Danazol-induced factor VIII and IX bypassing activity in hemophiliacs

Danazol therapy in factor X deficiency

Factor X (FX) deficiency is a rare coagulation disorder that usually presents with bleeding manifestations and is treated with fresh frozen plasma or prothrombin complex concentrates. We report a case of FX deficiency in which the patient presented with bleeding as well as thrombosis. The patient responded to Danazol and relapsed when the drug was stopped. The occurrence of thrombosis in FX deficiency and the role of Danazol in coagulopathies are reviewed.

Efficacy of danazol in pure red cell aplasia

Twenty-one unselected patients with refractory chronic anemias of various etiologies were treated with danazol, a synthetic attenuated androgen. All had previously failed treatment with hematinics, androgens, corticosteroids, high-dose intravenous immunoglobulin, antithymocyte globulin, cytotoxic immunosuppressive agents, and/or plasmapheresis. Three patients with pure red cell aplasia and one with aplastic anemia responded. No responses were observed in 11 patients with myelodysplastic syndromes, two patients with myelofibrosis, and two with paroxysmal nocturnal hemoglobinuria. Remission in pure red cell aplasia was maintained with danazol alone in one patient and required combined low-dose prednisone in two. Objective responses occurred in 2 to 3 weeks and therapy generally was well tolerated. To date, one patient with pure red cell aplasia remains in complete remission at 9 months on low-dose danazol alone. We conclude that danazol alone or combined with prednisone may induce and maintain remission in severe refractory pure red cell aplasia and possibly other chronic cytopenias characterized by immunologic marrow suppression. Further trials of danazol in treating these disorders are indicated.