Rivaroxaban is used to treat deep vein thrombosis (DVT; a blood clot, usually in the leg) and pulmonary embolism (PE; a blood clot in the lung) in adults. Rivaroxaban is also used to prevent DVT and PE from happening again after initial treatment is completed in adults. It is also used to help prevent strokes or serious blood clots in adults who have atrial fibrillation (a condition in which the heart beats irregularly, increasing the chance of clots forming in the body, and possibly causing strokes) that is not caused by heart valve disease. Rivaroxaban is also used to prevent DVT and PE in adults who are having hip replacement or knee replacement surgery or in people who are hospitalized for serious illnesses and are at risk of developing a clot due to decreased ability to move around or other risk factors. It is also used along with aspirin to lower the risk of a heart attack, stroke, or death in adults with coronary artery disease (narrowing of the blood vessels that supply blood to the heart) or peripheral arterial disease (poor circulation in the blood vessels that supply blood to the arms and legs). Rivaroxaban is also used to treat and prevent DVT and PE from happening again in children and certain infants who have received at least 5 days of initial anticoagulation (blood thinner) treatment. It is also used to prevent DVT and PE after heart surgery in children 2 years of age or older who have congenital heart disease (abnormality in the heart that develops before birth). Rivaroxaban is in a class of medications called factor Xa inhibitors. It works by blocking the action of a certain natural substance that helps blood clots to form.