Comparison of finasteride versus flutamide in the treatment of hirsutism.

OBJECTIVE: To compare the effectiveness of finasteride and flutamide in the treatment of hirsutism in patients with polycystic ovary syndrome (PCOS) and with idiopathic hirsutism. DESIGN: Randomized study. PATIENTS: One hundred and ten hirsute patients were selected: 64 women with PCOS and 46 with idiopathic hirsutism. METHODS: Patients were assigned randomly to receive 5mg finasteride once daily or 250mg of flutamide twice daily, for 12 consecutive months. Hirsutism was evaluated at 12 months of therapy, with the Ferriman-Gallwey score and with measurement of the terminal hair diameters (microm) taken from four different body areas. Blood samples were taken for assessment of endocrine and hematochemical parameters. Side effects were monitored during the treatment. RESULTS: Both finasteride and flutamide induced a significant decrease in the hirsutism scores and hair diameters at the end of 12 months. Finasteride reduced the Ferriman-Gallwey score by 31.4% in the PCOS cases and by 34.2% in the idiopathic hirsutism cases, and hair diameter by 27.0-34.1% in PCOS and by 29.6-37.9% in idiopathic hirsutism. Flutamide reduced the Ferriman-Gallwey score by 56.7% in PCOS and by 50.9% in idiopathic hirsutism, and hair diameter by 50. 3-60.0% in PCOS and by 47.7-56.5% in idiopathic hirsutism. Flutamide did not induce hormone variations, while finasteride increased testosterone levels by 40% in PCOS and by 60% in idiopathic hirsutism and decreased 3alpha-androstanediol glucuronide (3alpha-diolG) by 66.7% in PCOS and by 69.5% in idiopathic hirsutism. No important side effects or changes in the hematochemical parameters were observed with finasteride, while two patients (3.6%) in the flutamide group expressed abnormal transaminase levels after 6 months of treatment. Dry skin also appeared significantly more with flutamide (67.3%) than with finasteride (23.6%). CONCLUSIONS: Both drugs are effective in the treatment of hirsutism but flutamide is more effective than finasteride.

Management of hirsutism.

This review reports our own experience with, and literature studies of, the pharmacological management of hirsutism in women with hyperandrogenism (polycystic ovary syndrome) or with normal serum androgen levels and regular ovulatory menstrual cycles (idiopathic hirsutism). Treatment consists of suppressing ovarian or adrenal androgen secretion, or blocking androgen actions in the skin. The major drugs used are gonadotropin-releasing hormone (GnRH) agonists, combined oral contraceptives (COCs), and steroidal (cyproterone acetate and spironolactone) or nonsteroidal (flutamide and finasteride) antiandrogens. GnRH agonists, suppressing the pituitary, decrease androgen and estradiol secretion and improve severe hirsutism. To avoid estrogen deficiency problems, 'add back' therapy with estrogen-progestogen or COCs is advisable. This method of treatment is complicated and expensive, limiting its use to severe forms of ovarian hyperandrogenism with hyperinsulinemia. The third-generation COCs, containing new progestogens or cyproterone, have very restricted effectiveness in the short term (6 cycles), but their long term use (> 12 cycles) cures mild-to-moderate hirsutism and improves severe hirsutism. As well as suppressing gonadotropins and ovarian androgen steroidogenesis, these formulations decrease free testosterone levels and may also decrease adrenal androgen production. In women being treated with antiandrogens, COCs are important to provide control of the menstrual cycle and contraception. Cyproterone, a progestational agent, inhibits gonadotropin secretion and blocks androgen action. It is used in COCs or in a reverse sequential regimen. In the latter, it is very effective in the short term treatment of hirsutism. Spironolactone blocks androgen receptors. Its effectiveness in hirsutism is dosage-dependent: low dosages are less active than other antiandrogens, whereas high dosages (200 mg/day) are very effective at the cost of several adverse effects (particularly dysfunctional uterine bleeding), but the concomitant use of a COC may prevent these. Flutamide is a pure antiandrogen that blocks androgen receptors and inhibits hair growth. It is very effective in treating hirsutism within 6 to 12 months. Dry skin is very frequent during treatment with flutamide, and hepatotoxicity is possible at high dosages. Finasteride, a 5 alpha-reductase type 2 inhibitor, is the least effective antiandrogen, but a dosage of 5 mg/day decreases hirsutism without adverse effects. Pregnancy must be avoided during therapy with antiandrogens because of the possible risk of abnormal development of a male fetus. Antiandrogens, especially flutamide (250 to 500 mg/day) and cyproterone (12.5 to 50 mg/day in a reverse sequential regimen), alone or in association with COCs, seem to be the most effective agents for the treatment of hirsutism.