Warning: Pradaxa Linked to Increased Risk of Heart Attack

Boehringer Ingelheim’s Pradaxa is a new blood clot preventer, which is an alternative to half a century old warfarin.  Pradaxa, chemically known as dabigatran, has been approved in the United States in October 2010 for stroke prevention in patients with atrial fibrillation (irregular heart beat).  People with atrial fibrillation are at a higher risk for stroke and are often prescribed medication to prevent clotting.

Researchers from the Cleveland Clinic in Ohio conducted seven trials involving Pradaxa, which included more than 39,500 patients. This process, called meta-analysis, compared Pradaxa to either, warfarin, enoxaparin, another widely used blood thinner sold under the brand name Lovenox, or a placebo.  The researchers found Pradaxa was associated with an increased risk of heart attack or acute coronary syndrome (heart attack or angina), compared with two other commonly used blood thinners, warfarin (Coumadin, Jantoven) and enoxaparin (Lovenox). Pradaxa is often prescribed as an alternative to warfarin, a drug that has been prescribed for a long time, but raises the risk of bleeding and is difficult to properly dose.

Pradaxa is also used to prevent blood clots following hip and knee replacement surgery.

Among those taking Pradaxa, 1.19% had a heart attack or suffered from acute coronary syndrome compared with 0.79% of those taking either of the other drugs.

In the report published on January 9, 2012 in the Archives of Internal Medicine, it was said that the drug’s benefit for patients with atrial fibrillation outweighs the risk.  “The increase of heart attack risk associated with dabigatran (Pradaxa) is small, and the benefit in prevention of stroke among persons with atrial fibrillation is greater,” said Dr. Ken Uchino, director of the Vascular Neurology Fellowship Training Program at Cleveland Clinic.

Another expert said that the risk of heart attack does not outweigh the benefits of the drug, especially taking into account the risk of serious bleeding from warfarin.

Dr. William O’Neill, professor of cardiology and executive dean for clinical affairs at the University of Miami School of Medicine said he was “unimpressed by the data” and that “warfarin is a pretty lousy drug.”  He estimated about one in ten patients cannot tolerate Pradaxa because of severe gastrointestinal side effects, “you don’t have to monitor it the way you have to with warfarin. It’s a big improvement over warfarin.”

Of 20,000 patients taking Pradaxa, 237 had a heart attack or chest pain, compared with 83 patients out of 10,514 on the standard drug warfarin or a placebo, Unchino wrote.

Boehringer, based in Ingelheim, Germany, beat New Brunswick, N.J. based Johnson & Johnson and Bayer to the atrial fibrillation market. The drugs are vying to become the dominant replacement for warfarin. Pfizer and New York-based Bristol-Myers Squibb Co. are seeking approval for their rival pill, known as Eliquis.

Related Posts