Dalteparin new treatment duration: new dosage. Is prolonged prophylaxis needed?

(1) In the prevention of deep venous thrombosis after hip surgery, the recommended treatment period with dalteparin has been extended from seven days to 35 days. (2) The clinical file is based on two double-blind trials comparing dalteparin administered for 35 days with dalteparin administered for seven days followed by a placebo, in a total of 546 patients. (3) No clinical trials have compared prolonged dalteparin prevention to dalteparin for one week followed by oral anticoagulant therapy. (4) Clinical vascular events were infrequent between days 7 and 35. There was one death due to pulmonary embolism in the placebo group. One patient on dalteparin died, possibly because of a subdural haematoma discovered at autopsy. (5) Prolonged dalteparin prophylaxis necessitates laboratory monitoring to detect thrombocytopenia. (6) Cost-effectiveness studies of dalteparin administration for 35 days versus dalteparin for seven days followed by oral anticoagulants, are required.