New Blood Thinner Prevents Strokes in Heart Patients
Study Shows Xarelto Works as Well as Warfarin in Preventing Strokes for Patients With Atrial Fibrillation
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Significant bleeding, an expected risk of drugs that keep blood from clotting, occurred in 1,475 patients taking Xarelto and 1,449 patients taking warfarin.
Anemia, blood transfusions, and bleeding in the stomach and gut were more common in people taking Xarelto than those taking warfarin.
But people on Xarelto were less likely to experience bleeding in their brains or fatal bleeding than those on warfarin.
Experts say Xarelto may be less likely to cause bleeding in the brain than warfarin because it's a more targeted drug.
In the body, a chain of chemical reactions leads to blood clotting. Warfarin interferes with four steps in that chain, while Xarelto only blocks one part of the reaction, an enzyme called factor Xa.
Weighing Benefits and Risks
Gregory J. del Zoppo,MD, a hematologist and professor of medicine at the University of Washington School of Medicine, says the main benefit of this drug and several similar agents, including the drug Pradaxa, which was approved by the FDA last year to treat atrial fibrillation, is likely to be convenience.
"To have something that's easier to manage and takes less involvement is probably useful," he says, particularly for older patients who may have trouble keeping up with their medication.
But he says there are several potential downsides of the newer drugs that patients need to understand.
One is cost. The newer drugs cost between $6 and $9 a day to take compared to warfarin, which is available generically for $4 a month through several large U.S. retailers.
And he says while doctors know how to quickly reverse the effects of warfarin in the case of dangerous bleeding, it's less clear how to manage uncontrolled bleeding with the newer agents.
"The one worry I have with these agents is that so far we don't have a way of reversing their effect if we need to," del Zoppo says. "What happens when something goes wrong? And indeed, I think the companies are thinking about this."