Objective: To study the response of uterine leiomyoma to two different daily dosages of mifepristone.
Methods: Prospective nonrandomized clinical trial on women with symptomatic uterine leiomyoma was conducted. Twenty-eight patients were treated with 10mg of mifepristone daily and fifteen patients with 20mg daily for 12 weeks, beginning on day 1 to 3 of the menstrual cycle. Volume changes of leiomyoma and uterus were measured with ultrasonography before treatment (as baseline) and monthly during the course of therapy. Blood samples for hemoglobin, liver and renal function were obtained monthly.
Results: Ovarian acyclicity was induced in both groups of patients given different daily doses of mifepristone and dysmenorrhea and low abdominal pain disappeared. All symptoms and signs of anemia were resolved. The average hemoglobin level elevated 14-16g/L monthly. After 12 weeks of mifepristone treatment, the leiomyoma volume decreased to 41.4% of baseline in the 10mg daily dose group and 43.0% in the 20mg daily dose group. There was no significant difference between the two treatment groups; the side effects were similar.
Conclusion: Mifepristone of 10mg daily is considered to be a more ideal dosage for treatment. Mifepristone therapy is indicated in larger fibroids, and/or as preoperative medication for severely anemic patients and in perimenopausal patients with symptomatic fibroids.