EFFECTS OF THE 5-ALPHA-REDUCTASE INHIBITOR FINASTERIDE ON SERUM LEVELS OF GONADAL, ADRENAL, AND HYPOPHYSEAL HORMONES AND ITS CLINICAL-SIGNIFICANCE - A PROSPECTIVE CLINICAL-STUDY

In the present study we investigated the effects of a steroid 5 alpha- reductase inhibitor, finasteride, when given or orally (5 mg/day), on the serum levels of gonadal, hypophyseal, and adrenal hormones and the clinical significance of these effects. Forty-eight patients with a m ean age of 63 (range 49-81) were included in the study. All patients h ad symptoms of benign prostatic hyperplasia. Serum levels of testoster one, dihydrotestosterone, follicle-stimulating hormone (FSH) luteinizi ng hormone (LH), prolactin, aldosterone, cortisol, and dehydroepiandro sterone were determined before the study. The degree of symptoms in ea ch patient and serum prostate specific antigen levels Ir,ere determine d together with uroflowmetric studies. Sexual status of the patients w as also assessed with a self-administered questionnaire. All patients received finasteride 5 mg/day for 6 weeks. All of the above mentioned studies Were repeated at month 3 and, month 6, All of the patients had baseline hormonal values within the normal range. At month 3, the dih ydrotestosterone level decreased by 60%, while the testosterone level increased by 15%. FSH and LH levels decreased by 24% and 16%, respecti vely. The changes in the serum levels of these hormones were further e vident at month 6 No significant changes were noted in the serum level s of prolactin, aldosterone, cortisol, and dehydroepiandrosterone. Thi rty-sir patients (75%) were judged to be potent before the treatment. Finasteride caused erectile dysfunction in 8 patients (22%) by month 3 and in 12 (33%) by month 6 A substantial improvement was noted in sym ptoms of benign prostatic hyperplasia in all patients. The serum prost ate specific antigen level decreased by 42% and 50% at month 3 and at month 6, respectively. Continued administration of finasteride, 5 mg/d ay alters the serum levels of testosterone, dihydrotestosterone, FSH, and LH significantly. Finasteride also causes sexual dysfunction in a substantial number of patients and should be offered with caution to p atients who have an active sexual life. (C) 1998 by Elsevier Science I nc.