ABSTRACT
Drug elimination from the body involves excretion of the unchanged drug through various excretion pathways or drug metabolism via the different metabolic pathways. Drug metabolism involves enzymatic or chemical modication of the chemical structure of the drug molecule to form a new chemical entity called metabolite. Studying of the metabolite pharmacokinetics is important because in most cases the effect of the drug disappears when the drug is metabolized to pharmacologically inactive metabolites. However, some of the formed metabolites are pharmacologically active, and some metabolites are reactive and can cause serious adverse effects.
