Extended cycles with the combined oral contraceptive chlormadinone acetate 2 mg/ethinylestradiol 0.03 mg: pooled analysis of data from three large-scale, non-interventional, observational studies

Clin Drug Investig. 2011;31(4):269-77. doi: 10.2165/11586720-000000000-00000.


Background and objective: The prescribing of extended regimens of oral contraceptives (OCs) is increasing in routine gynaecological practice as a means of reducing the number of annual menstrual bleeds. Typically, this involves taking one pill per day for, say, 84 days continuously (4×21 days), followed by a 7-day pill-free interval. Low-dose OCs are suitable for extended use, and many gynaecologists in Germany prescribe the combination of chlormadinone acetate 2 mg/ethinylestradiol 0.03 mg (CMA 2 mg/EE 0.03 mg). The aim of the current study was to assess the risks and benefits of CMA 2 mg/EE 0.03 mg in extended regimens, using pooled data from observational studies.

Methods: This pooled analysis of three large-scale, non-interventional, observational studies assessed the results in women receiving Belara® (CMA 2 mg/EE 0.03 mg) according to an extended regimen compared with conventional regimens documented in the summary of product characteristics.

Results: A total of 625 women were identified as extended-regimen users (mean±SD age 24.9±9.0 years). Extended-cycle use was associated with decreases in skin problems, dysmenorrhoea symptoms (as shown by reductions in analgesic use; absence from school, university, or work; and restrictions in leisure and sporting activities), cycle-dependent symptoms (e.g. headache/migraine, breast tenderness), withdrawal bleeding, bleeding duration and reduced libido. Mean bodyweight remained almost constant over 6 months. Only nine adverse drug reactions, none severe, were reported in eight women (1.3%).

Conclusion: This pooled analysis confirms that extended regimens of CMA 2 mg/EE 0.03 mg reduce cycle-related complaints and are very well tolerated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Chlormadinone Acetate / adverse effects
  • Chlormadinone Acetate / analogs & derivatives*
  • Chlormadinone Acetate / pharmacology
  • Contraceptives, Oral, Combined / adverse effects
  • Contraceptives, Oral, Combined / pharmacology*
  • Ethinyl Estradiol / adverse effects
  • Ethinyl Estradiol / analogs & derivatives*
  • Ethinyl Estradiol / pharmacology
  • Female
  • Humans
  • Menstrual Cycle / drug effects*


  • Contraceptives, Oral, Combined
  • ethinylestradiol-chlormadinone acetate
  • Chlormadinone Acetate
  • Ethinyl Estradiol