Intervention to end recurrent unscheduled bleeding trial (INTERRUPT): A randomized-controlled trial of ulipristal acetate for unscheduled bleeding in etonogestrel implant users
Awarded 2017
Complex Family Planning Fellowship Research
Rachel Zigler, MD
Washington University School of Medicine

Background: While the etonogestrel (ENG) implant is among the most effective forms of contraception, unscheduled bleeding can be the cause of low uptake and high discontinuation rates. To date, therapies such as non-steroidal anti-inflammatory medications, estrogen and tamoxifen have been studied with mixed results with regards to efficacy and occasionally intolerable side effects and/or contraindications. Ulipristal acetate (UPA), a selective progesterone receptor modulator, has been shown to reduce bleeding symptoms in women with uterine fibroids. From these studies, there is biologic plausibility that UPA may provide an additional safe and effective option for women with irregular bleeding with the etonogestrel implant.
Purpose of the Study: To evaluate the effectiveness of UPA (15mg) in decreasing the number of bleeding days in users of the ENG implant as compared to placebo.
Methodology: We performed a double blind, randomized, placebo-controlled trial. Participants were randomized to receive 15mg of UPA or placebo daily for 7 days. Participants completed daily bleeding diaries via an automated text messaging service. Twenty participants from each group underwent weekly blood draws to measure serum progesterone levels to assess ovulatory status. Participants were contacted weekly either by phone or in person to assess for medication compliance and side effects, and to measure satisfaction with medication and bleeding pattern.
Important Findings: Compared to women randomized to placebo, women randomized to UPA reported 4 fewer days of bleeding over 30 days. Women were overall satisfied with UPA as a treatment and with their bleeding pattern. Ovulation was not detected.
Conclusion: Use of UPA by ENG implant users reduced bleeding days in the month following use, does not compromise ovulation suppression, and is an acceptable treatment to women.