Summary
The aim of the study was to compare the efficacy and safety of once-daily subcutaneous
injection of dalteparin, a low molecular weight heparin, with that of intravenous
unfractionated heparin in the treatment of deep venous thrombosis (DVT). Patients
were included if they had deep venous thrombosis distal to inguinal ligament and were
randomised either before, if it was considered necessary, or after phlebographic verification
of the diagnosis. There was no pre-inclusion treatment with unfractionated heparin.
One hundred and twenty patients received dalteparin, administered subcutaneously once-daily
at a fixed dose of 200 IU anti-factor Xa/kg, and 133 patients received a continuous
intravenous infusion of unfractionated heparin (UFH). Oral anticoagulation was started
on the first or second day, and initial treatment with dalteparin or UFH discontinued
when the prothrombin time was in the therapeutic range (2<INR<3) on two consecutive
days. Control phlebograms were taken within 4 days, thereafter. There were no significant
differences between the two initial treatment groups in improvements in Marder score.
Two major bleeding events occurred in the UFH group versus none in the dalteparin
group. One patient in each group experienced clinically significant pulmonary embolism.
During a mean follow-up period of 6.9 ± 1.5 months, recurrent DVT occurred in four
patients in the dalteparin group and in two of the UFH group. These results confirm
those of a previous study on dalteparin in the initial treatment of DVT, and suggest
that dalteparin administered once-daily at a fixed dose of 200 UI/kg is as effective
and well-tolerated as UFH in patients with DVT below the inguinal ligament. The present
study also demonstrates that dalteparin can be started as soon as the diagnosis of
DVT is suspected and without pre-treatment with UFH. Given that the administration
of once-daily subcutaneous injections needs not require a patient to be hospitalised,
studies to investigate the possibility of using dalteparin for the initial treatment
of DVT in the outpatient setting are warranted.
