Gestrinone

Danger

H360 (25%): May damage fertility or the unborn child [Danger Reproductive toxicity]

P203, P260, P263, P264, P270, P280, P318, P319, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 4 reports by companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

G - Genito urinary system and sex hormones

QG - Genito urinary system and sex hormones

Gestrinone is a synthetic steroidal hormone which has androgenic, anti-estrogenic and anti-progestogenic properties. The findings of several studies suggest that gestrinone is as effective as danazol in the treatment of infertility associated with endometriosis and is better tolerated, in terms of adverse effects. Gestrinone has moderate anti-estrogen, and anti-gonadal properties, which can lead to increased concentrations of free testosterone, and decrease the level of sex hormone-binding globulin, suppress the FSH and LH hormone peak levels and decrease the LH mean to reduce estrogen levels. In addition, gestrinone has a direct effect on the endometrium and ectopic endometrial receptors, which have the roles of anti-progesterone and anti-estrogen effects lead to endometrial and ectopic endometrial atrophy to achieve therapeutic effects. Gestrinone inhibits the release of pituitary gonadotropins. The effect on ovarian hormone secretion results in the atrophy of endometrial tissue, resulting in the regression of endometriosis. Gestrinone is structurally related to norgestrel and possesses some androgenic and progestogenic activity. However, the gestrinone has an antiprogesterone effect on endometrial tissue. The effect of oral gestrinone, 2.5 mg biweekly for 6 months, was studied in a group of 11 women with mild or moderate endometriosis laparoscopically confirmed. Painful symptoms were alleviated in all patients within 8 weeks from the start of treatment. Gonadotropins, prolactin (PRL) 17 beta-estradiol (17 beta-E2), estrone (E1), progesterone (P), androstenedione (A), and dehydroepiandrosterone sulfate (DHEA-S) remained in the physiological follicular phase range. Total testosterone (TT) and sex hormone-binding globulin (SHBG) decreased, and free testosterone (FT) slightly increased. Metabolic studies showed a decrease in total triglyceride level, very low-density lipoprotein (VLDL) triglycerides, and high-density lipoprotein (HDL) and VLDL cholesterol. Low-density lipoprotein cholesterol and apoprotein B were found to be increased during gestrinone therapy. It can be extrapolated that gestrinone possesses antiestrogenic, androgenic, and progestogenic effects at therapeutic dosages both by acting on both central and peripheral steroid receptors.

Gestrinone has weak agonist activity on progesterone receptors in the rabbit endometrium and progesterone antagonist activity in various other pharmacological test systems. In addition, it has moderate agonist activity on prostatic androgen receptors in vitro. In several in vivo experiments, this activity was found to be low. The primary action of gestrinone is on the hypothalamic-pituitary axis where it inhibits gonadotrophin release with a weak inhibitory effect on its synthesis. It also possesses anti-estrogen activity. The suppression of the ovular gonadotrophin peak is observed after the first month of treatment; the resulting decline in ovarian hormone secretion rapidly leads to endometrial atrophy. Aside from its central action, gestrinone also has anti-progesterone activity on cell receptors in both endometrium and extra-uterine ectopic implants. Gestrinone has no direct estrogen and/or uterotrophic effects. A study was done to examine the efficacy of gestrinone in emergency contraception. The data from the study suggest that the mechanism of action of gestrinone used for the purposes of emergency contraception is likely the inhibition of implantation by acting on the endometrium as opposed to the inhibition of ovulation.

Gestrinone undergoes hydroxylation in the liver. Gestrinone is actively metabolized in the liver, mainly by hydroxylation, to conjugated metabolites 16b-hydroxy,13-ethyl (1-OH) and D-homo gestrinone. In vitro studies have shown that the metabolites are active but weaker than the unchanged drug.

Oral contraceptives which owe their effectiveness to hormonal preparations.

Compounds that interact with PROGESTERONE RECEPTORS in target tissues to bring about the effects similar to those of PROGESTERONE. Primary actions of progestins, including natural and synthetic steroids, are on the UTERUS and the MAMMARY GLAND in preparation for and in maintenance of PREGNANCY.

The oral absorption of gestrinone is 30% ±30.

About 40-45% of a dose is excreted in the urine and 30-35% in the feces.

67 L

Renal Excretion accounts for < 1 %.