What does drug metabolism refer to?

Drug metabolism refers to the chemical alteration of a drug by the body. This process typically occurs in the liver, where various enzymes modify the drug to facilitate its elimination from the body. Drug metabolism can convert lipophilic (fat-soluble) drugs into more hydrophilic (water-soluble) metabolites, which can be more readily excreted in the urine or bile.

Understanding this process is crucial in pharmacotherapy since it influences the duration of action of the drug, its efficacy, and the potential for drug interactions. Metabolites formed through this process can also sometimes be active or toxic, further emphasizing its significance in drug therapy.

Other options focus on different aspects of pharmacokinetics or drug action but do not accurately define metabolism. For instance, the process of a drug entering the bloodstream relates to absorption, while removing drugs from the body is associated with excretion. Increased effectiveness of a drug pertains more to pharmacodynamics and how well a drug works, rather than the chemical changes it undergoes upon metabolism.