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Hormone replacement therapy, insulin-like growth factor I and breast cancer
Published in A. R. Genazzani, Hormone Replacement Therapy and Cancer, 2020
P. Sismondi, N. Biglia, R. Ponzone, S. Ambroggio
Progestins can be divided into four groups with different metabolic activities: Progesterone derivatives (dydrogesterone and medrogestone), devoid of androgenic, estrogenic or glucocorticoid action;19-Nortestosterone derivatives (norethisterone and norethisterone acetate (NETA)), characterized by a residual androgenic action and, at high doses, also by a certain estrogenic action;17-Hydroxyprogesterone derivatives (medroxyprogesterone acetate (MPA) and cyproterone acetate), both devoid of estrogenic action, but characterized by a weak androgenic action (MPA) and by a strong antiandrogenic action (cyproterone acetate);19-Norprogesterone (nomegestrol acetate), devoid of estrogenic or glucocorticoid activity and characterized by a certain antiandrogenic activity56–59.
Progestogen use and breast cancer
Published in Barry G. Wren, Progress in the Management of the Menopause, 2020
Using human breast-cancer cell lines in culture, Catherino ard co-workers33 described the estrogenic activity of some 19-nortestosterone derivatives such as norgestrel and gestodene, which were shown to stimulate breast-cancer cell growth through an estrogenreceptor mechanism. Later, Catherino and Jordan34 tested 19-norprogesterone derivatives using the same model. They showed that nomegestrol acetate, a 19-norprogesterone derivative, inhibited T47D-cell growth and did not exhibit any estrogenic effect. They found that only estradiol, norgestrel and RU486 stimulate cell proliferation while R5020, MPA and nomegestrol acetate were unable to provide a proliferative stimulus. They also demonstrated that this effect of the former molecules on proliferation was an estrogen receptor-mediated effect.
Saturation Analysis: Radioimmunoassay and Other Ligand Assays
Published in Joseph Chamberlain, The Analysis of Drugs in Biological Fluids, 2018
A human myometrium progesterone receptor has been used for determination of the abortifacient mifepristone. The method utilizes competitive replacement of [3H]16α-ethyl-21-hydroxy-19-norprogesterone, over a useful range of 10 to 120 pmol with a detection limit of 8.7 pmol.1243
Hormonal and natural contraceptives: a review on efficacy and risks of different methods for an informed choice
Published in Gynecological Endocrinology, 2023
Andrea R. Genazzani, Tiziana Fidecicchi, Domenico Arduini, Andrea Giannini, Tommaso Simoncini
Progestins are classified in categories according to their structural origins. They have been divided in generations according to the time of first synthesis. Among those used in the field of HC, pregnanes (17-hydroxyprogesterone derivatives and 19-norprogesterone derivatives, i.e. chlormadinone acetate) and estranes (testosterone derivatives, i.e. norethindrone, norethynodrel, norethindrone acetate, and ethynodiol diacetate) are considered first generation progestins. Only few of these are still used in HC due to their androgenic properties that cause bothersome side effects, as oily skin, acne, and reduced levels of high density lipoproteins (HDL) [30]. Second-generation progestins are called gonanes and derive from testosterone. This includes some of the most widely used progestins, such as levonorgestrel. Third generation include desogestrel, gestodene, norgestimate/norelgestromin, and etonogestrel. These molecules progressively lose the androgenic activity, acquiring a non-androgenic or an antiandrogenic effect. The newest progestins are the fourth-generation ones, that include nonethylated estranes (i.e. dienogest and drospirenone, a spironolactone derivative) and 19-norprogesterones-derivatives pregnanes (i.e. nomegestrol acetate) [29–31].
A technology evaluation of Annovera: a segesterone acetate and ethinyl estradiol vaginal ring used to prevent pregnancy for up to one year
Published in Expert Opinion on Drug Delivery, 2020
Elizabeth A. Micks, Jeffrey T. Jensen
SA (16-methylene-17α-acetoxy-19-norpregn-4-ene-3,20-dione, Figure 3) is a 19-norprogesterone derivative designed to specifically target the progesterone receptor with substantially reduced or no binding to the androgen receptor and mineralocorticoid receptor compared to 19-nortestosterone derived progestins [21]. Its specificity for the progesterone receptor is similar other newer progestins including nomegestrol acetate, cyproterone acetate, and dienogest [21]. The goal in developing SA was to increase endometrial potency and avoid side effects, particularly androgenic effects, caused by progestin binding to other receptor types. This progestin does not bind sex hormone binding globulin (SHBG) in circulation [21]. Other SA products under investigation include a ring combined with estradiol (E2) [22], a progestin-only ring [23], a contraceptive implant [24–26], and a transdermal gel [27].
Comprehensive overview of the recently FDA-approved contraceptive vaginal ring releasing segesterone acetate and ethinylestradiol: A new year-long, patient controlled, reversible birth control method
Published in Expert Review of Clinical Pharmacology, 2019
The most critical component that accounts for the success of this new CVR is the new progestin segesterone acetate. Segesterone acetate is a 19-nor-progesterone derivative, known as 19-norpregn-4-ene-3,20-dione, 17-hydroxy-16-methylene-19-nonpregn-4-ene-3,20-dione acetate ester and 16-methylene-17α-acetoxy-19-nor-pregn-4-ene-3,20-dione (see Figure 3). Its molecule formula is C23H3004 (see Figure 3). It is a white or yellowish-white powder with a molecular weight of 370.5 Dalton. This compound has significant potency; only low doses are needed for ovulation suppression. However, it is rapidly metabolized when administered orally, so a slow release, transdermal or transmucosal delivery system, such as the contraceptive vaginal ring, represents an excellent delivery system to utilize its strengths [11].