Division of Reproductive Endocrinology and Infertility, University of Tennessee Medical Center, Knoxville, TN, USA.
Ann Pharmacother. 2011 Jun;45(6):813-5. doi: 10.1345/aph.1Q248. Epub 2011 Jun 10.
Ulipristal acetate is the first selective progesterone receptor modulator approved for postcoital contraception in the US. It appears to be significantly more effective in inhibition of ovulation than other forms of emergency contraception. However, ulipristal acetate is structurally similar to mifepristone, and several lines of evidence suggest that a postfertilization mechanism of action is also operative. This mechanism of action is considered to be contragestive versus contraceptive. Ulipristal acetate administration is contraindicated in a known or suspected pregnancy; however, it could quite possibly be used as an effective abortifacient. Health-care providers should inform patients of the possibility of both mechanisms of action with use of this drug.
醋酸乌利司他是美国批准用于性交后避孕的首个孕激素受体选择性调节剂。它似乎比其他形式的紧急避孕药更能有效地抑制排卵。然而，醋酸乌利司他的结构与米非司酮相似，有几条证据表明，其作用机制也涉及受精后阶段。这种作用机制被认为是抗着床的，而不是避孕的。已知或疑似怀孕者禁用醋酸乌利司他；然而，该药极有可能被用作有效的堕胎药。使用这种药物时，医疗保健提供者应告知患者该药可能存在这两种作用机制。
