LONG TERM PROPHYLAXIS OF THROMBOEMBOLISM IN OUTPATIENTS WITH LOW MOLECULAR WEIGHT HEPARIN

The prophylaxis of thromboembolism with oral anticoagulants and low dose heparin is established. However, bleeding episodes and other side effects may occur. Alternative compunds for further anticoagulation do not exist so far. We report, therefore, of the experiences of 66 outpatients who were treated with low molecular weight heparin up to nineteen months.

All patients had major bleeding on conventional anticoagulants. Further anticoagulation was strongly indicated because of recurrent thromboembolism, artificial heart valves, dilative cardiomyopathy or heart valve diseases with artrial fibrillation. The dose ranged from 2.500 to 15.000 aXa units once daily subcutaneously. The LMW heparin Tedelparin (Kabi 2165) was used. The dose was chosen according to the risk ofbleeding or thromboembolism, and body weight of eachpatient. In patients with high bleeding risks (esophagiai varices) the average dose was 100 units/kg bodyweight and in patients with high risk of thromboembolism (artificial heart valves) the average dose was140 units/kg bodyweight. The dose was adjusted according to the aXa activity and aPTT inhibition: 2-4 hours after the s.c. administration 0,3 - 0,6 heparin units/ml or 0,6 - 1,0 units/ml in the above mentioned groups should be reached respectively, and the aPTT should be not more than 10 sec above the upper normal limit.

Four of 66 patients experienced rethrombosis, 2 of them were non- compliant. Six of 66 patients had minor haemorrhages, 0 major or fatal bleeding occured. Bleeding was more frequent when the aXa activity increased to more than 1 unit/ml. With a dose reduction of 20 % no recurrence of bleeding was seen and antithrombotic effect was still maintained.

The data demonstrate that LMW heparin can be safely and effectively used for long term anticoagulation in patients with major haemorrhage due to cönventional anticoagulants.