Dalteparin (Fragmin - Pharmacia), the second low-molecular-weight heparin to be marketed in the USA, is now available for prevention of deep vein thrombosis in high-risk patients after abdominal surgery. Enoxaparin (Lovenox -Rh ne-Poulenc Rorer) was approved in 1993 for prevention of deep vein thrombosis after hip replacement (Medical Letter, 35:75, 1993) and later approved for use in knee replacement. Five other low-molecular-weight heparins and one heparinoid are under investigation in the USA (MJ Cziraky and SA Spinler, Clin Pharm, 12:892, 1993).

View the Comparison Table: Some Parenteral Anticoagulants for VTE

Ardeparin sodium (Normiflo - Wyeth-Ayerst), a low-molecular-weight heparin, and danaparoid sodium (Orgaran - Organon), a heparinoid, have been approved by the FDA for prevention of deep vein thrombosis. Without anticoagulation, deep vein thrombosis occurs in up to 30% of patients after abdominal surgery, and in 40% to 70% of patients after major orthopedic operations on the lower limbs. Danaparoid sodium is approved in the USA only for use in hip replacement. Ardeparin is approved here only for use in knee replacement.

Tinzaparin sodium, a low molecular weight heparin, has been approved by the FDA for treatment of acute deep vein thrombosis.

Fondaparinux (Arixtra - Organon Sanofi-Synthelabo), a synthetic analog of heparin, has been approved by the FDA for prevention of deep vein thrombosis (DVT) after hip fracture surgery or knee or hip replacement.

Anticoagulants are the drugs of choice for treatment and prevention of deep venous thrombosis (DVT) and pulmonary embolism (PE), collectively referred to as venous thromboembolism (VTE). US guidelines for treatment of VTE were updated in 2020 and 2021.

Antiplatelet drugs are the drugs of choice for prevention and treatment of arterial thrombosis. Anticoagulants are the drugs of choice for prevention and treatment of venous thromboembolism and for prevention of cardioembolic events in patients with atrial fibrillation.