisolone for any reason. Abrupt termination of the drug commonly causes transient non-specific symptoms such as loss of appetite, upset stomach, vomiting, drowsiness, confusion, headache, fever, joint and muscle pain, peeling skin, and weight loss. These symptoms can be attributed to steroid withdrawal syndrome, adrenal insufficiency or disease relapse. Those who have been taking methylprednisolone as a long-term treatment may be gradually be tapered off to minimize withdrawal symptoms and potential for relapse. If symptoms are exacerbated, temporarily increasing methylprednisolone dosage has shown clinical relevancy. Studies retesting patients upon methylprednisolone withdrawal, showed persistent adrenal insufficiency, with one study showing 15% after 3 years. However, there was a wide range of prevalence and lack of uniformity in the follow-up timeline.
Drug interactions
Caution is advised when taking methylprednisolone concurrently with the medications described below.
Enzyme inducers
All drugs that fall within the class of enzyme inducers increase the clearance and decrease the half-life of methylprednisolone when co-administered. Phenobarbital, phenytoin, rifampin, carbamazepine and barbiturates, increase hepatic enzymes and rate of elimination, thus reducing the immunosuppressive effect of methylprednisolone. Increased dosages may be required to achieve desired effect of methylprednisolone.Cytochrome P450 (CYP) 3A4 inhibitors
Troleandomycin, ketoconazole, and Clarithromycin inhibit metabolism; and may decrease rate of elimination and increase half-life of methylprednisolone. Dosages should be decreased accordingly to avoid side effects. Another CYP 3A4 inhibitor, grapefruit juice, prolongs half-life of oral methylprednisolone.Oral contraceptives
Oral contraceptives inhibit oxidative processes, as highlighted by its ability to decrease methylprednisolone clearance.P-glycoprotein inhibitors
Methylprednisolone is shown to be a substrate of P-glycoprotein; its inhibition is thought to increase methylprednisone absorption and distribution. No clinical relevance has been linked.Ciclosporin, tacrolimus, sirolimus (Rapamycin)
Methylprednisolone and cyclosporin inhibit metabolism and therefore increase the likelihood of experiencing side effects associated with either of the individual drugs. In addition to known individual side effects, convulsions have been reported.Cox1 inhibitors
Methylprednisolone may increase rate of elimination with chronic high dose aspirin. Patients are susceptible to increased salicylate serum levels or salicylate toxicity upon termination |
Methylprednisolone | of methylprednisolone. Excessive caution should be taken when prescribing methylprednisolone and aspirin to patients with hypoprothrombinemia.Anticoagulants
Anticoagulants exhibit variable interactions; monitoring coagulation indices is recommended to achieve the desired effect.
Physical properties
Oral methylprednisolone (Medrol) and its derivatives are a white, odorless crystalline powder. Its solubility ranges from practically insoluble in water, very slightly soluble in ether, sightly soluble in acetone and chloroform to sparingly soluble in alcohol, dioxane and methanol. Methylprednisolone acetate suspension (Depo-Medrol) is a 6-methyl derivative of prednisolone that melts at 215 degrees Celsius with some decomposition. Methylprednisolone sodium succinate (Solu-Medrol) is the sodium succinate ester of methylprednisolone. Contrary to the solubilities above, methylprednisolone sodium succinate is soluble in water and alcohol, slightly soluble in acetone and insoluble in chloroform
Chemical properties
Methylprednisolone, or 6α-methylprednisolone, also known as 11β,17,21-trihydroxy-6α-methylpregna-1,4-diene-3,20-dione, is a synthetic pregnane steroid and a derivative of hydrocortisone (11β,17α,21-trihydroxypregn-4-ene-3,20-dione) and prednisolone (11β,17α,21-trihydroxypregn-1,4-diene-3,20-dione). A variety of methylprednisolone esters with differing characteristics exist and have been marketed for medical use. They include methylprednisolone aceponate (Advantan), methylprednisolone acetate (Depo-Medrol), methylprednisolone succinate (Solu-Medrol), and methylprednisolone suleptanate (Medrosol, Promedrol).
Synthesis
Synthetic steroids are synthesized from cholic acid and sapogenins obtained from cattle and plants, respectively.
History, society and culture
Methylprednisolone was first synthesized and manufactured by The Upjohn Company (now Pfizer) and Food and Drug Administration (FDA) approved in the United States on 2 October 1957. The patent has since expired, and generics are now available. In 2021, it is ranked as the 153rd most commonly prescribed medication in the United States, with more than four million prescriptions. It has jumped four spots in the rankings from 2017. Methylprednisolone has been a prescribed therapy amidst the COVID-19 pandemic, but there is no evidence it is either safe or effective for this purpose.
Research
Methylprednisolone has been a prescribed therapy amidst the COVID-19 pandemic, but there is no evidence it is either safe or effective for this purpose.
References
External links
"Methylprednisolone". Drug Information Portal. U.S. National Library of Medicine. |
Paroxetine | Paroxetine, sold under the brand names Paxil and Seroxat among others, is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. It is used to treat major depressive disorder, obsessive-compulsive disorder, panic disorder, social anxiety disorder, posttraumatic stress disorder, generalized anxiety disorder and premenstrual dysphoric disorder. It has also been used in the treatment of premature ejaculation and hot flashes due to menopause. It is taken by mouth.Common side effects include drowsiness, dry mouth, loss of appetite, sweating, trouble sleeping, and sexual dysfunction. Serious side effects may include suicidal thoughts in those under the age of 25, serotonin syndrome, and mania. While the rate of side effects appears similar compared to other SSRIs and SNRIs, antidepressant discontinuation syndromes may occur more often. Use in pregnancy is not recommended, while use during breastfeeding is relatively safe. It is believed to work by blocking the re-uptake of the chemical serotonin by neurons in the brain.Paroxetine was approved for medical use in the United States in 1992 and initially sold by GlaxoSmithKline. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2019, it was the 78th most commonly prescribed medication in the United States, with more than 9 million prescriptions. In 2018, it was in the top 10 of most prescribed antidepressants in the United States. In 2012, the United States Department of Justice fined GlaxoSmithKline $3 billion for withholding data, unlawfully promoting use in those under 18, and preparing an article that misleadingly reported the effects of paroxetine in adolescents with depression following its clinical trial study 329.
Medical uses
Paroxetine is primarily used to treat major depressive disorder, obsessive-compulsive disorder, post-traumatic stress disorder, social anxiety disorder, and panic disorder. It is also occasionally used for agoraphobia, generalized anxiety disorder, premenstrual dysphoric disorder and menopausal hot flashes.
Depression
A variety of meta analyses have been conducted to evaluate the efficacy of paroxetine in depression. They have variously concluded that paroxetine is superior or equivalent to placebo and that it is equivalent or inferior to other antidepressants. Despite this, there was no clear evidence that paroxetine was better or worse compared with other antidepressants at increasing response to treatment at any point in time.
Anxiety disorders
Paroxetine was the first antidepressant approved in the United States for the treatment of panic disorder. Several studies have concluded that paroxetine is superior to placebo in the treatment of panic disorder.Paroxetine has demonstrated efficacy for the treatment of social anxiety disorder in adults and children. It is also beneficial for people with co-occurring social anxiety disorder and alcohol use disorder. It appears to be similar to a number of other SSRIs.Paroxetine is used in the treatment of obsessive-compulsive disorder. Comparative efficacy of paroxetine is equivalent to that of clomipramine and venlafaxine. Paroxetine is also effective for children with obsessive-compulsive disorder.Paroxetine is approved for treatment of PTSD in the United States, Japan and Europe. In the United States it is approved for short-term use.Paroxetine is also FDA-approved for generalized anxiety disorder.
Menopausal hot flashes
In 2013, low-dose paroxetine was approved in the US for the treatment of moderate-to-severe vasomotor symptoms such as hot flashes and night sweats associated with menopause. At the low dose used for menopausal hot flashes, side effects are similar to placebo and dose tapering is not required for discontinuation.
Fibromyalgia
Studies have also shown paroxetine "appears to be well-tolerated and improve the overall symptomatology in patients with fibromyalgia" but is less robust in helping with the pain involved.
Adverse effects
Common side effects include drowsiness, dry mouth, loss of appetite, sweating, trouble sleeping, and sexual dysfunction. Serious side effects may include suicide in those under the age of 25, serotonin syndrome, and mania. While the rate of side effects appears similar compared to other SSRIs and SNRIs, antidepressant discontinuation syndromes may occur more often. Use in pregnancy is not recommended while use during breastfeeding is relatively safe.Paroxetine shares many of the common adverse effects of SSRIs, including (with the corresponding rates seen in people treated with placebo in parentheses):
nausea 26% (9%)
diarrhea 12% (8%)
constipation 14% (9%)
dry mouth 18% (12%)
somnolence 23% (9%)
insomnia 13% (6%)
headache 18% (17%)
hypomania 1% (0.3%)
blurred vision 4% (1%)
loss of appetite 6% (2%)
nervousness 5% (3%)
paraesthesia 4% (2%)
dizziness 13% (6%)
asthenia (weakness; 15% (6%))
tremor 8% (2%)
sweating 11% (2%)
sexual dysfunction (≥10% incidence).Most of these adverse effects are transient and go away with continued treatment. Central and peripheral 5-HT3 receptor stimulation is believed to result in the gastrointestinal effects observed with SSRI treatment. Compared to other SSRIs, it has a lower incidence of diarrhea, but a higher incidence of anticholinergic effects (e.g., dry mouth, constipation, blurred vision, etc.), sedation/somnolence/drowsiness, sexual side effects, and weight gain.Due to reports of adverse withdrawal reactions upon terminating treatment, the Committee for Medicinal Products for Human Use (CHMP) at the European Medicines Agency recommends gradually reducing over several weeks or months if the decision to withdraw is made. See also Discontinuation syndrome (withdrawal).
Mania or hypomania may occur in 1% of patients with depression and up to 12% of patients with bipolar disorder. This side effect can occur in individuals with no history of mania but it may be more likely to occur in those with bipolar or with a family history of mania.
Suicide
Like other antidepressants, paroxetine may increase the risk of suicidal thinking and behaviour in people under the age of 25. The FDA conducted a statistical analysis of paroxetine clinical trials in children and adolescents in 2004 and found an increase in suicidality and ideation as compared to placebo, which was observed in trials for both depression and anxiety disorders. In 2015 a paper published in The BMJ that reanalysed the original case notes argued that in Study 329, assessing paroxetine and imipramine against placebo in adolescents with depression, the incidence of suicidal behavior had been under-reported and the efficacy exaggerated for paroxetine.
Sexual dysfunction
Sexual dysfunction, including loss of libido, anorgasmia, lack of vaginal lubrication, and erectile dysfunction, is one of the most commonly encountered adverse effects of treatment with paroxetine and other SSRIs. While early clinical trials suggested a relatively low rate of sexual dysfunction, more recent studies in which the investigator actively inquires about sexual problems suggest that the incidence is higher than 70%. Symptoms of sexual dysfunction have been reported to persist after discontinuing SSRIs, although this is thought to be occasional.
Pregnancy
Antidepressant exposure (including paroxetine) is associated with shorter duration of pregnancy (by three days), increased risk of preterm delivery (by 55%), lower birth weight (by 75 g or 2.6 oz), and lower Apgar scores (by <0.4 points). The American College of Obstetricians and Gynecologists recommends that for pregnant women and women planning to become pregnant, paroxetine "be avoided, if possible", as it may be associated with increased risk of birth defects.Babies born to women who used paroxetine during the first trimester have an increased risk of cardiovascular malformations, primarily ventricular and atrial septal defects (VSDs and ASDs). Unless the benefits of paroxetine justify continuing treatment, consideration should be given to stopping or switching to another antidepressant. Paroxetine use during pregnancy is associated with about 1.5–1.7-fold increase in congenital birth defects, in particular, heart defects, cleft lip and palate, clubbed feet or any birth defects.
Discontinuation syndrome
Many psychoactive medications can cause withdrawal symptoms upon discontinuation from administration. Evidence has shown that paroxetine has among the highest incidence rates and severity of withdrawal syndrome of any medication of its class. Common withdrawal symptoms for paroxetine include nausea, dizziness, lightheadedness and vertigo; insomnia, nightmares and vivid dreams; feelings of electricity in the body, as well as rebound depression and anxiety. Liquid formulation of paroxetine is available and allows a very gradual decrease of the dose, which may prevent discontinuation syndrome. Another recommendation is to temporarily switch to fluoxetine, which has a longer half-life and thus decreases the severity of discontinuation syndrome.In 2002, the U.S. FDA published a warning regarding "severe" discontinuation symptoms among those terminating paroxetine treatment, including paraesthesia, nightmares, and dizziness. The Agency also warned of case reports describing agitation, sweating, and nausea. In connection with a Glaxo spokespersons statement that withdrawal reactions occur only in 0.2% of patients and are "mild and short-lived", the International Federation of Pharmaceutical Manufacturers Associations said GSK had breached two of the Federations codes of practice.Paroxetine prescribing information posted at GlaxoSmithKline has been updated related to the occurrence of a discontinuation syndrome, including serious discontinuation symptoms.
Overdose
Acute overdosage is often manifested by emesis, lethargy, ataxia, tachycardia, and seizures. Plasma, serum, or blood concentrations of paroxetine may be measured to monitor therapeutic administration, confirm a diagnosis of poisoning in hospitalized patients or to aid in the medicolegal investigation of fatalities. Plasma paroxetine concentrations are generally in a range of 40–400 μg/L in persons receiving daily therapeutic doses and 200–2,000 μg/L in poisoned patients. Postmortem blood levels have ranged from 1–4 mg/L in acute lethal overdose situations. Along with the other SSRIs, sertraline and fluoxetine, paroxetine is considered a low-risk drug in cases of overdose.
Interactions
Interactions with other drugs acting on the serotonin system or impairing the metabolism of serotonin may increase the risk of serotonin syndrome or neuroleptic malignant syndrome (NMS)-like reaction. Such reactions have been observed with SNRIs and SSRIs alone, but particularly with concurrent use of triptans, MAO inhibitors, antipsychotics, or other dopamine antagonists.
The prescribing information states that paroxetine should "not be used in combination with an MAOI (including linezolid, an antibiotic which is a reversible non-selective MAOI), or within 14 days of discontinuing treatment with an MAOI", and should not be used in combination with pimozide, thioridazine, tryptophan, or warfarin.Paroxetine interacts with the following cytochrome P450 enzymes:
CYP2D6 for which it is both a substrate and a potent inhibitor.
CYP2B6 (strong) inhibitor.
CYP3A4 (weak) inhibitor.
CYP1A2 (weak) inhibitor.
CYP2C9 (weak) inhibitor.
CYP2C19 (weak) inhibitor.Paroxetine has been shown to be an inhibitor of G protein-coupled receptor kinase 2 (GRK2).
Pharmacology
Pharmacodynamics
Paroxetine is the most potent and one of the most specific selective serotonin (5-hydroxytryptamine, 5-HT) reuptake inhibitors (SSRIs). It also binds to the allosteric site of the serotonin transporter, similarly, but less potently, than escitalopram. Paroxetine also inhibits the reuptake of norepinephrine to a lesser extent (<50 nmol/L). Based on evidence from four weeks of administration in rats, the equivalent of 20 mg paroxetine taken once daily occupies approximately 88% of serotonin transporters in the prefrontal cortex.
Pharmacokinetics
Paroxetine is well-absorbed following oral administration. It has an absolute bioavailability of about 50%, with evidence of a saturable first pass effect. When taken orally, it achieves maximum concentration in about 6–10 hours and reaches steady-state in 7–14 days. Paroxetine exhibits significant interindividual variations in volume of distribution and clearance. Less than 2% of an oral dose is excreted in urine unchanged.Paroxetine is a mechanism-based inhibitor of CYP2D6.
Society and culture
GlaxoSmithKline has paid substantial fines, paid settlements in class-action lawsuits, and become the subject of several highly critical books about its marketing of paroxetine, in particular the off-label marketing of paroxetine for children, the suppression of negative research results relating to its use in children, and allegations that it failed to warn consumers of substantial withdrawal effects associated with use of the drug. Paroxetine was approved for medical use in the United States in 1992 and initially sold by GlaxoSmithKline. It is currently available as a generic medication. In 2017, it was the 68th most commonly prescribed medication in the United States, with more than eleven million prescriptions. The United States Department of Justice fined GlaxoSmithKline $3 billion in 2012, for withholding data, unlawfully promoting use in those under 18, and preparing an article that misleadingly reported the effects of paroxetine in adolescents with depression following its clinical trial study 329.
Marketing
In early 2004, GSK agreed to settle charges of consumer fraud for $2.5 million. The legal discovery process also uncovered evidence of deliberate, systematic suppression of unfavorable Paxil research results. One of GSKs internal documents read, "It would be commercially unacceptable to include a statement that efficacy [in children] had not been demonstrated, as this would undermine the profile of paroxetine".In 2012 the U.S. Justice Department announced that GSK agreed to plead guilty and pay a $3 billion fine, in part for promoting the use of Paxil for children.On 12 February 2016, the UK Competition and Markets Authority imposed record fines of £45 million on companies which were found to have infringed European Union and UK Competition law by entering into agreements to delay the market entry of generic versions of the drug in the UK. GlaxoSmithKline received the bulk of the fines, being fined £37,600,757. Other companies, which produce generics, were issued fines which collectively total £7,384,146. UK public health services are likely to claim damages for being overcharged in the period where the generic versions of the drug were illegally blocked from the market, as the generics are over 70% less expensive. GlaxoSmithKline may also face actions from other generics manufacturers who incurred loss as a result of the anticompetitive conduct. On 18 April 2016, appeals were lodged with the Competition Appeal Tribunal by the companies which were fined.GSK marketed paroxetine through television advertisements throughout the late 1990s and early 2000s. Commercials also aired for the CR version of the drug beginning in 2003.
Sales
In 2007, paroxetine was ranked 94th on the list of bestselling drugs, with over $1 billion in sales. In 2006, paroxetine was the fifth-most prescribed antidepressant in the U.S. retail market, with more than 19.7 million prescriptions. In 2007, sales had dropped slightly to 18.1 million but paroxetine remained the fifth-most prescribed antidepressant in the U.S.
Trade names
Trade names include Aropax, Paretin, Brisdelle, Deroxat, Paxil, Pexeva, Paxtine, Paxetin, Paroxat, Paraxyl, Sereupin, Daparox and Seroxat.
Research
Several studies have suggested that paroxetine can be used in the treatment of premature ejaculation. In particular, intravaginal ejaculation latency time (IELT) was found to increase with 6- to 13-fold, which was somewhat longer than the delay achieved by the treatment with other SSRIs (fluvoxamine, fluoxetine, sertraline, and citalopram). However, paroxetine taken acutely ("on demand") 3–10 hours before coitus resulted only in a "clinically irrelevant and sexually unsatisfactory" 1.5-fold delay of ejaculation and was inferior to clomipramine, which induced a fourfold delay.There is also evidence that paroxetine may be effective in the treatment of compulsive gambling and hot flashes.Benefits of paroxetine prescription for diabetic neuropathy or chronic tension headache are uncertain.
Although the evidence is conflicting, paroxetine may be effective for the treatment of dysthymia, a chronic disorder involving depressive symptoms for most days of the year.There is evidence to support that paroxetine selectively binds to and inhibits G protein-coupled receptor kinase 2 (GRK2) in mice with heart failure. Since GRK2 regulates the activity of the beta adrenergic receptor, which becomes desensitized in cases of heart failure, paroxetine (or a paroxetine derivative) could be used as a heart failure treatment in the future.Paroxetine has been identified as a potential disease-modifying osteoarthritis drug.
Other organisms
Paroxetine is a common finding in waste water. It is highly toxic to the alga Pseudokirchneriella subcapitata (syn. Raphidocelis subcapitata).It also is toxic to the soil nematode Caenorhabditis elegans.Alberca et al., 2016 finds paroxetine acts as a trypanocide against T. cruzi.
See also
List of medical ethics cases
References
External links
"Paroxetine". Drug Information Portal. U.S. National Library of Medicine.
Detailed Paroxetine Consumer Information: Uses, Precautions, Side Effects from medlibrary.org |
Ribavirin | Ribavirin, also known as tribavirin, is an antiviral medication used to treat RSV infection, hepatitis C and some viral hemorrhagic fevers. For hepatitis C, it is used in combination with other medications such as simeprevir, sofosbuvir, peginterferon alfa-2b or peginterferon alfa-2a. Among the viral hemorrhagic fevers it is used for Lassa fever, Crimean–Congo hemorrhagic fever, and Hantavirus infection but should not be used for Ebola or Marburg infections. Ribavirin is taken by mouth or inhaled.Common side effects include feeling tired, headache, nausea, fever, muscle pains, and an irritable mood. Serious side effects include red blood cell breakdown, liver problems, and allergic reactions. Use during pregnancy results in harm to the baby. Effective birth control is recommended for both males and females for at least seven months during and after use. The mechanism of action of ribavirin is not entirely clear.Ribavirin was patented in 1971 and approved for medical use in 1986. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication.
Medical uses
Ribavirin is used primarily to treat hepatitis C and viral hemorrhagic fevers (which is an orphan indication in most countries). In this former indication the oral (capsule or tablet) form of ribavirin is used in combination with pegylated interferon alfa, including in people coinfected with hepatitis B, HIV and in the pediatric population. Statins may improve this combinations efficacy in treating hepatitis C. Ribavirin is the only known treatment for a variety of viral hemorrhagic fevers, including Lassa fever, Crimean-Congo hemorrhagic fever, Venezuelan hemorrhagic fever, and Hantavirus infection, although data regarding these infections are scarce and the drug might be effective only in early stages. It is noted by the USAMRIID that "Ribavirin has poor in vitro and in vivo activity against the filoviruses (Ebola and Marburg) and the flaviviruses (dengue, yellow fever, Omsk hemorrhagic fever, and Kyasanur forest disease)" The aerosol form has been used in the past to treat respiratory syncytial virus-related diseases in children, although the evidence to support this is rather weak.It has been used (in combination with ketamine, midazolam, and amantadine) in treatment of rabies.Experimental data indicate that ribavirin may have useful activity against canine distemper and poxviruses. Ribavirin has also been used as a treatment for herpes simplex virus. One small study found that ribavirin treatment reduced the severity of herpes outbreaks and promoted recovery, as compared with placebo treatment. Another study found that ribavirin potentiated the antiviral effect of acyclovir.Some interest has been seen in its possible use as a treatment for cancers, especially acute myeloid leukemia.
Adverse effects
The medication has two FDA "black box" warnings: One raises concerns that use before or during pregnancy by either sex may result in birth defects in the baby, and the other is regarding the risk of red blood cell breakdown.Ribavirin should not be given with zidovudine because of the increased risk of anemia; concurrent use with didanosine should likewise be avoided because of an increased risk of mitochondrial toxicity.
Mechanisms of action
It is a guanosine (ribonucleic) analog used to stop viral RNA synthesis and viral mRNA capping, thus, it is a nucleoside inhibitor. Ribavirin is a prodrug, which when metabolized resembles purine RNA nucleotides. In this form, it interferes with RNA metabolism required for viral replication. Over five direct and indirect mechanisms have been proposed for its mechanism of action. The enzyme inosine triphosphate pyrophosphatase (ITPase) dephosphorylates ribavirin triphosphate in vitro to ribavirin monophosphate, and ITPase reduced enzymatic activity present in 30% of humans potentiates mutagenesis in hepatitis C virus.
RNA viruses
Ribavirins amide group can make the native nucleoside drug resemble adenosine or guanosine, depending on its rotation. For this reason, when ribavirin is incorporated into RNA, as a base analog of either adenine or guanine, it pairs equally well with either uracil or cytosine, inducing mutations in RNA-dependent replication in RNA viruses. Such hypermutation can be lethal to RNA viruses.
DNA viruses
Neither of these mechanisms explains ribavirins effect on many DNA viruses, which is more of a mystery, especially given the complete inactivity of ribavirins 2 deoxyribose analogue, which suggests that the drug functions only as an RNA nucleoside mimic, and never a DNA nucleoside mimic. Ribavirin 5-monophosphate inhibits cellular inosine monophosphate dehydrogenase, thereby depleting intracellular pools of GTP.
History
Ribavirin was first made in 1972 under the national cancer institutes Virus-Cancer program. This was done by researchers from International Chemical and Nuclear Corporation including Roberts A. Smith, Joseph T. Witkovski and Roland K. Robins. It was reported that ribavirin was active against a variety of RNA and DNA viruses in culture and in animals, without undue toxicity in the context of cancer chemotherapies. By the late 1970s, the Virus-Cancer program was widely considered a failure, and the drug development was abandoned.
Names
Ribavirin is the INN and USAN, whereas tribavirin is the BAN. Brand names of generic forms include Copegus, Ribasphere, Rebetol.
Derivatives
Ribavirin is possibly best viewed as a ribosyl purine analogue with an incomplete purine 6-membered ring. This structural resemblance historically prompted replacement of the 2 nitrogen of the triazole with a carbon (which becomes the 5 carbon in an imidazole), in an attempt to partly "fill out" the second ring--- but to no great effect. Such 5 imidazole riboside derivatives show antiviral activity with 5 hydrogen or halide, but the larger the substituent, the smaller the activity, and all proved less active than ribavirin. Note that two natural products were already known with this imidazole riboside structure: substitution at the 5 carbon with OH results in pyrazofurin, an antibiotic with antiviral properties but unacceptable toxicity, and replacement with an amino group results in the natural purine synthetic precursor 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR), which has only modest antiviral properties.
Taribavirin
The most successful ribavirin derivative to date is the 3-carboxamidine derivative of the parent 3-carboxamide, first reported in 1973 by J. T. Witkowski et al., and now called taribavirin (former names "viramidine" and "ribamidine"). This drug shows a similar spectrum of antiviral activity to ribavirin, which is not surprising as it is now known to be a pro-drug for ribavirin. Taribavirin, however, has useful properties of less erythrocyte-trapping and better liver-targeting than ribavirin. The first property is due to taribavirins basic amidine group which inhibits drug entry into RBCs, and the second property is probably due to increased concentration of the enzymes which convert amidine to amide in liver tissue. Taribavirin completed phase III human trials in 2012.
References
External links
"Ribavirin". Drug Information Portal. U.S. National Library of Medicine. |
Lonapegsomatropin | Lonapegsomatropin, sold under the brand name Skytrofa, is a human growth hormone used for the treatment of growth hormone deficiency. Lonapegsomatropin is a prodrug of somatropin.Lonapegsomatropin was approved for medical use in the United States in August 2021.
Medical uses
Lonapegsomatropin is a growth hormone therapy indicated to treat growth hormone deficiency.
References
Further reading
External links
"Lonapegsomatropin". Drug Information Portal. U.S. National Library of Medicine.
Clinical trial number NCT02781727 for "A Phase 3 Trial of the Safety, Tolerability and Efficacy of TransCon hGH Weekly Versus Daily hGH in Children With Growth Hormone Deficiency (GHD)" at ClinicalTrials.gov |
Dinutuximab | Dinutuximab (Ch14.18, tradename Unituxin) and dinutuximab beta (tradename Qarziba) are monoclonal antibodies used as a second-line treatment for children with high-risk neuroblastoma. Each antibody is made of both mouse and human components and targets glycolipid GD2, expressed on neuroblastoma cells and on normal cells of neuroectodermal origin, including the central nervous system and peripheral nerves. They differ in that dinutuximab is manufactured using mouse cells, and dinutuximab beta is manufactured using hamster cells. The dosing regime differs, and dinutuximab is given in combination with granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin-2 (IL-2) and 13-cis-retinoic acid (RA), while dinutuximab beta can be given alone.
They both cause severe side effects, including severe pain that must be controlled with morphine, and a high risk of infusion reaction that must be controlled with antihistamines and anti-inflammatory drugs. They both work by binding to neurons and causing the bodys immune system to destroy them.
Dinutuximab received marketing approval in the US and in the European Union in March 2015; the marketing approval was withdrawn in 2017. Dinutuximab beta received marketing approval in Europe in 2017. The antibody was originally called Ch14.18 and was discovered by a group at University of California San Diego led by Alice Yu; this antibody and several others were brought into clinical trials funded by the National Cancer Institute.
Medical use
Dinutuximab is used as post-consolidation therapy for children with high-risk neuroblastoma, in combination with granulocyte-macrophage colony-stimulating factor, interleukin-2, 13-cis-retinoic acid. It is given in patients who have completed induction therapy and consolidation therapy (autologous bone marrow transplant and external beam radiation therapy), as part of standard-of-care therapy for newly-diagnosed high-risk neuroblastoma. It is given by intravenous infusion, over ten to twenty hours, four days in a row. It is also used second-line for relapsed/refractory neuroblastoma in combination with chemotherapy and GM-CSF.
Dinutuximab beta is also used as a second line treatment for children with high-risk neuroblastoma; it was tested and is used with a longer and slower dosing regime, and is given on its own, although it may be combined with IL-2 if a stronger immune response is needed.Morphine is administered prior to, during, and for two hours after infusion of dinutuximab and dinutuximab beta to manage the severe pain that this drug causes. An antihistamine and an anti-inflammatory are also given before, during, and after to manage the infusion reaction.Women who are pregnant or who might become pregnant should not take dinutuximab or dinutuximab beta, because it is very likely to cause harm to a fetus.
Adverse effects
The US label for dinutuximab carries black box warnings for life-threatening infusion reactions and neurotoxicity, as it causes severe neuropathic pain, and can cause severe sensory neuropathy and severe peripheral motor neuropathy. Dinutuximab beta also has these adverse effects.More than 25% of children taking these drugs experienced pain, fever, hives, vomiting, diarrhea, bone marrow suppression causing loss of platelets, red blood cells, white blood cells, and albumin, hypotension, electrolyte imbalance including low sodium, potassium, and calcium, elevated transaminases, infusion reactions, and capillary leak syndrome.Other common adverse effects include retention or urine for weeks to months after receiving the drugs, protein in urine, blurred vision or dilated pupils, infections, edema, high blood pressure, bleeding that wont stop, tachycardia, and weight gain.
Pharmacology
Dinutuximab and dinutuximab beta each work by binding to GD2, a glycolipid found on cells originating from the neuroectoderm during prenatal development, including neurons in the central nervous system and in the peripheral nervous system. Neuroblastoma cells have this as well. When dinutuximab binds to any cell that has GD2, that cell is destroyed via cell-mediated cytotoxicity and complement-dependent cytotoxicity.In clinical trials of dinutuximab, the maximum plasma concentration was 11.5 mcg/mL; the mean steady state volume distribution was 5.4 L; the clearance rate was 0.21 L/day; and the average half-life was 10 days.
Chemistry
Ch14.18 is a chimeric monoclonal antibody in which the variable heavy and light chain regions come from a mouse, with a human constant region for the heavy chain IgG1 and light chain kappa.The version of dinutuximab made by United Therapeutics, and marketed under the brand name Unituxin, is manufactured via industrial fermentation using a murine myeloma cell line, SP2/0. The version marketed by EUSA for Apeiron is called generically dinutuximab beta and is marketed under the brand name Isquette, and is manufactured in Chinese hamster ovary cells.
History
Dinutuximab (originally called Ch14.18) was discovered by a group at University of California San Diego led by Alice Yu; this antibody and several others were brought into clinical trials funded by the National Cancer Institute. The NCI manufactured the mAbs for the Phase III trial of Ch14.18 in combination with GM-CSF and IL-2, which was halted due to clear efficacy; the results published in 2009. No company had offered by that time to get FDA approval and commercialize the drug, so the NCI kept manufacturing it and making it available under compassionate use. In 2010, the NCI signed an agreement with United Therapeutics under which the company took over manufacturing and would bring the drug to market.In the meantime in Europe, oncologists and patient advocates wanted to have the drug available in Europe, and made efforts to obtain the cell line used to make it from United Therapeutics and the originating lab at the NCI itself; when those efforts failed they reached out to a group at Memorial Sloan Kettering that had generated an anti-GD2 mAb and was making at MSK for administration to patients there, but this didnt work out either. A lab at the Childrens Cancer Research Institute in Vienna, in collaboration with a network of European oncologists, had developed an anti-GD2 mAb that it made in CHO cells, and by 2011, it was in Phase III clinical trials, and the institute licensed its rights to Apeiron, a local biotech company.The FDA approved United Therapeutics application in March 2015, as did the European Medicines Agency.In 2017, United Therapeutics withdrew the European marketing authorization, and said that it was having trouble making enough of the drug to sell in Europe.In October 2016, Apeiron licensed the rights to Ch14.18 to the UK biotech company, EUSA, and in May 2017, Apeiron and EUSA obtained EMA approval to market Ch14.18, by then called dinutuximab beta.
References
External links
"Dinutuximab". Drug Information Portal. U.S. National Library of Medicine.
"Dinutuximab beta". Drug Information Portal. U.S. National Library of Medicine. |
Zoster vaccine | A zoster vaccine is a vaccine that reduces the incidence of herpes zoster (shingles), a disease caused by reactivation of the varicella zoster virus, which is also responsible for chickenpox. Shingles provokes a painful rash with blisters, and can be followed by chronic pain (postherpetic neuralgia), as well as other complications. Older people are more often affected, as are people with weakened immune systems (immunosuppression). Both shingles and postherpetic neuralgia can be prevented by vaccination.Two zoster vaccines have been approved for use in people over 50 years old. Shingrix (GSK) is a recombinant subunit vaccine which has been used in many countries since 2017. Zostavax (Merck), in use since 2006, is an attenuated vaccine which consists of a larger-than-normal dose of chickenpox vaccine. Unlike Shingrix, Zostavax is not suitable for people with immunosuppression or diseases that affect the immune system. Zostavax was discontinued in the United States in November 2020.Shingrix appears to prevent more cases of shingles than Zostavax, although side effects seem to be more frequent.Another vaccine, known as varicella vaccine, is used to prevent diseases caused by the same virus.
Medical uses
Zoster vaccination is used to prevent shingles and its complications, including postherpetic neuralgia. It can be considered a therapeutic vaccine, given that it is used to treat a latent virus that has remained dormant in cells since chicken pox infection earlier in life. The two available zoster vaccines are intended for use in people over the age of 50. As of 2021 it remained to be confirmed whether a booster dose was required, but the Advisory Committee on Immunization Practices (ACIP) in the United States recommends Shingrix for adults over the age of 50, including those who have already received Zostavax.
Shingrix
The ACIP voted that Shingrix is preferred over Zostavax for the prevention of zoster and related complications because data showed vaccine efficacy of more than 90% against shingles across all age groups. Unlike Zostavax, which is given as a single shot, Shingrix is given as two intramuscular doses, two to six months apart. Most of the studies conducted showed efficacy to at least 4 years post-vaccination, but it is possible the vaccine may provide protection for much longer.A large randomized clinical trial showed Shingrix reduced the incidence of shingles 96.6% in the 50–59 age group, and 91.3% in those over age 70. The absolute decrease in risk of herpes zoster following immunization over three and a half years is 3.3% (3.54% down to 0.28%) while the decrease in the risk of postherpetic neuralgia is 0.3% (0.34% down to 0.06%).
Zostavax
A Cochrane review concluded that Zostavax is "effective in preventing herpes zoster disease for up to three years". The duration of protection beyond four years after vaccination with the zoster vaccine is unknown. The need for re-vaccination remains to be confirmed.Zostavax was shown to reduce the incidence of shingles by 51% in a study of 38,000 adults aged 60 and older who received the vaccine. The vaccine also reduced by 67% the number of cases of postherpetic neuralgia (PHN) and reduced the severity and duration of pain and discomfort associated with shingles, by 61%. The FDA originally recommended it for individuals 60 years of age or older who are not severely allergic to any of its components and who meet the following requirements:
do not have a weakened immune system due to HIV/AIDS or another disease or medications (such as steroids, radiation and chemotherapy) that affect the immune system;
do not have a history of cancer affecting the bone marrow or lymphatic system, such as leukemia or lymphoma; and
do not have active, untreated tuberculosis.In 2006, the U.S. Advisory Committee on Immunization Practices (ACIP) recommended that the live vaccine be given to all adults age 60 and over, including those who have had a previous episode of shingles, and those who do not recall having had chickenpox, since more than 99% of Americans ages 40 and older have had chickenpox.
Side effects
Shingrix
Temporary side effects from the Shingrix shots are likely and can be severe enough in one out of six people to affect normal daily activities for up to three days. Mild to moderate pain at the injection site is common, and some may have redness or swelling. Side effects include fatigue, muscle pain, headache, shivering, fever, and nausea. Symptoms usually resolve in two to three days. Side effects with Shingrix are greater than those with Zostavax and occur more frequently in individuals aged 50 to 69 years compared with those 70 years and older.
Zostavax
The live vaccine (Zostavax) is very safe; one to a few percent of people develop a mild form of chickenpox, often with about five or six blisters around the injection site, and without fever. The blisters are harmless and temporary. In one study 64% of the Zostavax group and 14% of the controls had some adverse reaction. However, the rates of serious adverse events were comparable between the Zostavax group (0.6%) and those receiving the placebo (0.5%). A study including children with leukaemia found that the risk of getting shingles after vaccination is much lower than the risk of getting shingles for children with natural chicken pox in their history. Data from healthy children and adults point in the same direction.Zostavax is not used in people with compromised immune function.
Composition
Shingrix
Shingrix is a suspension for intramuscular injection consisting of a lyophilized recombinant varicella zoster virus glycoprotein E antigen that is reconstituted at the time of use with AS01B suspension as an immunological adjuvant. The antigen is a purified truncated form of the glycoprotein, expressed in Chinese hamster ovary cells. The AS01B adjuvant suspension is composed of 3-O-desacyl-4-monophosphoryl lipid A (MPL) from Salmonella (Minnesota strain) and a saponin molecule (QS-21) purified from Quillaja saponaria (soap bark tree) extract, combined in a liposomal formulation consisting of dioleoyl phosphatidylcholine (DOPC) and cholesterol in phosphate-buffered saline solution.
Zostavax
Zostavax contains live attenuated varicella-zoster virus. It is injected subcutaneously (under the skin) in the upper arm. The live vaccine is produced using the MRC-5 line of fetal cells. This has raised religious and ethical concerns for some potential users, since that cell line was derived from an aborted fetus.
Cost effectiveness
A 2007 study found that the live vaccine is likely to be cost-effective in the U.S., projecting an annual savings of US$82 to US$103 million in healthcare costs with cost-effectiveness ratios ranging from US$16,229 to US$27,609 per quality-adjusted life year gained. In 2007, the live vaccine was officially recommended in the U.S. for healthy adults aged 60 and over, but is now is no longer given out in the United States as of 2020, given the likely superiority of Shingrix.In Canada the cost of Shingrix is about CA$300 for the two doses. This likely represents a more cost effective intervention than the live vaccine given its lower cost and increased effectiveness.
History
European Union
In 2006, the European Medicines Agency (EMA) issued a marketing authorization for the zoster vaccine to Sanofi Pasteur for routine vaccination in individuals aged 60 and over. In 2007, the EMA updated the marketing authorization for routine vaccination in individuals aged 50 and over.Shingrix was approved for medical use in the European Union in March 2018, with an indication for the prevention of herpes zoster (HZ) and post-herpetic neuralgia (PHN) in adults 50 years of age or older.
United Kingdom
From 2013, the UK National Health Service (NHS) started offering shingles vaccination to elderly people. People aged either 70 or 79 on 1 September 2013, were offered the vaccine. People aged 71 to 78 on that date would only have an opportunity to have the shingles vaccine after reaching the age of 79. The original intention was for people aged between 70 and 79 to be vaccinated, but the NHS later said that the vaccination program was being staggered as it would be impractical to vaccinate everyone in their 70s in a single year.In 2021, vaccination against shingles is available on the NHS to people aged 70 to 79. Vaccination is with single-dose Zostavax, except for people for whom Zostavax is deemed unsuitable, for example, with a condition that affects the immune system, for whom two-dose Shingrix vaccine is recommended. The NHS stated "The shingles vaccine is not available on the NHS to anyone aged 80 or over because it seems to be less effective in this age group".
United States
Zostavax was developed by Merck & Co. and approved and licensed by the U.S. Food and Drug Administration (FDA) in May 2006, In 2011, the FDA approved the live vaccine for use in individuals 50 to 59 years of age. Shingrix is a zoster vaccine developed by GlaxoSmithKline that was approved in the United States in October 2017.On June 30, 2020, Merck discontinued the sale of Zostavax in the U.S. Vaccine already held by practitioners could still be administered up to the expiration date (none expired later than November 2020).The U.S. Centers for Disease Control and Prevention (CDC) recommends that healthy adults 50 years and older get two doses of Shingrix, at least two months apart. Initial clinical trials only tested a gap of less than six months between doses, but unexpected popularity and resulting shortages caused further testing to validate wider spacing of the two doses. Shingrix, which provides strong protection against shingles and PHN, was preferred over Zostavax before Zostavax was discontinued.The zoster vaccine is covered by Medicare Part D. In 2019, more than 90% of Medicare Part D vaccine spending was for the zoster vaccine. 5.8 million vaccine doses were administered to Part D beneficiaries that year at a cost of $857 million.
References
Further reading
World Health Organization (2014). "Varicella and herpes zoster vaccines : WHO position paper, June 2014" (PDF). Weekly Epidemiological Record. 89 (25): 265–287. hdl:10665/242227. PMID 24983077.
Hamborsky J, Kroger A, Wolfe S, eds. (2015). "Chapter 22: Varicella". Epidemiology and Prevention of Vaccine-Preventable Diseases (13th ed.). Washington D.C.: U.S. Centers for Disease Control and Prevention (CDC). ISBN 978-0990449119.
External links
Zostavax Product Page U.S. Food and Drug Administration (FDA)
Shingrix Product Page U.S. Food and Drug Administration (FDA)
"Shingrix Vaccine Information Statement". U.S. Centers for Disease Control and Prevention (CDC). 29 July 2021.
"Zostavax (Herpes Zoster Vaccine) Questions and Answers". Questions about Vaccines. U.S. Food and Drug Administration (FDA). 18 February 2021. |
Azelastine | Azelastine, sold under the brand name Optivar among others, is a medication primarily used as a nasal spray to treat allergic rhinitis (hay fever) and as eye drops for allergic conjunctivitis. Other uses may include asthma and skin rashes for which it is taken by mouth. Onset of effects is within minutes when used in the eyes and within an hour when used in the nose. Effects last for up to 12 hours.Common side effects include headache, sleepiness, change in taste, and sore throat. It is unclear if use is safe during pregnancy or breastfeeding. It is a second-generation antihistamine and works by blocking the release of a number of inflammatory mediators including histamine.Azelastine was patented in 1971 and came into medical use in 1986. It is available as a generic medication. In 2019, it was the 167th most commonly prescribed medication in the United States, with more than 3 million prescriptions.
Medical uses
Azelastine nasal spray is indicated for the local treatment of the symptoms of seasonal allergic rhinitis and perennial allergic rhinitis, such as rhinorrhea, sneezing and nasal pruritus in people five years of age and older. In some countries, it is also indicated for the treatment of vasomotor rhinitis in adults and children ≥ 12 years old. Azelastine eye drops are indicated for the local treatment of seasonal and perennial allergic conjunctivitis.
Side effects
Azelastine is safe and well tolerated in both adults and children with allergic rhinitis. Bitter taste, headache, nasal burning and somnolence are the most frequently reported adverse events. US prescribing recommendations warn against the concurrent use of alcohol and/or other central nervous system depressants, but to date there have been no studies to assess the effects of azelastine nasal spray on the CNS in humans. More recent studies have shown similar degrees of somnolence (approx. 2%) compared with placebo treatment.
The most common side effect is a bitter taste (about 20% of people). Due to this, the manufacturer has produced another formulation of azelastine with sucralose. The problem of bitter taste may also be reduced by correct application of the nasal spray (i.e. slightly tipping the head forward and not inhaling the medication too deeply), or alternatively using the azelastine/sucralose formulation.In addition, anosmia (loss in the ability to smell) can occur with nasal spray antihistamines (including both formulations of azelastine).
Pharmacology
Pharmacodynamics
Azelastine has a triple mode of action:
Anti-histamine effect,
Mast-cell stabilizing effect and
Anti-inflammatory effect.
Pharmacokinetics
The systemic bioavailability of azelastine is approximately 40% when administered intranasally. Maximum plasma concentrations (Cmax) are observed within 2–3 hours. The elimination half life, steady-state volume of distribution and plasma clearance are 22 h, 14.5 L/kg and 0.5 L/h/kg respectively (based on intravenous and oral administration data). Approximately 75% of an oral dose is excreted in feces. Pharmacokinetics of orally administered azelastine are not affected by age, gender or hepatic impairment.
Metabolism
Azelastine is oxidatively metabolized by the cytochrome P450 family into its active metabolite, desmethylazelastine, and two inactive carboxylic acid metabolites.
Chemical properties
The chemical nomenclature of azelastine is (±)-1-(2H)-phthalazinone, 4-[(4-chlorophenyl) methyl]-2-(hexahydro-1-methyl-1H-azepin-4-yl)-monohydrochloride. It is white, almost odorless with a bitter taste.
References
External links
"Azelastine". Drug Information Portal. U.S. National Library of Medicine.
"Azelastine hydrochloride". Drug Information Portal. U.S. National Library of Medicine. |
Ethambutol | Ethambutol (EMB, E) is a medication primarily used to treat tuberculosis. It is usually given in combination with other tuberculosis medications, such as isoniazid, rifampicin and pyrazinamide. It may also be used to treat Mycobacterium avium complex, and Mycobacterium kansasii. It is taken by mouth.Common side effects include problems with vision, joint pain, nausea, headaches, and feeling tired. Other side effects include liver problems and allergic reactions. It is not recommended in people with optic neuritis, significant kidney problems, or under the age of five. Use during pregnancy or breastfeeding has not been found to cause harm. In the United States the FDA has raised concerns about eye issues in the baby if used during pregnancy. Ethambutol is believed to work by interfering with the bacterias metabolism.Ethambutol was discovered in 1961. It is on the World Health Organizations List of Essential Medicines and is available as a generic medication.
Chirality and biological activity
(S,S)-(+)-Ethambutol is powerful and selective antitubercular drug. It is a typical example of an old drug that was introduced for clinical use in its unichiral form. Ethambutol contains two constitutionally symmetrical chiral centers in its structure and exists in three stereoisomeric forms. An enantiomeric pair (S,S)- and (R,R)-ethmabutol, along with the achiral stereoisomer called meso-form. The (S,S)-(+)-enantiomer harbors the antitubercular activity. This enantiomer is 500 and 12 fold more potent than the (R,R)-ethmabutol and the meso-form respectively. On the other hand, all the three isomers are equipotent in terms of the major side-effect of the drug, optic neuritis. Toxicity is associated to both dose and duration of treatment. Hence the use of (S,S)-enantiomer greatly improved the risk/benefit balance.
Medical uses
Ethambutol is used along with other medications to treat a number of infections including: tuberculosis, Mycobacterium avium complex, and Mycobacterium kansasii.
Adverse effects
Optic neuritis (hence contraindicated in children below six years of age)
Red-green color blindness People taking ethambutol should be monitored for changes in visual acuity and color discrimination.
Arthralgia
Hyperuricaemia
Vertical nystagmus
Milk skin reaction
Mechanism of action
Ethambutol is bacteriostatic against actively growing TB bacilli. It works by obstructing the formation of cell wall. Mycolic acids attach to the 5-hydroxyl groups of D-arabinose residues of arabinogalactan and form mycolyl-arabinogalactan-peptidoglycan complex in the cell wall. It disrupts arabinogalactan synthesis by inhibiting the enzyme arabinosyl transferase. Disruption of the arabinogalactan synthesis inhibits the formation of this complex and leads to increased permeability of the cell wall.
Pharmacokinetics
It is well absorbed from the gastrointestinal tract and well distributed in body tissues and fluids. 50% is excreted unchanged in urine.
See also
chiral drugs
chirality
enantiopure drug
stereochemistry
References
External links
"Ethambutol". Medicine Plus.
"Ethambutol". Drug Information Portal. U.S. National Library of Medicine. |
Lindane | Lindane, also known as gamma-hexachlorocyclohexane (γ-HCH), gammaxene, Gammallin and benzene hexachloride (BHC), is an organochlorine chemical and an isomer of hexachlorocyclohexane that has been used both as an agricultural insecticide and as a pharmaceutical treatment for lice and scabies.Lindane is a neurotoxin that interferes with GABA neurotransmitter function by interacting with the GABAA receptor-chloride channel complex at the picrotoxin binding site. In humans, lindane affects the nervous system, liver, and kidneys, and may well be a carcinogen. Whether lindane is an endocrine disruptor is unclear.The World Health Organization classifies lindane as "moderately hazardous", and its international trade is restricted and regulated under the Rotterdam Convention on Prior Informed Consent. In 2009, the production and agricultural use of lindane was banned under the Stockholm Convention on persistent organic pollutants. A specific exemption to that ban allows it to continue to be used as a second-line pharmaceutical treatment for lice and scabies.
History and use
The chemical was originally synthesized in 1825 by Faraday. It is named after the Dutch chemist Teunis van der Linden (1884–1965), the first to isolate and describe γ-hexachlorcyclohexane in 1912. The fact that mixtures of isomers of hexachlorocyclohexane have insecticidal activity is a case of multiple discovery. Work in the 1930s at the Jealotts Hill laboratories of Imperial Chemical Industries Ltd (ICI) led in 1942 to the realization that the γ isomer was the key active component in the mixture which had hitherto been tested. Development work in the UK was accelerated because at that time in World War II imports of derris containing the insecticide rotenone were restricted owing to the Japanese occupation of Malaya and alternatives were urgently needed. In trials in 1943 it was found that a five-fold increase in the yield of oats and wheat was achieved using a dust formulation of the available material, owing to its efficacy against wireworm pests. By the end of 1945, γ-hexachlorcyclohexane of 98% purity became available and ICI commercialised a seed treatment launched in 1949 as Mergamma A, containing 1% mercury and 20% lindane. Subsequently, lindane has been used to treat food crops and forestry products, as a seed or soil treatment, and to treat livestock and pets. It was used as a household pesticide as the active pesticide ingredient of an insecticidal floor wax product called "Freewax". It has also been used as pharmaceutical treatment for lice and scabies, formulated as a shampoo or lotion. Between 1950 and 2000, an estimated 600,000 tonnes of lindane were produced globally, and the vast majority of which was used in agriculture. It has been manufactured by several countries, including the United States, China, Brazil, and several European countries, but as of 2007, only India and possibly Russia are still producing it.
By November 2006, the use of lindane had been banned in 52 countries and restricted in 33 others. Seventeen countries, including the US and Canada, allowed either limited agricultural or pharmaceutical use. In 2009, an international ban on the use of lindane in agriculture was implemented under the Stockholm Convention on Persistent Organic Pollutants. A specific exemption allows for it to continue to be used in second-line treatments for the head lice and scabies for five more years. The production of the lindane isomers α- and β-hexachlorocyclohexane was also banned. Although the US has not ratified the Convention, it has similarly banned agricultural uses while still allowing its use as a second-line lice and scabies treatment.
United States
In the US, lindane pesticide products were regulated by the U.S. Environmental Protection Agency (EPA), while lindane medications are regulated by the Food and Drug Administration (FDA). It was registered as an agricultural insecticide in the 1940s, and as pharmaceutical in 1951. The EPA gradually began restricting its agricultural use in the 1970s due to concerns over its effects on human health and the environment. By 2002, its use was limited to seed treatments for just six crops, and in 2007, these last uses were cancelled.
Pharmaceutical uses
Lindane medications continue to be available in the US, though since 1995, they have been designated "second-line" treatments, meaning they should be prescribed when other "first-line" treatments have failed or cannot be used. In December 2007, the FDA sent a Warning Letter to Morton Grove Pharmaceuticals, the sole U.S. manufacturer of lindane products, requesting that the company correct misleading information on two of its lindane websites. The letter said, in part, that the materials "are misleading in that they omit and/or minimize the most serious and important risk information associated with the use of Lindane Shampoo, particularly in pediatric patients; include a misleading dosing claim; and overstate the efficacy of Lindane Shampoo."California banned the pharmaceutical lindane, effective 2002, and the Michigan House of Representatives passed a bill in 2009 to restrict its use to doctors offices. A recent analysis of the California ban concluded that a majority of pediatricians had not experienced problems treating lice or scabies since that ban took effect. The study also documented a marked decrease in lindane wastewater contamination and a dramatic decline in lindane poisoning incidents reported to poison control centers. The authors concluded, "The California experience suggests elimination of pharmaceutical lindane produced environmental benefits, was associated with a reduction in reported unintentional exposures and did not adversely affect head lice and scabies treatment."The Persistent Organic Pollutants Review Committee of the Stockholm Convention on Persistent Organic Pollutants considers the use of lindane in agriculture as largely redundant, with other, less toxic and less persistent pesticides. In the case of pharmaceutical use, the committee noted, "alternatives for pharmaceutical uses have often failed for scabies and lice treatment and the number of available alternative products for this use is scarce. For this particular case, a reasonable alternative would be to use lindane as a second-line treatment when other treatments fail, while potential new treatments are assessed."
Other uses
Pest repellent
Lindane is a bird repellent. Rudd & Genelly 1954 noticed that bird pests seemed uninterested in treated seeds, specifically pheasants and blackbirds around Davis, CA, US. They tested its repellent effect on pheasants and found it effective, speculating that it may be usable as a general bird repellent.
Preparation
Lindane is prepared by treating chlorine with benzene in the presence of sunlight and in the absence of oxygen as well as substitution catalysts.
Human health effects
The EPA and WHO both classify lindane as "moderately" acutely toxic. It has an oral LD50 of 88 mg/kg in rats and a dermal LD50 of 1000 mg/kg. Most of the adverse human health effects reported for lindane have been related to agricultural uses and chronic, occupational exposure of seed-treatment workers.Exposure to large amounts of lindane can harm the nervous system, producing a range of symptoms from headache and dizziness to seizures, convulsions, and more rarely, death. Lindane has not been shown to affect the immune system in humans, and it is not considered to be genotoxic. Prenatal exposure to β-HCH, an isomer of lindane and production byproduct, has been associated with altered thyroid hormone levels and could affect brain development.The Occupational Safety and Health Administration and National Institute for Occupational Safety and Health have set occupational exposure limits (permissible exposure and recommended exposure, respectively) for lindane at 0.5 mg/m3 at a time-weighted average of eight hours for skin exposure. People can be exposed to lindane in the workplace by inhaling it, absorbing it through their skin, swallowing it, and eye contact. At levels of 50 mg/m3, lindane is immediately dangerous to life and health.It is classified as an extremely hazardous substance in the United States as defined in section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.
Cancer risk
Based primarily on evidence from animal studies, most evaluations of lindane have concluded that it may possibly cause cancer. In 2015, the International Agency for Research on Cancer classified lindane as a known human carcinogen, and in 2001 the EPA concluded there was "suggestive evidence of carcinogenicity, but not sufficient to assess human carcinogenic potential." The U.S. Department of Health and Human Services determined that all isomers of hexachlorocyclohexane, including lindane, "may reasonably be anticipated to cause cancer in humans," and in 1999, the EPA characterized the evidence carcinogenicity for lindane as "suggestive ... of carcinogenicity, but not sufficient to assess human carcinogenic potential." Lindane and its isomers have also been on Californias Proposition 65 list of known carcinogens since 1989. In contrast, the World Health Organization concluded in 2004 that "lindane is not likely to pose a carcinogenic risk to humans." Indias BIS considers Lindane a "confirmed carcinogen".
Adverse reactions
A variety of adverse reactions to lindane pharmaceuticals have been reported, ranging from skin irritation to seizures, and, in rare instances, death. The most common side effects are burning sensations, itching, dryness, and rash. While serious effects are rare and have most often resulted from misuse, adverse reactions have occurred when used properly. The FDA, therefore, requires a so-called black box warning on lindane products, which explains the risks of lindane products and their proper use.The black box warning emphasizes that lindane should not be used on premature infants and individuals with known uncontrolled seizure disorders, and should be used with caution in infants, children, the elderly, and individuals with other skin conditions (e.g., dermatitis, psoriasis) and people who weigh less than 110 lb (50 kg), as they may be at risk of serious neurotoxicity.
Environmental contamination
Lindane is a persistent organic pollutant: it is relatively long-lived in the environment, it is transported long distances by natural processes like global distillation, and it can bioaccumulate in food chains, though it is rapidly eliminated when exposure is discontinued.The production and agricultural use of lindane are the primary causes of environmental contamination, and levels of lindane in the environment have been decreasing in the U.S., consistent with decreasing agricultural usage patterns. The production of lindane generates large amounts of waste hexachlorocyclohexane isomers, and "every ton of lindane manufactured produces about nine tons of toxic waste." Modern manufacturing standards for lindane involve the treatment and conversion of waste isomers to less toxic molecules, a process known as "cracking".When lindane is used in agriculture, an estimated 12–30% of it volatilizes into the atmosphere, where it is subject to long-range transport and can be deposited by rainfall. Lindane in soil can leach to surface and even ground water, and can bioaccumulate in the food chain. However, biotransformation and elimination are relatively rapid when exposure is discontinued. Most exposure of the general population to lindane has resulted from agricultural uses and the intake of foods, such as produce, meats, and milk, produced from treated agricultural commodities. Human exposure has decreased significantly since the cancellation of agricultural uses in 2006. Even so, the CDC published in 2005 its Third National Report on Human Exposures to Environmental Chemicals, which found no detectable amounts of lindane in human blood taken from a random sampling of about 5,000 people in the US as part of the NHANES study (National Health and Nutrition Examination Survey at: https://www.cdc.gov/nchs/nhanes/about_nhanes.htm). The lack of detection of lindane in this large human "biomonitoring" study likely reflects the increasingly limited agricultural uses of lindane over the last two decades. The cancellation of agricultural uses in the United States will further reduce the amount of lindane introduced into the environment by more than 99%.Over time, lindane is broken down in soil, sediment, and water into less harmful substances by algae, fungi, and bacteria; however, the process is relatively slow and dependent on ambient environmental conditions. Lindane residues in honey and beeswax are reported to be the highest of any historical or current pesticide and to continue to pose a threat to honeybee health. The ecological impact of lindanes environmental persistence continues to be debated.
The US EPA determined in 2002 that the agency does not believe that lindane contaminates drinking water in excess of levels considered safe. U.S. Geological Survey teams concluded the same in 1999 and 2000. With regard to lindane medications, the EPA conducted "down-the-drain" estimates of the amount of lindane reaching public water supplies and concluded that lindane levels from pharmaceutical sources were "extremely low" and not of concern.Note that the EPA has set the maximum contaminant level or "MCL" for lindane allowed in public water supplies and considered safe for drinking at 200 parts per trillion (ppt). By comparison, the state of California imposes a lower MCL for lindane of 19 ppt. However, the California standard is based on a dated 1988 national water criterion that was subsequently revised by the EPA in 2003 to 980 ppt. The EPA stated that the change resulted from "significant scientific advances made in the last two decades particularly in the areas of cancer and noncancer risk assessments." While the EPA considered raising the MCL standard for lindane to 980 ppt at that time, the change was never implemented because states had little difficulty in maintaining lindane levels below the 200 ppt MCL limit already in place. Today, the legally enforceable MCL standard for lindane is 200 ppt, while the national water criterion for lindane is 980 ppt.
Isomers
Lindane is the gamma isomer of hexachlorocyclohexane ("γ-HCH"). In addition to the issue of lindane pollution, some concerns are related to the other isomers of HCH, namely alpha-HCH and beta-HCH, which are notably more toxic than lindane, lack its insecticidal properties, and are byproducts of lindane production. In the 1940s and 1950s, lindane producers stockpiled these isomers in open heaps, which led to ground and water contamination. The International HCH and Pesticide Forum has since been established to bring together experts to address the clean-up and containment of these sites. Modern manufacturing standards for lindane involve the treatment and conversion of waste isomers to less toxic industrial chemicals, a process known as "cracking". Today, only a few production plants remain active worldwide to accommodate public-health uses of lindane and declining agricultural needs. Lindane has not been manufactured in the U.S. since the mid-1970s, but continues to be imported.
See also
Benzene hexachloride (disambiguation)
References
External links
Government and organizations
FDA Information on Lindane
EPA Information on Lindane
Gamma Hexachlorocyclohexane Fact Sheet
Agency for Toxics and Disease Registry: Toxicological Profile for Hexachlorocyclohexane
Lindane in the Pesticide Properties DataBase (PPDB)
World Health Organization Background Document on Lindane for Drinking-Water Quality Guidelines
Lindane Chemistry and Uses
World Health Organization: Lindane (EHC 124)
"Lindane Facts" - Website run by Morton Grove Pharmaceuticals
U.S. National Library of Medicine: Hazardous Substances Databank – Lindane
News stories and opinion articles
"Mom and Pros Tackle Lice" - NPR story from 2006
Pepsi and Coca-Cola - Lindane in drinks in India - news story from 2006
India - Pesticides in Coke & Pepsi drinks - news story from 2003 |
SPS | SPS may refer to:
Law and government
Agreement on the Application of Sanitary and Phytosanitary Measures of the WTO
NATO Science for Peace and Security
Single Payment Scheme, an EU agricultural subsidy
The Standard Procurement System, for the US Department of Defense
Somali Postal Service
Staff and Personnel Support Branch, part of the British Army Adjutant Generals Corps
Police and prisons
Scottish Prison Service
Singapore Prison Service, a government agency of the Government of Singapore under the hierarchy of the Ministry of Home Affairs
Station police sergeant or station sergeant, former UK police rank
State Police Services (India)
Surrey Police Service, British Columbia, Canada
Organisations
Sahara Press Service, of the Sahrawi Arab Democratic Republic
Sierra Peaks Section
SPS Commerce
SPS Technologies, Inc., acquired by Precision Castparts Corp.
Sussex Piscatorial Society, a fishing club in the UK
Swiss Society of Proteomics, of Life Sciences Switzerland
Education
Sadiq Public School, a school in Bahawalpur, Punjab, Pakistan
New York University School of Professional Studies
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Springfield Public Schools (Missouri), school district, US
St. Patricks Higher Secondary School, Asansol, India
St. Pauls School (disambiguation), various schools
Political parties
Socialist Party of Serbia (Socijalistička partija Srbije), a political party in Serbia
Union of Right Forces (Soyuz Pravykh Sil), a former political party in Russia
Religion
Saint Patrick’s Society for the Foreign Missions, Ireland, post-nominal
Society for Pentecostal Studies
Science and technology
Solanapyrone synthase, an enzyme
Spark plasma sintering
Special weather statement, US
Stand-alone power system, an off-the-grid electricity system
Standard positioning service, a Global Positioning System feature
Super Proton Synchrotron, a particle accelerator at CERN
Computing
Shell Processing Support, a file format for seismic data
IBM 1401 Symbolic Programming System and IBM 1620/1710 Symbolic Programming System, assemblers
Medicine and psychology
Sensory processing sensitivity, a personality trait of Highly Sensitive Persons
Stiff person syndrome, a rare neurologic disorder
Syntactic positive shift, a peak in brain activity
Military and space
Service propulsion system in Apollo service module
Solar power satellite, to beam power to Earth
Side protection system or torpedo beltof a warship
SR-1 Vektor (Samozaryadnyj Pistolet Serdjukova – Serdyukov Self-loading pistol)
Transportation
Wichita Falls Municipal Airport (IATA airport code)
Spokane, Portland and Seattle Railway, a defunct railroad in the United States
Other uses
Sony Imaging Pro Support, for photographers
SPS (Mongolia), a TV channel
See also
All pages with titles beginning with SPS
All pages with titles containing SPS
SPs
SP (disambiguation) |
Cisatracurium besilate | Cisatracurium besilate (INN; cisatracurium besylate (USAN); formerly recognized as 51W89; trade name Nimbex) is a bisbenzyltetrahydroisoquinolinium that has effect as a neuromuscular-blocking drug non-depolarizing neuromuscular-blocking drugs, used adjunctively in anesthesia to facilitate endotracheal intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation. It shows intermediate duration of action. Cisatracurium is one of the ten isomers of the parent molecule, atracurium. Moreover, cisatracurium represents approximately 15% of the atracurium mixture.
History
The generic name cisatracurium was conceived by scientists at Burroughs Wellcome Co. (now part of GlaxoSmithKline) by combining the name "atracurium" with "cis" [hence cisatracurium] because the molecule is one of the three cis-cis isomers comprising the ten isomers of the parent, atracurium. Atracurium itself was invented at Strathclyde University and licensed to Burroughs Wellcome Co., Research Triangle Park, NC, for further development and subsequent marketing as Tracrium. As the secondary pharmacology of atracurium was being developed, it became clear that the primary clinical disadvantage of atracurium was likely to be its propensity to elicit histamine release. To address this issue, a program was initiated to investigate the individual isomer constituents of atracurium to identify and isolate the isomer(s) associated with the undesirable histamine effects as well as identify the isomer that might possibly retain the desirable properties without the histamine release. Thus, in 1989, D A Hill and G L Turner, PhD (both chemists at Burroughs Wellcome Co., Dartford, UK) first synthesized cisatracurium as an individual isomer molecule. The pharmacological research of cisatracurium and the other individual isomers was then developed further primarily by R. Brandt Maehr and William B. Wastila, PhD (both of whom were pharmacologists within the Division of Pharmacology at Burroughs Wellcome Co.) in collaboration with John J. Savarese MD (who at the time was an anesthesiologist in the Dept. of Anesthesia, Harvard Medical School at the Massachusetts General Hospital, Boston, MA). Thereafter, the entire clinical development of cisatracurium was completed in a record short period from 1992 to 1994: the team of scientists was led by J. Neal Weakly PhD, Martha M. Abou-Donia PhD, and Steve Quessy PhD, in the Division of Clinical Neurosciences at Burroughs Wellcome Co., Research Triangle Park, NC. By the time of its approval for human use, in 1995, by the US Food and Drug Administration, Burroughs Wellcome Co. had merged with Glaxo Inc., and cisatracurium was approved to be marketed as Nimbex by GlaxoWellcome Inc. The trade name "Nimbex" was derived from inserting an "i" to the original proposal "Nmbex," which stood for excellent Neuromuscular blocker.
Preclinical pharmacology
In vitro studies using human plasma indicated that cisatracurium spontaneously degrades at physiological pH via Hofmann elimination to yield laudanosine and the quaternary monoacrylate. Subsequent ester hydrolysis of the monoacrylate generates the monoquaternary alcohol, although the rate-limiting step is Hofmann elimination. In rat plasma, cisatracurium is also metabolized by non-specific carboxylesterases (a rate-limiting step) to the monoquaternary alcohol and the monoquaternary acid.
Clinical pharmacology
As is evident with the parent molecule, atracurium, cisatracurium is also susceptible to degradation by Hofmann elimination and ester hydrolysis as components of the in vivo metabolic processes. See the atracurium page for information on Hofmann elimination in vivo versus the Hofmann degradation chemical reaction.
Because Hofmann elimination is a temperature- and plasma pH-dependent process, cisatracuriums rate of degradation in vivo is highly influenced by body pH and temperature just as it is with the parent molecule, atracurium: thus, an increase in body pH favors the elimination process, whereas a decrease in temperature slows down the process.
One of the metabolites of cisatracurium via Hofmann elimination is laudanosine – see the atracurium page for further discussion of the issue regarding this metabolite. 80% of cisatracurium is metabolized eventually to laudanosine and 20% is metabolized hepatically or excreted renally. 10-15% of the dose is excreted unchanged in the urine.Since Hofmann elimination is an organ-independent chemodegradative mechanism, there is little or no risk to the use of cisatracurium in patients with liver or renal disease when compared with other neuromuscular-blocking agents.The two reverse ester linkages in the bridge between the two isoquinolinium groups make atracurium and cisatracurium poor targets for plasma cholinesterase, unlike mivacurium which has two conventional ester linkages.
Adverse effects
Histamine release – hypotension, reflex tachycardia and cutaneous flush
Bronchospasm – Pulmonary compliance
To date, cisatracurium has not been reported to elicit bronchospasm at doses that are clinically prescribed.
Laudanosine – Epileptic foci
Cisatracurium undergoes Hofmann elimination as a primary route of chemodegradation: consequently one of the metabolites from this process is laudanosine, a tertiary amino alkaloid reported to be a modest CNS stimulant with epileptogenic activity and cardiovascular effects such as low blood pressure and a slowed heart rate. As a tertiary amine, Laudanosine is unionised and readily crosses the blood–brain barrier. Presently, there is little evidence that laudanosine accumulation and related toxicity will likely ever be seen with the doses of cisatracurium that are administered in clinical practice especially given that the plasma concentrations of laudanosine generated are lower with cisatracurium than those seen with atracurium.
Research
A recent study showed that cisatracurium pretreatment effectively decreases the incidence and severity of pain induced by propofol general anaesthesia.
Another study showed that hiccups accompanied by vomiting, insomnia, shortness of breath can also be relieved by the nondepolarizing muscle relaxant, cisatracurium, during total intravenous anesthesia.
Synthesis
Treatment of 1,5-Pentanediol with 3-bromopropionyl chloride gives the corresponding ester; dehydrohalogenation of the ester with triethylamine then gives the bis-acrylate (2). Reaction of that unsaturated ester with tetrahydropapaverine (3) leads to conjugate addition of the secondary amine and formation of the intermediate (4). Alkylation with methyl benzenesulfonate forms the bis-quaternary salt, affording cisatracuronium (5).
References
Further reading
Caldwell JE (1995). "New skeletal muscle relaxants". Int Anesthesiol Clin. 33 (1): 39–60. doi:10.1097/00004311-199500000-00003. PMID 7635557.
Hull CJ (1995). "Pharmacokinetics and pharmacodynamics of the benzylisoquinolinium muscle relaxants". Acta Anaesthesiol Scand. 106 Suppl: 13–17. doi:10.1111/j.1399-6576.1995.tb04302.x. PMID 8533537. S2CID 43784865.
Savarese JJ, Wastila WB (1995). "The future of the benzylisoquinolinium relaxants". Acta Anaesthesiol Scand. 106 Suppl: 91–93. doi:10.1111/j.1399-6576.1995.tb04317.x. PMID 8533554. S2CID 39461057.
Esmaoglu A, Akin A, Mizrak A, Turk Y, Boyaci A (2006). "Addition of cisatracurium to lidocaine for intravenous regional anesthesia". J Clin Anesth. 18 (3): 194–7. doi:10.1016/j.jclinane.2005.08.003. PMID 16731321.
Melloni C, De Vivo P, Launo C, Mastronardi P, Novelli G, Romano E (2006). "Cisatracurium versus vecuronium: a comparative, double blind, randomized, multicenter study in adult patients under propofol/fentanyl/N2O anesthesia". Minerva Anestesiol. 72 (5): 299–308. PMID 16675938.
Serra C, Oliveira A (2006). "Cisatracurium: myographical and electrophysiological studies in the isolated rat muscle". Fundam Clin Pharmacol. 20 (3): 291–8. doi:10.1111/j.1472-8206.2006.00395.x. PMID 16671964. S2CID 11980810.
Katzung, Bertram G. (2011). Basic and clinical pharmacology (12th ed.). New York: Mcgraw-Hill. ISBN 978-0-07-176401-8.
External links
"Cisatracurium besylate". Drug Information Portal. U.S. National Library of Medicine.
"Cisatracurium". Drug Information Portal. U.S. National Library of Medicine. |
Drospirenone/ethinylestradiol/levomefolic acid | Drospirenone/ethinylestradiol/levomefolic acid (EE/DRSP/LMF), sold under the brand names Beyaz among others, is a combination of ethinylestradiol (EE), an estrogen, drospirenone (DRSP), a progestogen, antimineralocorticoid, and antiandrogen, and levomefolic acid (LMF), a form of vitamin B9, which is used as a birth control pill to prevent pregnancy in women. The formulation contains folate as the calcium salt of levomefolic acid to lower the risk of complications such as fetal neural tube defects should the medication fail as a form of birth control. EE/DRSP/LMF was approved for use by the U.S. Food and Drug Administration (FDA) on 24 September 2010.
Medical uses
Studies have shown its uses to be oral contraception, lessening premenstrual dysphoric disorder (PMDD), and treatment of moderate acne in women over 14 years of age who choose an oral contraceptive for contraception. Five clinical trials were carried out for these labeled uses, “including a one-year contraceptive efficacy study, two 3-cycle studies in women with premenstrual dysphoric disorder (PMDD), and two 6-cycle studies in women with moderate acne.” The drug combination will also increase folate levels due to its extra ingredient, levomefolic calcium. This is equivalent to folic acid 0.4 mg and will help prevent neural tube defects in case of accidental pregnancy while taking, or shortly after stopping the drug.
Dosage and use
Each box, as supplied by the manufacturer, contains three blister packs of 28 tablets packaged in individual boxes. Each blister pack of 28 tablets contains 24 pink active pills containing drospirenone 3 mg, ethinylestradiol 20 mcg, and levomefolate calcium 0.451 mg and four light orange inactive pills containing of levomefolate calcium 0.451 mg.One tablet is taken by mouth at the same time every day. The failure rate may increase when pills are missed or taken incorrectly. Single missed pills should be taken as soon as remembered. It is important to know that when experiencing stomach upset in the form of diarrhea or vomiting (within 3–4 hours of taking), backup contraception methods should be utilized to account for possible absorption failure.
Side effects
Adverse reactions commonly reported by combined oral contraceptive users are irregular uterine bleeding, nausea, breast tenderness, and headache.
Interactions
Decreased efficacy
Drugs or herbal products that induce certain enzymes, including CYP3A4, may decrease the effectiveness of COCs or increase breakthrough bleeding. Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include phenytoin, barbiturates, carbamazepine, bosentan, felbamate, griseofulvin, oxcarbazepine, rifampicin, topiramate and products containing St. John’s wort. Interactions between oral contraceptives and other drugs may lead to breakthrough bleeding and/or contraceptive failure.” “Use an alternative method of contraception or a back-up method when enzyme inducers are used with COCs, and to continue back-up contraception for 28 days after discontinuing the enzyme inducer to ensure contraceptive reliability.CYP3A4 inhibitors such as itraconazole or ketoconazole may increase plasma hormone levels.”
Antivirals
‘Significant changes (increase or decrease) in the plasma levels of estrogen and progestin have been noted in some cases of co-administration with HIV protease inhibitors or with non-nucleoside reverse transcriptase inhibitors.”
Antibiotics
“There have been reports of pregnancy while taking hormonal contraceptives and antibiotics, but clinical pharmacokinetic studies have not shown consistent effects of antibiotics on plasma concentrations of synthetic steroids.”
Others
“COCs containing EE may inhibit the metabolism of other compounds. COCs have been shown to significantly decrease plasma concentrations of lamotrigine. This may reduce seizure control; therefore, dosage adjustments of lamotrigine may be necessary.”
Pharmacology
Combined oral contraceptives reduce the risk of pregnancy primarily by inhibiting ovulation. This product combines drospirenone, an analogue of spironolactone that has both antimineralocorticoid and antiandrogenic effects with an estrogen plus folate supplementation. Levomefolate calcium 0.451 mg is included for reducing the risk of neural tube defects in case of accidental pregnancy.
History
EE/DRSP/LMF is the first and only birth control approved by the FDA for four indications: pregnancy prevention, symptomatic treatment of premenstrual dysphoric disorder, treatment of moderate acne, and raising folate levels to prevent neural tube defects for women who chose an oral contraceptive method.
See also
Birth control pill formulations
Ethinylestradiol/drospirenone
Estradiol/drospirenone
Ethinylestradiol/drospirenone/prasterone
List of combined sex-hormonal preparations
References
External links
"Drospirenone mixture with ethinylestradiol and levomefolate calcium". Drug Information Portal. U.S. National Library of Medicine. |
Factor IX | Factor IX (or Christmas factor) (EC 3.4.21.22) is one of the serine proteases of the coagulation system; it belongs to peptidase family S1. Deficiency of this protein causes haemophilia B. It was discovered in 1952 after a young boy named Stephen Christmas was found to be lacking this exact factor, leading to haemophilia.Coagulation factor IX is on the World Health Organizations List of Essential Medicines.
Physiology
Factor IX is produced as a zymogen, an inactive precursor. It is processed to remove the signal peptide, glycosylated and then cleaved by factor XIa (of the contact pathway) or factor VIIa (of the tissue factor pathway) to produce a two-chain form, where the chains are linked by a disulfide bridge. When activated into factor IXa, in the presence of Ca2+, membrane phospholipids, and a Factor VIII cofactor, it hydrolyses one arginine-isoleucine bond in factor X to form factor Xa.
Factor IX is inhibited by antithrombin.Factor IX expression increases with age in humans and mice. In mouse models, mutations within the promoter region of factor IX have an age-dependent phenotype.
Domain architecture
Factors VII, IX, and X all play key roles in blood coagulation and also share a common domain architecture. The factor IX protein is composed of four protein domains: the Gla domain, two tandem copies of the EGF domain and a C-terminal trypsin-like peptidase domain which carries out the catalytic cleavage.
The N-terminal EGF domain has been shown to at least in part be responsible for binding tissue factor. Wilkinson et al. conclude that residues 88 to 109 of the second EGF domain mediate binding to platelets and assembly of the factor X activating complex.The structures of all four domains have been solved. A structure of the two EGF domains and the trypsin-like domain was determined for the pig protein. The structure of the Gla domain, which is responsible for Ca(II)-dependent phospholipid binding, was also determined by NMR.Several structures of super active mutants have been solved, which reveal the nature of factor IX activation by other proteins in the clotting cascade.
Genetics
The gene for factor IX is located on the X chromosome (Xq27.1-q27.2) and is therefore X-linked recessive: mutations in this gene affect males much more frequently than females. At least 534 disease-causing mutations in this gene have been discovered. The F9 gene was first cloned in 1982 by Kotoku Kurachi and Earl Davie.Polly, a transgenic cloned Poll Dorset sheep carrying the gene for factor IX, was produced by Dr Ian Wilmut at the Roslin Institute in 1997.
Role in disease
Deficiency of factor IX causes Christmas disease (hemophilia B). Over 3000 variants of factor IX have been described, affecting 73% of the 461 residues; some cause no symptoms, but many lead to a significant bleeding disorder. The original Christmas disease mutation was identified by sequencing of Christmas DNA, revealing a mutation which changed a cysteine to a serine.Recombinant factor IX is used to treat Christmas disease. Formulations include:
nonacog alfa (brand name BeneFix)
albutrepenonacog alfa (brand name Idelvion)
eftrenonacog alfa (brand name Alprolix)
nonacog beta pegol (brand name Refixia)Some rare mutations of factor IX result in elevated clotting activity, and can result in clotting diseases, such as deep vein thrombosis. This gain of function mutation renders the protein hyperfunctional and is associated with familial early-onset thrombophilia.Factor IX deficiency is treated by injection of purified factor IX produced through cloning in various animal or animal cell vectors. Tranexamic acid may be of value in patients undergoing surgery who have inherited factor IX deficiency in order to reduce the perioperative risk of bleeding.A list of all the mutations in Factor IX is compiled and maintained by EAHAD.Coagulation factor IX is on the World Health Organizations List of Essential Medicines.
References
Further reading
External links
"Coagulation Factor IX (Recombinant), Fc Fusion Protein". Drug Information Portal. U.S. National Library of Medicine.
"Eftrenonacog alfa". Drug Information Portal. U.S. National Library of Medicine.
"Nonacog alfa". Drug Information Portal. U.S. National Library of Medicine.
"Albutrepenonacog alfa". Drug Information Portal. U.S. National Library of Medicine.
"Nonacog beta pegol". Drug Information Portal. U.S. National Library of Medicine.
Overview of all the structural information available in the PDB for UniProt: P00740 (Coagulation factor IX) at the PDBe-KB.
GeneReviews/NCBI/NIH/UW entry on Hemophilia B
The MEROPS online database for peptidases and their inhibitors: S01.214 |
Nafcillin | Nafcillin sodium is a narrow-spectrum beta-lactam antibiotic of the penicillin class. As a beta-lactamase-resistant penicillin, it is used to treat infections caused by Gram-positive bacteria, in particular, species of staphylococci that are resistant to other penicillins.
Nafcillin is considered therapeutically equivalent to oxacillin, although one retrospective study found greater rates of hypokalemia and acute kidney injury in patients taking nafcillin compared to patients taking oxacillin.
Indications
Nafcillin is indicated in the treatment of staphylococcal infections, except those caused by MRSA.U.S. clinical practice guidelines recommend either nafcillin or oxacillin as the first-line treatment of choice for staphylococcal endocarditis in patients without artificial heart valves.
Side-effects
As with all penicillins, serious life-threatening allergic reactions can occur.Milder side-effects include:
Hypokalemia
Nausea and vomiting
Diarrhea, often due to suppression of normal gastrointestinal bacteria, which, on occasion, leads to a more serious super-infection with an organism like Clostridium difficile
Abdominal pain
Yeast infections (thrush) affecting the mouth and tongue or vagina
Agranulocytosis, neutropenia
Interactions
There is evidence that nafcillin induces cytochrome P-450 enzymes, specifically CYP2C9. Several drugs with a narrow therapeutic window, such as warfarin and nifedipine, are metabolized by CYP2C9.Nafcillin contains salts added as stability media. These added salts could cause edema or fluid accumulation. It would be prudent to avoid this medication if there were a concern for a congestive heart failure or kidney disease.
== References == |
Clofarabine | Clofarabine is a purine nucleoside antimetabolite marketed in the United States and Canada as Clolar. In Europe and Australia/New Zealand the product is marketed under the name Evoltra. It is FDA-approved for treating relapsed or refractory acute lymphoblastic leukaemia (ALL) in children after at least two other types of treatment have failed. Some investigations of effectiveness in cases of acute myeloid leukaemia (AML) and juvenile myelomonocytic leukaemia (JMML) have been carried out. Ongoing trials are assessing its efficacy for managing other cancers.
Approval
Clolar was Food and Drug Administration (FDA) approved 28 December 2004. (Under accelerated approval regulations requiring further clinical studies.)
Side effects
Tumor lysis syndrome (TLS). Clofarabine quickly kills leukaemia cells in the blood. The body may react to this. Signs include hyperkalemia, hyperuricemia, and hyperphosphatemia. TLS is very serious and can lead to death if it is not treated right away.
Systemic inflammatory response syndrome (SIRS): symptoms include fast breathing, fast heartbeat, low blood pressure, and fluid in the lungs.
Bone marrow problems (suppression). Clofarabine can stop the bone marrow from making enough red blood cells, white blood cells, and platelets. Serious side effects that can happen because of bone marrow suppression include severe infection (sepsis), bleeding, and anemia.
Effects on pregnancy and breastfeeding. Girls and women should not become pregnant or breastfeed during treatment which may harm the baby.
Dehydration and low blood pressure. Clofarabine can cause vomiting and diarrhea which may lead to low body fluid (dehydration). Signs and symptoms of dehydration include dizziness, lightheadedness, fainting spells, or decreased urination.
Other side effects. The most common side effects are stomach problems (including vomiting, diarrhea, and nausea), and effects on blood cells (including low red blood cells count, low white blood cell count, low platelet count, fever, and infection). Clofarabine can also cause tachycardia and can affect the liver and kidneys.
Contraindications
pregnancy or planned pregnancy
breast-feeding
liver problems
kidney problems
Drug interactions
nephrotoxic drugs
hepatotoxic drugs
Delivery
By intravenous infusion.
Dosage is a 2-hour infusion (52 mg/m2) every day for five days. The cycle is repeated every 2 to 6 weeks.
Regular blood tests to monitor his or her blood cells, kidney function, and liver function.
Biology
Clofarabine is a second-generation purine nucleoside analog designed to overcome biological limitations observed with ara-A and fludarabine. A 2´(S)-fluorine in clofarabine significantly increased the stability of the glycosidic bond in acidic solution and toward phosphorolytic cleavage as compared to fludarabine. A chlorine substitution at the 2-position of the adenine base avoids production of a 2-fluoroadenine analog, a precursor to the toxic 2-fluoro-adenosine-5´-triphosphate and prevents deamination of the base as compared to ara-A.Clofarabine can be administered intravenously or given orally. Clofarabine enters cells via hENT1, hENT2, and hCNT2, where upon it is phosphorylated by deoxycytidine kinase to generate clofarabine-5´-monophosphate. The rate-limiting step in clofarabine metabolism is clofarabine-5´-diphosphosphate. Clofarabine-5´-triphosphate is the active-metabolite, and it inhibits ribonucleotide reductase, resulting in a decrease cellular dNTP concentrations, which promotes greater incorporation of clofarabine-5´-triphosphate during DNA synthesis. Embedded clofarabine-5´-monophosphate in the DNA promotes polymerase arrest at the replication fork, triggering DNA repair mechanisms that without repair lead to DNA strand breaks in vitro and cytochrome c-mediated apoptosis in vitro. Studies using cell lines have shown that clofarabine-5´-triphosphate can also be incorporated into RNA.Mechanisms of resistance and turnover have been reported. Clofarabine-resistance arises from decreased deoxycytidine kinase activity in vitro. ABC transporter ABCG2 promotes export of clofarabine-5´-monophosphate and thus limits the cytotoxic effects of this analog in vivo. Biochemically, clofarabine-5’-triphosphate was shown to be substrate for SAMHD1, thus potentially limiting the amount of active compound in cells.
References
External links
"Clofarabine". Drug Information Portal. U.S. National Library of Medicine. |
Eletriptan | Eletriptan, sold under the brand name Relpax and used in the form of eletriptan hydrobromide, is a second generation triptan medication intended for treatment of migraine headaches. It is used as an abortive medication, blocking a migraine attack which is already in progress. Eletriptan is marketed and manufactured by Pfizer Inc.
Approval and availability
Eletriptan was approved by the US Food and Drug Administration (FDA) on December 26, 2002, for the acute treatment of migraine with or without aura in adults. It is available only by prescription in the United States and Canada. It is not intended for the prophylactic therapy of migraine or for use in the management of hemiplegic or basilar migraine. It is available in 20 mg and 40 mg strengths.
Eletriptan was covered by U.S. Patent no. 5545644 and U.S. Patent no. 6110940; both now expired.
Mechanism of action
Eletriptan is believed to reduce swelling of the blood vessels surrounding the brain. This swelling is associated with the head pain of a migraine attack. Eletriptan blocks the release of substances from nerve endings that cause more pain and other symptoms like nausea, and sensitivity to light and sound. It is thought that these actions contribute to relief of symptoms by eletriptan.
Eletriptan is a serotonin receptor agonist, specifically an agonist of certain 5-HT1 family receptors. Eletriptan binds with high affinity to the 5-HT[1B, 1D, 1F] receptors. It has a modest affinity to the 5-HT[1A, 1E, 2B, 7] receptors, and little to no affinity at the 5-HT[2A, 2C, 3, 4, 5A, 6] receptors.
Eletriptan has no significant affinity or pharmacological activity at adrenergic α1, α2, or β; dopaminergic D1 or D2; muscarinic; or opioid receptors. Eletriptan could be efficiently co-administrated with nitric oxide synthase (NOSs) inhibitors for the treatment of NOS-dependent diseases (US patent US 2007/0254940).
Two theories have been proposed to explain the efficacy of 5-HT1 receptor agonists in migraine. One theory suggests that activation of 5-HT1 receptors located on intracranial blood vessels, including those on the arteriovenous anastomoses, leads to vasoconstriction, which is correlated with the relief of migraine headache. The other hypothesis suggests that activation of 5-HT1 receptors on sensory nerve endings in the trigeminal system results in the inhibition of pro-inflammatory neuropeptide release.
Side effects
Common side effects include hypertension, tachycardia, headache, dizziness, drowsiness and symptoms similar to angina pectoris. Severe allergic reactions are rare.
Contraindications
Eletriptan is contraindicated in patients with various diseases of the heart and circulatory system, such as angina pectoris, severe hypertension, and heart failure, as well as in patients that have had a stroke or heart attack. This is due to the unusual side effect of coronary vasoconstriction due to serotonin 5HT1B antagonism, which can precipitate a heart attack in those already at risk. It is also contraindicated in severe renal or hepatic impairment due to its extensive liver metabolism through CYP3A4.
Interactions
Strong inhibitors of the liver enzyme CYP3A4, such as erythromycin and ketoconazole, significantly increase blood plasma concentration of eletriptan and should be separated by at least 72 hours. Ergot alkaloids, such as dihydroergotamine, add to the drugs hypertensive effect and should be separated by at least 24 hours.
Additional chemical names
Merck Index: 3-[[(2R)-1-Methyl-2-pyrrolidinyl]methyl]-5-[2-(phenylsulfonyl)ethyl]-1H-indole
5-[2-(benzenesulfonyl)ethyl]-3-(1-methylpyrrolidin-2(R)-ylmethyl)-1H-indole
(R)-5-[2-(phenylsulfonyl)ethyl]-3-[(1-methyl-2-pyrrolidinyl)methyl]-1H-indole
Society and culture
Brand names
It is sold in the United States, Canada, Australia, and the United Kingdom under the brand name Relpax, and in several other countries under the brand name Relert.
References
External links
"Eletriptan". Drug Information Portal. U.S. National Library of Medicine.
"Eletriptan hydrobromide". Drug Information Portal. U.S. National Library of Medicine. |
Drospirenone/estetrol | Drospirenone/estetrol, sold under the brand name Nextstellis among others, is a fixed-dose combination medication containing drospirenone, a progestin, and estetrol, an estrogen, which is used as a combined birth control pill for the prevention of pregnancy in women. It is taken by mouth.It was approved for medical use in Canada in March 2021, and in the United States in April 2021.
Medical uses
Drospirenone/estetrol is used as a combined birth control pill to prevent pregnancy in women.
Side effects
Estetrol-containing birth control pills, similarly to estradiol-containing birth control pills, may have a lower risk of venous thromboembolism (VTE) than ethinylestradiol-containing birth control pills based on studies of coagulation. However, it is likely that another decade will be required before post-marketing epidemiological studies of VTE incidence with these birth control pills are completed and able to confirm this.
Pharmacology
Pharmacodynamics
Drospirenone/estetrol has a much lower impact on liver protein synthesis, including of sex hormone-binding globulin, angiotensinogen, and coagulation factors, than does ethinylestradiol/drospirenone.
Society and culture
Legal status
Drospirenone/estetrol is approved for the use of hormonal contraception in the European Union, the United States, and Canada.
Brand names
Drospirenone/estetrol in sold under the brand names Nexstellis, Drovelis, and Lydisilka.
See also
Birth control pill formulations
List of combined sex-hormonal preparations § Estrogens and progestogens
References
External links
"Drospirenone". Drug Information Portal. U.S. National Library of Medicine.
"Estetrol". Drug Information Portal. U.S. National Library of Medicine.
Clinical trial number NCT02817828 for "E4 FREEDOM (Female Response Concerning Efficacy and Safety of Estetrol/Drospirenone as Oral Contraceptive in a Multicentric Study) - EU/Russia Study" at ClinicalTrials.gov
Clinical trial number NCT02817841 for "E4 FREEDOM (Female Response Concerning Efficacy and Safety of Estetrol/Drospirenone as Oral Contraceptive in a Multicentric Study) - United States/Canada Study" at ClinicalTrials.gov |
Meclizine | Meclizine, sold under the brand name Bonine, among others, is an antihistamine used to treat motion sickness and dizziness (vertigo). It is taken by mouth. Effects generally begin in an hour and last for up to a day.Common side effects include sleepiness and dry mouth. Serious side effects may include allergic reactions. Use in pregnancy appears safe, but has not been well studied while use in breastfeeding is of unclear safety. It is believed to work in part by anticholinergic and antihistamine mechanisms.Meclizine was patented in 1951 and came into medical use in 1953. It is available as a generic medication and often over the counter. In 2019, it was the 150th most commonly prescribed medication in the United States, with more than 4 million prescriptions.
Medical uses
Meclizine is used to treat symptoms of motion sickness. Safety and efficacy in children younger than twelve years of age has not been established; therefore, use in this population is not recommended. Meclizine should be taken with caution in the elderly due to increased risk of confusion and amnesia.
Motion sickness
Meclizine is effective in inhibiting nausea, vomiting, and dizziness caused by motion sickness.The drug is safe for treating nausea in pregnancy and is a first-line therapy for this use. Doxylamine is similarly safe. Meclizine may not be strong enough for especially sickening motion stimuli and second-line defenses should be tried in those cases.
Vertigo
Meclizine may be used to treat motion sickness or vertigo such as in those with Ménières disease.
Side effects
Some common side effects such as drowsiness, dry mouth, and tiredness may occur. Meclizine has been shown to have fewer dry mouth side effects than the traditional treatment for motion sickness, transdermal scopolamine. A very serious allergic reaction to this drug is unlikely, but immediate medical attention should be sought if it occurs. Symptoms of a serious allergic reaction may include rash, itching, swelling, severe dizziness, and trouble breathing.
Drowsiness
Drowsiness may result as a side effect of taking meclizine. Users are advised not to operate heavy machinery while under the influence. The consumption of alcohol while under the influence of meclizine may result in additional drowsiness.
Elderly
As with any anticholinergic agent, meclizine may cause confusion or aggravate symptoms in those with dementia in the geriatric population (older than 65 years). Therefore, caution should be used when administering meclizine to the elderly.
Mechanism of action
Meclizine is an antagonist at H1 receptors. It possesses anticholinergic, central nervous system depressant, and local anesthetic effects. Its antiemetic and antivertigo effects are not fully understood, but its central anticholinergic properties are partially responsible. The drug depresses labyrinth excitability and vestibular stimulation, and it may affect the medullary chemoreceptor trigger zone. It has however been suggested that meclizine only has an inhibitory effect under normal viewing-circumstances, as the drug has been shown to enhance an isolated vestibular response. Much like motion-sickness arises from a discrepancy between multiple senses, Meclizine most likely affects a wide array of sensory mechanisms related to self-motion.
Meclizine also is a dopamine antagonist at D1-like and D2-like receptors but does not cause catalepsy in mice, perhaps because of its anticholinergic activity.
Chemistry
Meclizine is a first-generation antihistamine (nonselective H1 antagonist) of the piperazine class. It is structurally and pharmacologically similar to buclizine, cyclizine, and hydroxyzine, but has a shorter half-life of six hours compared to cyclizine and hydroxyzine with about 20 hours (though half-life should not be confused with duration). It is used as an antivertigo/antiemetic agent, specifically in the prevention and treatment of nausea, vomiting, and dizziness associated with motion sickness. Meclizine is sometimes combined with opioids, especially ones of the open-chain class like methadone, dextropropoxyphene, and dipipanone. Similarly, Diconal is a combination drug containing dipipanone and cyclizine.
Synthesis
(4-Chlorphenyl)-phenylmethanol is halogenated with thionyl chloride before adding acetylpiperazine. The acetyl group is cleaved with diluted sulfuric acid. An N-alkylation of the piperazine ring with 3-methylbenzylchloride completes the synthesis.
Alternatively, the last step can be replaced by a reductive N-alkylation with 3-methylbenzaldehyde. The reductive agent is hydrogen, and Raney nickel is used as a catalyst.
Meclizine is obtained and used as a racemate, a 1:1 mixture of the two stereoisomers. Drug forms contain the racemic dihydrochloride.
Names
Meclizine is an international nonproprietary name.It is sold under the brand names Bonine, Bonamine, Antivert, Postafen, Sea Legs, and Dramamine II (Less Drowsy Formulation). Emesafene is a combination of meclizine (1/3) and pyridoxine (2/3). In Canada, Antivert Tab (which is no longer available) was a combination of meclizine and nicotinic acid.
Notes
References
External links
"Meclizine". Drug Information Portal. U.S. National Library of Medicine.
"Meclizine dihydrochloride". Drug Information Portal. U.S. National Library of Medicine. |
Cenobamate | Cenobamate, sold under the brand names Xcopri (US) and Ontozry (EU), is a medication used for the treatment of partial-onset seizures, a kind of epilepsy, in adults. It is taken by mouth.Cenobamate was approved for medical use in the United States in November 2019 and placed in Schedule V of the Controlled Substances Act in March 2020. Cenobamate was approved for medical use in the European Union in March 2021.
Medical uses
In the United States, cenobamate is indicated for the treatment of partial-onset seizures in adults.In the European Union, it is indicated for the adjunctive treatment of focal-onset seizures with or without secondary generalization in adults with epilepsy who have not been adequately controlled despite a history of treatment with at least two anti-epileptic medications.
Contraindications
Cenobamate shortens the QT interval of the heart rhythm. It is therefore contraindicated in people with familial short QT syndrome, a very rare disease of the electrical system of the heart.
Adverse effects
The most common side effects are drowsiness (in 37% of people taking the drug), dizziness (33%), and fatigue (24%). Sight disorders, headache and elevated potassium levels in the blood (over 5 mmol/L) are also common. Hypersensitivity occurs in fewer than 1% of patients, drug reaction with eosinophilia and systemic symptoms (DRESS) in fewer than 0.1%.
Overdose
There are few data regarding cenobamate overdose. It is expected that the described adverse effects such as drowsiness, dizziness and fatigue would occur, as well as possibly problems with the heart rhythm. No specific antidote exists.
Interactions
Using cenobamate together with other central nervous system depressants such as barbiturates, benzodiazepines or alcohol may result in increased drowsiness and other central nervous system symptoms.Cenobamate induces the enzymes CYP3A4 and CYP2B6 and can therefore decrease blood concentrations of drugs that are metabolized by these enzymes (for example midazolam and bupropion, respectively). Conversely, it inhibits the enzyme CYP2C19, potentially increasing concentrations of drugs metabolized by this enzyme (for example omeprazole).
Pharmacology
Mechanism of action
Cenobamate is a voltage-gated sodium channel (VGSC) blocker. It is a selective blocker of the inactivated state of VGSCs, preferentially inhibiting persistent sodium current. It has been proposed that cenobamate additionally enhances presynaptic release of γ-aminobutyric acid (GABA), thereby increasing inhibitory GABAergic neurotransmission.
Pharmacokinetics
Cenobamate is absorbed from the gut to at least 88% and reaches highest concentrations in the blood plasma after one to four hours. When in the bloodstream, 60% of the substance are bound to plasma proteins, mostly to albumin. Cenobamate is inactivated mainly by glucuronidation via the enzyme UGT2B7 and to a lesser extent UGT2B4. The enzymes CYP2E1, CYP2A6, CYP2B6, CYP2C19 and CYP3A4 play smaller roles in the drugs metabolism.Steady state conditions are reached after 14 days. Cenobamate and its metabolites are mostly eliminated via the urine and only to 5.2% via the faeces. The terminal half-life is 50 to 60 hours.
History
The safety and efficacy of cenobamate to treat partial-onset seizures was established in two randomized, double-blind, placebo-controlled studies that enrolled 655 adults. In these studies, patients had partial-onset seizures with or without secondary generalization for an average of approximately 24 years and median seizure frequency of 8.5 seizures per 28 days during an 8-week baseline period. During the trials, doses of 100, 200, and 400 milligrams (mg) daily reduced the number of seizures per 28 days compared with the placebo group.
Society and culture
Legal status
The U.S. Food and Drug Administration (FDA) approved cenobamate in November 2019, and granted the application for Xcopri to SK Life Science Inc.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 marketing authorization. The applicant for this medicinal product is Arvelle Therapeutics Netherlands B.V. Ontozry was approved on 26 March 2021.
References
External links
"Cenobamate". Drug Information Portal. U.S. National Library of Medicine (NLM). |
Dexrazoxane | Dexrazoxane hydrochloride (Zinecard, Cardioxane) is a cardioprotective agent. It was discovered by Eugene Herman in 1972. The IV administration of dexrazoxane is in acidic condition with HCl adjusting the pH.
Uses
Dexrazoxane has been used to protect the heart against the cardiotoxic side effects of chemotherapeutic drugs such as anthracyclines, such as daunorubicin or doxorubicin or other chemotherapeutic agents. However, in July 2011 the European Medicines Agency (EMA) released a statement restricting use only in adult patients with cancer who have received > 300 mg/m2 doxorubicin or > 540 mg/m2 epirubicin and general approval for use for cardioprotection. That showed a possibly higher rate of secondary malignancies and acute myelogenous leukemia in pediatric patients treated for different cancers with both dexrazoxane and other chemotherapeutic agents that are associated with secondary malignancies. On July 19, 2017, based on evaluation of the currently available data the European Commission issued an EU-wide legally binding decision to implement the recommendations of the Committee for Medicinal Products for Human Use (CHMP) on dexrazoxane and lifted its 2011-contraindication for primary prevention of anthracycline-induced cardiotoxicity with dexrazoxane in children and adolescents where high doses (≥ 300 mg/m3) of anthracyclines are anticipated.
Dexrazoxane was designated by the US FDA as an orphan drug for "prevention of cardiomyopathy for children and adults 0 through 16 years of age treated with anthracyclines". This decision allows virtually all children to receive dexrazoxane starting with the first dose of anthracycline at the discretion of the treating provider. The label change by the agency announcing dexrazoxane as an approved cardio-oncology protectant has been followed by a review by the agency. Currently, the only FDA and EMA approved cardioprotective treatment for anthracycline cardioprotection is dexrazoxane, which provides effective primary cardioprotection against anthracycline-induced cardiotoxicity without reducing anthracycline activity and without enhancing secondary malignancies.The United States Food and Drug Administration has also approved a dexrazoxane for use as a treatment of extravasation resulting from IV anthracycline chemotherapy. Extravasation is an adverse event in which chemotherapies containing anthracylines leak out of the blood vessel and necrotize the surrounding tissue.
Mechanism
As a derivative of EDTA, dexrazoxane chelates iron and thus reduces the number of metal ions complexed with anthracycline and, consequently, decrease the formation of superoxide radicals. The exact chelation mechanism is unknown, but it has been postulated that dexrazoxane can be converted into ring-opened form intracellularly and interfere with iron-mediated free radical generation that is in part thought to be responsible for anthryacycline induced cardiomyopathy. It was speculated that dexrazoxane could be used for further investigation to synthesize new antimalarial drugs.
References
External links
"Dexrazoxane". Drug Information Portal. U.S. National Library of Medicine.
"Dexrazoxane hydrochloride". Drug Information Portal. U.S. National Library of Medicine. |
Tasimelteon | Tasimelteon, sold under the brand name Hetlioz, is a medication approved by the U.S. Food and Drug Administration (FDA) in January 2014, for the treatment of non-24-hour sleep–wake disorder (also called non-24, N24 and N24HSWD). In June 2014, the European Medicines Agency (EMA) accepted an EU filing application for tasimelteon and in July 2015, the drug was approved in the European Union for the treatment of non-24-hour sleep-wake rhythm disorder in totally blind adults, but not in the rarer case of non-24 in sighted people.
The most common side effects include headache, somnolence, nausea (feeling sick) and dizziness.
Medical uses
In the United States, tasimelteon capsules are indicated for the treatment of non-24-hour sleep–wake disorder (Non-24) in adults and for the treatment of nighttime sleep disturbances in Smith-Magenis Syndrome (SMS) in people sixteen years of age and older. Tasimelteon oral suspension is indicated for the treatment of nighttime sleep disturbances in SMS in children from 3 to 15 years of age.In the European Union, tasimelteon capsules are indicated for the treatment of non-24-hour sleep–wake disorder (Non-24) in totally blind adults.The capsule and liquid suspension forms of tasimelteon are not interchangeable.Tasimelteon is a selective agonist for the melatonin receptors MT1 and MT2, similar to other members of the melatonin receptor agonist class of which ramelteon (2005), melatonin (2007), and agomelatine (2009) were the first approved. As a treatment for N24HSWD, as with melatonin or other melatonin derivatives, the patient may experience improved sleep timing while taking the drug. Reversion to baseline sleep performance occurs within a month of discontinuation.
Development
Tasimelteon (previously known as BMS-214,778) was developed for the treatment of insomnia and other sleep disorders. A phase II trial on circadian rhythm sleep disorders was concluded in March 2005. A phase III insomnia trial was conducted in 2006. A second phase III trial on insomnia, this time concerning primary insomnia, was completed in June 2008. In 2010, the FDA granted orphan drug status to tasimelteon, then regarded as an investigational medication, for use in totally blind adults with N24HSWD. (Through mechanisms such as easing the approval process and extending exclusivity periods, orphan drug status encourages development of drugs for rare conditions that otherwise might lack sufficient commercial incentive.)
On completion of Phase III trials, interpretations of the clinical trials by the research team concluded that the drug may have therapeutic potential for transient insomnia in circadian rhythm sleep disorders. A year-long (2011–2012) study at Harvard tested the use of tasimelteon in blind subjects with non-24-hour sleep-wake disorder. The drug has not been tested in children nor in any non-blind people.
FDA approval
In May 2013, Vanda Pharmaceuticals submitted a New Drug Application to the Food and Drug Administration for tasimelteon for the treatment of non-24-hour sleep–wake disorder in totally blind people. It was approved by the FDA on January 31, 2014, under the brand name Hetlioz. In the opinion of Public Citizen, an advocacy group, the FDA erroneously allowed it to be labelled without stating that it is only approved for use by totally blind people. However, FDA updated its press release on Oct. 2, 2014 to clarify the approved use of Hetlioz, which includes both sighted and blind individuals. The update did not change the drug labeling (prescribing information).
Toxicity
Experiments with rodents revealed fertility impairments, an increase in certain cancers, and serious adverse events during pregnancy at dosages in excess of what is considered the "human dose".
See also
Discovery and development of melatonin receptor agonists
References
External links
"Tasimelteon". Drug Information Portal. U.S. National Library of Medicine. |
Nystatin | Nystatin, sold under the brandname Mycostatin among others, is an antifungal medication. It is used to treat Candida infections of the skin including diaper rash, thrush, esophageal candidiasis, and vaginal yeast infections. It may also be used to prevent candidiasis in those who are at high risk. Nystatin may be used by mouth, in the vagina, or applied to the skin.Common side effects when applied to the skin include burning, itching, and a rash. Common side effects when taken by mouth include vomiting and diarrhea. During pregnancy use in the vagina is safe while other formulations have not been studied in this group. It works by disrupting the cell membrane of the fungal cells.Nystatin was discovered in 1950 by Rachel Fuller Brown and Elizabeth Lee Hazen. It was the first polyene macrolide antifungal. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. It is made from the bacterium Streptomyces noursei. In 2019, it was the 222nd most commonly prescribed medication in the United States, with more than 2 million prescriptions.
Medical uses
Skin, vaginal, mouth, and esophageal Candida infections usually respond well to treatment with nystatin. Infections of nails or hyperkeratinized skin do not respond well. It is available in many forms.
When given parenterally, its activity is reduced due to presence of plasma.Oral nystatin is often used as a preventive treatment in people who are at risk for fungal infections, such as AIDS patients with a low CD4+ count and people receiving chemotherapy. It has been investigated for use in patients after liver transplantation, but fluconazole was found to be much more effective for preventing colonization, invasive infection, and death. It is effective in treating oral candidiasis in elderly people who wear dentures.It is also used in very low birth-weight (less than 1500 g or 3 lb 5oz o) infants to prevent invasive fungal infections, although fluconazole is the preferred treatment. It has been found to reduce the rate of invasive fungal infections and also reduce deaths when used in these babies.Liposomal nystatin is not commercially available, but investigational use has shown greater in vitro activity than colloidal formulations of amphotericin B, and demonstrated effectiveness against some amphotericin B-resistant forms of fungi. It offers an intriguing possibility for difficult-to-treat systemic infections, such as invasive aspergillosis, or infections that demonstrate resistance to amphotericin B. Cryptococcus is also sensitive to nystatin. Additionally, liposomal nystatin appears to cause fewer cases of and less severe nephrotoxicity than observed with amphotericin B.In the UK, its license for treating neonatal oral thrush is restricted to those over the age of one month.It is prescribed in units, with doses varying from 100,000 units (for oral infections) to 1 million (for intestinal ones). As it is not absorbed from the gut, it is fairly safe for oral use and does not have problems of drug interactions. On occasion, serum levels of the drug can be identified from oral, vaginal, or cutaneous administration, and lead to toxicity.
Adverse effects
Bitter taste and nausea are more common than most other adverse effects.The oral suspension form produces a number of adverse effects including but not limited to:
Diarrhea
Abdominal pain
Rarely, tachycardia, bronchospasm, facial swelling, muscle achesBoth the oral suspension and the topical form can cause:
Hypersensitivity reactions, including Stevens–Johnson syndrome in some cases
Rash, itching, burning and acute generalized exanthematous pustulosis
Mechanism of action
Like amphotericin B and natamycin, nystatin is an ionophore. It binds to ergosterol, a major component of the fungal cell membrane. When present in sufficient concentrations, it forms pores in the membrane that lead to K+ leakage, acidification, and death of the fungus. Ergosterol is a sterol unique to fungi, so the drug does not have such catastrophic effects on animals or plants. However, many of the systemic/toxic effects of nystatin in humans are attributable to its binding to mammalian sterols, namely cholesterol. This is the effect that accounts for the nephrotoxicity observed when high serum levels of nystatin are achieved.
Nystatin also impacts cell membrane potential and transport by lipid peroxidation. Conjugated double bonds in nystatins structure steal electron density from ergosterol in fungal cell membranes. Lipid peroxidation alters the hydrophilicity of the interior of channels in the membrane, which is necessary to transport ions and polar molecules. Disruption of membrane transport from nystatin results in rapid cell death. Lipid peroxidation by nystatin also contributes significantly to K+ leakage due to structural modifications of the membrane.
Biosynthesis
Nystatin A1 (or referred to as nystatin) is biosynthesized by a bacterial strain, Streptomyces noursei. The structure of this active compound is characterized as a polyene macrolide with a deoxysugar D-mycosamine, an aminoglycoside. The genomic sequence of nystatin reveals the presence of the polyketide loading module (nysA), six polyketide syntheses modules (nysB, nysC, nysI, nysJ, and nysK) and two thioesterase modules (nysK and nysE). It is evident that the biosynthesis of the macrolide functionality follows the polyketide synthase I pathway.Following the biosynthesis of the macrolide, the compound undergoes post-synthetic modifications, which are aided by the following enzymes: GDP-mannose dehydratase (nysIII), P450 monooxygenase (nysL and nysN), aminotransferase (nysDII), and glycosyltransferase (nysDI). The biosynthetic pathway is thought to proceed as shown to yield nystatin.
The melting point of nystatin is 44 - 46 °C.
History
Like many other antifungals and antibiotics, nystatin is of bacterial origin. It was isolated from Streptomyces noursei in 1950 by Elizabeth Lee Hazen and Rachel Fuller Brown, who were doing research for the Division of Laboratories and Research of the New York State Department of Health. Hazen found a promising micro-organism in the soil of a friends dairy farm. She named it Streptomyces noursei, after Jessie Nourse, the wife of the farms owner. Hazen and Brown named nystatin after the New York State Health Department in 1954. The two discoverers patented the drug, and then donated the $13 million in profits to a foundation to fund similar research.
Other uses
It is also used in cellular biology as an inhibitor of the lipid raft-caveolae endocytosis pathway on mammalian cells, at concentrations around 3 μg/ml.
In certain cases, nystatin has been used to prevent the spread of mold on objects such as works of art. For example, it was applied to wood panel paintings damaged as a result of the Arno River Flood of 1966 in Florence, Italy.
Nystatin is also used as a tool by scientists performing "perforated" patch-clamp electrophysiologic recordings of cells. When loaded in the recording pipette, it allows for measurement of electrical currents without washing out the intracellular contents, because it forms pores in the cell membrane that are permeable to only monovalent ions.
Formulations
An oral suspension form is used for the prophylaxis or treatment of oropharyngeal thrush, a superficial candidal infection of the mouth and pharynx.
A tablet form is preferred for candidal infections in the intestines.
Nystatin is available as a topical cream and can be used for superficial candidal infections of the skin.
Additionally, a liposomal formulation of nystatin was investigated in the 1980s and into the early 21st century. The liposomal form was intended to resolve problems arising from the poor solubility of the parent molecule and the associated systemic toxicity of the free drug.
Nystatin pastilles have been shown to be more effective in treating oral candidiasis than nystatin suspensions.Due to its toxicity profile when high levels in the serum are obtained, no injectable formulations of this drug are currently on the US market. However, injectable formulations have been investigated in the past.
Brand names
The original brandname was Fungicidin
Nyamyc
Pedi-Dri
Pediaderm AF Complete
Candistatin
Nyaderm
Bio-Statin
PMS-Nystatin
Nystan (oral tablets, topical ointment, and pessaries, formerly from Bristol-Myers Squibb)
Infestat
Nystalocal from Medinova AG
Nystamont
Nystop (topical powder, Paddock)
Nystex
Mykinac
Nysert (vaginal suppositories, Procter & Gamble)
Nystaform (topical cream, and ointment and cream combined with iodochlorhydroxyquine and hydrocortisone; formerly Bayer now Typharm Ltd)
Nilstat (vaginal tablet, oral drops, Lederle)
Korostatin (vaginal tablets, Holland Rantos)
Mycostatin (vaginal tablets, topical powder, suspension Bristol-Myers Squibb)
Mycolog-II (topical ointment, combined with triamcinolone; Apothecon)
Mytrex (topical ointment, combined with triamcinolone)
Mykacet (topical ointment, combined with triamcinolone)
Myco-Triacet II (topical ointment, combined with triamcinolone)
Flagystatin II (cream, combined with metronidazole)
Timodine (cream, combined with hydrocortisone and dimethicone)
Nistatina (oral tablets, Antibiotice Iaşi)
Nidoflor (cream, combined with neomycin sulfate and triamcinolone acetonide)
Stamicin (oral tablets, Antibiotice Iaşi)
Lystin
Animax (veterinary topical ointment or cream; combined with neomycin sulfate, thiostrepton and triamcinolone acetonide)
Nyata (topical powder)
References
External links
"Nystatin". Drug Information Portal. U.S. National Library of Medicine. |
Cerliponase alfa | Cerliponase alfa, marketed as Brineura, is an enzyme replacement treatment for Batten disease, a neurodegenerative lysosomal storage disease. Specifically, Cerliponase alfa is meant to slow loss of motor function in symptomatic children over three years old with late infantile neuronal ceroid lipofuscinosis type 2 (CLN2). The disease is also known as tripeptidyl peptidase-1 (TPP1) deficiency, a soluble lysosomal enzyme deficiency. Approved by the United States Food and Drug Administration (FDA) on 27 April 2017, this is the first treatment for a neuronal ceroid lipofuscinosis of its kind, acting to slow disease progression rather than palliatively treat symptoms by giving patients the TPP1 enzyme they are lacking.The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication.
History
TPP1 was identified as the enzyme deficient in CLN2 Batten disease in 1997, via biochemical analysis that identified proteins missing a mannose-6-phosphate lysosomal targeting sequence. A gel electrophoresis was run for known brain proteins with lysosomal targeting sequences to see if a band was missing, indicating a deficiency in that protein. A band appeared to be missing at approximately 46 kDa, confirming its role in CLN2 disease, and almost the entire gene for this unknown protein was sequenced. The gene is located on chromosome 11. Today, it is known that varying mutation types occur in various locations of the gene including the proenzyme region, the mature enzyme region, or the signal sequence regions. After discovery, the recombinant form of TPP1, cerliponase alfa, was first produced in 2000, followed by testing in animal models until 2014. In 2012, BioMarin began the first clinical trial on affected patients using their recombinant DNA technology cerliponase alfa which is synthesized using Chinese hamster ovarian (CHO) cell lines.
After the success of this clinical trial, the U.S. FDA approved the marketing of cerliponase alfa to patients with CLN2 disease. The approval only applied to patients three years or older as the FDA wants to have more data available on children under the age of three before approving it for younger patients. A ten-year study is being performed to assess the long term effects of continued use of this drug. Cerliponase alfa is developed by BioMarin Pharmaceutical and the drug application was granted both orphan drug designation to provide incentives for rare disease research and the tenth Rare Pediatric Disease Priority Review Voucher. Cerliponase alfa was also approved by European Medicines Agency (EMA) on 30 May 2017. In the United Kingdom NICE evaluated cerliponase alfa for the treatment of CLN2 and deemed it not cost-effective. BioMarin announced that the price per infusion is $27,000, coming to $702,000 per year for treatment, though using Medicaid can decrease the cost.In March 2018, cerliponase alfa was approved in the United States as a treatment for a specific form of Batten disease. Cerliponase alfa is the first FDA-approved treatment to slow loss of walking ability (ambulation) in symptomatic pediatric patients three years of age and older with late infantile neuronal ceroid lipofuscinosis type 2 (CLN2), also known as tripeptidyl peptidase-1 (TPP1) deficiency.The efficacy of cerliponase alfa was established in a non-randomized, single-arm dose escalation clinical study in 22 symptomatic pediatric patients with CLN2 disease and compared to 42 untreated patients with CLN2 disease from a natural history cohort (an independent historical control group) who were at least three years old and had motor or language symptoms. Taking into account age, baseline walking ability and genotype, cerliponase alfa-treated patients demonstrated fewer declines in walking ability compared to untreated patients in the natural history cohort.The safety of cerliponase alfa was evaluated in 24 patients with CLN2 disease aged three to eight years who received at least one dose of cerliponase alfa in clinical studies. The trial was conducted in the United States, United Kingdom, Germany and Italy. The safety and effectiveness of cerliponase alfa has not been established in patients less than three years of age.Brineura-treated patients were compared to untreated patients from a natural history cohort by assessing disease progression through Week 96 of treatment. The investigators measured the loss of ability to walk or crawl using the Motor domain of the CLN2 Clinical Rating Scale. Scores from the Motor domain of the scale range from 3 (grossly normal) to 0 (profoundly impaired).The U.S. Food and Drug Administration (FDA) requires the cerliponase alfa manufacturer to further evaluate the safety of cerliponase alfa in CLN2 patients below the age of two years, including device related adverse events and complications with routine use. In addition, a long-term safety study will assess cerliponase alfa treated CLN2 patients for a minimum of ten years.The application for cerliponase alfa was granted priority review designation, breakthrough therapy designation, orphan drug designation, and a rare pediatric disease priority review voucher. The FDA granted approval of Brineura to BioMarin Pharmaceutical Inc.
Structure and biomolecular mechanism
Cerliponase alfa is an approximately 59 kDa molecule that codes for 544 amino acids in its proenzyme form while the activated mature enzyme only codes for 368 amino acids. Five amino acid residues have N-linked glycosylation sites. These five residues have additional mannose-6-phosphate (M6P) targeting sequences which function to target enzymes to the lysosome. When the cerliponase alfa proenzyme reaches target neurons during administration, it binds mannose-6-phosphate receptors on the cell surface to trigger vesicle formation around the receptor-proenzyme complex. The more neutral pH of the cytosol promotes binding of the proenzymes M6P targeting sequences to their receptors. Once brought into the cell, the receptor-proenzyme complex vesicle is transported to the lysosome where the lower pH promotes both dissociation of the proenzyme from the receptor and activation of the proenzyme to its active catalytic form via cleavage of the proenzyme sequence.Like natural TPP1, cerliponase alfa functions as a serine protease, cleaving N-terminal tripeptides from a broad range of protein substrates. The enzyme uses a catalytic triad active site composed of the three amino acids, aspartic acid, glutamic acid, and serine. Serine functions as the amino acid that performs the nucleophilic attack during the ping pong catalytic activity of a serine protease. The products of this reaction are a tripeptide and the remaining length of the protein substrate with a new N-terminal end that can be cleaved again. In CLN2 disease, TPP1 is deficient or not made at all, meaning that proteins are unable to be degraded in the lysosome and accumulate, leading to damage in nerves. As a protein, cerliponase alfa gets degraded by proteolysis. Therefore, cerliponase alfa is administered repeatedly to maintain sufficient levels of the recombinant TPP1 enzyme in place of the deficient form to degrade proteins and prevent further build up. Cerliponase alfa is a treatment that can potentially slow disease progression but does not cure the disease itself.
References
External links
"Cerliponase alfa". Drug Information Portal. U.S. National Library of Medicine. |
Dextromethorphan/quinidine | Dextromethorphan/quinidine, sold under the brand name Nuedexta, is a fixed-dose combination medication for the treatment of pseudobulbar affect (PBA). It contains dextromethorphan (DXM) and the class I antiarrhythmic agent quinidine.Dextromethorphan/quinidine was approved for medical use in the United States in October 2010, and is marketed by Avanir Pharmaceuticals.
Medical uses
DXM/quinidine is used in the treatment of PBA. In a 12-week randomized, double-blind trial, amyotrophic lateral sclerosis and multiple sclerosis patients with significant PBA were given either Nuedexta 20/10 mg or placebo. In 326 randomized patients, the PBA-episode daily rate was 46.9% (p < 0.0001) lower for Nuedexta than for placebo. The three deaths in each of the two drug treatment arms and the single death in the placebo arm of the study were believed to be due to the natural course of the disease.
Contraindications
Atrioventricular (AV) block, complete, without implanted pacemaker or at high risk of complete AV block
Concomitant use with drugs containing quinidine, quinine, or mefloquine
Concomitant use with drugs that both prolong the QT interval and are metabolized by CYP2D6 (e.g., thioridazine, pimozide); effects on QT interval may be increased
Concomitant use with MAOIs or use of MAOIs within 14 days; risk of serious, potentially fatal, drug interactions including serotonin syndrome
Heart failure
Hypersensitivity to dextromethorphan
Hypersensitivity to quinine, mefloquine, quinidine, or dextromethorphan/quinidine with a history of thrombocytopenia, hepatitis, bone marrow depression or lupus-like syndrome induced by these drugs
QT interval, prolonged or congenital long QT syndrome or a history suggesting torsades de pointes
Adverse effects
Common risks and side effects include:
Abdominal pain
Asthenia
Cough
Diarrhea (reported in 13% of patients)
Dizziness
Elevated gamma glutamyltransferase
Flu-like symptoms
Flatulence
Prolonged QT interval
Muscle spasm
Peripheral edema
Urinary tract infection
Vomiting
Interactions
Desipramine (CYP2D6 substrate) levels increase 8-fold with co-administration
Paroxetine (CYP2D6 inhibitor and substrate)
Memantine
Pharmacology
Pharmacodynamics
Dextromethorphan acts as a σ1 receptor agonist, serotonin–norepinephrine reuptake inhibitor, and NMDA receptor antagonist, while quinidine is an antiarrhythmic agent acting as a CYP2D6 inhibitor. Quinidine prevents the metabolism of dextromethorphan into its active metabolite dextrorphan, which is a much more potent NMDA receptor antagonist but much less potent serotonin reuptake inhibitor than dextromethorphan. The mechanism of action of dextromethorphan/quinidine in the treatment of PBA is unknown.
Research
Dextromethorphan/quinidine was investigated for the treatment of agitation associated with dementia, diabetic neuropathy, drug-induced dyskinesia, migraine, and neuropathic pain, but development for these indications was discontinued. Another formulation, deudextromethorphan/quinidine, is still under investigation for various indications. These include agitation, schizophrenia, and major depressive disorder, among others.
See also
Bupropion/dextromethorphan
Deudextromethorphan/quinidine
References
External links
"Dextromethorphan hydrobromide mixture with quinidine sulfate". Drug Information Portal. U.S. National Library of Medicine. |
Dextroamphetamine | Dextroamphetamine is a central nervous system (CNS) stimulant and an amphetamine enantiomer that is prescribed for the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It is also used as an athletic performance and cognitive enhancer, and recreationally as an aphrodisiac and euphoriant.
The amphetamine molecule exists as two enantiomers, levoamphetamine and dextroamphetamine. Dextroamphetamine is the dextrorotatory, or right-handed, enantiomer and exhibits more pronounced effects on the central nervous system than levoamphetamine. Pharmaceutical dextroamphetamine sulfate is available as both a brand name and generic drug in a variety of dosage forms. Dextroamphetamine is sometimes prescribed as the inactive prodrug lisdexamfetamine dimesylate, which is converted into dextroamphetamine after absorption.
Dextroamphetamine, like other amphetamines, elicits its stimulating effects via several distinct actions: it inhibits or reverses the transporter proteins for the monoamine neurotransmitters (namely the serotonin, norepinephrine and dopamine transporters) either via trace amine-associated receptor 1 (TAAR1) or in a TAAR1 independent fashion when there are high cytosolic concentrations of the monoamine neurotransmitters and it releases these neurotransmitters from synaptic vesicles via vesicular monoamine transporter 2. It also shares many chemical and pharmacological properties with human trace amines, particularly phenethylamine and N-methylphenethylamine, the latter being an isomer of amphetamine produced within the human body.
Uses
Medical
Dextroamphetamine is used to treat attention deficit hyperactivity disorder (ADHD) and narcolepsy (a sleep disorder), and is sometimes prescribed off-label for depression and obesity.
Long-term amphetamine exposure at sufficiently high doses in some animal species is known to produce abnormal dopamine system development or nerve damage, but in humans with ADHD, pharmaceutical amphetamines at therapeutic dosages appear to improve brain development and nerve growth. Reviews of magnetic resonance imaging (MRI) studies suggest that long-term treatment with amphetamine decreases abnormalities in brain structure and function found in subjects with ADHD, and improves function in several parts of the brain, such as the right caudate nucleus of the basal ganglia.Reviews of clinical stimulant research have established the safety and effectiveness of long-term continuous amphetamine use for the treatment of ADHD. Randomized controlled trials of continuous stimulant therapy for the treatment of ADHD spanning 2 years have demonstrated treatment effectiveness and safety. Two reviews have indicated that long-term continuous stimulant therapy for ADHD is effective for reducing the core symptoms of ADHD (i.e., hyperactivity, inattention, and impulsivity), enhancing quality of life and academic achievement, and producing improvements in a large number of functional outcomes across 9 categories of outcomes related to academics, antisocial behavior, driving, non-medicinal drug use, obesity, occupation, self-esteem, service use (i.e., academic, occupational, health, financial, and legal services), and social function. One review highlighted a nine-month randomized controlled trial of amphetamine treatment for ADHD in children that found an average increase of 4.5 IQ points, continued increases in attention, and continued decreases in disruptive behaviors and hyperactivity. Another review indicated that, based upon the longest follow-up studies conducted to date, lifetime stimulant therapy that begins during childhood is continuously effective for controlling ADHD symptoms and reduces the risk of developing a substance use disorder as an adult.Current models of ADHD suggest that it is associated with functional impairments in some of the brains neurotransmitter systems; these functional impairments involve impaired dopamine neurotransmission in the mesocorticolimbic projection and norepinephrine neurotransmission in the noradrenergic projections from the locus coeruleus to the prefrontal cortex. Psychostimulants like methylphenidate and amphetamine are effective in treating ADHD because they increase neurotransmitter activity in these systems. Approximately 80% of those who use these stimulants see improvements in ADHD symptoms. Children with ADHD who use stimulant medications generally have better relationships with peers and family members, perform better in school, are less distractible and impulsive, and have longer attention spans. The Cochrane reviews on the treatment of ADHD in children, adolescents, and adults with pharmaceutical amphetamines stated that short-term studies have demonstrated that these drugs decrease the severity of symptoms, but they have higher discontinuation rates than non-stimulant medications due to their adverse side effects. A Cochrane review on the treatment of ADHD in children with tic disorders such as Tourette syndrome indicated that stimulants in general do not make tics worse, but high doses of dextroamphetamine could exacerbate tics in some individuals.
Enhancing performance
Cognitive performance
In 2015, a systematic review and a meta-analysis of high quality clinical trials found that, when used at low (therapeutic) doses, amphetamine produces modest yet unambiguous improvements in cognition, including working memory, long-term episodic memory, inhibitory control, and some aspects of attention, in normal healthy adults; these cognition-enhancing effects of amphetamine are known to be partially mediated through the indirect activation of both dopamine receptor D1 and adrenoceptor α2 in the prefrontal cortex. A systematic review from 2014 found that low doses of amphetamine also improve memory consolidation, in turn leading to improved recall of information. Therapeutic doses of amphetamine also enhance cortical network efficiency, an effect which mediates improvements in working memory in all individuals. Amphetamine and other ADHD stimulants also improve task saliency (motivation to perform a task) and increase arousal (wakefulness), in turn promoting goal-directed behavior. Stimulants such as amphetamine can improve performance on difficult and boring tasks and are used by some students as a study and test-taking aid. Based upon studies of self-reported illicit stimulant use, 5–35% of college students use diverted ADHD stimulants, which are primarily used for enhancement of academic performance rather than as recreational drugs. However, high amphetamine doses that are above the therapeutic range can interfere with working memory and other aspects of cognitive control.
Physical performance
Amphetamine is used by some athletes for its psychological and athletic performance-enhancing effects, such as increased endurance and alertness; however, non-medical amphetamine use is prohibited at sporting events that are regulated by collegiate, national, and international anti-doping agencies. In healthy people at oral therapeutic doses, amphetamine has been shown to increase muscle strength, acceleration, athletic performance in anaerobic conditions, and endurance (i.e., it delays the onset of fatigue), while improving reaction time. Amphetamine improves endurance and reaction time primarily through reuptake inhibition and release of dopamine in the central nervous system. Amphetamine and other dopaminergic drugs also increase power output at fixed levels of perceived exertion by overriding a "safety switch", allowing the core temperature limit to increase in order to access a reserve capacity that is normally off-limits. At therapeutic doses, the adverse effects of amphetamine do not impede athletic performance; however, at much higher doses, amphetamine can induce effects that severely impair performance, such as rapid muscle breakdown and elevated body temperature.
Recreational
Dextroamphetamine is also used recreationally as a euphoriant and aphrodisiac, and like other amphetamines is used as a club drug for its energetic and euphoric high. Dextroamphetamine is considered to have a high potential for misuse in a recreational manner since individuals typically report feeling euphoric, more alert, and more energetic after taking the drug. Large recreational doses of dextroamphetamine may produce symptoms of dextroamphetamine overdose. Recreational users sometimes open dexedrine capsules and crush the contents in order to insufflate it or subsequently dissolve it in water and inject it. Injection into the bloodstream can be dangerous because insoluble fillers within the tablets can block small blood vessels. Chronic overuse of dextroamphetamine can lead to severe drug dependence, resulting in withdrawal symptoms when drug use stops.
Contraindications
According to the International Programme on Chemical Safety (IPCS) and the United States Food and Drug Administration (USFDA), amphetamine is contraindicated in people with a history of drug abuse, cardiovascular disease, severe agitation, or severe anxiety. It is also contraindicated in individuals with advanced arteriosclerosis (hardening of the arteries), glaucoma (increased eye pressure), hyperthyroidism (excessive production of thyroid hormone), or moderate to severe hypertension. These agencies indicate that people who have experienced allergic reactions to other stimulants or who are taking monoamine oxidase inhibitors (MAOIs) should not take amphetamine, although safe concurrent use of amphetamine and monoamine oxidase inhibitors has been documented. These agencies also state that anyone with anorexia nervosa, bipolar disorder, depression, hypertension, liver or kidney problems, mania, psychosis, Raynauds phenomenon, seizures, thyroid problems, tics, or Tourette syndrome should monitor their symptoms while taking amphetamine. Evidence from human studies indicates that therapeutic amphetamine use does not cause developmental abnormalities in the fetus or newborns (i.e., it is not a human teratogen), but amphetamine abuse does pose risks to the fetus. Amphetamine has also been shown to pass into breast milk, so the IPCS and the USFDA advise mothers to avoid breastfeeding when using it. Due to the potential for reversible growth impairments, the USFDA advises monitoring the height and weight of children and adolescents prescribed an amphetamine pharmaceutical.
Adverse effects
Physical
Cardiovascular side effects can include hypertension or hypotension from a vasovagal response, Raynauds phenomenon (reduced blood flow to the hands and feet), and tachycardia (increased heart rate). Sexual side effects in males may include erectile dysfunction, frequent erections, or prolonged erections. Gastrointestinal side effects may include abdominal pain, constipation, diarrhea, and nausea. Other potential physical side effects include appetite loss, blurred vision, dry mouth, excessive grinding of the teeth, nosebleed, profuse sweating, rhinitis medicamentosa (drug-induced nasal congestion), reduced seizure threshold, tics (a type of movement disorder), and weight loss. Dangerous physical side effects are rare at typical pharmaceutical doses.Amphetamine stimulates the medullary respiratory centers, producing faster and deeper breaths. In a normal person at therapeutic doses, this effect is usually not noticeable, but when respiration is already compromised, it may be evident. Amphetamine also induces contraction in the urinary bladder sphincter, the muscle which controls urination, which can result in difficulty urinating. This effect can be useful in treating bed wetting and loss of bladder control. The effects of amphetamine on the gastrointestinal tract are unpredictable. If intestinal activity is high, amphetamine may reduce gastrointestinal motility (the rate at which content moves through the digestive system); however, amphetamine may increase motility when the smooth muscle of the tract is relaxed. Amphetamine also has a slight analgesic effect and can enhance the pain relieving effects of opioids.USFDA-commissioned studies from 2011 indicate that in children, young adults, and adults there is no association between serious adverse cardiovascular events (sudden death, heart attack, and stroke) and the medical use of amphetamine or other ADHD stimulants. However, amphetamine pharmaceuticals are contraindicated in individuals with cardiovascular disease.
Psychological
At normal therapeutic doses, the most common psychological side effects of amphetamine include increased alertness, apprehension, concentration, initiative, self-confidence and sociability, mood swings (elated mood followed by mildly depressed mood), insomnia or wakefulness, and decreased sense of fatigue. Less common side effects include anxiety, change in libido, grandiosity, irritability, repetitive or obsessive behaviors, and restlessness; these effects depend on the users personality and current mental state. Amphetamine psychosis (e.g., delusions and paranoia) can occur in heavy users. Although very rare, this psychosis can also occur at therapeutic doses during long-term therapy. According to the USFDA, "there is no systematic evidence" that stimulants produce aggressive behavior or hostility.Amphetamine has also been shown to produce a conditioned place preference in humans taking therapeutic doses, meaning that individuals acquire a preference for spending time in places where they have previously used amphetamine.
Reinforcement disorders
Addiction
Addiction is a serious risk with heavy recreational amphetamine use, but is unlikely to occur from long-term medical use at therapeutic doses; in fact, lifetime stimulant therapy for ADHD that begins during childhood reduces the risk of developing substance use disorders as an adult. Pathological overactivation of the mesolimbic pathway, a dopamine pathway that connects the ventral tegmental area to the nucleus accumbens, plays a central role in amphetamine addiction. Individuals who frequently self-administer high doses of amphetamine have a high risk of developing an amphetamine addiction, since chronic use at high doses gradually increases the level of accumbal ΔFosB, a "molecular switch" and "master control protein" for addiction. Once nucleus accumbens ΔFosB is sufficiently overexpressed, it begins to increase the severity of addictive behavior (i.e., compulsive drug-seeking) with further increases in its expression. While there are currently no effective drugs for treating amphetamine addiction, regularly engaging in sustained aerobic exercise appears to reduce the risk of developing such an addiction. Sustained aerobic exercise on a regular basis also appears to be an effective treatment for amphetamine addiction; exercise therapy improves clinical treatment outcomes and may be used as an adjunct therapy with behavioral therapies for addiction.
Biomolecular mechanisms
Chronic use of amphetamine at excessive doses causes alterations in gene expression in the mesocorticolimbic projection, which arise through transcriptional and epigenetic mechanisms. The most important transcription factors that produce these alterations are Delta FBJ murine osteosarcoma viral oncogene homolog B (ΔFosB), cAMP response element binding protein (CREB), and nuclear factor-kappa B (NF-κB). ΔFosB is the most significant biomolecular mechanism in addiction because ΔFosB overexpression (i.e., an abnormally high level of gene expression which produces a pronounced gene-related phenotype) in the D1-type medium spiny neurons in the nucleus accumbens is necessary and sufficient for many of the neural adaptations and regulates multiple behavioral effects (e.g., reward sensitization and escalating drug self-administration) involved in addiction. Once ΔFosB is sufficiently overexpressed, it induces an addictive state that becomes increasingly more severe with further increases in ΔFosB expression. It has been implicated in addictions to alcohol, cannabinoids, cocaine, methylphenidate, nicotine, opioids, phencyclidine, propofol, and substituted amphetamines, among others.ΔJunD, a transcription factor, and G9a, a histone methyltransferase enzyme, both oppose the function of ΔFosB and inhibit increases in its expression. Sufficiently overexpressing ΔJunD in the nucleus accumbens with viral vectors can completely block many of the neural and behavioral alterations seen in chronic drug abuse (i.e., the alterations mediated by ΔFosB). Similarly, accumbal G9a hyperexpression results in markedly increased histone 3 lysine residue 9 dimethylation (H3K9me2) and blocks the induction of ΔFosB-mediated neural and behavioral plasticity by chronic drug use, which occurs via H3K9me2-mediated repression of transcription factors for ΔFosB and H3K9me2-mediated repression of various ΔFosB transcriptional targets (e.g., CDK5). ΔFosB also plays an important role in regulating behavioral responses to natural rewards, such as palatable food, sex, and exercise. Since both natural rewards and addictive drugs induce the expression of ΔFosB (i.e., they cause the brain to produce more of it), chronic acquisition of these rewards can result in a similar pathological state of addiction. Consequently, ΔFosB is the most significant factor involved in both amphetamine addiction and amphetamine-induced sexual addictions, which are compulsive sexual behaviors that result from excessive sexual activity and amphetamine use. These sexual addictions are associated with a dopamine dysregulation syndrome which occurs in some patients taking dopaminergic drugs.The effects of amphetamine on gene regulation are both dose- and route-dependent. Most of the research on gene regulation and addiction is based upon animal studies with intravenous amphetamine administration at very high doses. The few studies that have used equivalent (weight-adjusted) human therapeutic doses and oral administration show that these changes, if they occur, are relatively minor. This suggests that medical use of amphetamine does not significantly affect gene regulation.
Pharmacological treatments
As of December 2019, there is no effective pharmacotherapy for amphetamine addiction. Reviews from 2015 and 2016 indicated that TAAR1-selective agonists have significant therapeutic potential as a treatment for psychostimulant addictions; however, as of February 2016, the only compounds which are known to function as TAAR1-selective agonists are experimental drugs. Amphetamine addiction is largely mediated through increased activation of dopamine receptors and co-localized NMDA receptors in the nucleus accumbens; magnesium ions inhibit NMDA receptors by blocking the receptor calcium channel. One review suggested that, based upon animal testing, pathological (addiction-inducing) psychostimulant use significantly reduces the level of intracellular magnesium throughout the brain. Supplemental magnesium treatment has been shown to reduce amphetamine self-administration (i.e., doses given to oneself) in humans, but it is not an effective monotherapy for amphetamine addiction.A systematic review and meta-analysis from 2019 assessed the efficacy of 17 different pharmacotherapies used in randomized controlled trials (RCTs) for amphetamine and methamphetamine addiction; it found only low-strength evidence that methylphenidate might reduce amphetamine or methamphetamine self-administration. There was low- to moderate-strength evidence of no benefit for most of the other medications used in RCTs, which included antidepressants (bupropion, mirtazapine, sertraline), antipsychotics (aripiprazole), anticonvulsants (topiramate, baclofen, gabapentin), naltrexone, varenicline, citicoline, ondansetron, prometa, riluzole, atomoxetine, dextroamphetamine, and modafinil.
Behavioral treatments
A 2018 systematic review and network meta-analysis of 50 trials involving 12 different psychosocial interventions for amphetamine, methamphetamine, or cocaine addiction found that combination therapy with both contingency management and community reinforcement approach had the highest efficacy (i.e., abstinence rate) and acceptability (i.e., lowest dropout rate). Other treatment modalities examined in the analysis included monotherapy with contingency management or community reinforcement approach, cognitive behavioral therapy, 12-step programs, non-contingent reward-based therapies, psychodynamic therapy, and other combination therapies involving these.Additionally, research on the neurobiological effects of physical exercise suggests that daily aerobic exercise, especially endurance exercise (e.g., marathon running), prevents the development of drug addiction and is an effective adjunct therapy (i.e., a supplemental treatment) for amphetamine addiction. Exercise leads to better treatment outcomes when used as an adjunct treatment, particularly for psychostimulant addictions. In particular, aerobic exercise decreases psychostimulant self-administration, reduces the reinstatement (i.e., relapse) of drug-seeking, and induces increased dopamine receptor D2 (DRD2) density in the striatum. This is the opposite of pathological stimulant use, which induces decreased striatal DRD2 density. One review noted that exercise may also prevent the development of a drug addiction by altering ΔFosB or c-Fos immunoreactivity in the striatum or other parts of the reward system.
Dependence and withdrawal
Drug tolerance develops rapidly in amphetamine abuse (i.e., recreational amphetamine use), so periods of extended abuse require increasingly larger doses of the drug in order to achieve the same effect.
According to a Cochrane review on withdrawal in individuals who compulsively use amphetamine and methamphetamine, "when chronic heavy users abruptly discontinue amphetamine use, many report a time-limited withdrawal syndrome that occurs within 24 hours of their last dose." This review noted that withdrawal symptoms in chronic, high-dose users are frequent, occurring in roughly 88% of cases, and persist for 3–4 weeks with a marked "crash" phase occurring during the first week. Amphetamine withdrawal symptoms can include anxiety, drug craving, depressed mood, fatigue, increased appetite, increased movement or decreased movement, lack of motivation, sleeplessness or sleepiness, and lucid dreams. The review indicated that the severity of withdrawal symptoms is positively correlated with the age of the individual and the extent of their dependence. Mild withdrawal symptoms from the discontinuation of amphetamine treatment at therapeutic doses can be avoided by tapering the dose.
Overdose
An amphetamine overdose can lead to many different symptoms, but is rarely fatal with appropriate care. The severity of overdose symptoms increases with dosage and decreases with drug tolerance to amphetamine. Tolerant individuals have been known to take as much as 5 grams of amphetamine in a day, which is roughly 100 times the maximum daily therapeutic dose. Symptoms of a moderate and extremely large overdose are listed below; fatal amphetamine poisoning usually also involves convulsions and coma. In 2013, overdose on amphetamine, methamphetamine, and other compounds implicated in an "amphetamine use disorder" resulted in an estimated 3,788 deaths worldwide (3,425–4,145 deaths, 95% confidence).
Toxicity
In rodents and primates, sufficiently high doses of amphetamine cause dopaminergic neurotoxicity, or damage to dopamine neurons, which is characterized by dopamine terminal degeneration and reduced transporter and receptor function. There is no evidence that amphetamine is directly neurotoxic in humans. However, large doses of amphetamine may indirectly cause dopaminergic neurotoxicity as a result of hyperpyrexia, the excessive formation of reactive oxygen species, and increased autoxidation of dopamine. Animal models of neurotoxicity from high-dose amphetamine exposure indicate that the occurrence of hyperpyrexia (i.e., core body temperature ≥ 40 °C) is necessary for the development of amphetamine-induced neurotoxicity. Prolonged elevations of brain temperature above 40 °C likely promote the development of amphetamine-induced neurotoxicity in laboratory animals by facilitating the production of reactive oxygen species, disrupting cellular protein function, and transiently increasing blood–brain barrier permeability.
Psychosis
An amphetamine overdose can result in a stimulant psychosis that may involve a variety of symptoms, such as delusions and paranoia. A Cochrane review on treatment for amphetamine, dextroamphetamine, and methamphetamine psychosis states that about 5–15% of users fail to recover completely. According to the same review, there is at least one trial that shows antipsychotic medications effectively resolve the symptoms of acute amphetamine psychosis. Psychosis rarely arises from therapeutic use.
Interactions
Many types of substances are known to interact with amphetamine, resulting in altered drug action or metabolism of amphetamine, the interacting substance, or both. Inhibitors of the enzymes that metabolize amphetamine (e.g., CYP2D6 and FMO3) will prolong its elimination half-life, meaning that its effects will last longer. Amphetamine also interacts with MAOIs, particularly monoamine oxidase A inhibitors, since both MAOIs and amphetamine increase plasma catecholamines (i.e., norepinephrine and dopamine); therefore, concurrent use of both is dangerous. Amphetamine modulates the activity of most psychoactive drugs. In particular, amphetamine may decrease the effects of sedatives and depressants and increase the effects of stimulants and antidepressants. Amphetamine may also decrease the effects of antihypertensives and antipsychotics due to its effects on blood pressure and dopamine respectively. Zinc supplementation may reduce the minimum effective dose of amphetamine when it is used for the treatment of ADHD.
Pharmacology
Pharmacodynamics
Amphetamine and its enantiomers have been identified as potent full agonists of trace amine-associated receptor 1 (TAAR1), a GPCR, discovered in 2001, that is important for regulation of monoaminergic systems in the brain. Activation of TAAR1 increases cAMP production via adenylyl cyclase activation and inhibits the function of the dopamine transporter, norepinephrine transporter, and serotonin transporter, as well as inducing the release of these monoamine neurotransmitters (effluxion). Amphetamine enantiomers are also substrates for a specific neuronal synaptic vesicle uptake transporter called VMAT2. When amphetamine is taken up by VMAT2, the vesicle releases (effluxes) dopamine, norepinephrine, and serotonin, among other monoamines, into the cytosol in exchange.Dextroamphetamine (the dextrorotary enantiomer) and levoamphetamine (the levorotary enantiomer) have identical pharmacodynamics, but their binding affinities to their biomolecular targets vary. Dextroamphetamine is a more potent agonist of TAAR1 than levoamphetamine. Consequently, dextroamphetamine produces roughly three to four times more central nervous system (CNS) stimulation than levoamphetamine; however, levoamphetamine has slightly greater cardiovascular and peripheral effects.
Related endogenous compounds
Amphetamine has a very similar structure and function to the endogenous trace amines, which are naturally occurring neuromodulator molecules produced in the human body and brain. Among this group, the most closely related compounds are phenethylamine, the parent compound of amphetamine, and N-methylphenethylamine, an isomer of amphetamine (i.e., it has an identical molecular formula). In humans, phenethylamine is produced directly from L-phenylalanine by the aromatic amino acid decarboxylase (AADC) enzyme, which converts L-DOPA into dopamine as well. In turn, N-methylphenethylamine is metabolized from phenethylamine by phenylethanolamine N-methyltransferase, the same enzyme that metabolizes norepinephrine into epinephrine. Like amphetamine, both phenethylamine and N-methylphenethylamine regulate monoamine neurotransmission via TAAR1; unlike amphetamine, both of these substances are broken down by monoamine oxidase B, and therefore have a shorter half-life than amphetamine.
Pharmacokinetics
The oral bioavailability of amphetamine varies with gastrointestinal pH; it is well absorbed from the gut, and bioavailability is typically over 75% for dextroamphetamine. Amphetamine is a weak base with a pKa of 9.9; consequently, when the pH is basic, more of the drug is in its lipid soluble free base form, and more is absorbed through the lipid-rich cell membranes of the gut epithelium. Conversely, an acidic pH means the drug is predominantly in a water-soluble cationic (salt) form, and less is absorbed. Approximately 20% of amphetamine circulating in the bloodstream is bound to plasma proteins. Following absorption, amphetamine readily distributes into most tissues in the body, with high concentrations occurring in cerebrospinal fluid and brain tissue.The half-lives of amphetamine enantiomers differ and vary with urine pH. At normal urine pH, the half-lives of dextroamphetamine and levoamphetamine are 9–11 hours and 11–14 hours, respectively. Highly acidic urine will reduce the enantiomer half-lives to 7 hours; highly alkaline urine will increase the half-lives up to 34 hours. The immediate-release and extended release variants of salts of both isomers reach peak plasma concentrations at 3 hours and 7 hours post-dose respectively. Amphetamine is eliminated via the kidneys, with 30–40% of the drug being excreted unchanged at normal urinary pH. When the urinary pH is basic, amphetamine is in its free base form, so less is excreted. When urine pH is abnormal, the urinary recovery of amphetamine may range from a low of 1% to a high of 75%, depending mostly upon whether urine is too basic or acidic, respectively. Following oral administration, amphetamine appears in urine within 3 hours. Roughly 90% of ingested amphetamine is eliminated 3 days after the last oral dose.CYP2D6, dopamine β-hydroxylase ( |
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