Journal of Drug Metabolism & Toxicology
Open Access

Drug Disposition Innovations

Drug disposition is a general term that encompasses the four processes that determine drug and metabolite concentrations in plasma, in tissue, and within cells: absorption, distribution, metabolism, and excretion. Metabolism is generally accomplished by phase I enzymes that generate more polar  metabolites; the liver is the site of most drug metabolism, although some can occur in extrahepatic loci, such as the gut, kidney, or plasma.