Vaginal Bromocriptine Improves Pain, Menstrual Bleeding, and Quality of Life in Women With Adenomyosis: A Pilot Study

Animal models suggest that increased uterine prolactin concentration is a risk factor for adenomyosis. Prolactin is produced in the human endometrium, myometrium, and the pituitary gland and acts as a smooth muscle cell mitogen in vitro. Both murine and human studies suggest a link between the action of antidepressants and prolactin in the development of adenomyosis. Bromocriptine, a dopamine agonist, inhibits pituitary secretion of prolactin and is the criterion standard of treatment for hyperprolactinemia. This agent is inexpensive and safe and has no serious adverse effects. The aim of this pilot study was to evaluate the effect of bromocriptine on menstrual bleeding and pain in women with adenomyosis. Participants were 23 women aged 35 to 50 years with diffuse adenomyosis characterized by regular heavy menstrual bleeding (HMB). Patients were enrolled from a university hospital in Sweden and a tertiary care hospital in the United States. A total of 19 patients completed 6 months of treatment with vaginal bromocriptine 5 mg daily. Study staff and participants were not blinded to treatment. Several self-administered validated questionnaires were utilized to assess changes in symptoms from baseline to 3 and 6 months of treatment and at 9 months (3 months after cessation of bromocriptine). The questionnaires included Pictorial Blood Loss Assessment Chart (PBLAC), Aberdeen Menorrhagia Clinical Outcomes Questionnaire, visual analog scale for pain, McGill Pain Questionnaire, Endometriosis Health Profile (EHP-30), Female Sexual Function Index, and the Fibroid Symptom Quality of Life (UFS-QOL) symptom severity and health-related quality-of-life subscores. The Wilcoxon signed rank test was used to compare scores between baseline and 9 months. All treatment scores were compared with baseline. Mean patient age was 44.8 years. The PBLAC scores greater than 250 were reported by 77.8% of patients, and moderate to severe pain at baseline was reported by 68.4%. Following bromocriptine treatment, patients had lower 9-month scores (median [interquartile range] for all) on PBLAC (baseline, 349 [292-645] vs 9-month, 233 [149-515], P = 0.003), visual analog scale for pain (5.0 [4-8.3] vs 2.5 [0-4.5], P < 0.001), EHP Core Pain (15.9 [9.1-50.0] vs 3.4 [2.3-34.1], P = 0.029), EHP Core Self-image (41.7 [16.7-58.3] vs 25 [0-5], P = 0.048), and Symptom Severity Score (60 [44-72] vs 44 [25-56], P < 0.001) and higher health-related quality-of-life scores (57 [37-63] vs 72 [51-85], P < 0.001). Other EHP core parameters and Female Sexual Function Index did not show any significant changes during the study period. These data demonstrate significant improvement after bromocriptine treatment in menstrual bleeding, pain, and quality of life in women with adenomyosis and suggest a novel therapeutic agent for this common disease. Further studies are needed to examine the role of prolactin in adenomyosis and the mechanism of action of bromocriptine for symptom relief.