Prodrugs and active metabolites among antidepressive compounds.

Clinical effect of drugs is influenced by the composition of the pharmaceutical preparation but substantially by the fate of the drug in the body. Metabolism of the xenobiotic drug compounds may result in pharmacologically inactive metabolites, however, metabolites with higher pharmacological activity can also be produced. These active metabolites may have different pharmacokinetic properties than the parent drug. Co-existence of the parent drug and the active metabolite in the body may significantly modify the therapeutic effect. Knowledge-based system of pharmacokinetics and metabolism of the drugs has a high impact in understanding both the pharmacokinetic and the pharmacodynamic interactions. Cytochrome P450 isoenzymes taking part in the metabolic activity of the central nervous system is a developing area in metabolic studies. In the present study CYP isoenzymes with significant activity in the brain and the clinically important pharmacokinetic and metabolic data of antidepressive compounds are summarized.