A comparison of high-dose versus conventional-dose heparin therapy for deep vein thrombosis.

Although heparin has been used for the treatment of deep vein thrombosis (DVT) for more than 40 years, controversy still exists regarding optimal doses and the need for monitoring. In this retrospective survey (January 1979 to December 1981) we compared two approaches to heparin therapy--high-dose heparin without monitoring versus conventional-dose heparin with monitoring. All patients had objectively documented DVT and each group was comparable with respect to age, gender, risk, factors, and extent of thrombosis. The high-dose group (n = 26) received a heparin bolus of 150 mu/kg followed by continuous intravenous infusion of 30 to 40 mu/kg/hr. The conventional-dose group (n = 95) received a bolus of 25 to 50 mu/kg with subsequent continuous intravenous doses adjusted to maintain the activated clotting time within a therapeutic range (150 to 190 seconds). There were no thromboembolic complications in the high-dose group, symptom resolution was prompt, and significant bleeding occurred in 8%. In the conventional-dose group, thromboembolic complications occurred in 10%, bleeding occurred in 12%, and only one third experienced prompt resolution of symptoms.