Vinblastine and danazol therapy in steroid resistant childhood chronic idiopathic thrombocytopenic purpura.

Various drugs such as vinca alkaloids, immunoglobulins and immunosuppressant drugs have been used with variable benefits in patients with chronic idiopathic thrombocytopenic purpura (CITP) refractory to steroid therapy. Vinblastine and danazol have been shown to decrease the expression of Fc (IgG) receptors on macrophages by different mechanisms. These two drugs were used in combination, with the presumption that they will have an additive effect in the treatment of CITP. Sixteen patients with CITP between 2 and 17 years of age, resistant to steroids, were treated with vinblastine given as an intravenous bolus dose at weekly intervals for 8 weeks (the induction phase), followed at monthly intervals for the next 6 months (the maintenance phase). Danazol was given daily in doses of 2-3 mg/kg body weight during both phases. Ten of the 16 (62.5%) patients had partial to complete response and 5 of these 10 patients had sustained remission after cessation of therapy. The initial outcome with the combination of these two drugs in CITP appears to be quite promising and requires further evaluation in a larger controlled study.