Pharmacogenetics in rheumatology: the prospects and limitations of an emerging field.

OBJECTIVES To review the fundamental concepts of pharmacogenetics and analyse how the broad principles of this rapidly emerging field may influence the treatment of rheumatic disease in future. METHODS The names of common rheumatic drugs and the terms 'pharmacogenetics', 'pharmacogenomics' and 'genetic polymorphism' were used as keywords to search the Medline and Current Contents databases. General review articles on pharmacogenetics were also examined. RESULTS Pharmacogenetics is the study of how genetic differences influence the variability in drug toxicity and efficacy. Although the principles of pharmacogenetics have been known for several decades, recent technological advances have hastened the possibility of direct clinical applications. Most studies so far have been phenotypic analyses, but genotyping is now readily available for many polymorphisms. There are several examples pertinent to rheumatology that illustrate the important principles and foretell the usefulness of pharmacogenetics in individualizing therapy. However, further studies are needed. CONCLUSIONS Because traditional pharmacotherapy in rheumatology has been empirical and because of the slow acting nature of many anti-rheumatic medications, the risk of significant side-effects and the increasing armamentarium of drugs available, pharmacogenetics is particularly relevant to rheumatology. There are many scientific and non-scientific concerns that should be addressed in future studies.