Mifepristone

Mifepristone
Clinical data
Pronunciation	/ˌmɪfəˈprɪˌstoʊn/
Trade names	Mifegyne, Mifeprex, Korlym, others
Other names	RU-486; RU-38486; ZK-98296; 11β-[p-(Dimethylamino)phenyl]-17α-(1-propynyl)estra-4,9-dien-17β-ol-3-one
AHFS/Drugs.com	Monograph
MedlinePlus	a600042
License data	US DailyMed: Mifepristone;
Pregnancy; category	Not recommended;
Routes of; administration	By mouth
Drug class	Antiprogestogen; Antiglucocorticoid
ATC code	G03XB01 (WHO) ;
Legal status
Legal status	AU: S4 (Prescription only); CA: ℞-only; US: ℞-only; In general: ℞ (Prescription only);
Pharmacokinetic data
Bioavailability	69%
Protein binding	98%
Metabolism	Liver
Excretion	Feces: 83%; urine: 9%
Identifiers
	IUPAC name (8S,11R,13S,14S,17S)-11-[4-(dimethylamino)phenyl]-17-hydroxy-13-methyl-17-prop-1-ynyl-1,2,6,7,8,11,12,14,15,16-decahydrocyclopenta[a]phenanthren-3-one;
CAS Number	84371-65-3 ;
PubChem CID	55245;
IUPHAR/BPS	2805;
DrugBank	DB00834 ;
ChemSpider	49889 ;
UNII	320T6RNW1F;
KEGG	D00585 ;
ChEBI	CHEBI:50692 ;
ChEMBL	ChEMBL157 ;
CompTox Dashboard (EPA)	DTXSID5023322 ;
ECHA InfoCard	100.127.911
Chemical and physical data
Formula	C29H35NO2
Molar mass	429.604 g·mol−1
3D model (JSmol)	Interactive image;
Density	1.189 g/cm3
Melting point	194 °C (381 °F)
Boiling point	629 °C (1,164 °F)
	SMILES O=C5\C=C4/C(=C3/[C@@H](c1ccc(N(C)C)cc1)C[C@]2([C@@H](CC[C@]2(C#CC)O)[C@@H]3CC4)C)CC5;
	InChI InChI=1S/C29H35NO2/c1-5-15-29(32)16-14-26-24-12-8-20-17-22(31)11-13-23(20)27(24)25(18-28(26,29)2)19-6-9-21(10-7-19)30(3)4/h6-7,9-10,17,24-26,32H,8,11-14,16,18H2,1-4H3/t24-,25+,26-,28-,29-/m0/s1 ; Key:VKHAHZOOUSRJNA-GCNJZUOMSA-N ;
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Mifepristone, and also known by its developmental code name RU-486, is a drug typically used in combination with misoprostol to bring about a medical abortion during pregnancy. This combination is 97% effective during the first 63 days (9 weeks) of pregnancy, yet effective in the second trimester as well. It is also used on its own to treat Cushing's syndrome or for use as a low-dose emergency contraceptive.

The most common adverse effects include abdominal pain, feeling tired, and vaginal bleeding. Serious side effects may include heavy vaginal bleeding, bacterial infection, and, if pregnant, birth defects. When used, appropriate follow-up care needs to be available. Mifepristone is primarily an antiprogestogen. It works by blocking the effects of progesterone, making both the cervix and uterine vessels dilate and causing uterine contraction. Mifepristone also works, to a less extent, as an antiglucocorticoid and diminishes the effects of hypercortisolism.

Mifepristone was developed in 1980 and came into use in France in 1987. It became available in the United States in 2000, for medication abortion, and in 2010, for Cushing's syndrome. It is on the World Health Organization's List of Essential Medicines. Mifepristone was approved in Canada in January 2017.