The use of pharmacogenetic testing in psychiatry

Psychiatric pharmacogenetic testing is commonly used by providers in primary care and mental health settings. The purpose of this article is to describe the extent to which psychiatric pharmacogenetic testing supports clinical practice. human leukocyte antigen (HLA)-A and HLA-B should be tested before initiating carbamazepine and oxcarbazepine due to risk of serious skin reactions. For psychotropic medications metabolized through the liver, limited evidence suggests testing for variation in metabolism through CYP2D6 and CYP2D19. For specific medication and genotype-phenotype variations, guidance through the Clinical Pharmacogenetics Implementation Consortium (CPIC) or the International Society of Psychiatric Genetics (ISPG) should be reviewed. Commercial tests interpret this information differently and should not be used for broad guidance. Clinicians should follow current guidelines from professional bodies such as CPIC or ISPG and test for HLA-A or HLA-B before initiating carbamazepine or oxcarbazepine. Evidence is limited for psychiatric pharmacogenetic testing. Clinicians should continue to follow best practice and clinical practice guidelines.