title: A historical cycle control comparison of two drospirenone-containing combined oral contraceptives: ethinylestradiol 30 μg/drospirenone 3 mg administered in a 21/7 regimen versus ethinylestradiol 20 μg/drospirenone 3 mg administered in a 24/4 regimen.
abstract: OBJECTIVE
  To compare the bleeding patterns and cycle control of an oral contraceptive (OC) containing ethinylestradiol (EE) 30 μg/drospirenone (drsp) 3mg administered in a 21/7 regimen versus a lower-dose OC containing EE 20 μg/drsp 3mg administered in a 24/4 regimen, using data from two identically designed studies.
  
  
  METHODS
  In the first study, 326 healthy women (18-35 years) received EE 30 μg/drsp 3mg in a 21/7 regimen. In the second study, 1027 healthy women (17-36 years) received EE 20 μg/drsp 3mg in a 24/4 regimen. Participants recorded bleeding using daily completed diaries over 13 treatment cycles.
  
  
  RESULTS
  During cycles 1-12, the prevalence of scheduled withdrawal bleeding was lower with EE 20 μg/drsp 3mg 24/4 than with EE 30 μg/drsp 3mg 21/7 (82.0-91.7% versus 94.8-100.0% of women, respectively); moreover, a higher proportion of women reported a maximum intensity of light scheduled withdrawal bleeding with EE 20 μg/drsp 3mg 24/4 than with EE 30 μg/drsp 3mg 21/7 (30.9-39.0% versus 13.8-20.5% of women, respectively). In cycles 2-13, unscheduled intracyclic bleeding was reported by 7.7-13.8% of EE 20 μg/drsp 3mg 24/4 recipients and 3.8-7.9% of EE 30 μg/drsp 3mg 21/7 recipients; these were mainly single bleeding days. During reference periods 1-4, the mean number of bleeding episodes was similar between groups (3.1-3.3 episodes with EE 20 μg/drsp 3mg 24/4 versus 3.2 episodes with EE 30 μg/drsp 3mg 21/7).
  
  
  CONCLUSIONS
  A low-dose 24/4 regimen OC containing EE 20 μg/drsp 3mg is generally comparable in terms of bleeding to a higher-dose 21/7 regimen OC containing EE30 μg/drsp 3mg. Between-treatment differences in bleeding intensity and unscheduled intracyclic bleeding rates were observed.
authors.affiliation: Global Clinical Development, Women's Healthcare, Bayer HealthCare Pharmaceuticals, Berlin, Germany. joachim.marr@bayer.com
authors.forename: Joachim
authors.initials: J
authors.lastname: Marr
authors.forename: Christoph
authors.initials: C
authors.lastname: Gerlinger
authors.forename: Michael
authors.initials: M
authors.lastname: Kunz
mesh_terms: D000293:Adolescent; D000328:Adult; D000736:Androstenes / Q000008:administration & dosage* / Q000627:therapeutic use; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage* / Q000627:therapeutic use; D003278:Contraceptives, Oral, Hormonal / Q000008:administration & dosage* / Q000627:therapeutic use; D004997:Ethinyl Estradiol / Q000008:administration & dosage* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000187:drug effects*; D016896:Treatment Outcome
chemical_list: D000736:Androstenes; D003277:Contraceptives, Oral, Combined; D003278:Contraceptives, Oral, Hormonal; C534342:drospirenone and ethinyl estradiol combination; D004997:Ethinyl Estradiol