Apixaban is an oral anticoagulant (blood thinner) that selectively inhibits clotting factor Xa, slowing the coagulation cascade and reducing the formation of fibrin clots in blood vessels. It is commonly used to prevent stroke and systemic embolism in people with nonvalvular atrial fibrillation, and to treat or prevent deep vein thrombosis and pulmonary embolism, including around hip or knee replacement surgery. Marketed under the brand name Eliquis, it is available only on prescription and is classified among the newer direct factor Xa inhibitors.