Health care experts in the United States and abroad are reconsidering the safety and efficacy of the blood thinner Pradaxa. The U.S. Food and Drug Administration recently issued a warning that Pradaxa, or dabigatran etexilate mesylate, was not safe to use in patients with mechanical heart valves. Officials in Australia have also re-evaluated whether the potentially defective pharmaceutical will be paid for by that country's state-backed insurers.
"Pradaxa should not be used to prevent stroke or blood clots in patients with mechanical heart valves, also known as mechanical prosthetic heart valves," the FDA said in its warning letter to cardiology patients. "A clinical trial in Europe (the RE-ALIGN trial) 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. There was also more bleeding after valve surgery in the Pradaxa users than in the warfarin users."
Pradaxa was supposed to replace warfarin, which is a tablet blood thinner that is supposed to prevent blood clots from forming and expanding in a patient's blood and blood vessels. Side effects of warfarin include tiredness, hair loss, fever, chest pain, loss of appetite and flu-like symptoms. Side effects of Pradaxa can include nosebleeds, rash, dizziness, heartburn, stomach pain and swelling.
The FDA recommended that doctors promptly transition patients with mechanical heart valves away from Pradaxa to other medications. The FDA has not evaluated the safety of Pradaxa in patients with bioprosthetic valves, which are heart valve replacements made of biological tissue.
Source: PharmaTimes, "Australia: warning over Pradaxa PBS listing," Lynne Taylor, Dec. 20, 2012