A double blind controlled study of the hormonal and clinical effects of bromocriptine in the polycystic ovary syndrome.

Previous studies on the efficacy of bromocriptine for the treatment of patients with the polycystic ovary syndrome failed to include control groups. This study, therefore, was undertaken to determine the clinical and endocrine effects of bromocriptine and a placebo (given in a random double blind fashion) in 55 patients with PCOS. The plasma levels of estrone, estradiol, testosterone, androstenedione, dehydroepiandrosterone, dehydroepiandrosterone sulfate, 17-hydroxyprogesterone, and serum PRL and gonadotropins (LH and FSH) were measured before treatment. In addition the serum PRL response to TRH and the serum LH and FSH response to GnRH were determined. The effects of acute administration of bromocriptine (2 X 2.5 mg at 12-h intervals) on serum gonadotropins and their response to GnRH were studied to explore the possibility that this test might predict the response to chronic bromocriptine treatment. Bromocriptine then was given at an initial dose of 1.25 mg twice daily. If no clinical improvement occurred 2.5 mg were given twice daily for at least 6 months. Hormonal measurements and dynamic tests were repeated after 3 and 6 months of therapy. The endocrine profile of the two groups was not different before treatment. The clinical results were not better in the treatment group than in the placebo-treated patients: therapy was successful (restoration of ovulatory cycles of less than 35 days duration) in 12 of 28 patients taking bromocriptine vs. 8 of 27 taking placebo. Slight improvement (1 or 2 ovulations) occurred in 3 of 28 vs. 3 of 27, and failure (no clinical change) in 13 of 28 taking bromocriptine vs. 16 of 27 taking placebo, respectively. Serum PRL fell significantly in the bromocriptine group, and there was a significant fall in the serum LH response to GnRH in both groups. No hormonal measurement or response predicted the clinical response to treatment. The only significant effect of chronic bromocriptine therapy (5 mg/day) in patients with the polycystic ovary syndrome was to lower the serum PRL concentration.