Prophylaxis of deep venous thrombosis by hydroxychloroquine sulfate and heparin.

A double blind study of 134 patients was undertaken to compare the effectiveness of hydroxychloroquine sulfate, Plaquenil, and heparin in the prophylaxis of deep venous thrombosis. By the 125I fibrinogen scanning technique, deep venous thrombosis was detected in six patients in the placebo group, in one patient in the Plaquenil group and none in the heparin group. These results indicate that both heparin and Plaquenil do diminish the incidence of thrombosis.