Refractory bleeding from intestinal angiodysplasias successfully treated with danazol in three patients with von Willebrand disease.

von Willebrand disease (VWD) is associated with development of gastrointestinal (GI) vascular malformations that lead to chronic GI bleeding. Conventional management, including von Willebrand factor concentrate replacement and endoscopic ablation or bowel resection, does not consistently reduce hemorrhage. We describe three patients with VWD for whom conventional management failed to control GI bleeding. We retrospectively reviewed medical records of patients with VWD and GI bleeding. After patients began treatment with danazol, we observed long-term reductions in GI bleeding and packed red blood cell transfusion requirements. One patient had severe liver toxicity and was found to have concomitant primary biliary cirrhosis. Danazol use may be considered in patients with VWD and GI bleeding due to angiodysplasia that otherwise fails to respond to conventional treatment; the primary aim of treatment is to reduce transfusion dependence. The benefits are variable and possibly transient. Monitoring for toxicity is important when this treatment is pursued.