title: Maintenance of ovulation inhibition with the 75-microg desogestrel-only contraceptive pill (Cerazette) after scheduled 12-h delays in tablet intake.
abstract: BACKGROUND
  In contrast to traditional progestagen-only pills (POPs), the desogestrel-only pill Cerazette consistently inhibits ovulation. This study was performed to test the hypothesis that desogestrel alone will keep inhibiting ovulation even when pills are taken 12 h late, indicating that delays in tablet intake of up to 12 h do not jeopardize contraceptive efficacy.
  
  
  METHODS
  Women aged between 19 and 40 years with confirmed ovulation were admitted to this open-label pharmacodynamic study. They were treated with Cerazette for 56 days with three tablets to be taken 12 h late, having been randomized to a regimen with scheduled late tablets on Days 39, 42 and 49 (Group A) or on Days 11, 14 and 21 (Group B). The occurrence of ovulation during treatment was determined by measuring progesterone serum levels every 2 days.
  
  
  RESULTS
  One of the 103 treated subjects ovulated during treatment. The ovulation incidence thus amounts to 1.0% (two-sided 95% confidence interval 0.02-5.29%). There was no apparent relationship between these ovulations and scheduled late tablets. The minimum time to first posttreatment ovulation was 7 days, whereas it took 17.2 days on average from last tablet intake until ovulation.
  
  
  CONCLUSIONS
  Ovulation inhibition with Cerazette is maintained after 12-h delays in tablet intake and return of ovulation takes at least 7 days. These properties distinguish Cerazette from all other POPs.
authors.affiliation: Clinical Development Department, NV Organon, PO Box 20, 5340 BH Oss, The Netherlands. tjeerd.korver@organon.com
authors.forename: Tjeerd
authors.initials: T
authors.lastname: Korver
authors.forename: Christine
authors.initials: C
authors.lastname: Klipping
authors.forename: Doris
authors.initials: D
authors.lastname: Heger-Mahn
authors.forename: Ingrid
authors.initials: I
authors.lastname: Duijkers
authors.forename: Gonnie
authors.initials: G
authors.lastname: van Osta
authors.forename: Thom
authors.initials: T
authors.lastname: Dieben
mesh_terms: D000293:Adolescent; D000328:Adult; D003280:Contraceptives, Oral, Synthetic / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D017135:Desogestrel / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D005260:Female; D006801:Humans; D010060:Ovulation / Q000187:drug effects; D034445:Ovulation Inhibition / Q000187:drug effects*; D010349:Patient Compliance; D013607:Tablets; D016896:Treatment Outcome
chemical_list: D003280:Contraceptives, Oral, Synthetic; D013607:Tablets; D017135:Desogestrel