A prospective, double-blind, placebo-controlled study was designed to evaluate the clinical efficacy and tolerance of danazol and high-dose medroxyprogesterone acetate (MPA) in the treatment of mild-moderate endometriosis. After laparoscopical confirmation of endometriosis, 59 patients were randomized to receive danazol (200 mg 3 times daily), MPA (100 mg daily) or placebo for 6 months. Clinical examinations were done before and 1, 3, 6 and 12 months after the beginning of the study, and a 2nd laparoscopy 6 months after termination of the medication. Eighteen patients in the danazol group, 16 in the MPA group and 17 in the placebo group completed the trial.

Total or partial resolution of peritoneal implants was observed in 60% of the patients receiving danazol and in 63% of the patients receiving MPA. In the placebo group, resolution was observed in 18%, while the size of the implants was estimated to be increased in 23% of the patients. In relation to placebo, danazol and MPA significantly alleviated endometriosis-associated pelvic pain, lower back pain and defecation pain, but they did not differ from each other in these actions. The appearance of acne, muscle cramps, edema, weight gain and spotting bleeding complicated danazol treatment, but only edema and spotting bleeding complicated MPA treatment.

The present results indicate that because of good efficacy and tolerance, high-dose MPA is a useful alternative in the hormonal treatment of endometriosis.