ELIQUIS (Apixaban) is a medication that may be prescribed for one of the following reasons: Treat deep vein thrombosis (DVT) or pulmonary embolism (PE) and to reduce the risk of it happening again, Provide prophylaxis for DVT and PE in certain high-risk patients, like those undergoing knee or hip replacement surgery, Reduce the risk of stroke in patients with nonvalvular atrial fibrillation If a clot forms in the veins, it can break off and lead to harmful and sometimes deadly events like a cardiovascular accident (stroke), myocardial infarction (heart attack), or PE (clot in the lungs). Certain people are at high risk of clot formation, including those who have had a clot before and those with atrial fibrillation. Atrial fibrillation is an irregular heart rhythm where one of the chambers of the heart "quivers" instead of efficiently pumping blood. This causes blood to stay in one spot and increases the risk of a clot. ELIQUIS works by targeting a protein in the clotting cascade, called factor Xa (Ten A). Shutting off this protein slows down clot formation, preventing their formation.