title: Cycle control with a 21-day compared with a 24-day oral contraceptive pill: a randomized controlled trial.
abstract: OBJECTIVE
  To compare bleeding patterns between a 21/7-day triphasic norgestimate/ethinyl estradiol (E2) 25-microgram oral contraceptive pill (OCP) and a 24/4-day drospirenone/ethinyl E2 20-microgram OCP.
  
  
  METHODS
  In a three-cycle, open-label, multicenter study, healthy, sexually active women were assigned randomly to a 21/7-day (norgestimate/ethinyl E2) or 24/4-day (drospirenone/ethinyl E2) OCP regimen. Randomization was stratified to assure a balanced distribution between regimens for "fresh starts" and "switchers." Bleeding data were collected daily using an interactive voice-response system. Bleeding was defined according to the 2007 U.S. Food and Drug Administration's Reproductive Health Drug Advisory Committee-endorsed criteria.
  
  
  RESULTS
  Across the three cycles, the 21/7-day OCP group (n=165) reported fewer unscheduled bleeding days than did the 24/4-day OCP group (n=167) (mean 4.6 compared with 6.1 days, P=.003). Women using the 21/7-day OCP had significantly fewer episodes of unscheduled bleeding than did those using the 24/4-day OCP (mean 1.47 compared with 2.01, P=.001). Moreover, women using the 21/7-day OCP had a significantly lower absence of scheduled bleeding at each cycle (P<.001). Both regimens were well-tolerated.
  
  
  CONCLUSIONS
  A 21-day norgestimate/ethinyl E2 25-microgram regimen results in less unscheduled bleeding and more scheduled bleeding than does a 24-day drospirenone/ethinyl E2 20-microgram regimen.
  
  
  BACKGROUND
  ClinicalTrials.gov, www.ClinicalTrials.gov, NCT00745901.
  
  
  METHODS
  I.
authors.affiliation: From the Department of Obstetrics and Gynecology, University of Florida College of Medicine, Jacksonville, Florida; the Department of Obstetrics and Gynecology, Baystate Medical Center, Springfield, Massachusetts; and Ortho-McNeil-Janssen Scientific Affairs, Raritan, New Jersey.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Kaunitz
authors.forename: Ronald T
authors.initials: RT
authors.lastname: Burkman
authors.forename: Alan C
authors.initials: AC
authors.lastname: Fisher
authors.forename: Katherine D
authors.initials: KD
authors.lastname: LaGuardia
mesh_terms: D000328:Adult; D000736:Androstenes / Q000008:administration & dosage* / Q000009:adverse effects; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage* / Q000009:adverse effects; D004338:Drug Combinations; D004997:Ethinyl Estradiol / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000187:drug effects*; D008796:Metrorrhagia / Q000139:chemically induced; D000451:Mineralocorticoid Receptor Antagonists / Q000008:administration & dosage* / Q000009:adverse effects; D009644:Norgestrel / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D055815:Young Adult
chemical_list: D000736:Androstenes; D003277:Contraceptives, Oral, Combined; D004338:Drug Combinations; D000451:Mineralocorticoid Receptor Antagonists; C109079:norgestimate, ethinyl estradiol drug combination; D009644:Norgestrel; D004997:Ethinyl Estradiol; C035144:drospirenone