The clearance of a drug is the primary parameter that quantifies the body's efficiency in eliminating the drug per unit time, reflecting the volume of plasma completely cleared of the drug. It directly determines the rate at which the drug is removed, impacting dosing and steady-state concentrations. Unlike half-life, which depends on both clearance and volume of distribution, clearance alone solely governs elimination rate. Understanding clearance is crucial for optimizing drug therapy, especially in impaired organ function.

Reference: Goodman & Gilman’s The Pharmacological Basis of Therapeutics, Brunton et al., 13th Edition.