PHARMACOGENOMICS AND PRECISION MEDICINE IN PHARMACY PRACTICE: CURRENT EVIDENCE, CLINICAL APPLICATIONS, IMPLEMENTATION STRATEGIES, AND FUTURE DIRECTIONS

Pharmacogenomics (PGx) is an important component of precision medicine that uses genetic information to explain interindividual variability in medication response. Its clinical value is greatest when a validated genetic result can be translated into a specific therapeutic action, such as selection of an alternative drug, dose adjustment, intensified monitoring, or avoidance of a medicine associated with severe toxicity. The role of pharmacy practice is expanding because pharmacists possess expertise in pharmacology, pharmacokinetics, pharmacodynamics, medication safety, medication therapy management, patient counseling, and longitudinal follow-up. This review examines the current role of pharmacogenomics in pharmacy practice, including clinically actionable gene–drug relationships, pharmacist-led testing, community and hospital implementation, electronic health record (EHR) integration, clinical decision support, medication safety, health equity, ethics, pharmacoeconomics, and future research. Evidence from pharmacogenomic implementation literature, Clinical Pharmacogenetics Implementation Consortium (CPIC) guidance, and regulatory resources was considered. Important examples include CYP2C19–clopidogrel, CYP2D6–opioids and selected antidepressants, DPYD–fluoropyrimidines, TPMT/NUDT15–thiopurines, HLA-B–abacavir, HLA-B–carbamazepine and allopurinol, SLCO1B1–statins, CYP3A5–tacrolimus, and VKORC1/CYP2C9/CYP4F2–warfarin. Pharmacists can contribute across the complete PGx pathway: identifying candidates, arranging testing, interpreting results, documenting genotype/phenotype, recommending evidence-based medication changes, communicating with prescribers, counseling patients, monitoring outcomes, and evaluating service quality. Contemporary implementation studies indicate that community-pharmacy delivery is feasible and generally acceptable, but barriers include pharmacist knowledge and confidence, reimbursement, workflow integration, interoperability, standardized guidance, privacy, and equitable access. A successful precision-pharmacy model should therefore combine pharmacogenomic information with clinical phenotype, comorbidities, organ function, concomitant medicines, patient preferences, and therapeutic monitoring. Future pharmacy research should emphasize prospective clinical outcomes, cost-effectiveness, implementation science, Indian population data, diverse genomic representation, and responsible artificial-intelligence-supported clinical decision support.