A new anti-clotting drug has been approved by the U.S. Food and Drug Administration. Called apixaban and marketed by Bristol-Myers Squibb and Pfizer as Eliquis, the drug has been approved to reduce the risk of stroke and blood clots for patients with an irregular heart beat that is not caused by a heart valve problem.

“Blood clots in the heart can cause a disabling stroke if the clots travel to the brain,” said Dr. Norman Stockbridge, director of the Division of Cardiovascular and Renal Products in the FDA’s Center for Drug Evaluation and Research. “Anti-clotting drugs lower the risk of having a stroke by helping to prevent blood clots from forming.”

Eliquis was approved following a safety and efficacy clinical trial that compared the drug to another anti-clotting drug called warfarin. The trial, which looked at over 18,000 patients, found that patients on Eliquis had fewer strokes than those on warfarin.

The medication is not, however, for those who have heart valve problems. Likewise, patients with prosthetic heart valves are not recommended to take the new drug, as they were not part of the clinical trial. As with most anti-clotting drugs, bleeding uncontrollably is the biggest risk for those on Eliquis, as the FDA states there is no agent that can reverse the drug’s anti-coagulant effects.

“With a population that is living longer, the prevalence of nonvalvular atrial fibrillation is increasing, but many patients are still not being managed effectively with warfarin,” said Dr. Christopher Granger, lead investigator on the Eliquis trial and a professor of medicine at the Duke Clinical Research Institute. “Eliquis represents a significant advance over warfarin for health care professionals to reduce the risk of stroke in patients with nonvalvular atrial fibrillation.”