where does the majority of drug absorption occur
gastrointestinal tract
8408148
drugs, especially when they are enteral. The gastrointestinal tract is lined with epithelial cells. Drugs must pass or permeate through these cells in order to be absorbed into the circulatory system. One particular cellular barrier that may prevent absorption of a given drug is the cell membrane. Cell membranes are essentially lipid bilayers which form a semipermeable membrane. Pure lipid bilayers are generally permeable only to small, uncharged solutes. Hence, whether or not a molecule is ionized will affect its absorption, since ionic molecules are charged. Solubility favors charged species, and permeability favors neutral species. Some molecules have special exchange
Absorption (pharmacology)
7116520
such as immunosuppression and hospitalisation are present. Rifaximin is active against Clostridium difficile. Rifaximin is not significantly absorbed from the gut and therefore does not have significant interactions with other drugs in people with normal liver function. Rifaximin is a semisynthetic broad spectrum antibacterial drug, that has very low bioavailability due to its poor absorption after oral administration. Because of this local action within the gut and the lack of horizontal transfer of resistant genes the development of bacterial resistance is rare. Because of this poor absorption, most of the drug taken orally stays in the gastrointestinal tract where the
Rifaximin
4750783
to its active metabolite, L-triiodothyronine (T3). T4 and T3 bind to thyroid receptor proteins in the cell nucleus and cause metabolic effects through the control of DNA transcription and protein synthesis. Like its naturally secreted counterpart, levothyroxine is a chiral compound in the "L"-form. Absorption of orally administered levothyroxine from the gastrointestinal tract ranges from 40 to 80%, with the majority of the drug absorbed from the jejunum and upper ileum. Levothyroxine absorption is increased by fasting and decreased in certain malabsorption syndromes, by certain foods, and with age. The bioavailability of the drug is decreased by dietary fiber. Greater
Levothyroxine
9274154
faster transit time of food through the gut. Capillaries of the blood–brain barrier have only transcellular transport, in contrast with normal capillaries which have both transcellular and paracellular transport. The paracellular pathway of transport is also important for the absorption of drugs in the gastrointestinal tract. The paracellular pathway allows the permeation of hydrophilic molecules that are not able to permeate through the lipid membrane by the transcellular pathway of absorption. This is particularly important for hydrophilic pharmaceuticals, which may not have affinity for membrane-bound transporters, and therefore may be excluded from the transcellular pathway. The vast majority of drug
Paracellular transport
6633853
50% of all specimens obtained from patients. Flucytosine is well absorbed (75 to 90%) from the gastrointestinal tract. Intake with meals slows the absorption, but does not decrease the amount absorbed. Following an oral dose of 2 grams peak serum levels are reached after approximately 6 hours. The time to peak level decreases with continued therapy. After 4 days peak levels are measured after 2 hours. The drug is eliminated renally. In normal patients flucytosine has reportedly a half-life of 2.5 to 6 hours. In patients with impaired renal function higher serum levels are seen and the drug tends to
Flucytosine
5241173
and systemic absorption of the drug and subsequent cardiac arrest. The 0.75% formulation is contraindicated in epidural anesthesia during labor because of the association with refractory cardiac arrest. Compared to other local anaesthetics, bupivacaine is markedly cardiotoxic. However, adverse drug reactions (ADRs) are rare when it is administered correctly. Most ADRs are caused by accelerated absorption from the injection site, unintentional intravascular injection, or slow metabolic degradation. However, allergic reactions can rarely occur. Clinically significant adverse events result from systemic absorption of bupivacaine and primarily involve the central nervous system (CNS) and cardiovascular system. CNS effects typically occur at lower
Bupivacaine
4147702
bacterial growth, sulfamethoxazole is considered a bacteriostatic antibiotic. Sulfonamides are selective against bacteria because they interfere with the synthesis of folate, a process which does not occur in humans. Humans do not synthesize folate, and must acquire it through diet. Absorption Sulfamethoxazole is well-absorbed when administered topically. It is rapidly absorbed when it is orally administered. Distribution Sulfamethoxazole distributes into most body tissues as well as into sputum, vaginal fluid, and middle ear fluid. It also crosses the placenta. About 70% of the drug is bound to plasma proteins. Its Tmax (or time to reach maximum drug concentration in plasma)
Sulfamethoxazole
3960010
the same effect in the organism and heterergic if their effects are different. Some drugs, such as the prokinetic agents increase the speed with which a substance passes through the intestines. If a drug is present in the digestive tract's absorption zone for less time its blood concentration will decrease. The opposite will occur with drugs that decrease intestinal motility. Certain drugs require an acid stomach pH for absorption. Others require the basic pH of the intestines. Any modification in the pH could change this absorption. In the case of the antacids, an increase in pH can inhibit the absorption
Drug interaction
8408142
Absorption (pharmacology) In pharmacology (and more specifically pharmacokinetics), absorption is the movement of a drug from the site of administration to bloodstream. Absorption involves several phases. First, the drug needs to be introduced via some route of administration (oral, topical-dermal, "etc".) and in a specific dosage form such as a tablet, capsule, solution and so on. In other situations, such as intravenous therapy, intramuscular injection, enteral nutrition and others, absorption is even more straightforward and there is less variability in absorption and bioavailability is often near 100%. It is considered that intravascular administration (e.g. IV) does not involve absorption, and
Absorption (pharmacology)
9296183
Ci/mmol (2.31 TBq/mol). It is used in applications such as radiometric dating or drug tests. C-14 labeling is common in drug development to do ADME (absorption, distribution, metabolism and excretion) studies in animal models and in human toxicology and clinical trials. Since tritium exchange may occur in some radiolabeled compounds, this does not happen with C-14 and may thus be preferred. Sodium-22 and chlorine-36 are commonly used to study ion transporters. However, sodium-22 is hard to screen off and chlorine-36, with a half-life of 300,000 years, has low activity. Sulfur-35 is used to label proteins and nucleic acids. Cysteine is
Radioactivity in the life sciences
9771600
models used in "non-linear pharmacokinetics" are largely based on Michaelis–Menten kinetics. A reaction’s factors of non-linearity include the following: It can therefore be seen that non-linearity can occur because of reasons that affect the entire pharmacokinetic sequence: absorption, distribution, metabolism and elimination. Variable volume pharmacokinetic models can be drug centered models that imply a volume of drug distribution to be that volume in which the drug is distributed at that elapsed time following drug administration. Another possibility occurs when the body volume is changing in time, which would occur, for example, during dialysis when the volume in which a drug
Pharmacokinetics
2235757
negotiations occur between pharmaceutical companies and private insurers or vendors. In 2003, a Republican-majority Congress created Medicare Part D, which prevented Medicare the country's largest single-payer health care system from negotiating drug prices. In effect, drug manufacturers in the US were allowed to set their own prices resulting in the unregulated pricing variation for prescription drugs. However, the government does employ drug pricing strategies for other smaller government health programs like the Veterans Health Administration, the Department of Defense, the 340B Drug Pricing Program (1992), and Medicaid. In 2005, the Government Accountability Office (GAO) examined the change in US drug
Prescription drug prices in the United States
2291495
overall line is therefore broader yet. Absorption and transmission spectra represent equivalent information and one can be calculated from the other through a mathematical transformation. A transmission spectrum will have its maximum intensities at wavelengths where the absorption is weakest because more light is transmitted through the sample. An absorption spectrum will have its maximum intensities at wavelengths where the absorption is strongest. Emission is a process by which a substance releases energy in the form of electromagnetic radiation. Emission can occur at any frequency at which absorption can occur, and this allows the absorption lines to be determined from
Absorption spectroscopy
7050931
products, antacids and preparations containing iron should be avoided near the time of taking the drug. Partial exceptions to these rules occur for doxycycline and minocycline, which may be taken with food (though not iron, antacids, or calcium supplements). Minocycline can be taken with dairy products because it does not chelate calcium as readily, although dairy products do decrease absorption of minocycline slightly. The history of the tetracyclines involves the collective contributions of thousands of dedicated researchers, scientists, clinicians, and business executives. Tetracyclines were discovered in the 1940s, first reported in scientific literature in 1948, and exhibited activity against a
Tetracycline antibiotics
5507290
is unknown. Mebendazole sometimes causes diarrhea, abdominal pain, and elevated liver enzymes. In rare cases, it has been associated with a dangerously low white blood cell count, low platelet count, and hair loss, with a risk of agranulocytosis in rare cases Carbamazepine and phenytoin lower serum levels of mebendazole. Cimetidine does not appreciably raise serum mebendazole (in contrast to the similar drug albendazole), consistent with its poor systemic absorption. Stevens–Johnson syndrome and the more severe toxic epidermal necrolysis can occur when mebendazole is combined with high doses of metronidazole. Mebendazole is thought to work by selectively inhibiting the synthesis of
Mebendazole
7632579
1 out of every 10 people has its heterozygous form. Neither individuals with the homozygous or heterozygous form should take iron supplements. Non-heme iron forms an insoluble complex with several other drugs, resulting in decreased absorption of both iron and the other drug. Examples include tetracycline, penicillamine, methyldopa, levodopa, bisphosphonates and quinolones. The same can occur with elements in food, such as calcium. Absorption of iron is better at a low pH (i.e. an acidic environment), and absorption is decreased if there is a simultaneous intake of antacids. Many other substances decrease the rate of non-heme iron absorption. Examples are
Iron supplement
2010275
of a generic drug to be between 80% and 125% of the innovator product. (This range is part of a statistical calculation, and does not mean that generic drugs are allowed to differ from their brand-name counterparts by up to 25 percent.) The FDA evaluated 2,070 studies conducted between 1996 and 2007 that compared the absorption of brand-name and generic drugs into a person's body. The average difference in absorption between the generic and the brand-name drug was 3.5 percent, comparable to the difference between two batches of a brand-name drug. Non-innovator versions of biologic drugs, or biosimilars, require clinical
Generic drug
510303
the small intestine, where the extraction of nutrients begins. Depending on the quantity and contents of the meal, the stomach will digest the food into chyme within anywhere between forty minutes and a few hours. The average human stomach can comfortably hold about a litre of food. Gastric juice in the stomach also contains pepsinogen. Hydrochloric acid activates this inactive form of enzyme into the active form, pepsin. Pepsin breaks down proteins into polypeptides. Although the absorption in the human digestive system is mainly a function of the small intestine, some absorption of certain small molecules nevertheless does occur in
Stomach
13463313
dose. But after oral administration,C and t are dependent on the extent, and the rate of drug absorption and the disposition profile of the drug. They could be used to characterize the properties of different formulations in the same subject. Short term drug side effects are most likely to occur at or near the C, whereas the therapeutic effect of drug with sustained duration of action usually occurs atconcentrations slightly above the C. The C is often measured in an effort to show bioequivalence (BE) between a generic and innovator drug product. According to the FDA, drug quality bioavailability (BA)
Cmax (pharmacology)
11105024
Electromagnetic absorption by water The absorption of electromagnetic radiation by water depends on the state of the water. The absorption in the gas phase occurs in three regions of the spectrum. Rotational transitions are responsible for absorption in the microwave and far-infrared, vibrational transitions in the mid-infrared and near-infrared. Vibrational bands have rotational fine structure. Electronic transitions occur in the vacuum ultraviolet regions. Liquid water has no rotational spectrum but does absorb in the microwave region. The water molecule, in the gaseous state, has three types of transition that can give rise to absorption of electromagnetic radiation In reality, vibrations
Electromagnetic absorption by water
3145427
a reduction in receptor density (usually associated with receptor agonists), or other mechanisms leading to changes in action potential firing rate. Pharmacodynamic tolerance to a receptor antagonist involves the reverse, i.e., increased receptor firing rate, an increase in receptor density, or other mechanisms. While most occurrences of pharmacodynamic tolerance occur after sustained exposure to a drug, instances of acute or instant tolerance (tachyphylaxis) can occur. Pharmacokinetics refers to the absorption, distribution, metabolism, and excretion of drugs. All psychoactive drugs are first absorbed into the bloodstream, carried in the blood to various parts of the body including the site of action
Drug tolerance
9185372
override the majority protest. As a result of the absolute majority requirement, majority protests for proposed property-related fees and charges occasionally occur but not that often. They are most likely to occur in situations where the proposed levy is controversial and the number of affected parcels is small. Where the number of affected parcels is large, a majority protest is very difficult to attain even for controversial levies. Proposition 218 does not require that a protest document for a proposed property-related fee or charge be included with the required written notice. However, some agencies may include a protest document with
1996 California Proposition 218
8088461
the subject of clinical pharmacokinetics. Variations in MTC can occur at any point in the ADME (absorption, distribution, metabolism, and excretion) process. For example, a patient could possess a genetic defect in a drug metabolizing enzyme in the cytochrome P450 superfamily. While most individuals will possess the effective metabolizing machinery, a person with a defect will have a difficult time trying to clear the drug from their system. Thus, the drug will accumulate within the blood to higher-than-expected concentrations, reaching a MTC at a dose that would otherwise be considered normal for the average person. In other words, in a
Drug intolerance
276230
concentrations of the drug. This percentage actually changes very little when the concentration is varied. C (peak levels) occurs approximately 2–3 hours after administration. Food slows absorption, but does not affect the total AUC(AUC – area under the curve – meaning, food may slow absorption, but the total amount of the chemical will be absorbed with or without food). Half-life is generally in the 10–12 hour range, subject to differences in CYP genotypes, liver function and renal function. It is metabolized in the liver, and its inactive metabolite is excreted in the urine. Urinary excretion of the unchanged drug ranges
Modafinil
607422
one glucose unit and one fructose unit, which are then each absorbed. After absorption, it enters the hepatic portal vein and is directed toward the liver. The mechanism of fructose absorption in the small intestine is not completely understood. Some evidence suggests active transport, because fructose uptake has been shown to occur against a concentration gradient. However, the majority of research supports the claim that fructose absorption occurs on the mucosal membrane via facilitated transport involving GLUT5 transport proteins. Since the concentration of fructose is higher in the lumen, fructose is able to flow down a concentration gradient into the
Fructose
3134320
generally being employed for analgesic and anti-inflammatory purposes. Clinical trials of "Arnica montana" have yielded mixed results: "A. montana" has also been the subject of studies of homeopathic preparations. A 1998 systematic review of homeopathic "A. montana" conducted at the University of Exeter found that there are no rigorous clinical trials that support the claim that it is efficacious beyond a placebo effect. The US Food and Drug Administration has classified "Arnica montana" as an unsafe herb because of its toxicity. It should not be taken orally or applied to broken skin where absorption can occur. "A. montana" contains the
Arnica montana
3960009
mechanisms. This wide diversity also means that, in all but the most obvious cases, it is important to investigate and understand these mechanisms. The well-founded suspicion exists that there are more unknown interactions than known ones. Pharmacodynamic interactions can occur on: Modifications in the effect of a drug are caused by differences in the absorption, transport, distribution, metabolization or excretion of one or both of the drugs compared with the expected behaviour of each drug when taken individually. These changes are basically modifications in the concentration of the drugs. In this respect two drugs can be homergic if they have
Drug interaction
2544842
changing and differing physiology and psychology. Changes in physiology with aging may alter the absorption, the effectiveness and the side effect profile of many drugs. These changes may occur in oral protective reflexes (dryness of the mouth caused by diminished salivary glands), in the gastrointestinal system (such as with delayed emptying of solids and liquids possibly restricting speed of absorption), and in the distribution of drugs with changes in body fat and muscle and drug elimination. Psychological considerations include the fact that elderly persons (in particular, those experiencing substantial memory loss or other types of cognitive impairment) are unlikely to
Geriatrics
7523700
consequences. For example, medicated lotions such as Diprolene are often used with the intention of exerting only local effects, but absorption of the drug through the skin can occur to a small degree, resulting in systemic side effects such as hyperglycemia and glycosuria. Absorption is increased when lotions are applied and then covered with an occlusive layer, when they are applied to large areas of the body, or when they are applied to damaged or broken skin. A 2015 study funded by the California Breast Cancer Research Program found that parabens, a common ingredient in cosmetic lotions, stimulate breast cancer
Lotion
3425857
be used concomitantly with rilpivirine, an anti-HIV therapy, which requires acid for absorption. Lowered plasma concentrations of rilpivirine could lead to progression of HIV infection. Other drugs that require acid for absorption include antifungal drugs like ketoconazole and itraconazole, digoxin, iron, mycophenolate, and tyrosine kinase inhibitors like erlotinib, dasatinib, and nilotinib. There is no clinically relevant drug interaction between rabeprazole and antacids. Food does not affect the amount of rabeprazole that enters the body, but it does delay its onset of effect by about 1.7 hours. Rabeprazole's mechanism of action first involves getting absorbed into the parietal cells of the
Rabeprazole
3898115
must be formed before platelet function normalizes. Ticlopidine is ingested orally with 80% bioavailability with rapid absorption. Even higher absorption can occur if ticlopidine is taken with food. It is metabolized by the liver with both renal and fecal elimination. Clearance is nonlinear and varies with repeated dosing. After the first dose the half life is 12.6 hours, but with repeated dosing the maximum half life is 4–5 days. Clearance is also slower in the elderly. The drug is 98% reversibly bound to proteins. Ticlopidine interacts with several classes of medications. It increases the antiplatelet effects of aspirin and other
Ticlopidine
399175
is because of sound trapping in the channel with no losses at the boundaries. Similar propagation can occur in the 'surface duct' under suitable conditions. However, in this case there are reflection losses at the surface. In shallow water propagation is generally by repeated reflection at the surface and bottom, where considerable losses can occur. Sound propagation is affected by absorption in the water itself as well as at the surface and bottom. This absorption depends upon frequency, with several different mechanisms in sea water. Long-range sonar uses low frequencies to minimise absorption effects. The sea contains many sources of
Sonar
6076348
or death. Class II recalls refer to drugs that induce temporary and/or medically reversible health effects. Class III recalls occur when adverse health effects are not likely to occur when consuming the drug or being exposed to it. There are also market withdrawals and medical device safety alerts'. Market withdrawals occur when a product has a minor violation that does not require FDA legal action. Medical device safety alerts occur when there are unreasonable safety risks associated with using a product. A more comprehensive list of drug recalls worldwide can be found here: List of withdrawn drugs. Mrs. Winslow's Soothing
Drug recall
20892843
is in LTE when the fraction of molecules in an excited state is determined by the Boltzmann distribution. LTE exists when collisional excitation and collisional relaxation of any excited state occur much faster than absorption and emission. (LTE does not require the rates of absorption and emission to be equal.) The vibrational and rotational excited states of greenhouse gases that emit thermal infrared radiation are in LTE up to about 60 km. Radiative transfer calculations show negligible change (0.2%) due to absorption and emission above about 50 km. Schwarzschild’s equation therefore is appropriate for most problems involving thermal infrared in
Schwarzschild's equation for radiative transfer
1555162
very different clinical scenarios. The failure to clear parasitemia and recover from an acute clinical episode when a suitable treatment has been given is anti-malarial resistance in its true form. Drug resistance may lead to treatment failure, but treatment failure is not necessarily caused by drug resistance despite assisting with its development. A multitude of factors can be involved in the processes including problems with non-compliance and adherence, poor drug quality, interactions with other pharmaceuticals, poor absorption, misdiagnosis and incorrect doses being given. The majority of these factors also contribute to the development of drug resistance. The generation of resistance
Antimalarial medication
12215700
Absorption edge An absorption edge, absorption discontinuity or absorption limit is a sharp discontinuity in the absorption spectrum of a substance. These discontinuities occur at wavelengths where the energy of an absorbed photon corresponds to an electronic transition or ionization potential. When the quantum energy of the incident radiation becomes smaller than the work required to eject an electron from one or other quantum states in the constituent absorbing atom, the incident radiation ceases to be absorbed by that state. For example, incident radiation on an atom of a wavelength that has a corresponding energy just below the binding energy
Absorption edge
17062379
or animal based or else according to their site of action. Bioenhancers so far almost exclusively discovered in plants, increase the bioavailability of other substances in different ways: Reduced bioavailability of orally administered drugs by Destruction, elimination and wastage inside the body • After oral ingestion and absorption, drugs reach the blood stream where the drug needs to attain a certain desired drug level in the blood to cause desired drug action. • After oral ingestion and absorption, drugs while passing from the gut via the liver to blood stream are inadequately absorbed, wasted, eliminated and destroyed and therefore a
Bioenhancer
5000097
benzonatate (a local anesthetic) in the oral mucosa will result in the rapid development of numbness of the mouth and throat. In extreme cases, the mouth and pharynx may become so numb that pulmonary aspiration may occur. Excessive absorption of benzonatate will occur if the gelcaps are chewed or allowed to dissolve in the mouth. This may lead to an overdose of the drug. Overdose of benzonatate may manifest as central nervous system side effects, such as mental confusion and hallucination, restlessness and tremors, followed in extreme cases by convulsions and death. Benzonatate Benzonatate—marketed under the trade names Tessalon, Tessalon
Benzonatate
9771604
(pH at which there is an equilibrium between its ionized and non ionized molecules), it is possible to calculate the non ionized concentration of the drug and therefore the concentration that will be subject to absorption: When two drugs have the same bioavailability, they are said to be biological equivalents or bioequivalents. This concept of bioequivalence is important because it is currently used as a yardstick in the authorization of generic drugs in many countries. A number of phases occur once the drug enters into contact with the organism, these are described using the acronym LADME: Some textbooks combine the
Pharmacokinetics
12215701
of the K-shell electron in that atom cannot eject the K-shell electron. Absorption edge An absorption edge, absorption discontinuity or absorption limit is a sharp discontinuity in the absorption spectrum of a substance. These discontinuities occur at wavelengths where the energy of an absorbed photon corresponds to an electronic transition or ionization potential. When the quantum energy of the incident radiation becomes smaller than the work required to eject an electron from one or other quantum states in the constituent absorbing atom, the incident radiation ceases to be absorbed by that state. For example, incident radiation on an atom of
Absorption edge
1602714
boiling point of these chemicals. The majority of the gaseous production of BTEX occurs during tank cleaning and fuel transfer, which causes offgassing of these chemicals into the air. It should be noted that exposure can also occur through ingestion via contaminated water, but this is unlikely in an occupational setting. Dermal exposure and absorption is also possible, but is again less likely in an occupational setting where appropriate personal protective equipment is in place. OSHA, NIOSH, and ACGIH have all established occupational exposure limits (OEL's) for many of the chemicals above that workers may be exposed to in petroleum
Oil refinery
8042049
thus dosage. Enteral administration may be divided into three different categories, depending on the entrance point into the GI tract: oral (by mouth), gastric (through the stomach), and rectal (from the rectum). (Gastric introduction involves the use of a tube through the nasal passage (NG tube) or a tube in the belly leading directly to the stomach (PEG tube). Rectal administration usually involves rectal suppositories.) The mechanism for drug absorption from the intestine is for most drugs passive transfer, a few exceptions include levodopa and fluorouracil, which are both absorbed through carrier-mediated transport. For passive transfer to occur, the drug
Enteral administration
18271346
As a consequence of the decreased dietary phosphate absorption, serum phosphorus concentrations are reduced. Sucroferric oxyhydroxide is approved by the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the control of serum phosphorus levels in patients with chronic kidney disease (CKD) on dialysis. The most frequently reported adverse drug reactions reported from trials were diarrhoea and discoloured faeces. The vast majority of gastrointestinal adverse events occurred early during treatment and abated with time under continued dosing. Drug-interaction studies and post hoc analyses of Phase 3 studies showed no clinically relevant interaction of sucroferric oxyhydroxide
Sucroferric oxyhydroxide
18069108
Toxgnostics Toxgnostics is part of Personalized medicine as it describes the guiding principles for the discovery of pharmacogenomic biomarker tests, also referred to as companion diagnostic tests, which identify if an individual patient is likely to suffer severe drug toxicity from treatment with a specific therapeutic agent. Once at risk individuals are identified drug toxicity can be prevented using elective dose reduction or prescription of an alternative medication. The majority of toxgnostic studies have been candidate gene studies restricted to the known Absorption, Distribution, Metabolism, and Excretion genes (ADME) of drug treated patients. The PharmaADME consortium identified 32 core genes
Toxgnostics
2291489
radiation absorbed by the material over a range of frequencies. The absorption spectrum is primarily determined by the atomic and molecular composition of the material. Radiation is more likely to be absorbed at frequencies that match the energy difference between two quantum mechanical states of the molecules. The absorption that occurs due to a transition between two states is referred to as an absorption line and a spectrum is typically composed of many lines. The frequencies where absorption lines occur, as well as their relative intensities, primarily depend on the electronic and molecular structure of the sample. The frequencies will
Absorption spectroscopy
12928865
wings, cores, and superpositions of absorption and emission features. In some cases, particular absorption of emission features are only visible as modifications to a line profile, or a weakening of another line. This leads to double and triple-peaked lines, or asymmetric lines. Shell stars very commonly have emission lines and thus are often Be stars, although they can also occur in spectral classes O, A, and occasionally F. Shell stars have been subdivided into four categories, although these categories are no longer recognised as meaningful and are rarely seen in modern publications: The vast majority of known shell stars are
Shell star
4211547
our pulse in time by coinciding new parts of it with the gating pulse at the detector. A purge box is typically used so that absorption of THz radiation by gaseous water molecules does not occur. Water is known to have many discrete absorptions in the THz region, which are rotational modes of the water molecules. Nitrogen, as a diatomic molecule, has no electric dipole moment, and does not (for the purposes of typical THz-TDS) absorb THz radiation. Thus, a purge box can be filled with nitrogen so that unintended discrete absorptions in the THz frequency range do not occur.
Terahertz time-domain spectroscopy
1783543
bioavailability after oral administration is 100%, and 90% after rectal administration. The half-life of diazepam in general is 30–56 hours. Peak plasma levels occur between 30 and 90 minutes after oral administration and between 30 and 60 minutes after intramuscular administration; after rectal administration, peak plasma levels occur after 10 to 45 minutes. Diazepam is highly protein-bound, with 96 to 99% of the absorbed drug being protein-bound. The distribution half-life of diazepam is two to 13 minutes. When diazepam is administered IM, absorption is slow, erratic, and incomplete. Diazepam is highly lipid-soluble, and is widely distributed throughout the body after
Diazepam
15911971
what substantially reduces absorption of a drug. Problems with delivery of drags to the tumor occur also when active agent has high molecular weight which limits tissue penetration or the tumor has large volume prevent for penetration. Multidrug resistance is the most important limitation in anticancer therapy. It can develop in many chemically distinct compounds. Until now, several mechanisms are known to develop the resistance. The most common is production of so-called "efflux pumps". The pumps remove drugs from tumor cells which lead to low drug concentration in the target, below therapeutic level. Efflux is caused by P-glycoprotein called also
Discovery and development of tubulin inhibitors
18640650
10% of people taking ledipasvir/sofosbuvir have headaches or fatigue; rashes, nausea, diarrhea, and insomnia occur in between 1% and 10% of people taking it. More severe reactions are connected with allergic reactions to the medications and cardiovascular problems. Harvoni side effects are considered relatively mild compared to older interferon-based treatment. Ledipasvir/sofosbuvir is a substrate for the drug transporters P-Glycoprotein (P-gp) and breast cancer resistance protein (BCRP). Intestinal absorption of these drug transporter substrates may be decreased by inducers such as rifampin and St. John's wort . Patients are also advised to stay away from H2 Receptor Antagonists (H2RA) and Proton
Ledipasvir/sofosbuvir
4732836
"sealed non-transparent rebates" to occur from the manufacturer of the drug to the state agency. These are legally sanctioned kickbacks in which the public by federal law does not have a right to know the amount of the rebate below the average wholesale price (AWP). In cases where "no sufficient evidence exists" a drug is any less safe, (according to the evidence report) the drug is declared "substitutable", and eligible for placement on the PDL, and for the supplemental rebate program. Omnibus Budget Reconciliation Act of 1990 The Omnibus Budget Reconciliation Act of 1990 (OBRA-90; ) is a United States
Omnibus Budget Reconciliation Act of 1990
12872755
cord compression. Drug agencies have issued boxed warnings regarding this phenomenon in the prescribing information for GnRH agonists. As testosterone surge does not occur with GnRH antagonists, there is no need for patients to receive an antiandrogen as flare protection during prostate cancer treatment. GnRH agonists also induce an increase in testosterone levels after each reinjection of the drug – a phenomenon that does not occur with GnRH antagonists such as degarelix. GnRH antagonists have an immediate onset of action leading to a fast and profound suppression of testosterone and are therefore especially valuable in the treatment of patients with
Degarelix
3960000
present in the organism (i.e. foods or alcohol). Or in certain specific situations a drug may even react with itself, such as occurs with dehydration. In other situations, the interaction does not involve any effect on the drug. In certain cases, the presence of a drug in an individual's blood may affect certain types of laboratory analysis (analytical interference). It is also possible for interactions to occur outside an organism before administration of the drugs has taken place. This can occur when two drugs are mixed, for example, in a saline solution prior to intravenous injection. Some classic examples of
Drug interaction
733643
of moderately to severely active ulcerative colitis in 2018 in the US, the first oral medication indicated for long term use in this condition. The evidence on methotrexate does not show a benefit in producing remission in people with ulcerative colitis. Off-label use of drugs such as ciclosporin and tacrolimus has shown some benefits. Fexofenadine, an antihistamine drug used in treatment of allergies, has shown promise in a combination therapy in some studies. Opportunely, low gastrointestinal absorption (or high absorbed drug gastrointestinal secretion) of fexofenadine results in higher concentration at the site of inflammation. Thus, the drug may locally decrease
Ulcerative colitis
3402619
nutrient uptake through the tegument by pinocytosis and phagocytosis by the syncitium. Most adult digeneans occur in the vertebrate alimentary canal or its associated organs, where they most often graze on contents of the lumen (e.g., food ingested by the host, bile, mucus), but they may also feed across the mucosal wall (e.g., submucosa, host blood). The blood flukes, such as schistosomes, spirorchiids and sanguinicolids, feed exclusively on blood. Asexual stages in mollusc intermediate hosts feed mostly by direct absorption, although the redia stage found in some groups does have a mouth, pharynx and simple gut and may actively consume
Digenea
94661
social taboos in many cultures. The rectum and the vaginal canal is where the majority of the drug would be taken up through the membranes lining its walls. With excessive or prolonged use, the drug can cause itching, fast heart rate, hallucinations, and paranoid delusions. Overdoses cause hyperthermia and a marked elevation of blood pressure, which can be life-threatening, arrhythmias, and death. Anxiety, paranoia, and restlessness can also occur, especially during the comedown. With excessive dosage, tremors, convulsions and increased body temperature are observed. Severe cardiac adverse events, particularly sudden cardiac death, become a serious risk at high doses due
Cocaine
10780916
than one thousandth of the IC for SGLT1 (1.1 versus 1390 nmol/L), so that the drug does not interfere with intestinal glucose absorption. Clinical trials to assess effectiveness for patients with type 1 diabetes are underway. Dapagliflozin Dapagliflozin (INN, USAN, trade name Farxiga in the U.S. and Forxiga in the EU and Russia) is a drug of the gliflozin class, used to treat type 2 diabetes. It was developed by Bristol-Myers Squibb in partnership with AstraZeneca. In July 2011 a U.S. Food and Drug Administration (FDA) endocrinologic and metabolic drugs advisory committee recommended against approval until more data were available.
Dapagliflozin
10382753
fruit juices on other potentially important mechanisms of drug absorption. Current research found that grapefruit and other juices (orange and apple) inhibited a specific intestinal drug uptake transporter (organic anion transporting polypeptide 1A2; OATP1A2) to diminish oral drug absorption discernibly in humans. The initial publication in 2002, which has been cited more than 100 times, supported a new model of intestinal drug absorption and novel mechanism of food-drug interactions. Most recently, he showed that the major flavonoid in grapefruit, naringin, was an important clinically active inhibitor of intestinal OATP1A2. This appeared to be the first example of a single dietary
Dave Bailey (athlete)
16081869
limits the amount of further digestion or absorption that can occur after the food is fermented. In smaller hindgut fermenters of the order Lagomorpha (rabbits, hares, and pikas), cecotropes formed in the cecum are passed through the large intestine and subsequently reingested to allow another opportunity to absorb nutrients. Cecotropes are surrounded by a layer of mucus which protects them from stomach acid but which does not inhibit nutrient absorption in the small intestine. Coprophagy is also practiced by some rodents, such as the capybara, guinea pig and related species, and by the marsupial common ringtail possum. This process is
Hindgut fermentation
8408143
there is no loss of drug. The fastest route of absorption is inhalation, and not as mistakenly considered the intravenous administration. Absorption is a primary focus in drug development and medicinal chemistry, since the drug must be absorbed before any medicinal effects can take place. Moreover, the drug's pharmacokinetic profile can be easily and significantly changed by adjusting factors that affect absorption. In the most common situation, a tablet is ingested and passes through the esophagus to the stomach. The rate of dissolution is a key target for controlling the duration of a drug's effect, and as such, several dosage
Absorption (pharmacology)
6643048
Drug agencies have issued warnings regarding this phenomenon in the prescribing information for GnRH agonists. As testosterone surge does not occur with GnRH antagonists, there is no need for patients to receive an antiandrogen as flare protection during prostate cancer treatment. GnRH agonists also induce an increase in testosterone levels after each reinjection of the drug – a phenomenon that does not occur with GnRH antagonists. The reduction in testosterone levels that occurs during GnRH antagonist therapy subsequently reduces the size of the prostate cancer. This in turn results in a reduction in prostate-specific antigen (PSA) levels in the patient’s
Gonadotropin-releasing hormone antagonist
2065020
who state "The term vitreous generally signifies less than 0.5% absorption. except for floor and wall tile and low-voltage electrical insulators which are considered vitreous up to 3% water absorption." Glazing alone does not make pottery impermeable to water. Porcelain, bone china and sanitaryware are examples of vitrified pottery, and are impermeable even without glaze. Stoneware may be vitrified or semi-vitrified, the latter type would not be impermeable without glaze. When sucrose is cooled slowly it results in crystal sugar (or rock candy), but when cooled rapidly it can form syrupy cotton candy (candyfloss). Vitrification can also occur when starting
Vitrification
4499468
moderate/low affinity for the D and 5-HT receptors. Cabergoline functions as an agonist at all of these receptors except for 5-HT and α-, where it acts as an antagonist. Following a single oral dose, resorption of cabergoline from the gastrointestinal (GI) tract is highly variable, typically occurring within 0.5 to 4 hours. Ingestion with food does not alter its absorption rate. Human bioavailability has not been determined since the drug is intended for oral use only. In mice and rats the absolute bioavailability has been determined to be 30 and 63 percent, respectively. Cabergoline is rapidly and extensively metabolized in
Cabergoline
6857883
Neurosyphilis Neurosyphilis refers to infection of the central nervous system in a patient with syphilis and can occur at any stage. The majority of neurosyphilis cases have been reported in HIV-infected patients. Meningitis is the most common neurological presentation in early syphilis. Tertiary syphilis symptoms are exclusively neurosyphilis, though neurosyphilis may occur at any stage of infection. To diagnose neurosyphilis, patients undergo a lumbar puncture to obtain cerebrospinal fluid (CSF) for analysis. The CSF is tested for antibodies for specific "Treponema pallidum" antigens. The preferred test is the VDRL test, which is sometimes supplemented by fluorescent treponemal antibody absorption test
Neurosyphilis
2913100
Because DMSO increases the rate of absorption of some compounds through organic tissues, including skin, it is used in some transdermal drug delivery systems. Its effect may be enhanced with the addition of EDTA. It is frequently compounded with antifungal medications, enabling them to penetrate not just skin but also toenails and fingernails. DMSO has been examined for the treatment of numerous conditions and ailments, but the U.S. Food and Drug Administration (FDA) has approved its use only for the symptomatic relief of patients with interstitial cystitis. A 1978 study concluded that DMSO brought significant relief to the majority of
Dimethyl sulfoxide
6149972
for a saturable absorber are its wavelength range (where it absorbs), its dynamic response (how fast it recovers), and its saturation intensity and fluence (at what intensity or pulse energy it saturates). They are commonly used for passive Q-switching. Within the simple model of saturated absorption, the relaxation rate of excitations does not depend on the intensity. Then, for the continuous-wave operation, the absorption rate (or simply absorption) formula_1 is determined by intensity formula_2: where formula_4 is linear absorption, and formula_5 is saturation intensity. These parameters are related with the concentration formula_6 of the active centers in the medium, the
Saturable absorption
1848561
a degradation product, anhydro-4-epitetracycline. Minocycline's absorption is impaired if taken at the same time of day as calcium or iron supplements. Unlike some of the other tetracycline group antibiotics, it can be taken with calcium-rich foods such as milk, although this does reduce the absorption slightly. Minocycline, like other tetracyclines, is associated with esophageal irritation and ulceration if insufficient fluids are taken with the drug before sleep. A 2007 study suggested that minocycline harms amyotrophic lateral sclerosis patients. Patients on minocycline declined more rapidly than those on placebo. The mechanism of this side effect is unknown, although a hypothesis is
Minocycline
2486105
conditions and many psychological or neurological conditions, like epilepsy, hypertension, schizophrenia and psychosis. With careful physician attention, however, medication prioritization and discontinuation can decrease costs, simplify prescription regimens, decrease risks of adverse drug events and poly-pharmacy, focus therapies where they are most effective, and prevent cost-related under-use of medications. Drug withdrawal Drug withdrawal is the group of symptoms that occur upon the abrupt discontinuation or decrease in intake of medications or recreational drugs. In order for the symptoms of withdrawal to occur, one must have first developed a form of drug dependence. This may occur as physical dependence, psychological dependence
Drug withdrawal
7360070
can cause adverse effects. Conversely, if the medication is a prodrug, it needs to be metabolised to be converted to the active drug. Compromising its metabolism lowers concentrations of the active drug, reducing its therapeutic effect, and risking therapeutic failure. Low drug concentrations can also be caused when the fruit suppresses drug absorption from the intestine. The effect of grapefruit juice with regard to drug absorption was originally discovered in 1989. The first published clinical report on grapefruit drug interactions was in 1991 in "The Lancet" entitled "Interactions of Citrus Juices with Felodipine and Nifedipine." However, the effect only became
Grapefruit–drug interactions
5507428
poor. Any obstructions or factors which impair GI motility may increase the absorption of the drug from the digestive tract. In addition, any structural damage, such as lesions or ulcerations, will tend to increase drug absorption. For intramuscular (IM) injection, the absorption is rapid. Paromomycin will reach peak plasma concentration within one hour following IM injection. The invitro and invivo activities parallel those of neomycin. Information not available. Almost 100% of the oral dose is eliminated unchanged via feces. Any absorbed drug will be excreted in urine. Paromomycin Paromomycin is an antimicrobial used to treat a number of parasitic infections
Paromomycin
3974606
the cell membrane of fungi, where it serves a role similar to cholesterol in animal cells. Phytosterols, more commonly known as plant sterols, have been shown in clinical trials to block cholesterol absorption sites in the human intestine, thus helping to reduce cholesterol absorption in humans. They are currently approved by the U.S. Food and Drug Administration for use as a food additive; however, there is some concern that they may block absorption not only of cholesterol, but of other important nutrients as well. At present, the American Heart Association has recommended that supplemental plant sterols be taken only by
Sterol
4845200
food. Ion channels located on the surface membrane of the neuron allows for an influx of sodium ions and outward movement of potassium ions during an action potential. Selectively blocking these ion channels will decrease the likelihood of an action potential to occur. The drug riluzole is a neuroprotective drug that blocks sodium ion channels. Since these channels cannot activate, there is no action potential, and the neuron does not perform any transduction of chemical signals into electrical signals and the signal does not move on. This drug is used as an anesthetic as well as a sedative. One form
Neuropharmacology
3647743
significantly increases it. Food consumption inhibits its absorption from the GI tract, and the drug is more quickly eliminated. When rifampicin is taken with a meal, its peak blood concentration falls by 36%. Antacids do not affect its absorption. The decrease in rifampicin absorption with food is sometimes enough to noticeably affect urine color, which can be used as a marker for whether or not a dose of the drug has been effectively absorbed. Distribution of the drug is high throughout the body, and reaches effective concentrations in many organs and body fluids, including the cerebrospinal fluid. Since the substance
Rifampicin
3614981
intensity is above a threshold value. This nonlinear optical behavior is termed saturable absorption and the threshold value is called the saturation fluence. Graphene can be saturated readily under strong excitation over the visible to near-infrared region, due to the universal optical absorption and zero band gap. This has relevance for the mode locking of fiber lasers, where fullband mode locking has been achieved by a graphene-based saturable absorber. Due to this special property, graphene has wide application in ultrafast photonics. The optical response of graphene/graphene oxide layers can be tuned electrically. Saturable absorption in graphene could occur at the
Graphene
8599166
potential dose of contaminant by multiplying it by the relevant contact rate, such as breathing rate, food intake rate etc. The contact rate itself may be a function of time. Contact between a contaminant and an organism can occur through any route. The possible routes of exposure are: inhalation, if the contaminant is present in the air; ingestion, through food, drinking or hand-to-mouth behavior; and dermal absorption, if the contaminant can be absorbed through the skin. Exposure to a contaminant can and does occur through multiple routes, simultaneously or at different times. In many cases the main route of exposure
Exposure assessment
11927632
of the Consortium. Simcyp Simcyp Limited is a research-based company which provides modelling and simulation software to the pharmaceutical industry for use during drug development. Simcyp is based in Sheffield, UK. Simcyp’s Simulators allow "in silico" prediction of drug absorption, distribution, metabolism and excretion (ADME) and potential drug-drug interactions. Simcyp’s R&D activities focus on the development of algorithms along with population and drug databases for modelling and simulation (M&S) of the absorption and disposition of drugs in patients and specific subgroups of patients across different age ranges. The Simcyp models use experimental data generated routinely during pre-clinical drug discovery and
Simcyp
11927630
Simcyp Simcyp Limited is a research-based company which provides modelling and simulation software to the pharmaceutical industry for use during drug development. Simcyp is based in Sheffield, UK. Simcyp’s Simulators allow "in silico" prediction of drug absorption, distribution, metabolism and excretion (ADME) and potential drug-drug interactions. Simcyp’s R&D activities focus on the development of algorithms along with population and drug databases for modelling and simulation (M&S) of the absorption and disposition of drugs in patients and specific subgroups of patients across different age ranges. The Simcyp models use experimental data generated routinely during pre-clinical drug discovery and development from "in
Simcyp
3105863
include: Rare (0.01–0.1% incidence) adverse effects including: The FDA of the US has issued a black box warning for suicidal behaviour/ideation. Similar warnings have been issued in Australia. Unlike stimulant medications, atomoxetine does not have abuse liability or the potential to cause withdrawal effects on abrupt discontinuation. Atomoxetine is relatively non-toxic in overdose. Single-drug overdoses involving over 1500 mg of atomoxetine have not resulted in death. The most common symptoms of overdose include: Less common symptoms: The recommended treatment for atomoxetine overdose includes use of activated charcoal to prevent further absorption of the drug. Atomoxetine is a substrate for CYP2D6.
Atomoxetine
3439070
body, including their absorption, distribution, metabolism, and excretion ("ADME"). However, the rule does not predict if a compound is pharmacologically active. The rule is important to keep in mind during drug discovery when a pharmacologically active lead structure is optimized step-wise to increase the activity and selectivity of the compound as well as to ensure drug-like physicochemical properties are maintained as described by Lipinski's rule. Candidate drugs that conform to the RO5 tend to have lower attrition rates during clinical trials and hence have an increased chance of reaching the market. Lipinski's rule states that, in general, an orally active
Lipinski's rule of five
428551
death does not occur. The majority in "Coker" stated that "death is indeed a disproportionate penalty for the crime of raping an adult woman." The dissent countered that the majority "takes too little account of the profound suffering the crime imposes upon the victims and their loved ones." The dissent also characterized the majority as "myopic" for only considering legal history of "the past five years". In "Kennedy v. Louisiana", 554 U.S. 407 (2008), the Court extended the reasoning of "Coker" by ruling that the death penalty was excessive for child rape "where the victim's life was not taken." The
Eighth Amendment to the United States Constitution
8408151
chosen so that the drug is more likely to be in a non-ionic form. Also, prodrugs of a compound may be developed by medicinal chemists-- these chemical variants may be more readily absorbed and then metabolized by the body into the active compound. However, changing the structure of a molecule is less predictable than altering dissolution properties, since changes in chemical structure may affect the pharmacodynamic properties of a drug. Other facts that affect absorption include, but are not limited to, bioactivity, resonance, the inductive effect, isosterism, bio-isosterism, and consideration. Absorption (pharmacology) In pharmacology (and more specifically pharmacokinetics), absorption is
Absorption (pharmacology)
2195960
detoxification, other treatments must be undergone to deal with the underlying addiction that caused the alcohol use. Clinicians use drug detoxification to reduce or relieve withdrawal symptoms while helping an addicted individual adjust to living without drug use; drug detoxification does not aim to treat addiction but rather represents an early step within long-term treatment. Detoxification may be achieved drug-free or may use medications as an aspect of treatment. Often drug detoxification and treatment will occur in a community program that lasts several months and takes place in a residential setting rather than in a medical center. Drug detoxification varies
Detoxification
10825513
geology, and hydrology. Characteristics discussed included particle size and shape, packing, electrical, optical, chemical and surface science. Particle size and surface area influence the release of a drug from a dosage form that is administered orally, rectally, parenterally, and topically. Higher surface area brings about intimate contact of the drug with the dissolution fluids in vivo and increases the drug solubility and dissolution. Particle size and surface area influence the drug absorption and subsequently the therapeutic action. The higher the dissolution, the faster the absorption and hence the quicker and greater the drug action. Micromeritic properties of a particle, i.e.
Micromeritics
6251182
including drug solubility, gastrointestinal motility and pH. If a medication is administered orally the amount of food in the stomach may also affect the rate of absorption. Once absorbed medications must be distributed throughout the body, or usually with the case of psychiatric medication, past the blood–brain barrier to the brain. With all of these factors affecting the rapidity of effect, the time until the effects are evident varies. Generally, though, the timing with medications is relatively fast and can occur within several minutes. As an example, physicians usually expect to see a remission of symptoms thirty minutes after haloperidol,
Emergency psychiatry
8556382
release of norepinephrine in the central and peripheral nervous system, thereby reducing some of the symptoms of opioid withdrawal, but it has no documented effect on drug craving and endogenous opioid levels. Lofexidine's oral bioavailability is about 90%, with extensive oral absorption. Peak plasma concentrations occur at 3 hours after a single administration, with a half-life of 11 hours. Lofexidine is extensively metabolized by the liver, and primarily cleared by the kidney. It is 80-90% plasma protein bound. Lofexidine exists as a solid at room temperature, with a melting point of 127 degrees C. The pair of ortho chlorine (Cl)
Lofexidine
1521030
be the most common aggravating factor. Orlistat is an anti-obesity (weight loss) drug that blocks the absorption of fats. This may give side effects of FI, diarrhea and steatorrhea. This may occur when there is a large mass of feces in the rectum (fecal loading), which may become hardened (fecal impaction). Liquid stool elements are able to pass around the obstruction, leading to incontinence. Megarectum (enlarged rectal volume) and rectal hyposensitivity are associated with overflow incontinence. Hospitalized patients and care home residents may develop FI via this mechanism, possibly a result of lack of mobility, reduced alertness, constipating effect of
Fecal incontinence
3433195
differs from earlier azole antifungals (such as ketoconazole) in that its structure contains a triazole ring instead of an imidazole ring. While the imidazole antifungals are mainly used topically, fluconazole and certain other triazole antifungals are preferred when systemic treatment is required because of their improved safety and predictable absorption when administered orally. Fluconazole's spectrum of activity includes most "Candida" species (but not "Candida krusei" or "Candida glabrata"), "Cryptococcus neoformans", some dimorphic fungi, and dermatophytes, among others. Common uses include: Fungal resistance to drugs in the azole class tends to occur gradually over the course of prolonged drug therapy, resulting
Fluconazole
8825885
compound's effectiveness in Parkinson's disease, particularly since it allows for more continuous stimulation of brain dopaminergic receptors than short-acting drugs such as levodopa. Though the exact reason is not known, continuous stimulation is considered to reduce risk for motor complications. The second pharmacokinetic advantage is the lack of dietary influence on drug absorption. This characteristic also allows for more sustained dopamine receptor stimulation. DHEC can be taken with a single oral dose and is rapidly absorbed. Peak plasma concentrations occur between 30 and 120 minutes after administration. The strong first-pass hepatic metabolism results in poor bioavailability. Less than 5% of
Dihydroergocryptine
2094717
due to overdoses, and the number is growing rapidly. Paulozzi also testified that all available evidence suggests that unintentional overdose deaths are related to the increasing use of prescription drugs, especially opioid painkillers. However, the vast majority of overdoses are also attributable to alcohol. It is very rare for a victim of an overdose to have consumed just one drug. Most overdoses occur when drugs are ingested in combination with alcohol. Drug overdose was the leading cause of injury death in 2013. Among people 25 to 64 years old, drug overdose caused more deaths than motor vehicle traffic crashes. There
Drug overdose
12912205
to be very effective in invasive amoebiasis although the drug is a weaker amoebicide when compared to emetine. It is only feebly amoebicidal in the intestinal lumen. The high concentration in the liver parenchyma and the lung allows the drug to act upon E. Histolytica in cases of amoebic liver abscess and pleuropulmonary amoebiasis. It is usually well tolerated, but in some individuals it may cause mild headache, itching, nausea, vomiting or blurred vision. Rarely incoordination, convulsions, peripheral neuritis and bleaching of hair can occur. Diminution of T waves has been noticed on routine electrocardiographic recordings. Retinopathy does not occur
Amoebic liver abscess
19993703
to manufacture generic versions of drugs. These generic drug companies were able to produce low-priced drugs that were considered among the lowest in the world. This allowed India to provide free antiretroviral treatment to 340,000 HIV infected individuals in the country. Majority of adult antiretroviral drugs purchased for donor-funded programs in developing countries were supplied by Indian generic drug companies. In compliance to the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS), India reintroduced patent laws for drugs in 2015. The majority of deaths from vaccine-preventable diseases occur in low and middle income countries. In low-income countries, more than
Access to medicines
6137793
yeasts, and fungi. It is commercially attractive due to its debittering properties. The typical concentration of naringin in grapefruit juice is around 400 mg/l. The reported LD50 of naringin in rodents in 2000 mg/kg. Naringin inhibits some drug-metabolizing cytochrome P450 enzymes, including CYP3A4 and CYP1A2, which may result in drug-drug interactions. Ingestion of naringin and related flavonoids can also affect the intestinal absorption of certain drugs, leading to either an increase or decrease in circulating drug levels. To avoid interference with drug absorption and metabolism, the consumption of citrus (especially grapefruit) and other juices with medications is advised against. However,
Naringin
2678121
absorbance: the "natural logarithm" of the ratio of incident to "transmitted" radiant power through a material. The optical depth equals the absorbance times ln(10). The term absorption refers to the physical process of absorbing light, while absorbance does not always measure absorption: it measures attenuation (of transmitted radiant power). Attenuation can be caused by absorption, but also reflection, scattering, and other physical processes. Absorbance of a material, denoted "A", is given by where Absorbance is related to optical depth by where "τ" is the optical depth. Spectral absorbance in frequency and spectral absorbance in wavelength of a material, denoted "A"
Absorbance
5514109
strict thermodynamic equilibrium, the radiation field is said to be black-body radiation and is described by Planck's law. For local thermodynamic equilibrium, the radiation field does not have to be a black-body field, but the rate of interatomic collisions must vastly exceed the rates of absorption and emission of quanta of light, so that the interatomic collisions entirely dominate the distribution of states of atomic excitation. Circumstances occur in which local thermodynamic equilibrium does not prevail, because the strong radiative effects overwhelm the tendency to the Maxwell–Boltzmann distribution of molecular velocities. For example, in the atmosphere of the Sun, the
Einstein coefficients
20333257
Chappuis absorption Chappuis absorption refers to the absorption of electromagnetic radiation by ozone, that is especially noticeable in the ozone layer, which absorbs a small part of sunlight in the visible part of the electromagnetic spectrum. The Chappuis absorption bands occur at wavelengths between 400 and 650 nm. Within this range are two absorption maxima of similar height at 575 and 603 nm wavelengths. Compared to the absorption of ultraviolet light by the ozone layer, known as the Hartley and Huggins absorptions, Chappuis absorption is distinctly weaker. Along with Rayleigh scattering, it contributes to the blue color of the sky,
Chappuis absorption
5241176
to cartilage and its intra-articular infusions may lead to postarthroscopic glenohumeral chondrolysis. Bupivacaine binds to the intracellular portion of voltage-gated sodium channels and blocks sodium influx into nerve cells, which prevents depolarization. Without depolarization, no initiation or conduction of a pain signal can occur. The rate of systemic absorption of bupivacaine and other local anesthetics is dependent upon the dose and concentration of drug administered, the route of administration, the vascularity of the administration site, and the presence or absence of epinephrine in the preparation. Like lidocaine, bupivacaine is an amino-amide anesthetic; the aromatic head and the hydrocarbon chain are
Bupivacaine
7187438
resection of bladder tumor, TURBT). For intravesical use, thiotepa is given in 30 mg doses weekly, for four to six weeks. Efficacy in tumor control may reach 55 percent. The main toxicity of this therapy is bone marrow suppression due to systemic absorption of the drug. The main side effect of thiotepa is bone marrow suppression resulting in leukopenia, thrombocytopenia and anemia. Liver and lung toxicity may also occur. Thiotepa Thiotepa (INN, chemical name: "N","N′","N′′"-triethylenethiophosphoramide) is an alkylating agent used to treat cancer. Thiotepa is an organophosphorus compound with the formula SP(NCH). It is an analog of "N","N′","N′′"-triethylenephosphoramide (TEPA), which
Thiotepa
6432025
to how much bacterial killing will occur. Various studies have shown that, for maximum bacterial killing, drug concentrations must be above the MIC for 50-60% of the time for the penicillin group of antibiotics. This means that longer durations of adequate concentrations are more likely to produce therapeutic success. However, when ampicillin is given in combination with sulbactam, regrowth of bacteria has been seen when sulbactam levels fall below certain concentrations. As with many other antibiotics, under-dosing of ampicillin/sulbactam may lead to resistance. Ampicillin/sulbactam has poor absorption when given orally. The two drugs have similar pharmacokinetic profiles that appear unchanged
Ampicillin/sulbactam
10308900
is unsuitable for regular use as it can seep from the anus and cause irritation. Efficacy of liquid paraffin is suggested by 2016 Cochrane review. It might interfere with the absorption of fat-soluble vitamins, though evidences seem low. It can be absorbed into the intestinal wall, and may cause foreign-body granulomatous reactions in some rat species but not in others and that reaction might not occur with human. There are evidences suggesting the lack of carcinogenicity. If it enters the lungs, it can cause lipoid pneumonia. Liquid paraffin is also used in combination with magnesium as an osmotic laxative, sold
Liquid paraffin (drug)
5419276
affect the absorption of dutasteride. Peak plasma levels occur 2 to 3 hours after administration. Levels of dutasteride in semen have been found to be 3 ng/mL, with no significant effects on DHT levels in sexual partners. The drug is extensively metabolized in the liver by CYP3A4. It has three major metabolites, including 6'-hydroxydutasteride, 4'-hydroxydutasteride, and 1,2-dihydrodutasteride; the former two are formed by CYP3A4, while the latter is not. All three metabolites are active; 6'-hydroxydutasteride has similar potency as a 5α-reductase inhibitor to dutasteride, while the other two are less potent. Dutasteride has an extremely long terminal or elimination half-life
Dutasteride
19184478
bone as compared to other tissues. Since lithium is almost exclusively excreted by the kidneys, people with preexisting renal insufficiency are at high risk of developing lithium intoxication. Lithium toxicity can be mistaken for other syndromes associated with antipsychotic use, such as serotonin syndrome because lithium increases serotonin metabolites in the cerebrospinal fluid. There are several drug interactions with lithium. Interactions can occur from typical antipsychotics or atypical antipsyhcotics. In particular, certain drugs enhance lithium levels by increasing renal re-absorption at the proximal tubule. These drugs are angiotensin-converting enzyme inhibitors, non-steroidal anti-inflammatory drugs and thiazide diuretics. When lithium toxicity is
Lithium toxicity