Transforming medicine through pharmacogenomics: Current status, challenges, and emerging horizons

Abstract Pharmacogenomics – an essential pillar of personalized or precision medicine – focuses on how genetic differences shape a person’s response to medications. By understanding these genetic influences, clinicians can tailor therapy to improve drug effectiveness and reduce the likelihood of adverse drug reactions (ADRs). This review highlights the mechanistic basis of pharmacogenomics, encompassing genetic variability in pharmacokinetics, pharmacodynamics, and immunologic responses. Key examples such as CYP450 polymorphisms, VKORC1 variants, and human leukocyte antigen alleles illustrate how genetic differences affect drug metabolism, efficacy, and toxicity. The implementation of pharmacogenomics has transformed therapeutic strategies across oncology, cardiology, psychiatry, and infectious diseases, enabling genotype-guided treatments such as trastuzumab, warfarin, and abacavir. Global initiatives such as the Clinical Pharmacogenetics Implementation Consortium, PharmGKB, and Food and Drug Administration pharmacogenetic guidelines have facilitated clinical integration. In contrast, countries such as the USA, the UK, and the Netherlands have demonstrated successful models of system-wide adoption. In India, though infrastructure remains limited, efforts by premier institutions and the Genome India Project aim to bridge the gap by identifying population-specific pharmacogenetic variants. Despite the benefits – including reduced ADRs, improved treatment outcomes, and cost savings – widespread implementation faces challenges such as high setup costs, limited clinician awareness, and ethical concerns surrounding genetic discrimination and data privacy. The review underscores the need for national policy support, public–private partnerships, and low-cost genotyping technologies to scale pharmacogenomics in India. As the field evolves toward multigene panels and artificial intelligence-driven clinical decision-making tools, pharmacogenomics promises to revolutionize healthcare by personalizing therapy, improving public health outcomes, and positioning India as a leader in genomic medicine. Strategic investments and ethical governance will be key to realizing its full potential.