(CNN) - The anti-clotting drug Warfarin is no longer recommended for treating atrial fibrillation (AFib), except for a select group of patients.
That's according to guidelines released Monday by the American College of Cardiology and the American Heart Association.
Instead of Warfarin, commonly known by the brand name Coumadin, doctors and patients are encouraged to use drugs called "novel oral anticoagulants," or NOACs.
Examples of NOACs include rivaroxaban (brand name Xarelto), apixaban (Eliquis) and dabigatran (Pradaxa).
NOACs have been developed and approved during the past decade by the U.S. Food and Drug Administration.
There are 3-6 million Americans who have some form of AFib.
People with AFib describe the sensation as a flutter in their chest, as if the heart is quivering instead of beating.
According to the National Library of Medicine, Warfarin “works by decreasing the clotting ability of the blood” and helps thin blood.
It can, however, increase risk for serious bleeding, and requires close monitoring for patients taking it.