Heparin sodium injection is indicated for anticoagulant therapy in prophylaxis and treatment of venous thrombosis and its extension, in low-dose regimen for prevention of postoperative deep venous thrombosis and pulmonary embolism in patients undergoing major abdominothoracic surgery who are at risk of developing thromboembolic disease (see DOSAGE AND ADMINISTRATION ), for prophylaxis and treatment of pulmonary embolism, in atrial fibrillation with embolization, for diagnosis and treatment of acute and chronic consumptive coagulopathies (disseminated intravascular coagulation), for prevention of clotting in arterial and cardiac surgery, and for prophylaxis and treatment of peripheral arterial embolism.

　　Heparin may also be employed as an anticoagulant in blood transfusions, extracorporeal circulation, dialysis procedures, and in blood samples for laboratory purposes.