Mifepristone is a kind of antagonist of the progestational and glucocorticoid hormone. It is mainly used for the treatment of hypercortisolism in patients with nonpituitary cushing syndrome. During the treatment of Cushing’s syndrome, mifepristone takes effect through interfering with the binding of cortisol to its receptor. It reduces the effects of excess cortisol (e.g., high blood sugar levels) without causing decreased cortisol production. It can also be used to end a pregnancy. Its inhibition on progesterone can induce bleeding during the luteal phase and in early pregnancy.
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.
Mifepristone (brand name: Mifeprex) is an abortion drug approved by the FDA in 2000 for the medical termination of pregnancy, up to 7 weeks of gestation, an extension extended to 10 weeks in 2016. A generic version of Mifeprex, mifepristone tablets (200 mg), was approved in 2019. The drug has been in use for 25 years. However, following a study by the Center for Ethics and Public Policy (EPPC) showing that nearly 11% of women using the drug experience serious adverse events, the FDA is reviewing the safety of mifepristone.
A progesterone and glucocorticoid antagonist, suppresses VEGF production.
glutamate uptake inhibitor, AMPA blocker
Mifepristone is a progesterone receptor antagonist with partial agonist activity. Abortifacient.
A progesterone receptor antagonist with partial agonist activity. Abortifacient.
ChEBI: Mifepristone is a 3-oxo-Delta(4) steroid, an acetylenic compound and a tertiary amino compound. It has a role as an abortifacient, a contraceptive drug, a synthetic oral contraceptive and a hormone antagonist. It derives from a hydride of an estrane.
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.
1st method of synthesis of mifepristone:A solution of 24 g of 4-(N,N-dimethylaminoethoxy)bromobenzene was addeddropwise over 45 min to magnesium in 90 ml of anhydrous tetrahydrofuran. 2ml of 1,2-dibromoethane were added as catalyst. After the addition, themixture was stirred at 25°C for one hour to obtain a solution of 0.7 M of 4-(N,N-dimethylaminoethoxy)-benzene magnesium bromide which was thenadded to a solution of 6.16 g of dimethylsulfide-cuprous bromide complex in20 ml of tetrahydrofuran. The mixture was stirred at room temperature for 20min and a solution of 3.7 g of 3,3-[1,2-(ethanediyl-bisoxy)]-5α,10α-epoxy-17α-prop-1-ynyl-δ(9(11))-estrene-17β-ol in 50 ml of tetrahydrofuran was addedthereto dropwise over a few minutes. The mixture was stirred under an inertatmosphere for one hour and was then poured into a solution of 15 g ofammonium chloride in 20 ml of iced water. The mixture was extracted withether and the organic phase was washed with aqueous saturated sodiumchloride solution, was dried and evaporated to dryness under reducedpressure. The 18.3 g of oil were chromatographed over silica gel and elutedwith chloroform to obtain 4.5 g of 3,3-[1,2-ethanediyl-bisoxy]-11β-[4-(N,N-dimethylaminoethoxy)phenyl]-17α-(prop-1-ynyl)-δ9-estrene-5α,17β-diol with aspecific rotation of [α]D20=-44(+/-)1.5° (c = 1% in chloroform).
9.5 ml of 2 N hydrochloric acid were added to a solution of 4.5 g of 3,3-[1,2-ethanediyl-bisoxy]-11β-[4-(N,N-dimethylaminoethoxy)phenyl]-17α-(prop-1-ynyl)-δ9-estrene-5α,17β-diol in 20 ml of methanol and the solution was stirredat room temperature for 2 hours. 260 ml of ether and 110 ml of an aqueoussaturated sodium bicarbonate solution were added to the mixture which wasstirred at room temperature for 15 min. The decanted aqueous phase wasextracted with ether and the organic phase was dried and evaporated todryness under reduced pressure. The 3.3 g of residue were chromatographedover silica gel and eluted with a 92.5/7.5 methylene chloride-methanolmixture to obtain 1.8 g of amorphous 11β-[4-(N,N-dimethylaminoethoxy)phenyl]-17α-(prop-1-ynyl)-δ4,9-estradiene-17β-ol-3-one with a specificrotation of [α]D20=+71° (c = 1% in chloroform).
2th method of synthesis of mifepristone (see scheme):The oxidation of the diene I, which constitutes an intermediate for totalsynthesis of 19-nor steroids, with a reagent prepared from trifluoroaceticanhydride/hydrogen peroxide was obtained exclusively α-epoxide II. Thecondensation of II with the Grignard reagent from 4-bromo-N,N-dimethylaniline results in addition of the reagent at the 11β-position. Thisresults in rearragement of the olefin to 9,10 and opening of the epoxide. Thestereochemistry of the product obtained III is consistent with trans-opening ofthe oxirane, albeit at a remove of two carbon atoms. Mild hydrolysis removesthe silyl cyanohydrin protecting group at the 17-position to give a ketone IV.Reaction of the ketone with propargyl lithium leads to V. Hydrolysis of thatproduct under more strenuous condition results in removal of the acetal at 3;the resulting β-hydroxyketone then dehydrates to afford the 4,10(9)-dienoneVI. Another name of VI is estra-4,9-dien-3-one, 11-(4-(dimethylamino)phenyl)-17-hydroxy-17-(1-propynyl)-, (11β,17β)- or mifepristone.
Mifeprex (Danco);Ru-486;Mifegyne.
World Health Organization (WHO)
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.
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.
Therefore, mifepristone is considered to be a potent abortifacient. It is also known to inhibit human chorionic gonadotropin. Mifepristone results in decidual necrosis.
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.
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.
https://pubchem.ncbi.nlm.nih.gov/compound/mifepristone#section=Top
https://www.drugbank.ca/drugs/DB00834
https://www.drugs.com/cdi/mifepristone-tablets.html
