Comment: The quality of evidence is downgraded by study quality and by sparse data.
A Cochrane review [Abstract] 2 assessed different medical interventions for hirsutism. Finasteride 5mg to 7.5 mg daily was more effective than placebo in reducing Ferriman-Gallwey scores (score 0 to 36) (MD -5.73, 95% CI -6.87 to -4.58). Spironolactone showed similar effectiveness to finasteride (MD 1.49, 95% CI -0.58 to 3.56 and MD 0.40, 95% CI -1.18 to 1.98; 2 trials). However, results were inconsisntent when comparing finasteride with flutamide.
A topic in Clinical Evidence 1 summarizes the results of 2 RCTs. The first RCT (n=24 women, 14 with polycystic ovary syndrome) found that finasteride 5 mg daily significantly reduced hirsutism compared with placebo (Ferriman-Gallwey score 6.7 vs 10.6, p<0.01). The second RCT (n=40, 21 with polycystic ovary syndrome) found that finasteride, spironolactone, and flutamide reduced hirsutism compared with placebo (p<0.01 for all treatments).
A meta-analysis 3 assessing treatment options for hirsutism included 43 trials. Antiandrogen monotherapy with flutamide, finasteride, and spironolactone were each superior to placebo but similar to each other in efficacy.
Another meta-analysis 4 included 13 studies (n = 961). Seven studies had a high risk of bias, 9 moderate and 4 low. Anti-androgens included were finasteride, flutamide, spironolactone, or bicalutamide. For hirsutism anti-androgens + lifestyle were superior to metformin + lifestyle (weighted mean difference [WMD] -1.59, 95% CI -3.06 to -0.12, I²=74) but were not superior to placebo + lifestyle (WMD -0.93, 95% CI -3.37 to 1.51; I²=76%). Daily use was more effective than use every three days, and resulted in lower androstenedione levels. There were no differences in hirsutism when anti-androgens + metformin + lifestyle were compared with either anti-androgens + lifestyle or metformin + lifestyle.
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