Blood-Thinner Pradaxa: What You Should Know
Editor's note: This story was updated Nov. 5, 2014, with information on two new studies regarding Pradaxa.
July 25, 2014 -- Two recent studies that compare the newer blood-thinner drug Pradaxa (dabigatran) with the old standby drug, warfarin, have found that people on higher doses of Pradaxa have a greater risk of gastrointestinal bleeding.
The recent research follows an investigation in the BMJ published in July that suggested more frequent blood testing with Pradaxa might help prevent major bleeding problems. When Pradaxa was approved by the FDA in 2010 to prevent stroke in people at high risk, a major selling point was that it didn't require frequent blood tests as warfarin (Coumadin, Jantoven) does.
WebMD turned to experts and Pradaxa's maker, Boehringer Ingelheim, to explain further.
What did the two new studies find?
In one study, published Oct. 30 in Circulation, researchers looked at more than 134,000 patients, all on Medicare, who took either Pradaxa or warfarin for their atrial fibrillation, a heart rhythm problem that increases stroke risk.
They found that Pradaxa was linked with a lower risk of ischemic stroke (in which an artery to the brain is blocked), hemorrhage within the brain, and death, compared with warfarin. But it had an increased risk of major stomach bleeding or brain hemorrhage. The higher risk was more pronounced in those treated with the 150-milligram doses of Pradaxa twice daily. The 75-mg dose twice daily was comparable to warfarin in terms of pros and cons, except Pradaxa had a lower risk of hemorrhage within the brain than warfarin.
In another study, published online Nov. 3 in JAMA Internal Medicine, researchers compared the use of Pradaxa in more than 1,300 Medicare patients and warfarin in more than 8,000 Medicare patients to determine the risk of bleeding as a side effect.
While 9% of the Pradaxa group had major bleeding, 5.9% of the warfarin group did. The risk of hemorrhage within the brain was higher among warfarin users. Those on Pradaxa had an increased risk of major bleeding and GI bleeding. That risk was especially high for those with chronic kidney disease and for African-Americans.