The FDA announced Dec. 7 that it is evaluating post-marketing reports of serious bleeding events in patients taking dabigatran (Pradaxa, Boehringer Ingelheim). However, the agency did not indicate in its drug safety communication how many patients have reported bleeding events, but did state that "serious, even fatal events have been reported."

"Bleeding that may lead to serious or even fatal outcomes is a well-recognized complication of all anticoagulant therapies," according to the agency. Dabigatran's label contains a warning about significant and sometimes fatal bleeds. In a large clinical trial (18,000 patients) comparing dabigatran with warfarin, major bleeding events occurred at similar rates with the two drugs.

The FDA said it is working to determine whether the reports of bleeding in patients taking Pradaxa are "occurring more commonly than would be expected, based on observations in the large clinical trial that supported the approval of Pradaxa." The agency added that it is working closely with  Boehringer Ingelheim to evaluate the post-market reports of bleeding, and is using its Mini-Sentinel active surveillance system to compare new users of Pradaxa and warfarin with respect to the likelihood of being hospitalized for bleeding.

Pradaxa is an anticoagulant medication used to reduce the risk of stroke in patients with nonvalvular atrial fibrillation (AF).

At this time, the FDA said it "continues to believe that Pradaxa provides an important health benefit when used as directed and recommends that healthcare professionals who prescribe Pradaxa follow the recommendations in the approved drug label."

Patients with AF should not stop taking Pradaxa without talking to their healthcare professional, the agency recommended. Stopping use of blood thinning medications can increase the risk of stroke. Strokes can lead to permanent disability and death.

The FDA said it will communicate any new information on the risk of bleeding and Pradaxa when it becomes available.