October 09, 2006

October 9, 2006 — At the request of the Food and Drug Administration (FDA), Bristol-Myers Squibb has strengthened its US label for warfarin ( Coumadin) to include a black-box warning about the risk for major or fatal bleeding. The previous label also warned about bleeding risk, but this was not highlighted in a black box.

The new black box notes that warfarin can cause major or fatal bleeding. It says that bleeding is more likely to occur during the starting period and with a higher dose (resulting in a higher INR). Risk factors for bleeding are listed as: high intensity of anticoagulation (INR greater than 4.0), age 65 or over, highly variable INRs, history of gastrointestinal bleeding, hypertension, cerebrovascular disease, serious heart disease, anemia, malignancy, trauma, renal insufficiency, concomitant drugs, and long duration of warfarin therapy.

The black box also contains the recommendations that regular monitoring of INR should be performed on all treated patients; those at high risk for bleeding may benefit from more frequent INR monitoring, careful dose adjustment to desired INR, and a shorter duration of therapy; and patients should be instructed about prevention measures to minimize risk of bleeding and to report immediately to physicians signs and symptoms of bleeding.

The FDA Medwatch announcement also notes that warfarin prescriptions will also be issued with a new patient medication guide warning about potentially serious bleeding with the drug. FDA regulations state that such medication guides are to be provided with each prescription that is dispensed for products that the FDA determines pose a serious and significant public health concern.


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