title: Efficacy and safety of a levonorgestrel enteric-coated tablet as an over-the-counter drug for emergency contraception: a Phase IV clinical trial.
abstract: BACKGROUND
  An enteric-coated levonorgestrel emergency contraceptive pill (E-LNG-ECP) is an improved formulation, in terms of side effects, which both dissolves and is absorbed in the intestine. Our aim was to evaluate the efficacy and safety of E-LNG-ECP as an over-the-counter (OTC) drug for emergency contraception (EC) in Chinese women.
  
  
  METHODS
  A Phase IV clinical trial was conducted in five family planning clinics in China. Women seeking EC within 72 h after unprotected sexual intercourse or contraceptive failure who met the inclusion criteria were recruited. The efficacy of contraception (primary end-point was pregnancy rate), side effects (i.e. safety) and the value of E-LNG-ECP for EC were investigated.
  
  
  RESULTS
  Of 2445 women (aged 15-48 years) who took E-LNG-ECP with follow-up to determine pregnancy, only five pregnancies (0.2%) occurred. The efficacy of contraception was 95.3%. In total, 6.5% of women reported at least one adverse event after taking E-LNG-ECP, and no serious adverse events were reported. Only four subjects (0.16%) reported vomiting. The incidence of menstrual cycle disturbance was 20.1% after taking E-LNG-ECP. Subjects who had previously taken ECPs (54.4% of these women) rated the acceptability of E-LNG-ECP at 9.36 (on a 10-point scale) higher (P<0.05) than the rating of other LNG-EC pills taken previously.
  
  
  CONCLUSIONS
  The study found that E-LNG-ECP was effective, safe and well tolerated as an OTC drug. However, an randomized controlled trial should be performed to compare standard LNG tablets with E-LNG-ECP.
authors.affiliation: Shanghai Institute of Planned Parenthood Research, Shanghai, PR China.
authors.forename: Q-J
authors.initials: QJ
authors.lastname: Chen
authors.forename: W-P
authors.initials: WP
authors.lastname: Xiang
authors.forename: D-K
authors.initials: DK
authors.lastname: Zhang
authors.forename: R-P
authors.initials: RP
authors.lastname: Wang
authors.forename: Y-F
authors.initials: YF
authors.lastname: Luo
authors.forename: J-Z
authors.initials: JZ
authors.lastname: Kang
authors.forename: L-N
authors.initials: LN
authors.lastname: Cheng
mesh_terms: D000293:Adolescent; D000328:Adult; D002681:China; D044363:Contraception, Postcoital / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D016912:Levonorgestrel / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D008875:Middle Aged; D004366:Nonprescription Drugs / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D011247:Pregnancy; D018873:Pregnancy Rate; D013608:Tablets, Enteric-Coated
chemical_list: D004366:Nonprescription Drugs; D013608:Tablets, Enteric-Coated; D016912:Levonorgestrel