Interpreting and applying CYP450 genomic test results to psychotropic medications.

The promises of personalized medicine have health care professionals and the public at large in great anticipation of the idea that understanding a patient's genetic composition will provide clear answers to their treatment needs. For many practitioners in mental health care, there has been a question about whether or not CYP450 genetic polymorphisms can reliably inform psychotropic treatment response and tolerability. Unfortunately, the published evidence addressing this issue is mixed with only some researchers finding a positive correlation between a patient's inherited metabolizer status and either response or tolerability to a specific medication or a therapeutic class of medications. Despite this mixed evidence, clinical practitioners have started genotyping CYP450 enzymes for some of their patients with the hope that these data may shed some light on difficult treatment decisions. This review will focus on the metabolism of psychotropics and important aspects of understanding the genomics of the cytochrome P450 enzymes 2C9, 2C19, and 2D6. Additionally this review will illustrate sample laboratory reports from 4 different laboratories which test for CYP450 genomics and then finally provide 3 different case scenarios which illustrate a process that pharmacists can use when applying genomic laboratory data to patient care.