A topic in Clinical Evidence summarizes the results of one RCT (n=93) in women with severe cyclical mastalgia. Danazol 200 mg daily resulted in significantly more women achieving greater than 50% pain relief compared with placebo over 6 months (21/32 (66%) with danazol vs 11/29 (38%) with placebo, RR 1.7, 95% CI 1.0 to 2.9, NNT 4). In the same trial, tamoxifen resulted in pain relief in 23/32 (72%) of patients. Adverse effects included weight gain (31%), deepening of voice, menorrhagia, and muscle cramps.
Comment: The quality of evidence is downgraded by sparse data.