EFFECTS OF FINASTERIDE, A 5-ALPHA-REDUCTASE INHIBITOR, ON CIRCULATINGANDROGENS AND GONADOTROPIN-SECRETION IN HIRSUTE WOMEN

An oral 5-mg dose of finasteride, a 5 alpha-reductase inhibitor, was a dministered for 3 months to 10 hirsute women to determine the effect o n gonadotropin secretion, on basal and stimulated androgen secretion, and on hair growth. Hair growth was assessed by the Ferriman-Gallwey s core. All of the above determinations were evaluated before and after 1 and/or 3 months of finasteride treatment. Basal and GnRH-stimulated gonadotropin secretions were not affected. Indeed, finasteride did not modify the pulsatility of LH secretion. No change was seen in estradi ol, PRL, free testosterone, androstenedione, dehydroepiandrosterone su lfate, and sex hormone-binding globulin concentrations. Serum concentr ations of cortisol (F) were significantly reduced after 1 month of fin asteride treatment. The F levels returned to pretreatment levels after 3 months. Plasma levels of dihydrotestosterone and 3 alpha-androstane diol glucuronide significantly decreased during finasteride treatment. A significant increase in testosterone concentrations was observed af ter 3 months. Finasteride did not modify the responses of testosterone , androstenedione, and dehydroepiandrosterone sulfate to ACTH-(1-24) i njection. Conversely, finasteride blunted the F response to corticotro pin stimulation. Three months of finasteride treatment significantly d ecreased the Ferriman-Gallwey score. In conclusion, finasteride signif icantly decreased dihydrotestosterone and hair growth in hirsute women without negatively affecting gonadotropin secretion.