Dosage aspects of danazol therapy in endometriosis: short-term and long-term effectiveness

The use of danazol (Danocrine) appears to be the most effective medical form of therapy for endometriosis. A double-blind study on 32 patients with laparoscopically proved pelvic endometriosis was designed to evaluate the immediate short-term and long-term effectiveness of daily dosages of danazol (100, 200, 400, and 600 mg) on the amelioration of the disease, with the use of posttreatment surgical findings and symptomatic changes. The American Fertility Society classification based on a point system was used. The clinical and surgical improvement rates varied from 75% to 85% and 50% to 70%, respectively. Ovarian endometriomas of even 1 cm in size generally do not respond to danazol. The pregnancy rate was 45%. We have demonstrated that lower than maximum doses of danazol produce similar beneficial effects in the treatment. With the low dosages, we did not achieve freedom from side-effects. The average symptomatic recurrence rate was 36%, with a mean duration of 19 months of follow-up, and was dose dependent.