Is mifepristone effective and safe for the treatment of women with adenomyosis and significant pain symptoms?
This study found that mifepristone (which is currently difficult to obtain in the United States) is effective and safe for the treatment of adenomyosis, including both the primary outcome of dysmenorrhea and the secondary outcomes of heavy menstrual bleeding and anemia remission. Follow-up only occurred for 3 months, so long-term outcomes remain uncertain.
Randomized controlled trial (double-blinded)
Adenomyosis is defined as the presence of ectopic endometrial tissue in the uterine myometrium. Adverse outcomes include severe dysmenorrhea, menorrhagia, secondary anemia, dyspareunia, and other obstetric and gynecologic complications. So far, medical treatment has been of minimal effectiveness and many women choose hysterectomy for definitive treatment. These investigators identified premenopausal women, aged 18 to 50 years, with adenomyosis (confirmed by ultrasonography or magnetic resonance imaging) and associated dysmenorrhea. Eligible patients (N = 134) randomly received (concealed allocation assignment) mifepristone (10 mg orally once daily) or matched placebo. Study patients masked to treatment group assignment self-assessed outcomes using standard visual analog scale (VAS) scoring tools. Complete follow-up occurred for 94.1% of patients at 12 weeks.
Using both intention-to-treat and per-protocol analyses, the mean changes in baseline VAS scores (0 - 10, with 10 indicating the most severe pain) were –6.63 points in the mifepristone group and –0.95 points in the placebo group (between-group difference –5.68; 95% CI –6.37 to –4.99). Total efficacy, defined as the proportion of patients with a VAS score reduced by at least 30% (with 20% considered clinically significant) was significantly greater in the mifepristone group than in the placebo group (91.8% vs 23.1%; number needed to treat = 1.6; 1.4 - 2.2). Other outcomes — including complete remission of all symptoms, reduction in heavy bleeding, and remission of anemia — also occurred significantly more often with mifepristone than with placebo. All adverse events were considered mild or moderate and occurred similarly in both treatment groups.
David C. Slawson, MD
Professor and Vice Chair of Family Medicine for Education and Scholarship
Professor of Family Medicine, UNC Chapel Hill