Write note on metabolism of drugs

Drug metabolism, also known as biotransformation, is the process by which the body chemically modifies drugs. This is primarily carried out by enzymes, mainly in the liver, but also in other tissues like the intestines, kidneys, lungs, and skin. The main goal of metabolism is to convert drugs into more water-soluble forms, making them easier to excrete from the body, usually via the kidneys (urine) or liver (bile). Metabolism can also inactivate drugs, but sometimes it can activate prodrugs (inactive precursors) or produce active metabolites that contribute to the drug's overall effect or toxicity. Drug metabolism is typically divided into two phases: 1. Phase I reactions: These reactions introduce or expose a functional group (like hydroxyl -OH, amino -NH₂, or sulfhydryl -SH) on the drug molecule. Common Phase I reactions include oxidation, reduction, and hydrolysis. The cytochrome P450 (CYP) enzyme system is the most important group of enzymes involved in Phase I metabolism, particularly oxidation. 2. Phase II reactions: If the drug or its Phase I metabolite is still not sufficiently water-soluble, it undergoes conjugation. In Phase II reactions, an endogenous molecule (like glucuronic acid, sulfate, or acetate) is attached to the drug or its metabolite, forming a larger, more polar, and readily excretable compound. Factors like genetics, age, disease states, and interactions with other drugs can significantly affect an individual's drug metabolism rate, leading to variations in drug response and potential toxicity. Got more? Send 'em 🧪