Cytochrome P450 Monooxygenases and Interactions of Psychotropic Drugs: A Five-Year Update

Abstract

Objective: This article is a five-year update on a previous review article (International Journal of Psychiatry in Medicine, 21:47–56, 1991) on cytochrome P450 monooxygenases and interactions of psychotropic drugs. Method: In the literature review, the recent committee work on nomenclature of the P450 superfamily are highlighted. Then, the author reviewed gene clusters of three human cytochrome P450s—CYP1A2, CYP2D6, and CYP3A4 with the focus on the changes of serum levels of the coadministered psychotropic drugs in the context of enzymatic induction and inhibition of these three hepatic enzymes. Results: As indicated in one table, the author stratified probes, inducers, inhibitors, chemical reactions, and substrates under these three gene clusters. As shown in another simple table, the author compared the hepatic enzymatic inhibitions of four selective serotonin reuptake inhibitors and pointed out the inhibition potentials of fluvoxamine at CYP1A2, fluoxetine and paroxetine at CYP2D6, and fluoxetine and fluvoxamine at CYP3A4 if these two SSRIs have higher serum concentrations. Conclusion: The author suggests that with these systematic approaches, this rapidly adding knowledge can help psychiatrists better understand psychotropic drug interactions and maximize the benefits of patients' psychopharmacotherapy.