Mifepristone for the treatment of uterine leiomyomas: a randomized controlled trial

Abstract

Objective: To estimate the efficacy of daily administration of 5 mg compared with 10 mg of mifepristone for the treatment of uterine myomas.

Methods: One hundred women were randomly assigned to receive oral mifepristone 5 mg or 10 mg daily for 3 months (50 per group). Abdominal ultrasonography was performed before treatment, at 45 days, and at 3 months to evaluate leiomyoma and uterine volumes. Endometrial biopsy specimens were taken before and after treatment. Efficacy was estimated by the reduction percentages of the leiomyoma and uterine volumes.

Results: After 90 days treatment there was a 45% (95% confidence interval [CI] 37-54, P<.001) and a 57% (95% CI 48-67, P<.001) reduction in the leiomyoma volume in the 10-mg and 5-mg groups, respectively, and one of 40% (95% CI 34-46, P=.002), and 36% (95% CI 31-40, P<.001), respectively, in the uterine volume. Symptomatic improvement was noted, and the prevalence of symptoms diminished significantly. There were no significant differences in reduction of volume and symptoms in the treatment groups, P>.05 in all cases. After treatment, 44 of 49 (89.8%) women from the mifepristone 10 mg group and 45 of 50 (90.0%) from the 5-mg group, respectively, were amenorrheic (P=.487). Endometrial biopsy after treatment showed simple hyperplasia in 1 of 50 (2.0%) in the mifepristone 10 mg group.

Conclusion: Five-milligram doses of mifepristone produce reductions in leiomyoma and uterine volumes and symptomatic improvement similar to 10-mg doses.

Level of evidence: I.