Norethisterone

Norethisterone

Clinical data
Trade names	Conludag, Gesta Plan, Locilan 28 Day, Menzol, Micronor, Micronovum, Mini-Pe, Mini-Pill, Minovlar, Nor-Q.D., Norcolut, Noretisteron Dak, Norfor, Noriday 28, Noriday, Norlutin, Primolut N, Primolutin, Utovlan
AHFS/Drugs.com	International Drug Names
MedlinePlus	a604034
Routes of administration	Oral
ATC code	G03AC01 (WHO) G03DC02 (WHO)
Pharmacokinetic data
Bioavailability	47–73% (mean 64%)
Protein binding	>95%: Albumin: 61%; SHBG: 36%
Metabolism	Mainly CYP3A4 (liver); also 5α-/5β-reductase, 3α-/3β-HSD, and aromatase
Biological half-life	5.2–12.8 hours (mean 8.0)
Identifiers
IUPAC name (17α)-17-Hydroxy-19-norpregn-4-en-20-yn-3-one; (8R,9S,10R,13S,14S,17R)-17-Ethynyl-17-hydroxy-13-methyl-1,2,6,7,8,9,10,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthren-3-one
Synonyms	NET; Norethindrone; NSC-9564; LG-202; Ethinylnortestosterone; Norpregneninolone; 17α-Ethynyl-19-nortestosterone; 17α-Ethynylestra-4-en-17β-ol-3-one
CAS Number	68-22-4 Y
PubChem CID	6230
IUPHAR/BPS	2880
DrugBank	DB00717 Y
ChemSpider	5994 Y
UNII	T18F433X4S
KEGG	D00182 Y
ChEBI	CHEBI:7627 Y
ChEMBL	CHEMBL1162 Y
ECHA InfoCard	100.000.619
Chemical and physical data
Formula	C20H26O2
Molar mass	298.419 g/mol
3D model (Jmol)	Interactive image
SMILES O=C4\C=C3/[C@@H]([C@H]2CC[C@]1([C@@H](CC[C@]1(C#C)O)[C@@H]2CC3)C)CC4
InChI InChI=1S/C20H26O2/c1-3-20(22)11-9-18-17-6-4-13-12-14(21)5-7-15(13)16(17)8-10-19(18,20)2/h1,12,15-18,22H,4-11H2,2H3/t15-,16+,17+,18-,19-,20-/m0/s1 Y Key:VIKNJXKGJWUCNN-XGXHKTLJSA-N Y

Norethisterone (NET), also known as norethindrone, is a medication that is used in combination with estrogen or alone in hormonal contraceptives, hormone replacement therapy, and in the treatment of gynecological disorders. It is a synthetic progestogen (or progestin) of the 19-nortestosterone group and has similar effects to those of natural progesterone, including suppression of gonadotropins, ovulation inhibition, and endometrial transformation. In addition to its progestogenic activity, NET also has weak androgenic and estrogenic effects at high dosages.

A number of prodrugs of NET, including norethisterone acetate (NETA), norethisterone enanthate (NETE), etynodiol diacetate, lynestrenol, and quingestanol acetate, have been marketed as well.

NET is used as a hormonal contraceptive in combination with an estrogen – usually ethinylestradiol (EE) – in combined oral contraceptive pills and alone in progestogen-only pills. Aside from its use as a contraceptive, NET can be used to treat premenstrual syndrome, dysmenorrhea, menorrhagia, irregular menstruation, menopausal symptoms (in combination with estrogen), or to postpone a period. It is also commonly used to help prevent uterine hemorrhage in complicated non-surgical or pre-surgical gynecologic cases and in treating non responsive cyclical mastalgia.