The ABCD of clinical pharmacokinetics
ADME is the four-letter acronym for absorption, distribution, metabolism and excretion that has described pharmacokinetics for 50 years. These terms were first presented together in English by Nelson in , rephrasing resorption, distribution, consumption and elimination used by Teorell in [ Nelson, ; Teorell, ]. ADME T has become a standard term, widely used in the literature, in teaching, in drug regulation and in clinical practice. ADME, as originally used, stood for descriptors quantifying drug: entering the body A , moving about the body D , changing within the body M and leaving the body E. Over time, the use of ADME has diversified according to the needs of the user. In particular, it is used to describe mechanisms: crossing the gut wall A ; movement between compartments D ; mechanisms of metabolism M ; excretion or elimination E ; and transport T is sometimes added.
Pharmacokinetics from Ancient Greek pharmakon "drug" and kinetikos "moving, putting in motion"; see chemical kinetics , sometimes abbreviated as PK , is a branch of pharmacology dedicated to determine the fate of substances administered to a living organism. The substances of interest include any chemical xenobiotic such as: pharmaceutical drugs , pesticides , food additives , cosmetics , etc. It attempts to analyze chemical metabolism and to discover the fate of a chemical from the moment that it is administered up to the point at which it is completely eliminated from the body. Pharmacokinetics is the study of how an organism affects a drug, whereas pharmacodynamics PD is the study of how the drug affects the organism. These may affect the absorption rate.