Essence of this Article

Anticoagulants are effective in treating deep vein thrombosis (DVT) and pulmonary embolism (PE) but can be associated with an increased risk of bleeding and other adverse events. The balance between benefit and risk often centers on the optimal duration of anticoagulant treatment. Because longer-term treatment can increase the risk of bleeding, it should generally be given to patients at high risk of venous thromboembolism (VTE) recurrence or for specific patient subgroups. Other adverse events that should be considered include heparin-induced thrombocytopenia (HIT) and osteoporosis.

Balancing the benefits and risks of treatment

Anticoagulants are effective in treating DVT and PE but can be associated with an increased risk of bleeding and, in some cases, other adverse events. The balance between benefit and risk often centres around the optimal duration of anticoagulant treatment. Because longer-term treatment can increase the risk of bleeding, it should generally be given to patients at high risk of VTE recurrence or for specific patient subgroups. For patients whose DVT or PE is linked to transient factors such as surgery, trauma or immobilization, 3–6 months’ treatment appears adequate. Patients with idiopathic VTE or VTE associated with thrombophilia may benefit from treatment beyond 12 months, but treatment decisions in these patients must be individualized.146

Another adverse event that should be considered when using unfractionated heparin, and to a lesser extent low molecular weight heparins and fondaparinux, is heparin-induced thrombocytopenia (HIT). Patients with a history of HIT should receive an alternative anticoagulant, such as argatroban, lepirudin or danaparoid. Limited evidence suggests that fondaparinux may be another alternative treatment for patients with a history of HIT.166 Osteoporosis is another potential adverse effect when heparin is administered for longer than 1 month.146