Xarelto okayed by FDA for treating atrial fibrillation

(CBS/AP) The FDA has approved a "next generation" blood thinner called Xarelto for the treatment of atrial fibrillation, a common heart disorder that can lead to stroke.

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Atrial fibrillation, a.k.a. afib, is an irregular heartbeat that results when the upper chambers of the heart beat chaotically and ineffectively. Afib can cause blood clots that can trigger a stroke by traveling via the bloodstream to the brain.

"This approval gives doctors and patients another treatment option for a condition that must be managed carefully," said Dr. Norman Stockbridge, director of FDA's cardiovascular and renal products division.

The once-a-day pill - from Johnson & Johnson and Bayer - was first approved in July to prevent strokes in patients receiving hip and knee replacements.

For more than half a century, afib patients have relied on the blood thinner warfarin (Coumadin), which is tough to use. Doctors often have trouble gauging the right dose. Too much warfarin can trigger dangerous internal bleeding, and too little can result in stroke.

Xarelto's makers had asked the FDA to approve a claim that Xarelto (rivaroxaban) is superior to warfarin at preventing stroke and blood clots. But the agency declined, instead saying that the companies' 14,000-patient study showed Xarelto and warfarin to be similarly effective at preventing strokes.

Xarelto will carry a boxed safety warning, the most serious kind, stating that patients should not stop taking the drug without first notifying their doctors. Discontinuing the drug can up the risk of stroke.

Xarelto is the first in a new class of blood thinners that work by blocking a clotting protein called factor Xa. Older drugs, including warfarin, work by keeping blood platelets from sticking together.

The National Heart Lung and Blood Institute has more on atrial fibrillation.