Subcutaneous unfractionated heparin for the initial treatment of venous thromboembolism

Thrombosis of the deep veins and subsequent embolism to the lungs are both prevalent and dangerous. They usually require either subcutaneous or intravenous injections of medications which aim to stop this hyper-coagulant state, followed by oral medication for long periods of time. Certain conditions require continuous intravenous application of unfractionated heparin. We set to explore the effectiveness of the intermittent subcutaneous route of administration, in view of its simplicity compared with the continuous application, and its low price, compared with other alternatives. We searched MEDLINE, EMBASE and The Cochrane Library for randomised controlled trials, in which treatment with subcutaneous unfractionated heparin was compared with control, in patients with acute venous thromboembolism. Fifteen randomised controlled trials were identified that included a total of 1475 patients in the intervention group and 1579 patients in the control group. The results for all the major outcomes of efficacy and safety did not favour one of the options with statistical significance. We conclude that subcutaneous unfractionated heparin cannot be considered non-inferior to other forms of anticoagulant treatment for recurrent deep vein thrombosis at three months, but appears to be as safe and effective compared with other anticoagulant treatment when comparing rates of major bleeding and death.