PHARMACOGENOMICS AND PERSONALIZED DRUG THERAPY: TOWARD SAFER PRESCRIPTIONS

Abstract

Pharmacogenomics (PGx) examines how inherited genetic variation influences drug disposition, efficacy, and toxicity. Across cardiology, oncology, infectious diseases, and psychiatry, variation in pharmacokinetic genes (e.g., CYP2D6, CYP2C19, CYP2C9, SLCO1B1) and pharmacodynamic or hypersensitivity loci (e.g., HLA-B*57:01, HLA-B*15:02, DPYD) contributes to avoidable adverse drug reactions (ADRs) and suboptimal outcomes. Implementation science now demonstrates that pre-emptive or point-of-care genotyping integrated with clinical decision support can reduce ADRs, shorten time-to-therapeutic response, and improve cost-effectiveness when deployed at scale. This article synthesizes core concepts, evidence for clinical validity and utility, and operational models for integrating PGx into prescribing workflows, with attention to equity, data governance, and contexts with constrained resources. We outline a pragmatic roadmap—test selection, EHR integration, structured reporting, education, and measurement of outcomes—culminating in future directions such as multi-omic risk stratification and learning health systems. Pharmacogenomics is transitioning from promise to practice; the remaining challenges are organizational rather than conceptual, and the opportunity is safer, more effective, and more equitable prescribing.