title: Oral ultra-low dose continuous combined hormone replacement therapy with 0.5 mg 17β-oestradiol and 2.5 mg dydrogesterone for the treatment of vasomotor symptoms: results from a double-blind, controlled study.
abstract: OBJECTIVE
  Guidelines recommend using the lowest effective dose of oestrogen for the management of vasomotor symptoms in postmenopausal women. The primary aim of this double-blind, multi-centre, randomised study was to assess the efficacy of oral ultra-low dose continuous combined hormone replacement therapy with 17β-oestradiol and dydrogesterone.
  
  
  METHODS
  313 women with ≥50 moderate to severe hot flushes during the previous week were randomised to 0.5 mg 17β-oestradiol/2.5 mg dydrogesterone (E 0.5 mg/D 2.5 mg), 1mg 17β-oestradiol/5mg dydrogesterone (E 1mg/D 5 mg) or placebo for 13 weeks. The placebo group then switched to E 0.5 mg/D 2.5 mg for a further 39 weeks, whilst the other groups continued on the same treatment.
  
  
  RESULTS
  After 13 weeks, the reduction in the number of moderate to severe hot flushes/day in the E 0.5 mg/D 2.5 mg group was greater than in the placebo group (-6.4 vs. -4.9, p<0.001) and comparable to that in the 1/5 mg group (-6.3). E 0.5 mg/D 2.5 mg and E 1mg/D 5 mg significantly improved the total Menopause Rating Scale score. The number of bleeding/spotting days was lower with E 0.5 mg/D 2.5 mg than with E 1 mg/D 5 mg. The overall amenorrhoea rate with E 0.5 mg/D 2.5 mg was 81%; this increased to 91% in months 10-12.
  
  
  CONCLUSIONS
  Continuous combined 0.5 mg 17β-oestradiol and 2.5mg dydrogesterone was effective in alleviating vasomotor symptoms and improving quality of life, and was associated with a high amenorrhoea rate and a good tolerability profile.
authors.affiliation: National Heart and Lung Institute, Imperial College London, Royal Brompton NHS Foundation Trust, London, UK. j.stevenson@imperial.ac.uk
authors.forename: John C
authors.initials: JC
authors.lastname: Stevenson
authors.forename: Gemma
authors.initials: G
authors.lastname: Durand
authors.forename: Elke
authors.initials: E
authors.lastname: Kahler
authors.forename: Tomasz
authors.initials: T
authors.lastname: Pertyński
mesh_terms: D000284:Administration, Oral; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D004394:Dydrogesterone / Q000008:administration & dosage*; D004958:Estradiol / Q000008:administration & dosage*; D015914:Estrogen Replacement Therapy / Q000379:methods*; D004967:Estrogens / Q000008:administration & dosage*; D005260:Female; D019584:Hot Flashes / Q000188:drug therapy*; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause / Q000187:drug effects*; D011788:Quality of Life; D016896:Treatment Outcome; D014666:Vasomotor System / Q000187:drug effects
chemical_list: D003277:Contraceptives, Oral, Combined; D004967:Estrogens; D004958:Estradiol; D004394:Dydrogesterone