Mechanism of Action of Ulipristal Acetate for Emergency Contraception: A Systematic Review.
Mechanism of Action of Ulipristal Acetate for Emergency Contraception: A Systematic Review.
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DOI：
10.3389/fphar.2015.00315
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发表时间：
2015
影响因子：
5.6
通讯作者：
Bastianelli C
中科院分区：
文献类型：
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作者：
Rosato E;Farris M;Bastianelli C
醋酸利普司特(UPA)是目前推荐的首选激素紧急避孕药(EC)，与左旋诺孕酮EC相比，它具有更高的有效性和相似的安全性。尽管所有试验都表明，第一种作用机制是抑制排卵，但一些作者仍然假设，受精后的效应也是可能的，这提高了人们对药物的警觉，并引发了伦理辩论。检索Medline数据库，检索最近有关uPA对排卵、输卵管和子宫内膜影响的文章。我们还分析了对精子功能和妊娠的影响。所有研究都得出结论，uPA在抑制排卵方面是有效的，即使在黄体生成素高峰之前给药也是如此。UPA对输卵管的作用尚不清楚：有人认为uPA通过激动孕酮受体抑制纤毛搏动，也有人认为uPA拮抗孕酮诱导的纤毛搏动减少。关于uPA对子宫内膜和胚胎着床的影响，大多数研究得出的结论是，小剂量uPA用于EC对子宫内膜厚度的减少和胚胎的附着没有明显的影响，但这些结果仍然存在争议。最后，最近的证据表明，uPA调节人类精子功能，而对已确定的妊娠没有影响。到目前为止，大多数证据都同意排除uPA的受精后影响，尽管还需要更多的研究来阐明其作用机制。
Ulipristal acetate (UPA) is now recommended as first choice hormonal emergency contraception (EC), due to its higher efficacy and similar safety compared to Levonorgestrel – EC. Even though all trials demonstrated that the first mechanism of action is inhibition of ovulation, some authors still postulate that a post fertilization effect is also possible, raising the alert on medication and fostering the ethical debate. A Medline database search was performed in order to find recent articles related to UPA’s effects on ovulation, on fallopian tube and on endometrium. We also analyzed the effects on sperm function and pregnancy. All studies conclude that UPA is effective in inhibition of ovulation even when administered shortly before LH peak. The effects on fallopian tube are unclear: according to some authors UPA inhibits ciliar beat through an agonistic effect on progesterone receptors, according to others it antagonizes the progesterone-induced ciliar beat decrease. Concerning the action on endometrium and on embryo implantation most of the studies concluded that low dose UPA used for EC has no significant effect on the decrease of endometrial thickness and on embryo’s attachment, but these results are still matter of debate. Finally recent evidence suggests that UPA modulates human sperm functions while it has no effect on established pregnancy. To date the majority of the evidence concurs in excluding a post-fertilization effect of UPA, even though more studies are needed to clarify its mechanism of action.