850. Clinical implementation of pharmacogenomics in the United States

Abstract

Abstract Background Pharmacogenomic (PGx) testing is increasingly recognized by clinicians as an essential tool to guide medication decisions for treatment of psychiatric disorders. Extensive implementation of PGx testing, however, varies by setting and location. PGx testing utilizes genomic sequencing to determine pharmacokinetic, immune-related, and pharmacodynamic effects of variants in specific genes that can affect an individual’s response to medications; this approach helps personalize treatment. The value of PGx testing in psychiatry has been demonstrated predominantly in individuals with depression who have failed at least one medication. Aims & Objectives The goal of this quality improvement (QI) study was to demonstrate how PGx testing utilization and implementation at an academic medical center changed prescribing practices of clinicians for individuals with psychiatric disorders. Method Selection of charts was guided by identification of any individual in the Ambulatory Service of the Department of Psychiatry who received PGx testing during the decade preceding this retrospective chart analysis. All patient information was deidentified prior to data analysis. Inclusion criteria for chart review included the following at the time of PGx testing: diagnosis of a psychiatric disorder, age greater than eight years and availability of relevant clinical information. A total of 600 charts were reviewed and 592 were deemed eligible for inclusion in this analysis. The PGx test used was Genesight which is marketed by Myriad Genetics in the USA and is covered by federal and private insurers. Results 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). This retrospective data analysis demonstrated a reduction in polypharmacy and an increase in recommendation-congruent medication prescribing resulting from implementation of PGx testing. Probably, the most striking finding from this study is the reduction of polypharmacy of psychiatric medications from pre- to post-PGx testing. Discussion & Conclusions This study demonstrates that PGx testing may decrease polypharmacy, which may also reduce not only the number of drug–drug interactions, but also the cost to healthcare systems and patients. Reducing polypharmacy also reduces the risk for adverse reactions, a top reason for emergency room visits. Last but certainly not least, reversing TRD by means of PGx testing enables the patient who has suffered from repeated medication failures to regain a reasonable degree of functionality, if not outright full remission of symptoms. This study illustrates the advantage of performing pharmacogenomic testing prior to prescribing medication. Worldwide acceptance and implementation of PGx is strongly recommended.