Danazol in chronic idiopathic thrombocytopenic purpura resistant to corticosteroids.

16 patients (11 women and 5 men) with chronic idiopathic thrombocytopenic purpura (ITP) were treated for 3-6 months with Danazol in a daily dose of 300 mg. In 6 women and 1 man an increase in blood platelet count was observed and in all but 2 patients clinical symptoms of haemorrhagic diathesis disappeared. The platelet factor 3 availability and circulating immune complexes level determined before and after 2 months therapy disclosed normalization of both tests in the majority of patients. This amelioration in immunological tests in several, but not in all patients, coincided with platelet count increase. Side-effects were negligible. The authors conclude that Danazol may be of valuable in the management of chronic refractory to corticosteroids ITP patients and that its possible mechanism of action may be an interaction with the immunologic pathways of blood platelet destruction.