The Medical Letter on Drugs and Therapeutics
Ella: A New Emergency Contraceptive
Subscribers: Log in to read full article.  Not a subscriber?  Subscribe or purchase article.

The FDA has approved the use of ulipristal acetate (ella – Watson) as an emergency contraceptive that can be taken up to 5 days after unprotected intercourse. It is available only by prescription.

MECHANISM OF ACTION — Ulipristal acetate, a progesterone-receptor agonist/antagonist structurally similar to mifepristone (Mifeprex), when taken immediately before ovulation has been shown to delay follicular rupture.1 It may also cause endometrial changes that could interfere with implantation of a fertilized ovum.

PROBABILITY OF PREGNANCY — The probability of pregnancy after unprotected intercourse has been estimated to be about 15% when coitus occurs 3 days before ovulation, 30% 1 or 2 days before ovulation, and 12% on the day of ovulation.2 One or 2 days after ovulation, the probability of pregnancy ... more      

The Medical Letter is a subscriber-funded nonprofit organization that publishes critical appraisals of new prescription drugs and comparative reviews of drugs for common diseases.

Would you like to read the rest of this article?  Gain access below.

Subscriptions to The Medical Letter on Drugs and Therapeutics include:
  • Print version published and mailed biweekly (26 issues/year)
  • Unlimited online access to current and past issues (1988 - present)
  • Mobile App for iOS, Android, and Kindle Fire
  • FREE online per issue CME/CE
Purchase this article:
Title: Ella: A New Emergency Contraceptive
Article code: 1355c
 Electronic, downloadable article - $45
Gain access through your organization
Ask your librarian to consider an Institutional Subscription to The Medical Letter.
Recommend to your librarian