Biologic effects of various doses of ethinyl estradiol in postmenopausal women
Mandel, F.P.; Geola, F.L.; Lu, J.K.; Eggena, P.; Sambhi, M.P.; Hershman, J.M.; Judd, H.L.
Obstetrics and Gynecology 59(6): 673-679
1982
ISSN/ISBN: 0029-7844 PMID: 6281707 Document Number: 188937
To determine which dosage of estrogen might provide physiologic replacement while minimizing adverse effects, 20 postmenopausal women were studied before and after oral administration of ethynyl estradiol. Twenty premenopausal women studied in the early and late follicular phases of the menstrual cycle were presumed to reflect normal physiologic function. Variable responses of the different biochemical and biologic markers to the actions of ethynyl estradiol were observed. Liver protein synthesis was the most sensitive measure of the action of ethynyl estradiol. In comparing the relative potencies of ethynyl estradiol with previously reported results observed with the usage of conjugated equine estrogens, the actions of 10 .mu.g ethynyl estradiol were approximately equivalent to the biologic effects of 1.25 mg conjugated estrogens. Ethynyl estradiol is far more potent than previously believed and the daily administration of 10 .mu.g, a dose lower than currently available commercial preparations, may be adequate for relief of symptoms of vaginal atrophy and may provide protection from the occurrence of osteoporotic fractures.