Pharmacogenetic Testing in an Academic Psychiatric Clinic: A Retrospective Chart Review.

Pharmacogenomic (PGx) testing is being increasingly recognized by clinicians as an essential tool to guide medication decisions for treatment of psychiatric illnesses. Extensive implementation of PGx testing, however, varies by setting and location. In this retrospective study, we reviewed charts from 592 patients diagnosed with a psychiatric disorder at the Loyola University Medical Center, for whom PGx testing was performed. Information collected included demographics at the time of testing, psychiatric diagnosis, medical and psychiatric history and medications prior and after PGx testing. Of the 592 charts analyzed, the most common primary diagnoses were depression (52%) and anxiety (12%). Prior to PGx testing, 72% of patients were prescribed three or more medications, whereas, after testing, only 44% were prescribed three or more medications included in the test panel (p < 0.0001). The most common clinical consideration on the PGx reports was recommendation to reduce dosages (33%). After PGx testing, the proportion of patients taking incongruent medications decreased from 26% to 19% and that of patients taking congruent medications increased from 74% to 81% (p = 0.006). The results from this retrospective data analysis demonstrated a reduction in polypharmacy and an increase in recommendation-congruent medication prescribing resulting from implementation of PGx testing.

Obesogenic Medications and Weight Gain Over 24 Weeks in Patients with Depression: Results from the GUIDED Study.

Weight gain is a common side-effect of medications used to treat major depressive disorder (MDD). We sought to estimate the frequency of weight gain for obesogenic medications prescribed for MDD and to evaluate if bupropion mitigated risk for weight gain. We analyzed a prospective cohort of patients with weight available at baseline and 12 weeks (n = 1,032) or 24 weeks (n = 871) in a post hoc analysis of the Genomics Used to Improve DEpression Decisions (GUIDED) study of patients with MDD who failed at least one medication trial. We compared weight gain between those on versus not on medications with high risk for weight gain, including a subgroup receiving combination treatment with bupropion. A second analysis evaluated weight gain across traditional medication classes, adjusting for potential confounding variables. Those on medications identified as high risk for weight gain were significantly more likely to experience clinically significant weight gain (≥3%) at 12 weeks (29.3% vs. 16.3%, p < .001) and 24 weeks (33.5% vs. 23.5%, p = .015). No protection from clinically significant weight gain was observed among patients treated with a high-risk medication concomitantly with bupropion (N = 31, 35% and 52% with clinically significant weight gain at 12 and 24 weeks). Antipsychotic medications and tricyclic antidepressants were most often associated with clinically significant weight gain. This study helps quantify the real-world risk of weight gain for patients with MDD on medications with high risk for weight gain, especially for patients taking antipsychotics. Concurrent treatment with bupropion does not appear to mitigate the weight gain risk.

The clinical utility of combinatorial pharmacogenomic testing for patients with depression: a meta-analysis.

Aim: To perform a meta-analysis of prospective, two-arm studies examining the clinical utility of using the combinatorial pharmacogenomic test, GeneSight Psychotropic, to inform treatment decisions for patients with major depressive disorder (MDD). Patients & methods: The pooled mean effect of symptom improvement and pooled relative risk ratio (RR) of response and remission were calculated using a random effect model. Results: Overall, 1556 patients were included from four studies, with outcomes evaluated at week 8 or week 10. Patient outcomes were significantly improved for patients with MDD whose care was guided by the combinatorial pharmacogenomic test results compared with unguided care (symptom improvement Δ = 10.08%, 95% CI: 1.67-18.50; p = 0.019; response RR = 1.40, 95% CI: 1.17-1.67; p < 0.001; remission RR = 1.49, 95% CI: 1.17-1.89; p = 0.001). Conclusion: GeneSight Psychotropic guided care improves outcomes among patients with MDD.

Canadian Medication Cost Savings Associated with Combinatorial Pharmacogenomic Guidance for Psychiatric Medications.

OBJECTIVE: To estimate Canadian pharmacy cost savings associated with psychiatric medication prescribing that is guided by combinatorial pharmacogenomic testing in patients switching or augmenting their psychiatric medication. METHODS: Pharmacy claims data from a United States (US) pharmacy benefit manager were analyzed for 1662 patients who recently augmented or switched to a different antidepressant or antipsychotic medication and underwent combinatorial pharmacogenomic testing. Costs of prescription medications were translated to the Canadian healthcare system by matching drug names and doses using the Ontario Drug Benefit Formulary. One-year costs (2017 CAD) were compared between patients whose clinician prescribed antidepressants or antipsychotics that were consistent (congruent) or inconsistent (incongruent) with the combinatorial pharmacogenomic test recommendations. RESULTS: Patients whose psychiatric medication treatment was congruent with the combinatorial pharmacogenomic test report saved $1061 CAD per member per year (PMPY) on prescription medication costs relative to patients whose medications were incongruent with their test report (p<0.0001). For patients ages <65 and ≥65, prescription medication costs were $979 and $1178 CAD PMPY lower, respectively, for patients who followed the report recommendations (p=0.0004 and p=0.13). Prescription drug fills from the US pharmacy claims were concordant with the Canadian Formulary; 62% of fills matched at both the drug name and dose strength, 81% matched at drug name, and >99% matched at the therapeutic chapter. CONCLUSIONS: Antidepressant and antipsychotic prescribing that was congruent with combinatorial pharmacogenomic test guidance was associated with significant cost savings on Canadian prescription medications according to the Ontario Drug Benefit Formulary.