Nestorone: clinical applications for contraception and HRT.
The 19-nor derivatives of progesterone are referred to as "pure" progestational molecules as they bind almost exclusively to the progesterone receptor (PR) without interfering with receptors of other steroids. In this category is Nestorone, which has strong progestational activity and antiovulatory potency with no androgenic or estrogenic activity in vivo. These properties make it highly suitable for use in contraception and hormonal therapy (HT). Due to its high potency, very low doses of Nestorone may be delivered via long-term sustained-release delivery systems. Nestorone, 75 or 100 microg per day, released by vaginal ring has suppressed ovulation in women, with inhibition of follicular maturation. A vaginal ring releasing both 150 microg of Nestorone and 15 microg of ethinyl estradiol per day has effectively suppressed ovulation for 13 consecutive cycles. Nestorone has also been used effectively in a single implant for contraception in breastfeeding women and shows promise for use in transdermal systems as a contraceptive or for HT when combined with estrogen.
Sitruk-Ware
Regine
R
Center for Biomedical Research, Population Council, Rockefeller University, 1230 York Avenue, Weiss Bldg., 6th Floor, New York, NY 10021, USA. rsitukware@popcbr.rockefeller.edu
Small
Margaret
M
Kumar
Narender
N
Tsong
Yun-Yen
YY
Sundaram
Kalyan
K
Jackanicz
Theodore
T
D000818:Animals; D003267:Contraception; D003271:Contraceptive Agents, Female / Q000627:therapeutic use*; D004997:Ethinyl Estradiol / Q000378:metabolism; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D008956:Models, Chemical; D009653:Norprogesterones / Q000378:metabolism / Q000494:pharmacology / Q000627:therapeutic use*; D010060:Ovulation; D011374:Progesterone / Q000378:metabolism; D011485:Protein Binding; D051381:Rats; D013997:Time Factors
D003271:Contraceptive Agents, Female; D009653:Norprogesterones; C030703:19-norprogesterone; D004997:Ethinyl Estradiol; D011374:Progesterone; C029167:ST 1435