Anticoagulation

A new test was recently released to predict excessive bleeding risks among patients who take warfarin, which is the most frequently prescribed oral anticoagulant used for the prevention and treatment of thromboembolic events. Warfarin is a difficult drug to manage due to its narrow therapeutic range and inconsistent patient response resulting from inter-individual variability.

Genetic information available from the new Warfarin Sensitivity DNA Test, created by Kimball Genetics, will help predict response. The test determines the presence of specific variations in the CYP2C9 andVKORC1 genes that confer sensitivity to warfarin and thus significantly reduce the required maintenance dose. CYP2C9 is involved in warfarin metabolism and VKORC1 influences warfarin's anticoagulation effect through vitamin K. Kimball Genetics expects to offer the Warfarin Sensitivity DNA Test for routine clinical use early in 2007.

The FDA Clinical Pharmacology Subcommittee of the Advisory Committee for Pharmaceutical Sciences has recommended testing for variations in the CYP2C9 and VKORC1 in patients requiring warfarin therapy. The drug label will reflect this recommendation soon. The Warfarin Sensitivity DNA Test that Kimball offers informs the prescriber about the presence of genetic risk factors for over-anticoagulation and should help achieve the correct maintenance dose faster. It is also likely to increase the safety and efficacy of warfarin treatment.