New Educational Effort Launched On Genetic Testing For Dosing A Common Blood Thinner

Main Category: Blood / Hematology
Also Included In: Cardiovascular / Cardiology;  Stroke / Neuroprotection
Article Date: 13 Mar 2008 - 3:00 PDT

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A new educational effort focused on improving the safety and reducing the complications of a life-saving heart drug was launched by the American Medical Association (AMA) and the Critical Path Institute (C-Path), as part of an ongoing program to support personalized medicine. The groups collaborated on a new educational brochure to inform health care practitioners about how patients' genetics influence their response to warfarin, and the genetic tests available to determine the best initial dose of the drug. Warfarin is commonly prescribed to patients to prevent blood clots, heart attacks and strokes and is also known under the brand names of Coumadin, Jantoven, Marevan and Waran.

The FDA estimates that two million patients in the U.S. start taking warfarin every year and it has been prescribed to patients for more than 50 years. Warfarin can provide enormous benefits, but the safe and effective dose varies greatly among patients. It is the second most common drug, after insulin, implicated in emergency room visits for adverse drug events, especially bleeding complications.

"Warfarin's effectiveness is widely known within the medical community, but it is underutilized because of concerns about the risk of bleeding complications," said AMA Board Member and cardiovascular disease specialist James Rohack, MD.

In August, the FDA changed the official labeling of warfarin to inform practitioners that genetic testing may help providers improve the initial dosing for individual patients.

"Studies show that genetic factors explain why 40 percent of patients taking warfarin are more sensitive to the drug and require a smaller dose," said Dr. Rohack. "Genetic testing can identify patients at high risk for bleeding complications when warfarin is started, and allow the physician to use smaller doses to reduce the initial bleeding risk."

"The brochure outlines the science behind genetic testing for warfarin dosing so physicians can incorporate this form of personalized health care into their practices," said Raymond Woosley, MD, PhD, President and CEO, C-Path. "The FDA is to be commended for its work to update the label and help inform the medical community of this modern scientific advancement that can improve a commonly prescribed medicine."

American Medical Association