Secondary Prophylaxis with Warfarin for Venous Thromboembolism

There are two phases in the treatment of patients with symptomatic venous thromboembolism: initial treatment and secondary prophylaxis. Initial therapy usually consists of either subcutaneous low-molecular-weight heparin or intravenous unfractionated heparin, whereas oral vitamin K antagonists (such as warfarin) are generally prescribed for secondary prophylaxis.The evidence that an initial five-to-seven-day course of the direct-acting anticoagulant heparin is indeed warranted comes from two clinical trials. The first is the landmark 1960 study by Barritt and Jordan, who compared a combination of heparin and warfarin with no treatment in patients with symptomatic pulmonary embolism.1 The study was stopped prematurely after only . . .