Metabolism of Drugs

Drug metabolism is a vital process that involves the biotransformation of drugs into metabolites that are more easily excreted from the body. The liver is the primary site of drug metabolism, where enzymes such as cytochrome P450 (CYP) play a significant role in catalyzing metabolic reactions. These enzymes can either activate or inactivate drugs, leading to changes in their pharmacological activity. Metabolism involves phase I and phase II reactions, where phase I reactions typically involve oxidation, reduction, or hydrolysis reactions to modify the drug's structure. Phase II reactions involve conjugation of the drug or its metabolites with endogenous substances to increase water solubility for excretion. Genetic variations in drug-metabolizing enzymes can lead to inter-individual differences in drug metabolism, impacting drug efficacy and toxicity. Knowledge of drug metabolism pathways is crucial for predicting drug interactions, devising dosing regimens, and understanding the pharmacokinetics of various drugs.