Approved by the FDA in October 2010, Pradaxa (Dabigatran) is marketed by Boehringer Ingelheim Pharmaceuticals, Inc., to reduce the risk of strokes and blood clots in people who have atrial fibrillation, a common heart rhythm abnormality. Pradaxa is in a class of anticoagulant medications known as "blood thinners."
Pradaxa is a direct thrombin inhibitor. It prevents the formation of blood clots by counteracting the effects of thrombin, which is responsible for clotting. Boehringer Ingelheim Pharmaceuticals markets Pradaxa as the preferred blood thinner. It became the first alternative to warfarin for this indication.
According to Boehringer, it is easier to dose, requires less monitoring, and is more effective at preventing clots compared to warfarin (Coumadin). However, unlike warfarin, Pradaxa's anticoagulation effect cannot be reversed with vitamin K, significantly increasing the odds that a bleeding event will turn fatal.
To date, there have been significant numbers of fatal bleeds reported to the FDA. The lack of a reversal agent is believed to be the cause of the significant number of bleeding-related adverse events.
Within the first 14 months of its approval, Pradaxa was linked to more than 900 gastrointestinal bleeds and 500 bleeding deaths. Boehringer, in an official statement on November 2, 2011, linked about 50 bleeding deaths to Pradaxa, which Boehringer asserted is consistent with expectations from the Pradaxa clinical trials.
Earlier this year, the FDA required Boehringer to modify the Pradaxa warning label to reflect the lack of a reversal agent, which had not been included in the original warnings. The FDA is currently evaluating the reports of bleeding deaths and investigating whether the rate of severe bleeding reports is higher than what was seen in Pradaxa clinical trials. At this point, there is no black box warning for Pradaxa.
However, in February 2013, the FDA approved new language on Pradaxa's safety label to include new warnings, precautions and contraindications informing patients not to take the drug if they have ever had or plan to have a valve in their hearts replaced. The updated safety label and medication guide comes after an interim analysis of results from a study showed increased incidents of thromboembolic events (blood clots) and bleeding events in patients with mechanical prosthetic heart valve replacements who used the new anticoagulant.