Role of Pharmacogenomics in Predicting and Preventing Adverse Drug Reactions: A Systematic Review of Gene–Drug Interactions and Clinical Outcomes

Background: : Adverse drug reactions (ADRs) are an important concern in clinical practice and can lead to treatment failure, hospitalization and increased healthcare costs. Genetic variations among individuals can influence drug-metabolizing enzymes, transport proteins and drug targets, resulting in differences in drug response and susceptibility to toxicity. Pharmacogenomics (PGx) provides an approach to understanding these genetic differences and supporting personalized drug therapy. Objective: To systematically evaluate the role of pharmacogenomics in predicting and preventing adverse drug reactions, with particular emphasis on clinically relevant gene–drug interactions and pharmacogenomics-guided treatment outcomes. Methods: : A systematic literature review will be conducted using databases including PubMed, Google Scholar, and the Cochrane Library. Relevant studies will be identified using keywords such as pharmacogenomics, pharmacogenetics, adverse drug reactions, genetic polymorphism, drug toxicity and personalized medicine. Studies investigating associations between genetic variations, medication-related adverse reactions and genotype-guided prescribing will be considered. Study selection and reporting will follow PRISMA 2020 guidelines. Expected results: The review is expected to identify clinically important gene–drug associations, evaluate the evidence supporting pharmacogenomics-guided prescribing and examine its potential to reduce medication-related toxicity. It will also explore challenges associated with implementing pharmacogenomic testing in routine clinical practice. Conclusion: : Pharmacogenomics has the potential to improve medication safety by identifying individuals at increased risk of specific adverse drug reactions. Its effective implementation requires reliable genetic testing, clinical interpretation, healthcare professional education and accessible prescribing guidelines.