Danazol for heavy menstrual bleeding

Heavy menstrual bleeding (HMB) is an important cause of ill health in pre menopausal women. Medical therapy, with the avoidance of possibly unnecessary surgery is an attractive treatment option, but there is considerable variation in practice and uncertainty about the most effective therapy. Danazol is a synthetic steroid with anti-oestrogenic and anti progestogenic activity, and weak androgenic properties. Danazol suppresses oestrogen and progesterone receptors in the endometrium, leading to endometrial atrophy (thinning of the lining of the uterus) and reduced menstrual loss and to amenorrhoea in some women.

To determine the effectiveness and tolerability of danazol when used for heavy menstrual bleeding in women of reproductive years.

All studies which might describe randomised controlled trials of danazol for the treatment of heavy menstrual bleeding were obtained by electronic searches of MEDLINE, EMBASE, Current Contents, CINAHL, National Research Register and the Menstrual Disorders and Subfertility Group's Specialist Register of controlled trials (on 6 November 2001). Attempts were also made to identify trials from citation lists of included trials and relevant review articles. In most cases the first author of each included trial was contacted for unpublished additional information.

Randomised controlled trials of danazol versus placebo, any other medical (non-surgical) therapy or danazol in different dosages for heavy menstrual bleeding in women of reproductive age with regular HMB measured either subjectively or objectively. Trials that included women with post menopausal bleeding, intermenstrual bleeding and pathological causes of heavy menstrual bleeding were excluded.

Nine RCTs, with 353 women, were identified that fulfilled the inclusion criteria for this review. Quality assessment and data extraction were performed independently by two reviewers. The main outcomes were menstrual blood loss, the number of women experiencing adverse effects, weight gain, withdrawals due to adverse effects and dysmenorrhoea. If data could not be extracted in a form suitable for meta-analysis, they were presented in a descriptive format.

Most data were not in a form suitable for meta analysis, and the results are based on a small number of trials, all of which are under-powered. Danazol appears to be more effective than placebo, progestogens, NSAIDs and the OCP at reducing MBL, but confidence intervals were wide. Treatment with danazol caused more adverse events than NSAIDs (OR 7.0; 95% CI 1.7, 28.2) and progestogens (OR 4.05, 95% CI 1.6, 10.2), but this did not appear to affect adherence to treatment. Danazol was shown to significantly lower the duration of menses when compared with NSAIDs (WMD -1.0; 95% CI -1.8, -0.3) and a progesterone releasing IUD (WMD -6.0; 95% CI -7.3, -4.8). There were no randomised trials comparing danazol with tranexamic acid or the levonorgestrel-releasing intrauterine system.

Danazol appears to be an effective treatment for heavy menstrual bleeding compared to other medical treatments, though it is uncertain whether it is acceptable to women. The use of danazol may be limited by its side effect profile, its acceptability to women and the need for continuing treatment. Overall no strong recommendations can be made due to the small number of trials, and the small sample sizes of the included trials.