The Food and Drug Administration on Thursday approved a new blood thinner to reduce the risk of stroke and blood clots in patients with atrial fibrillation, a common type of irregular heartbeat that affects more than 2.7 million Americans.

The agency also approved Savaysa (edoxaban tablets), developed by Tokyo-based Daiichi Sankyo Co., for patients with deep vein thrombosis and pulmonary embolism who have already been taking an anti-clotting drug.

Deep vein thrombosis is a blood clot that forms in a vein deep in the body, usually in the lower leg or thigh. Pulmonary embolism most often occurs when a blood clot travels to an artery in the lungs and blocks blood flow.

Savaysa joins several other new blood-thinning oral drugs already on the market: Boehringer Ingelheim’s Pradaxa (dabigatran), Merck Sharp & Dohme Corp.’s Zontivity (vorapaxar), Janssen Pharmaceuticals’ Xarelto (rivaroxaban) and Pfizer and Bristol-Myers Squibb’s Eliquis (apixaban).

The new medicines provide an alternative to warfarin, a generic drug that has long been the blood-thinning drug of choice for atrial fibrillation patients. But the proper dosing is often hard to manage in some people and taking warfarin requires frequent blood testing.

The most common side effects of Savaysa include bleeding and anemia.