每周口服25mg米非司酮避孕的多中心临床研究

目的探讨25mg米非司酮用于常规避孕的可行性。方法在全国7个研究中心选择自愿参加的健康妇女,受试者月经周期第2~3天首次服用1片(25mg)米非司酮,以后每周服药1次,每次1片,共服4次。每4周随访一次,以28d为一个研究周期,持续6个周期。观察其避孕效果、对月经的影响以及副反应。结果研究在全国7家研究所/医院进行,共接收504名受试者。在完成随访的502名妇女,共3 006个研究周期中,有3例妊娠,其中2例未按照要求服药。与服药前周期相比,服药第4、5、6周期出血天数减少、无出血天数增加,且无出血妇女占比增加,均有统计学差异(P0.05)。恶心、乳胀等副反应较少见且轻微。结论每周一次口服25mg米非司酮避孕效果好,胃肠道等副反应轻微。但随着服药时间的延长,米非司酮会对妇女的月经模式产生比较显著的影响。

A multicenter study on weekly contraception with 25 mg mifepristone

Objective: To investigate the contraceptive effect of weekly administration of 25 mg mifepristone.
Methods: A multicenter clinical trial with weekly doses of 25 mg mifepristone was carried out in seven centers in China. The women were given mifepristone at weekly doses of 25 mg,starting on cycle Day 2 or 3,for 6 consecutive cycles. Each woman received 4 doses of mifepristone in each cycle and was followed up once every 4 weeks. We defined each study cycle as 28 days. The outcome measures were contraceptive efficacy, menstrual pattern changes and side effects.
Results: A total of 502 women were enrolled for the study in seven centers. Three pregnancies were found in 3006 study cycles,and of whom two women did not follow a strict regimen. In the fourth,fifth and sixth cycles,the average number of days with bleeding were significantly less than those before the treatment, and the average number of days with no bleeding and the percentage of women who reported no bleeding in each 28-day study cycle were significantly more than those before the treatment ( P<0. 05 ) . Side effects, such as nausea and breast distension were uncommon and mild.
Conclusions: Once weekly administration with 25 mg mifepristone is a potentially good method for regular contraception for good contraceptive efficacy as well as less and mild side effects. However, the longer the treatment,the greater impact on menstrual patterns could be found.