Medication Optimization Using Pharmacogenomic Testing in a Complex Mental Health Population Prescribed Psychiatric Polypharmacy.

The use of polypharmacy has become significantly more common over the past two decades, increasing the risk of drug-drug interactions and adverse drug reactions. Pharmacogenomic (PGx) assays have the purported benefit of being able to predict an individual's response to a specific medication based on genetic markers, which may facilitate the development of optimized medication regimens for patients prescribed polypharmacy. This 12-week pilot study examined the impact of the PGx results on the clinical management of Veterans who were prescribed psychiatric polypharmacy. Psychiatric medication providers were given access to the PGx assay results, including notification of drug-drug-gene interactions computed from an algorithm decision tool, to assist with medication management decisions. Veteran outpatients (N = 53) prescribed polypharmacy (mean = 13.15 medications) were enrolled into the study. In 92.4% of cases, providers changed medications at baseline, with 83% of providers indicating that they changed their original medication plan based on the PGx results. Clinical improvement over the 12-week treatment phase was seen in depression (F(1.63, 45) = 5.45, P = .01, η²  = .11) and mental health quality of life (F(2.00, 45) = 4.16, P < .05, η²  = .16). Adverse drug effects were unchanged or improved over time. Rates of polypharmacy remained unchanged. The results suggest that medication changes based on the PGx assay may be beneficial in a complex patient population prescribed polypharmacy.