During which phase of pharmacokinetics do drugs leave the body?

In pharmacokinetics, the phase during which drugs leave the body is known as excretion. This phase involves the elimination of the drug and its metabolites from the body. Typically, this process occurs mainly through the kidneys in urine, but can also include elimination through bile, feces, sweat, saliva, and breath. Understanding this phase is crucial as it impacts the duration of the drug's effect and its overall therapeutic efficacy.

The other phases—absorption, distribution, and metabolism—play different roles in the pharmacokinetic process. Absorption involves the process through which the drug enters the bloodstream after administration. Distribution refers to how the drug disperses throughout the body's fluids and tissues after it has entered the circulation. Metabolism involves the chemical modification of the drug in the body, often leading to inactivation or preparation for excretion, but it is during excretion that the drug actually leaves the body.