Advances in pharmacogenetics and pharmacogenomics.

Large differences among normal human subjects in the efficacy and safety of many therapeutic agents are caused by genetically controlled polymorphisms of drug-metabolizing enzymes, drug transporters, and drug receptors. Development of pharmacogenomics as a new field has accelerated progress in pharmacogenetics by elucidating at the level of the human genome the inherited basis for those large interindividual variations. Examples discussed in this review illustrate how this approach can be used not only to guide new drug discovery but also to individualize therapy. Adverse drug reactions, often attributable to large differences among subjects in drug response, constitute a leading cause of death in the USA. Such high morbidity and mortality could be reduced by application of the principles of pharmacogenetics and pharmacogenomics, defined broadly as the study of genetically caused variability in drug response.