Overview of parenteral anticoagulants

Parenteral anticoagulants available in Australia at the time of writing are listed in Parenteral anticoagulant drugs.

In most cases, oral anticoagulant therapy is preferred to parenteral therapy; however, parenteral anticoagulants are required in some specific situations:

• In the perioperative setting, when the risk of bleeding from anticoagulant therapy is high, unfractionated heparin (UFH) may be preferred because it is short acting and fully reversible with protamine.
• In patients with severe kidney impairment, UFH is preferred because its excretion is not dependent on kidney function.
• For treatment of cancer-associated thrombosis, low molecular weight heparin (LMWH) is superior to warfarin but not to direct-acting oral anticoagulants (DOACs)Lyon, 2022.
• For prophylaxis or treatment of venous thromboembolism during pregnancy, LMWH or UFH is used; the safety of oral anticoagulants during pregnancy has not been proven.
• For treatment of patients with heparin-induced thrombocytopenia (HIT), danaparoid, fondaparinux, bivalirudin or argatroban is used for initial treatment.
• If using warfarin to treat acute venous thromboembolism, a parenteral anticoagulant is given concurrently when starting therapy. This overcomes the delay in achieving therapeutic anticoagulation and the initial increase in prothrombotic potential associated with starting warfarin therapy.

The bleeding risk for parenteral anticoagulant therapy is determined by patient-specific factors or factors that affect anticoagulant exposure, such as the adequacy of therapeutic monitoring or the anticoagulant pharmacokinetics; weigh the harm–benefit balance for parenteral anticoagulants for each patient.