Drug metabolism refers to the biochemical process by which the body transforms and eliminates drugs. This process is crucial for determining the duration and intensity of a drug's effect. The liver plays a significant role in drug metabolism, where enzymes modify the chemical structure of drugs, making them easier to excrete from the body. There are two main phases of drug metabolism: Phase I reactions involve the introduction or exposure of functional groups, while Phase II reactions involve conjugation, where the drug is linked to another substance to enhance its solubility. Understanding these processes helps in predicting drug interactions and individual responses to medications.