Мифепристон

Описание

Mifepristone is an orally-active progesterone and glucocorticoid receptor antagonist indicated for use as a post-coital contraceptive. In addition to being an abortifacient, mifepristone is reported to be effective in the treatment of ocular hypertension; its potential therapeutic effect in hormone-dependent tumors is currently under investigation.

Химические свойства

Pale Yellow Solid

Использование

Mifepristone is a progesterone receptor antagonist with partial agonist activity. Abortifacient.

Показания

Mifepristone is a progesterone receptor antagonist that has a high affinity for glucocorticoid receptors and little agonist effect.This drug has recently been approved for use in the United States for the treatment of hypercortisolism. At high doses, mifepristone blocks negative feedback of the hypothalamic–pituitary axis, thereby increasing endogenous corticotrophin and cortisol levels. Because mifepristone exerts its effects at the receptor level and not by altering glucocorticoid production, elevated serum cortisol and corticotrophin levels may not accurately reflect the effectiveness of the therapeutic regimen. Mifepristone does not inhibit cortisol binding to the mineralocorticoid receptor, so that the resulting corticotrophin disinhibition may cause potassium depletion. Thus, administration of a mineralocorticoid receptor antagonist such as spironolactone may be indicated with mifepristone. Hypoadrenalism, nausea, and drowsiness have been reported during prolonged administration of mifepristone.

Всемирная организация здравоохранения(ВОЗ)

Mifepristone, an antiprogesterone used in combination with a prostaglandin for the termination of early pregnancy, was introduced in 1990. Use of the combination has been associated with episodes of coronary spasm that are attributed to administration of the prostaglandin and which have resulted in several cases of cardiac infarction and ventricular fibrillation. At least one of these incidents has been fatal.

Биологическая активность

Selective antagonist at progesterone (PR) and glucocorticoid (GR) receptors in vitro and in vivo . Is a silent antagonist at PR and has a higher affinity than progesterone. Has higher affinity for GR than dexamethasone.

Фармакокине?тика

Following oral administration, mifepristone is rapidly absorbed, with a peak plasmaconcentration in approximately 90 minutes , an oral bioavailability of approximately 70%, and a term inal elimination half-life of 18 hours. It is 98% protein bound, primarily to album in and α1-acid glycoprotein. Mifepristone is metabolized primarily via CYP3A4 pathways involving mono- and di-N-demethylation and terminal hydroxylation of the 17-propynyl chain. The fact that approximately 83% of the drug is recovered in the feces and 9% in the urine suggests a biliary route of elimination. Mifepristone also demonstrates antiglucocorticoid activity.

Клиническое использование

An antiprogestin is a substance that competes with progesterone for its receptor and, ultimately, prevents progesterone from binding to and activating its receptor. Because progesterone is integral to the continuation of an early pregnancy, it is expected that antipro-gestins will interfere with pregnancy maintenance. In 1982, the first antiproges tin, mifepristone (RU 486), was reported. Mifepristone was shown to interrupt early stages of implantation and pregnancy in humans.

использованная литература

https://pubchem.ncbi.nlm.nih.gov/compound/mifepristone#section=Top
https://www.drugbank.ca/drugs/DB00834
https://www.drugs.com/cdi/mifepristone-tablets.html