Failure of bromocriptine to restore the menstrual cycle in normoprolactinemic post-pill amenorrhea

Abstract

A double-blind placebo-controlled randomized study to test the efficacy of bromocriptine in women with normoprolactinemic postpill amenorrhea (NPPA) is described. 29 patients had secondary amenorrhea of at least 6 months duration after discontinuation of oral contraceptives (OCs), plasma prolactin (PRL) 0.6mU/ml, no galactorrhea, no recognizable cause of anovulation after intensive endocrinologic screening, and no history of use of drugs known to interfere with PRL metabolism except OCs. The dosage of bromocriptine was 3 mg/day for 12 weeks or until the 2nd vaginal bleeding. PRL, estradiol, and progesterone levels were measured at 2-week intervals. All patients kept basal body temperature charts and registered vaginal bleeding. 13 women received bromocriptine daily for 10-12 weeks and 16 received placebos for 9-12 weeks. No significant differences in age, weight, menstrual cycles before OC use, duration of OC use, or duration of amenorrhea were observed between the 2 groups. Menstruation occurred in 4 women using bromocriptine; ovulation was likely in 1 of them according to the basal body temperature and/or progesterone levels in the luteal phase. Ovulation appeared likely in 8 of 9 women in the placebo group who reported bleeding. The results clearly show that bromocriptine has no effect on the restoration of menstruation in NPPA.