Pharmacogenomics and Personalized Medicine

Large inter-individual variability in clinical drug response has led to drug treatment failure, severe adverse drug reactions, increased emergency department visits and hospital admissions. Variability in drug response can be attributed to genetic and non-genetic factors. The non-genetic factors such as, organ function, concomitant medications, infections, nutrition and others are often taken into account to adjust drug dose or select alternative drugs to optimize patient outcome and prevent adverse drug reactions. Genetic variations in drug target genes, drug metabolizing enzymes and transporters have been associated with drug efficacy and toxicity. Genetic testing and application of clinically actionable genotypes can help clinicians maximize drug treatment and identify patients at high risk for developing preventable adverse reactions. Pharmacogenomics applies genome science (genomic information) to study human variability in drug response and disposition. The goal of pharmacogenomics is to identify genetic polymorphisms (biomarkers) that significantly affect the functions or expression of proteins that are involved in therapeutic drug metabolism and disposition. Personalized Medicine (also referred as Precision Medicine), is an emerging practice of medicine that uses an individual’s genetic information along with family history, diseases and environmental factors to personalize or individualize care. Here we review the principals of pharmacogenomics and clinical implications of pharmacogenomics and personalized medicine in a few therapeutic drugs.