The impact of vaginal bromocriptine on reducing pain and menstrual bleeding in women with adenomyosis: a randomized controlled trial

Bromocriptine, a dopamine receptor agonist that suppresses prolactin secretion from the pituitary gland, is an inexpensive and widely accessible medication with few adverse effects. The study aim was to assesse the efficacy of vaginal bromocriptine in reducing pelvic pain, menstrual bleeding, and cycle irregularities among patients with adenomyosis. In this randomized controled trial, 64 women diagnosed with adenomyosis were randomly assigned to either an intervention group receiving vaginal bromocriptine or a routine-treatment group. The intervention consisted of 5 mg bromocriptine administered vaginally once daily for three months. The control group received standard treatment comprising oral contraceptive pills (OCPs) and mefenamic acid. Primary outcome measures were menstrual bleeding volume, pain intensity, and menstrual cycle regularity. Linear regression models were used to evaluate changes in menstrual bleeding after adjusting for potential confounders. All 64 participants (32 per group) completed the study and were included in the analysis. Baseline demographic, obstetric, and ultrasonographic characteristics were comparable between groups (P > 0.05). After treatment, the mean pain score was significantly lower in the intervention group than in the control group (2.01 vs. 5.10; P = 0.011). Mean menstrual bleeding volume also decreased significantly with vaginal bromocriptine (280.8 mL vs. 525.9 mL; P = 0.001). Final analysis indicated that bromocriptine significantly reduced menstruation bleeding after adjusting for potential confounders (Beta= - 1.157, P = 0.001). Vaginal bromocriptine appears to be an effective and well-tolerated therapeutic option for alleviating symptoms of adenomyosis, particularly pelvic pain, excessive menstrual bleeding, and irregular cycles. The beneficial effects may result from reduced prolactin levels, inhibition of angiogenesis, and modulation of the hypothalamic-pituitary-ovarian axis.Trail registration number IRCT20240806062668N3.