Personalized Medicine and Pharmacogenomics: Impact of Genetic variation on Drug Response and Individualized Therapy - A Review

The emergence of personalized medicine represents a paradigm shift in modern healthcare, where treatments are increasingly tailored to the unique genetic, environmental, and lifestyle factors of individual patients. Central to this transformation is pharmacogenomics the study of how genetic variations influence drug response. Understanding the genetic determinants of drug metabolism, efficacy, and toxicity enables healthcare providers to optimize therapeutic strategies, minimize adverse drug reactions (ADRs), and enhance overall treatment outcomes. This review presents a comprehensive overview of the critical role of genetic polymorphisms and pharmacogenes in influencing interindividual variability in drug response. It discusses key examples such as CYP450 enzymes, TPMT, HLA alleles, and drug transporters, which have demonstrated significant clinical relevance in guiding drug selection and dosage adjustments. The integration of pharmacogenomic data into routine clinical practice is explored, with a focus on its application in targeted therapies, chronic disease management, and ADR prevention. Furthermore, this paper examines the practical challenges in clinical implementation, including issues related to cost, education, healthcare infrastructure, and population diversity. It also outlines future perspectives, highlighting the potential of emerging technologies such as whole-genome sequencing, artificial intelligence (AI), and point-of-care genetic testing in facilitating broader adoption of pharmacogenomics. As the field evolves, pharmacogenomics is poised to become an essential component of precision medicine offering more predictive, preventive, and personalized healthcare for diverse populations worldwide.