Adding pharmacogenetics to the clinical laboratory: narrow therapeutic index medications as a place to start.

A pharmacogenetics is a new discipline, it is anticipated to have applications in many fields, including drug development, therapeutic dosing guidance, and disease risk stratification. Rai1 has suggested that pharmacogenetic testing during drug development trials could create a large number of drug compounds targeted to particular pharmacogenetic phenotypes. This approach in turn would necessitate clinical pharmacogenetic testing as a requirement for therapy with that drug. Specific pharmacogenetic dosing guidelines would advance the science of prescribing drugs toward truly individualized drug therapy. It is anticipated that in turn, individualized drug therapy will enable physicians to predict and, ideally, to prevent many adverse drug reactions (ADRs), which are a leading cause of morbidity and mortality in this country, estimated to be the fifth leading cause of death among hospitalized patients (see Table 1). The aim of pharmacogenetic testing is to describe how people will re-