The pharmacogenetics of asthma treatment.

The treatment response to each of the three major classes of asthma medications-beta agonists, leukotriene modifiers, and inhaled corticosteroids-demonstrates substantial interindividual variability. Evidence indicates that this variability is mediated, at least in part, by genetic factors. Pharmacogenetics is the study of the role of heritable factors in the response to pharmacologic therapy. The goal of pharmacogenetics is "predictive medicine," whereby a genetic profile, combined with clinical characteristics, can be used to predict response to medications a priori, allowing for maximal therapeutic response while minimizing side effects. In this review, we discuss the rationale behind conducting asthma pharmacogenetics studies, provide an overview of asthma pharmacogenetic phenotypes, and detail the most important results of asthma pharmacogenetics studies conducted to date. Although no specific predictive tests have been developed thus far, the existing studies serve as strong proof of concept of the applicability of pharmacogenetics in the future management of asthma.