Pharmacogenetics: from discovery to patient care

The basic concepts of pharmacogenetics, pharmacogenetic study approaches, factors to consider when applying pharmacogenetic discoveries to patient care, and potential roles for pharmacists in pharmacogenetics are discussed.

The Food and Drug Administration (FDA) has recognized pharmacogenomics as an opportunity to identify new biomarkers that may expedite the drug development process. Currently, there are over 50 drugs with pharmacogenetic discoveries on their labeling. Sequence variations in drug disposition genes can alter the pharmacokinetics of a drug, while sequence variations in drug target genes can change the pharmacodynamics of the drug. The two most common strategies to test a pharmacogenetic question are the candidate-gene approach and genomewide association study. Given the complex interplay among the many factors that influence a drug dose, determination of an appropriate dose of a particular drug for a given patient will eventually require knowledge about both genetic and nongenetic factors that affect drug disposition and pharmacodynamics. Many factors can influence the application of pharmacogenetic discoveries to patient care. Before these discoveries find widespread application in clinical practice, additional work is needed, including randomized clinical trials to evaluate the clinical utility of a pharmacogenetic test, the development of guidelines for the clinical use of various pharmacogenetic tests, and provider education on pharmacogenetics.

Pharmacogenetics has made significant progress in the past decade, and many pharmacogenetic discoveries have now been included on FDA-approved drug labeling. Pharmacogenetic discoveries may further promote safe and effective use of medications by more accurately predicting an individual's drug response.