title: Ulipristal acetate  as an emergency contraceptive agent.
abstract: BACKGROUND
  Emergency contraceptive agents play a crucial role in preventing unplanned pregnancy. These agents and devices have been studied since the 1960s and have had varied results in terms of side effects and efficacy. A new oral tablet for emergency contraception (EC), ulipristal acetate (UPA) , is a selective progesterone receptor modulator and can be used up to 120 h following unprotected intercourse, without an increase in adverse effects or a decrease in efficacy.
  
  
  METHODS
  This article reviews studies that evaluate the pharmacodynamics, pharmacokinetics, clinical efficacy, and safety profile of UPA as an emergency contraceptive agent.
  
  
  CONCLUSIONS
  UPA, a selective progesterone receptor modulator, is administered as a single 30 mg dose for EC. This agent provides a comparable, if not better, efficacy and side effect profile than seen with levonorgestrel or mifepristone. Because it has both agonistic and antagonistic effects on the progesterone receptor, ongoing clinical trials are documenting UPA's use for patients with endometriosis and as an extended use contraceptive.
authors: University of Cincinnati, Center for Reproductive Health, Cincinnati, OH, USA.
authors: Alan M
authors: AM
authors: Martinez
authors: Michael A
authors: MA
authors: Thomas
mesh_terms: D000284:Administration, Oral; D000818:Animals; D044363:Contraception, Postcoital / Q000379:methods*; D003281:Contraceptives, Postcoital / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D016912:Levonorgestrel / Q000009:adverse effects / Q000627:therapeutic use; D015735:Mifepristone / Q000009:adverse effects / Q000627:therapeutic use; D009649:Norpregnadienes / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D011980:Receptors, Progesterone / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors
chemical_list: D003281:Contraceptives, Postcoital; D009649:Norpregnadienes; D011980:Receptors, Progesterone; D015735:Mifepristone; D016912:Levonorgestrel; C555622:ulipristal acetate