Endometrial effects of three doses of trimegestone, a new orally active progestogen, on the postmenopausal endometrium.
OBJECTIVE
To study the effects of oral trimegestone on endometrial histology and vaginal bleeding when given in combination with oral 17-beta-oestradiol.


METHODS
This was a prospective, randomised, double-blind, parallel groups, pilot comparative study. Thirty-eight healthy postmenopausal women with normal endometrial histology were given oral 17-beta-oestradiol, 2 mg/day for three continuous cycles of 28 days, plus oral trimegestone, 0.10, 0.25 or 0.50 mg/day from day 15 to day 28 of each cycle. A Vabra biopsy was performed late in the oestradiol/trimegestone phase of cycle 3 and examined for histological evidence of secretory transformation of the endometrium. Characteristics of vaginal bleeding were recorded on a daily basis.


RESULTS
Thirty-seven women completed the study, of whom 31 yielded adequate tissue for histological assessment. All showed secretory transformation of the endometrium. Bleeding was of earlier onset and longer duration with the lowest dose of trimegestone.


CONCLUSIONS
Trimegestone is a highly effective oral progestogen for endometrial protection, all doses inducing secretory endometrial transformation. Although bleeding patterns suggest a weaker effect of the lowest dose used, the minimum effective dose for endometrial protection has still to be determined and may be lower than those used in this study.
Ross
D
D
Menopause Clinic, King's College Hospital, London, U.K.
Godfree
V
V
Cooper
A
A
Pryse-Davies
J
J
Whitehead
M I
MI
D000284:Administration, Oral; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004717:Endometrium / Q000187:drug effects*; D015914:Estrogen Replacement Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000187:drug effects; D008875:Middle Aged; D010865:Pilot Projects; D017698:Postmenopause / Q000187:drug effects*; D011397:Promegestone / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology; D011446:Prospective Studies
C050319:trimegestone; D011397:Promegestone