Biochemical modification of drugs or foreign compounds by living organisms
This article is about the scientific concept of drug metabolism. For alternative medicine, see Detoxification (alternative medicine).
Drug metabolism is the metabolic breakdown of drugs by living organisms, usually through specialized enzymatic systems. More generally, xenobiotic metabolism (from the Greek xenos "stranger" and biotic "related to living beings") is the set of metabolic pathways that modify the chemical structure of xenobiotics, which are compounds foreign to an organism's normal biochemistry, such as any drug or poison. These pathways are a form of biotransformation present in all major groups of organisms and are considered to be of ancient origin. These reactions often act to detoxify poisonous compounds (although in some cases the intermediates in xenobiotic metabolism can themselves cause toxic effects). The study of drug metabolism is called pharmacokinetics.
The metabolism of pharmaceutical drugs is an important aspect of pharmacology and medicine. For example, the rate of metabolism determines the duration and intensity of a drug's pharmacologic action. Drug metabolism also affects multidrug resistance in infectious diseases and in chemotherapy for cancer, and the actions of some drugs as substrates or inhibitors of enzymes involved in xenobiotic metabolism are a common reason for hazardous drug interactions. These pathways are also important in environmental science, with the xenobiotic metabolism of microorganisms determining whether a pollutant will be broken down during bioremediation, or persist in the environment. The enzymes of xenobiotic metabolism, particularly the glutathione S-transferases are also important in agriculture, since they may produce resistance to pesticides and herbicides.
Drug metabolism is divided into three phases. In phase I, enzymes such as cytochrome P450 oxidases introduce reactive or polar groups into xenobiotics. These modified compounds are then conjugated to polar compounds in phase II reactions. These reactions are catalysed by transferase enzymes such as glutathione S-transferases. Finally, in phase III, the conjugated xenobiotics may be further processed, before being recognised by efflux transporters and pumped out of cells. Drug metabolism often converts lipophilic compounds into hydrophilic products that are more readily excreted.[citation needed]
Drugmetabolism is the metabolic breakdown of drugs by living organisms, usually through specialized enzymatic systems. More generally, xenobiotic metabolism...
and vinyl chloride. Drugs continue to be taken off the market due to late discovery of hepatotoxicity. Due to its unique metabolism and close relationship...
pass effect (also known as first-pass metabolism or presystemic metabolism) is a phenomenon of drugmetabolism at a specific location in the body which...
foods, beverages, or other drugs. A popular example of drug-food interaction is the effect of grapefruit in the metabolism of drugs. Interactions may occur...
Molecule DrugMetabolism". Ionsource.com. September 1, 2012. Retrieved April 21, 2013. "Comparison of the Levels of Enzymes Involved in DrugMetabolism between...
DrugMetabolism and Disposition is a peer-reviewed scientific journal covering the fields of pharmacology and toxicology. It was established in 1973 and...
effect or expected/normal responses (especially based on drugmetabolism). Abnormal drugmetabolism may be due to inherited factors of either Phase I oxidation...
and illicit drugs, extensive food-drug and drug-drug interactions as well as ADMET (absorption, distribution, metabolism, excretion and toxicity) parameters...
Metabolism (/məˈtæbəlɪzəm/, from Greek: μεταβολή metabolē, "change") is the set of life-sustaining chemical reactions in organisms. The three main functions...
as for hormone synthesis and breakdown, steroid hormone synthesis, drugmetabolism, and the biosynthesis of defensive compounds, fatty acids, and hormones...
predict or evaluate the metabolism of pharmaceutical compounds, and to better understand the pharmacokinetic profile of a drug. Pharmacometabolomics can...
Current DrugMetabolism is a peer-reviewed medical journal covering the study of drugmetabolism. It was established in 2000 and is published 10 times...
enzymes. Several other members of this family are also involved in drugmetabolism, but CYP3A4 is the most common and the most versatile one. Like all...
enzyme protein. The enzyme is involved in the metabolism, by oxidation, of both xenobiotics, including drugs, and endogenous compounds, including fatty acids...
the route of drug administration is important because it affects drugmetabolism, drug clearance, and thus dosage. The term is from Greek enteros 'intestine'...
(MAO) intermediate products. AO plays an important role in the metabolism of several drugs. AO catalyzes the conversion of an aldehyde in the presence of...
majority of small-molecule drugmetabolism is carried out in the liver by redox enzymes, termed cytochrome P450 enzymes. As metabolism occurs, the initial (parent)...
Established in 1972, DrugMetabolism Reviews is an academic journal that publishes review articles on all aspects of drugmetabolism research. It is the...
contrary, gut microbiota may also alter the metabolism of the drugs by modulating the host drugmetabolism. This mechanism can be mediated by microbial...
a drug when they can tolerate its adverse effects. Some instances of drug intolerance are known to result from genetic variations in drugmetabolism. Drugs...
absorption and first-pass metabolism. Thereby, mathematically, bioavailability equals the ratio of comparing the area under the plasma drug concentration curve...
suspension or culture to explore mechanisms of drugmetabolism and even predict in vivo drugmetabolism. For these purposes, hepatocytes are usually isolated...
5-methoxy-N,N-dimethyltryptamine: metabolism, pharmacokinetics, drug interactions, and pharmacological actions". Current DrugMetabolism. 11 (8): 659–666. doi:10...
PMID 26361585. Docampo R, Moreno SN (1990). "The metabolism and mode of action of gentian violet". DrugMetabolism Reviews. 22 (2–3): 161–78. doi:10.3109/03602539009041083...
organosulfur inducers of phase 2 enzymes: dithiolethiones and dithiins". DrugMetabolism and Drug Interactions. 17 (1–4): 3–22. doi:10.1515/DMDI.2000.17.1-4.3. PMID 11201301...
carcinogens, drugs, environmental pollutants, food additives, hydrocarbons, and pesticides. The body removes xenobiotics by xenobiotic metabolism. This consists...
superfamily of enzymes. CYP1A1 is involved in phase I xenobiotic and drugmetabolism (one substrate of it is theophylline). It is inhibited by hesperetin...
from the spleen, pancreas and visceral fat. The benefit of first-pass metabolism, whereby substances absorbed from food in the gut pass through the liver...
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