The blood-thinning drug Pradaxa has starred in a long-running drama with hundreds of adverse event reports, scores of lawsuits and more than 500 deaths. Introduced in 2010 as an option to Coumadin (warfarin), Pradaxa is under fire for dire side effects including hemorrhage and internal bleeding, as we wrote earlier this year. Unlike older anti-clotting drugs, Pradaxa has no antidote for uncontrolled bleeding.
The latest chapter in this tale was told earlier this month by the New York Times, when the FDA released a report concluding that Pradaxa did not show a higher risk of bleeding than warfarin. As The Times noted, the report did not mention the lack of an antidote.
Medical professionals and patients alike have complained about Pradaxa, expressing concern that the approval process was insufficient, and that such a potentially dangerous drug should not be on the market without a way to reverse its unwanted effects. Pradaxa has made $1 billion for its manufacturer, Boehringer Ingelheim, but critics say it’s exemplary, as The Times puts it, “of what can happen when a drug that performs well in tightly controlled trials is released into the messy world of real-life medicine.”
The FDA report says that bleeding rates associated with Pradaxa don’t appear to be higher than those associated with warfarin. At the American Heart Association Scientific Session a week after the FDA report, Boehringer Ingelheim presented findings that, according to its news release, an antidote in development shows promise, and clinical trials are being initiated.
We have to ask: Didn’t they put the cart so far in front that you can’t even see the horse?
When reports began to surface of bleeding problems, Boehringer Ingelheim recommended dialysis to flush the drug out. Dialysis involves bypassing the kidneys to purify the blood through a machine. But the company, according to The Times, acknowledges that “the amount of data supporting this approach is limited.”
The boneheaded dialysis advice was described perfectly by one doctor in The Times’ story: “People that are bleeding to death aren’t going to tolerate being put on dialysis.”
The problem is compounded, according to The Times, if doctors prescribe the drug to the wrong patients. Older people and people with kidney problems are not good candidates for Pradaxa—their bleeding risks are higher than for other people. Boehringer Ingelheim advises testing a patient’s kidney function before prescribing Pradaxa, and notes that the risk of bleeding increases with age.
“The problem is that the people that prescribe this, as a general rule, are cardiologists and family practitioners,” Dr. Mark L. Mosley, director of the emergency room at Wesley Medical Center in Wichita, Kan., told The Times. “The people that see the harm are your E.R. docs and your trauma docs.”
When Pradaxa was approved, its lower maintenance seemed superior to the nearly 60-year-old warfarin (Coumadin) for preventing prevent strokes in people with atrial fibrillation (a heart-rhythm disorder commonly called A-fib). Warfarin patients must be carefully monitored for diet and drugs, and must have frequent blood tests. Not so for Pradaxa patients.
In little more than a year, The Times reports, 17 in 100 a-fib patients got Pradaxa; 44 in 100 got warfarin. The FDA estimates that in the U.S., about 725,000 patients have taken Pradaxa.
But in 2011, according to The Times, Pradaxa “was linked to more reports of injury or death than any of the more than 800 drugs regularly monitored by the Institute for Safe Medication Practices.”
Other new drugs intended as an option to warfarin (Xarelto, which has been approved to treat blot clots, and Eliquis, for which FDA approval is pending) also lack antidotes, but they haven’t shown the same bleeding-death risk as Pradaxa.
All medicine carries a risk of side effects; some can be life-threatening. Sometimes, the risk is worth it, which is the position adopted by medical professionals who believe in Pradaxa. The Times referred to a recent study showing that about 4 in 10 people with atrial fibrillation don’t take any drugs, leaving them at risk for strokes. Many cardiologists say the risk of stroke is more dangerous than the risk of bleeding complications.
Maybe. But if you’re an A-fib patient whose doctor recommends Pradaxa, find out why he or she prefers it to warfarin, which also can cause a host of side effects, some of them serious. If you’re older or have a history of kidney problems, beware, and seek a second opinion.