Metabolism (biotransformation) Same like metabolism of carbohydrate, protein, lipids, the drug will metabolized by enzymes present in the body. The conversion of lipid soluble substances or drug in to water soluble compound by enzymatic reaction is called as bio-transformation. It involves alteration of drug molecule. Table of Content Metabolising Enzymes Chemical Phases The
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 biochemist...
Phase 1 metabolism by CYPs and phase 2 conjugation to a glucuronide is one of the most common drug-metabolism combinations. There are many drugs that alter the normal action of drug metabolizing enzymes. Some drugs induce CYPs. This is typically due to the production of the new protein (drug metabolizing enzyme). When
isozymes responsible for metabolism of drugs of abuse, understanding regulation of gene expressions resulting in polymorphism, understanding induction of enzymes, development of selective substrates and inhibitors, and development of kinetic models, to name a few. Selective enzyme inhibitors hold promise for ameliorating the
Drug metabolism, which is the biochemical translation of pharmaceuticals by internal human organ systems, can be hindered or accelerated by multiple factors.Modified metabolism of drugs can lead to toxication, which is an exaggerated activation of the chemical compound, or detoxication, which is an over deactivation.
Only recently have detailed investigations into drug metabolism in the kidney been carried out. These studies have shown that the kidney is meta-bolically very active in effecting the biotransformation of a variety of chemicals and drugs and, in some cases, surpasses the liver.
Metabolism of drugs occurs in 2 phases. In the phase 1 reaction, the drug is made polar by oxidation or hydroxylation. All drugs may not undergo this step, and some may directly undergo the phase 2 reaction. The cytochrome P-450 enzymes catalyze phase 1 reactions. Most of these intermediate products are transient and highly reactive.
Lipophilic drugs may have an increased volume of distribution (Vd) with a prolonged half-life, and water-soluble drugs tend to have a smaller Vd. In the elderly, hepatic drug clearance of some drugs can be reduced by up to 30% and CYP-mediated phase I reactions are more likely to be impaired than phase II metabolism, which is relatively ...
Drug Response With Advancing Age. Aging, Effects on Drug Metabolism and Drug Response – Many drugs have different therapeutic effects as well as potential adverse drug reactions, depending on a person’s age. The very young and the very old often have limited liver function, which affects the ways in which the liver metabolizes drugs, resulting in lower thresholds for toxicity and ...
CYP2C19-related poor drug metabolism is a condition in which the body is unable to properly process certain types of medications such as clopidogrel, mephenytoin, omeprazole, and/or proguanil.As a result, these medications are less effective in affected people who are treated with them. The condition is caused by changes (mutations) in the CYP2C19 gene and is inherited in an autosomal ...