Summary

Warfarin is a widely used medication with a very narrow therapeutic window. Limited evidence suggests that utilizing pharmacogenetic information on top of clinical information could improve warfarin dosing, but large, well-conducted studies are lacking. This article discusses the key results of the Clarification of Optimal Anticoagulation Through Genetics trial [COAG; Kimmel SE et al. N Engl J Med 2013], which compared warfarin initiation using a clinical algorithm with or without the addition of pharmacogenetic information.