Why doesn’t the effect of the drug after a single dose last forever? That’s because your body has a variety of ways of eliminating it. One of those ways is through metabolism. Pharmacology is what the drug does to you and drug metabolism is what you do to the drug in order to inactivate it and eliminate it.
What Determines Your Drug Metabolism? Several factors affect your body’s rate of metabolism. Genetic Factors. Of all the metabolic enzymes, the ones produced by the cytochrome P450 (CYP450) gene group are among the most important. They make up 70 to 80 percent of enzymes involved in drug metabolism.
Most drugs must pass through the liver, which is the primary site for drug metabolism. Once in the liver, enzymes convert prodrugs to active metabolites or convert active drugs to inactive forms. The liver’s primary mechanism for metabolizing drugs is via a specific group of cytochrome P-450 enzymes.
3. Chemistry of Drug Metabolism Drug metabolism is a chemical process, where enzymes play a crucial role in the conversion of one chemical species to another. The major family of enzymes associated with these metabolic reactions is the cytochrome P450 family. The structural features and functional activity of these enzymes comprise the bioinorganic
Understanding the metabolism of drugs is important. Drugs can be metabolized by oxidization, hydration, reduction, and hydrolysis to name a few internal processes. Drug metabolism often converts the drug into readily excreted products and metabolism occurs in many bodily tissues however most predominately located in the liver.
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 ...
The target drug may need to be substituted or the dose adjusted to account for a potential decrease or increase in metabolism. Information regarding a drug's CYP450 metabolism and its potential ...
Hence metabolism deals with making the drug more hydrophilic such that it can be excreted out from the body. In some cases the metabolites can be more active than the drug itself e.g. anxiolytic benzodiazepines. Some enzymes are highly specific and will breakdown only compounds that they recognize for e.g. glucose dehydrogenase. But there are ...
As previously mentioned, CYPs are involved in both activation and detoxication of xenobiotics, including therapeutic drugs. CYP3A4 plays an important role in the metabolism of several anticancer agents (e.g. taxanes, vinca-alkaloids and new drugs such as imatinib, sorafenib and gefitinib).
Why is drug metabolism important for drug excretion? The metabolic conversion of drug to water-soluble metabolites so it' can be readily excreted. How does biotransformation either activate (prodrugs, toxic metabolites) or inactivate (detoxify) drugs?