CLINICAL AND HORMONAL EFFECTS OF THE 5-ALPHA-REDUCTASE INHIBITOR FINASTERIDE IN IDIOPATHIC HIRSUTISM

Hyperactivity of 5 alpha-reductase in the skin is considered a major m echanism of excessive hair growth in hirsute women with normal levels of serum androgens (idiopathic hirsutism). Preventing the conversion o f testosterone to dihydrotestosterone by inhibiting Sa-reductase activ ity could thus be the most rational and effective treatment in this co ndition. The present study evaluated the effects of the oral administr ation of finasteride (5 mg once daily) for 6 months in 17 young women with idiopathic hirsutism, 5 of whom were also given an oral contracep tive. The degree of hirsutism (graded by a modified Ferriman-Gallwey s core), serum sex hormone levels, and serum and urinary 5 alpha-metabol ism steroid profiles were determined basally and periodically during t he treatment period. The modified Ferriman-Gallwey score showed a rema rkable reduction after 6 months of finasteride treatment (5.9 +/- 0.6 us. 11.7 +/- 1.3; P < 0.01). Serum 5 alpha-dihydrotestosterone and 3 a lpha-androstanediol glucuronide levels were decreased, acid urinary C- 19 and C-21 5 beta/5 alpha metabolite ratios were increased compared w ith pretreatment values. No significant adverse effect was reported. I n women treated with finasteride and oral contraceptive, clinical effi cacy was slightly more pronounced. In conclusion, the 5 alpha-reductas e inhibitor finasteride is well tolerated and seems to be a useful too l in the treatment of idiopathic hirsutism.