A newly-published analysis of Pradaxa clinical trials has found that patients taking the blood thinner have a higher risk for heart attacks and chest pain. Accord to a report in The Wall Street Journal, the findings of the new study may prompt some doctors to continue treating patients with warfarin, a decades-old blood thinner, rather than Pradaxa and other new generation medications.
Pradaxa, approved by the U.S. Food & Drug Administration (FDA) in October 2010, is used to prevent strokes in people with atrial fibrillation. It was expected to be adopted as a replacement for warfarin, which can have dangerous interactions with certain foods. However, in recent months, concerns have been mounting about potentially dangerous Pradaxa side effects. Last month, for example, the FDA said it was conducting a safety review of Pradaxa aimed at determining if serious bleeding is occurring in Pradaxa patients more commonly than would be expected. In its Drug Safety Communication, the agency said was evaluating post-marketing reports of serious bleeding events in patients taking the blood thinner, but did not indicate how many such reports it had received.
A month prior, Boehringer Ingelheim, the maker of Pradaxa, revealed it had received 260 reports of fatal bleeding among Pradaxa patients worldwide, including 21 in Europe. The events occurred between March 2008 and October 31, 2011.
The large study used to gain approval of Pradaxa did hint at a small increased risk of heart attack among people taking the medication, according to The Wall Street Journal. Since then, researchers have been trying to determine if Pradaxa does pose an increased risk.
This newest Pradaxa study, published in The Archives of Internal Medicine, consisted of an analysis of seven earlier clinical trials for the drug involving more than 30,000 people taking either Pradaxa, warfarin, enoxaparin or a placebo. Of 20,000 patients taking Pradaxa, 237 had a heart attack or chest pain, compared with 83 patients out of 10,514 on one of the other drugs, or a placebo.
The study found that Pradaxa boosted the risk of a heart attack and a condition known as acute coronary syndrome by 33%. The added risk for any one individual of having a heart attack if on Pradaxa – known as the absolute increased risk – was 0.27 percent.
While the authors of the study stated that Pradaxa’s benefit still outweighed its risks, they also advised that “clinicians should consider the potential of these serious harmful cardiovascular effects.”
“For persons with atrial fibrillation, dabigatran has a favorable benefit-risk profile, but for other uses the risk of heart attack has to be taken into account,” said lead researcher Dr. Ken Uchino, director of the Vascular Neurology Fellowship Training Program at the Cleveland Clinic.