FDA OKs warfarin sensitivity lab test

WASHINGTON, Sept. 18 (UPI) -- The U.S. Food and Drug Administration has approved a genetic test that determines a patient's sensitivity to the "blood-thinning" drug warfarin.

Warfarin (Coumadin) is used to prevent potentially fatal clots in blood vessels but one-third of patients receiving the drug metabolize it quite differently than expected and experience a higher risk of bleeding.

Research has shown some of the unexpected response to warfarin depends on variants of two genes, CYP2C9 and VKORC1. The newly approved procedure -- the Nanosphere Verigene Warfarin Metabolism Nucleic Acid Test -- detects some variants of both genes.

"Today’s action offers physicians the first FDA-cleared genetic test for warfarin sensitivity, which is another step in our commitment to personalized medicine," said Dr. Daniel Schultz, director of the FDA’s Center for Devices and Radiological Health. "With this test, physicians may be able to use genetic information along with other clinical information to treat their patients."

Warfarin is the second most common drug, after insulin, implicated in emergency room visits for adverse drug events.

The new test was cleared for use on the Verigene System, a clinical laboratory test system. Both products are manufactured by Nanosphere Inc. of Northbrook, Ill.