Blood-Thinner Pradaxa: What You Should Know
July 25, 2014 -- When the blood-thinner drug Pradaxa (dabigatran) was FDA-approved in 2010 to prevent stroke in people at high risk, a major selling point was that it doesn't require frequent blood tests like the old standby drug, warfarin.
Now, an investigation in the BMJ has raised concerns again about this newer-generation blood thinner, or anticoagulant. Doctors might prevent serious bleeding, a potential side effect of all anticoagulants, by checking the blood levels of people on Pradaxa, these experts say.
In the report, published Wednesday, experts argue that the guidelines for using Pradaxa could be flawed. Those who approved it did not see drug company information showing that testing blood levels of the drug could reduce major bleeding problems greatly, the experts say.
In response, Boehringer Ingelheim, the drug maker, issued a statement, reassuring those who take the drug that it is safe and effective as it is now used.
WebMD turned to experts, the FDA, and Boehringer Ingelheim to explain further.
How does Pradaxa compare to warfarin, the drug used for years to lower stroke risk?
Both drugs are prescribed for people with atrial fibrillation, an abnormal heart rhythm that raises the risk of stroke. More than 3 million Americans have the condition, the FDA says.
Blood thinners work to prevent strokes by keeping the blood thin enough to prevent clots. If the blood becomes too thin, the risk is serious bleeding.
Warfarin (Coumadin, Jantoven), the standard treatment, requires frequent blood testing to be sure the levels are correct. Pradaxa was approved without the need for frequent blood tests.
According to the FDA, Pradaxa -- as well as two others new oral blood-thinners, Xarelto (rivaroxaban) and Eliquis (apixaban) -- were found either equal to or better than warfarin at preventing strokes. The drugs were approved based on clinical trials including more than 50,000 patients, the FDA says.
More than 850,000 patients have been prescribed Pradaxa since its approval, according to Boehringer Ingelheim.
A typical dose of Pradaxa costs about $300 a month, compared to $4 a month for a typical dose of generic warfarin.
What are the major concerns raised in this investigation about Pradaxa?
Safety is the major one, says Thomas J. Moore, senior scientist at the Institute for Safe Medication Practices. He wrote an analysis to accompany the investigation.
Any anticoagulant treatment carries risks, he says. "Anticoagulant treatment for people with atrial fibrillation ranks as one of the highest-risk treatments in older Americans," he says. More than 15% of older patients treated for atrial fibrillation with blood thinners for 1 year have bleeding, he says.
Concerns about Pradaxa surfaced 2 years ago, he says, when doctors began reporting a larger number of serious and sometimes fatal bleeding problems in older patients on the drug.