Comparing the clinical utility of pharmacogenomic genotyping and next generation sequencing in a military health system adult medicine clinic

Introduction: Pharmacogenetic (PGx) screening is intended to optimize drug efficacy and reduce adverse drug reactions. Current screening options include genotyping assays for preselected PGx variants and broader next-generation sequencing panels (NGS). Few studies have directly compared preemptive PGx screening methods. Materials and Methods: The two PGx methods were compared in a cross-sectional study of adult Military Health System (MHS) clinic beneficiaries. Participants had initial targeted CYP2C19/CYP2D6 genotyping at a Military Health System Laboratory. Genotyping was followed by multi-gene NGS testing. Current prescriptions were recorded and potential drug–drug interactions screened to evaluate prescribing risk. Results: All participants (100%) had at least one clinically actionable NGS panel result compared to 81% with targeted CYP2C19/CYP2D6 genotyping. Participants (n = 162) had an average of 6.6 (range 0–22) prescriptions and 2.7 (range 0–24) drug–drug interactions. Among those with at least one clinically actionable NGS result, 42% were currently taking medication with actionable CPIC guidelines (Level A/B), compared with 24% with CYP2C19/CYP2D6 genotyping. Sixteen participants (10%) had uncertain NGS panel results, with none for CYP2C19/CYP2D6 genotyping. Conclusions: Preemptive multi-gene NGS detected more clinically actionable PGx results than targeted CYP2C19/CYP2D6 genotyping. Effective PGx screening in the MHS may decrease preventable adverse effects and improve military readiness.