THE AREA UNDER THE CURVE OF METABOLITES FOR DRUGS AND METABOLITES CLEARED BY THE LIVER AND EXTRAHEPATIC ORGANS - ITS DEPENDENCE ON THE ADMINISTRATION ROUTE OF PRECURSOR DRUG

Abstract

The venous equilibrium model (or well-stirred model) is used to be determine the area under the blood concentration vs. time curve of a metabolite formed from a precursor drug. The AUC [area under the curve] of a metabolite will change according to the route of precursor drug administration (whether intraarterially, i.v., via the portal vein or orally) when the drug and/or metabolite is eliminated by more than one organ. Elimination includes hepatic and extrahepatic metabolism and renal excretion. The validity of the model is probed using literature data for drug and metabolite areas. The use of metabolite areas for evaluating the complete/incomplete absorption of orally administered precursor drug is discussed.