Mifepristone for the Treatment of Uterine Leiomyomas

Abstract

To estimate the efficacy of daily administration of 5 mg compared with 10 mg of mifepristone for the treatment of uterine myomas. 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. 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. Five-milligram doses of mifepristone produce reductions in leiomyoma and uterine volumes and symptomatic improvement similar to 10-mg doses. I.