Pharmacokinetics is the study of how the body affects a drug, detailing the quantitative time course of drug movement through biological systems. This field analyzes the disposition of a drug, which is commonly summarized by the ADME processes: absorption, distribution, metabolism, and excretion. Absorption describes the rate and extent to which a drug moves from its site of administration into the bloodstream. Distribution accounts for the movement of a drug from the blood plasma into the interstitial fluid and surrounding tissues. Metabolism involves the biochemical modification of the drug, typically occurring in the liver, which converts the drug into metabolites that can be eliminated. Finally, excretion is the irreversible removal of the drug and its metabolites from the body, primarily via the urine or bile. Understanding these processes is crucial for determining optimal dosing schedules, predicting drug efficacy, and minimizing potential toxicity.