Danazol treatment of chronic cystic mastopathy: a clinical and hormonal evaluation.

Danazol, a new synthetic steroid, was administered at a dose of 400 mg daily for two months to 16 premenopausal women with chronic cystic mastopathy. The clinical and hormonal effects (serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, progesterone, testosterone and urinary oestrogens, pregnanediol, pregnanetriol, androsterone and etiocholanolone) were evaluated after 4 and 8 weeks of treatment. Using the same dosage and duration of treatment, danazol (13 patients) was compared with placebo (12 patients) in a double blind randomized clinical trial. Danazol proved to be significantly more effective than placebo in relieving symptoms. Combining the open and double blind study (27 patients), danazol treatment resulted in complete relief in 14 patients and improvement in 11. The main endocrine changes during danazol treatment were related to the drug's ovulation inhibiting effect. Amenorrhoea, irregular bleeding and weight gain (mean 2.1 kg) were significant side effects.