Comparison of the eefect of low molecular weight heparin and unfractionatedheparin on platelet counts and anti-platelet antibody formation in patients with lower extremities deep vein thrombosis

Heparin can induce a number of complications, including decreased number of platelets and inducing anti-platelet antibodies. This study was designed to compare these adverse effects between low molecular heparin and unfractionated heparin in patients diagnosed as deep vein thrombosis. In a clinical trial study, 124 cases diagnosed as deep vein thrombosis were divided randomly in 2 groups, 62 in each one. The first group was treated with enoxaparine and the 2nd treated with unfractionated heparin. Changes in platelet number and any new development of anti-platelet antibodies were assessed and compared between the groups. The cases in the 2 groups were compared regarding age, sex, and the platelet number. The decrease in platelet number was statistically significant in the unfractionated heparin while the 2nd group did not have any statistically significant decrease. The difference between the two groups was statistically significant regarding platelet count. The introduction of new anti-platelet antibody was significant in the unfractionated heparin group but not the enoxaparin group. None of the cases had a platelet number less than 100.000/ml. The study suggests that the enoxaparin is superior to unfractionated heparin regarding production of anti-platelet antibodies and decrease in platelet count. Serial platelet counts and the risk of thrombocytopenia should be considered when admininstering unfractionated heparin in deep vein thrombosis cases.