Efficacy of Low-Dose Estrogen–Progestins and Progestins in Japanese Women with Dysmenorrhea: A Systematic Review and Network Meta-analysis

INTRODUCTION: Although several studies suggest beneficial effects of low-dose estrogen–progestins (LEPs) and progestins on dysmenorrhea in Japanese women, the difference in efficacy between drugs remains unknown. METHODS: We identified studies by searching the MEDLINE, Cochrane Library, and ICHUSHI databases and included randomized controlled trials (RCTs) that used total dysmenorrhea score and visual analogue scale (VAS) as outcome measures to evaluate LEPs and progestins for primary and secondary dysmenorrhea. We analyzed results by meta-analysis and network meta-analysis (NMA). RESULTS: We identified 10 articles on eight RCTs and included seven drugs (six LEPs and one progestin, i.e., dienogest) and placebo in the analysis. Meta-analysis showed improvements in total dysmenorrhea score and VAS for almost all drugs compared with placebo. In NMA, VAS in secondary dysmenorrhea improved more with dienogest than with norethisterone/ethinylestradiol (mean difference − 25.84 [95% CrI − 44.46 to − 7.15]). In the comparison of administration regimens, VAS improved more with progestin-continuous than LEP-cyclic and the surface under the cumulative ranking (SUCRA) of LEP-extended and progestin-continuous appeared to be higher than that of LEP-cyclic. CONCLUSIONS: We confirmed that LEPs and dienogest are effective for primary and secondary dysmenorrhea and suggest that continuous regimens may be more effective than cyclic regimens in improving outcomes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12325-022-02298-9.