Summary

More than 2 million patients in the United States take warfarin as anticoagulant therapy. The dose of warfarin may vary depending on patient genotypes, which has resulted in changes in the prescribing guidelines for this agent. The effect of pharmacogenetic (PG)-guided dosing, however, has not been established in controlled studies. The Couma-Gen study was a prospective, randomized, double-blind trial of a PG-guided algorithm for warfarin dosing compared with standard dosing in patients starting oral anticoagulation therapy [Anderson JL, Horne BD, Stevens SM et al. Circulation 2007].