The FDA is informing healthcare professionals and the public that the anticoagulant dabigatran (Pradaxa, Boehringer Ingelheim Pharmaceuticals) should not be used to prevent stroke or major thromboembolic events in patients with mechanical heart valves, or mechanical prosthetic heart valves.
The European RE-ALIGN trial (Am Heart J 2012;163:931-937.e1) was recently stopped because Pradaxa users were more likely to experience strokes, heart attacks, and blood clots forming on the mechanical heart valves than were users of the anticoagulant warfarin, according to the agency. There was also more bleeding after valve surgery in Pradaxa users than in warfarin users. On Dec. 12, Boehringer announced that it was pulling the plug on its Phase 2 heart valve trail with dabigatran.
Dabigatran, a blood-thinning drug used to reduce the risk of stroke and blood clots in patients with nonvalvular atrial fibrillation (AF), is not approved in the U.S. for patients with AF caused by heart valve problems. With this notification, the FDA is requiring a contraindication of dabigatran in patients with mechanical heart valves.
Healthcare professionals should promptly transition any patient with a mechanical heart valve who is taking dabigatran to another medication, according to the FDA MedWatch notification. The use of dabigatran in patients with a bioprosthetic valve replacement has not been evaluated and cannot be recommended. The agency recommended that patients with all types of prosthetic heart valve replacements taking dabigatran should talk to their healthcare professional as soon as possible to determine the most appropriate anticoagulation treatment; however, patients should not stop taking anticoagulant medications without guidance from their healthcare professional, as stopping dabigatran or other anticoagulants suddenly can increase the risk of blood clots and stroke.
Additional information can be found on the FDA's drug safety and communication website.