PMID: 6793811Aug 1, 1981

Pharmacokinetics and pharmacodynamic effects of vaginal oestradiol administration from silastic rings in post-menopausal women

D E EnglundE D Johansson


Silastic rings releasing approximately 200 microgram of 17beta-oestradiol per day were inserted into the vaginas of 4 post-menopausal women for one to three 21-day periods. Plasma concentrations of oestrone and oestradiol were analysed by radioimmunoassay. The effect of circulating oestrogens on FSH, LH and sex-hormone binding globulin (SHBG) levels as the well as on the endometrium was studied. During the first 24 h of treatment the plasma oestradiol levels were higher than the oestrone levels. But during the following days of the 21-day periods, the levels of the two oestrogens were almost equal, varying between about 100 and 200 pg/ml plasma, a pattern similar to that seen in fertile women. the release of oestradiol from the ring gave stable plasma oestrogen levels. The FSH and LH levels were clearly depressed while the SHBG levels did not change. Characteristics of oestrogen influence were found in endometrial biopsies. The rings were well accepted and could be inserted and removed easily by the women. Absorption of oestradiol from the vagina is good and more complete than after oral administration allowing lower doses to be used for treatment.


Jan 26, 1978·The New England Journal of Medicine·L A RiggS S Yen
Jan 1, 1977·Acta Obstetricia Et Gynecologica Scandinavica. Supplement·D E Englund, E D Johansson
Dec 1, 1972·Acta Endocrinologica·L E Edqvist, E D Johansson


Sep 9, 1999·Journal of Controlled Release : Official Journal of the Controlled Release Society·A D WoolfsonC M Passmore
Jan 1, 1993·Baillière's Clinical Endocrinology and Metabolism·M S Marsh, M I Whitehead
Aug 21, 2003·Archives of Gynecology and Obstetrics·Jochen ReinsbergHans van der Ven
Mar 15, 2006·Journal of Controlled Release : Official Journal of the Controlled Release Society·Jin-Wook Yoo, Chi H Lee
Jan 1, 1981·Upsala Journal of Medical Sciences·D E Englund, E D Johansson
Sep 30, 1999·The Journal of Pharmacy and Pharmacology·A D Woolfson

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