Biologic effects of transdermal estradiol.

Authors: Chetkowski RJ, Meldrum DR, Steingold KA, Randle D, Lu JK, Eggena P, Hershman JM, Alkjaersig NK, Fletcher AP, Judd HL.

Publication Year: 1986

Citation: N Engl J Med 1986 Jun 19;314(25):1615-20.

Twenty-three postmenopausal women were randomly assigned to use of transdermal estradiol in four increasing doses (25, 50, 100, 100 micrograms per 24 hours) followed by daily oral dose of conjugated equine estrogens in two doses (0.625 mg, 1.25 mg) or to use of oral conjugated equine estrogens followed by transdermal estradiol. Results showed a dose-response relationship between the amount of estradiol delivered and the serum measure of the hormone. Estrone concentrations also rose with transdermal application. At the 50 and 100 microgram transdermal dose levels, results were comparative to the 0.625 and 1.25 mg conjugated equine estrogen results. Non-hepatic markers (serum gonadotropin, vaginal cytologic studies, urinary calcium levels and urinary calcium/creatinine ratios all increased in dose-dependent fashion. Hepatic markers (hepatic protein level, lipid metabolism, clotting factors, renin substrate) were not affected by transdermal doses of estradiol. Transdermal estradiol provided benefit of increased serum hormone levels without hepatic protein effects of oral conjugated equine estrogens.