It is used for the treatment and prophylaxis of thromboembolic disorders, venous thromboembolism (deep-vein thrombosis and pulmonary embolism), especially prophylaxis in surgical patients and in those pregnant women at particular risk. It is also used in the management of arterial thromboembolism including that associated with unstable angina pectoris, myocardial infarction, acute peripheral arterial occlusion and stroke. It is often used as a precursor to oral anticoagulation and is withdrawn once the oral anticoagulant is exerting its full effect. It has been tried in the treatment of disseminated intravascular coagulation. It is also used to prevent coagulation during haemodialysis and other extracorporeal circulatory procedures such as cardiopulmonary bypass.