Levonorgestrel

From Wikipedia, the free encyclopedia

Levonorgestrel
Systematic (IUPAC) name
13-ethyl-17-ethynyl-17-hydroxy- 1,2,6,7,8,9,10,11,12,13,14,15,16, 17- tetradecahydrocyclopenta[a] phenanthren-3-one
Identifiers
CAS number 17489-40-6
ATC code G03AC03
PubChem 13109
DrugBank APRD00754
Chemical data
Formula C21H28O2 
Mol. mass 312.446 g/mol
Pharmacokinetic data
Bioavailability ~100%
Protein binding 55%
Metabolism Hepatic
Half life  ?
Excretion Renal: 45%; Fecal:32%
Therapeutic considerations
Pregnancy cat.

?
Legal status
Routes Implant; insert (extended-release); oral

Levonorgestrel (or l-norgestrel or D-norgestrel) is a synthetic progestagen, normally used as an active ingredient in hormonal contraceptives.

Contents

Chemically, it is a hormonally active levorotatory enantiomer of the racemic mixture norgestrel. It is a gonane progestin derived from 19-nortestosterone.[1]

Its in vitro relative binding affinities at human steroid hormone receptors are: 323% that of progesterone at the progesterone receptor, 58% that of testosterone at the androgen receptor, 17% that of aldosterone at the mineralocorticoid receptor, 7.5% that of cortisol at the glucocorticoid receptor, and <0.02% that of estradiol at the estrogen receptor.[2]

Main article: birth control

At low doses, levonorgestrel is used in monophasic and triphasic formulations of combined oral contraceptive pills, with available monophasic doses ranging from 100-250 µg, and triphasic doses of 50 µg/75 µg/125 µg.

At very low daily dose of 30 µg, levonorgestrel is used in some progestogen only pill formulations.

Levonorgestrel is used in emergency contraception pills, both in a combined regimen which includes estrogen, and as a levonorgestrel-only method. For the latter, a single dose of 1500 ug within 3 days is almost 100% effectve. There are many names for levonorgestrel-only emergency contraception products, including Plan B, Levonelle One Step, and Postinor-2.

Levonorgestrel is the active ingredient in Mirena.

Levonorgestrel is the active ingredient in Norplant and Jadelle.

  1. ^ Edgren RA, Stanczyk FZ (1999). "Nomenclature of the gonane progestins". Contraception 60 (6): 313. PMID 10715364. 
  2. ^ Sitruk-Ware R (2006). "New progestagens for contraceptive use". Hum Reprod Update 12 (2): 169-78. PMID 16291771. 

v • d • e
Sex hormones and related agents (primarily G03, also L02, H01C) - human endogenous in CAPS
Progestogens:
(receptor)		 PROGESTERONE, Desogestrel, Drospirenone, Dydrogesterone, Ethisterone, Etonogestrel, Ethynodiol diacetate, Gestodene, Gestonorone, Levonorgestrel, Lynestrenol, Medroxyprogesterone, Megestrol, Norelgestromin, Norethisterone, Norethynodrel, Norgestimate, Norgestrel, Norgestrienone, Tibolone
Antiprogestogen: Mifepristone
Androgens:
(receptor)		 TESTOSTERONE, Androstanolone, Fluoxymesterone, Mesterolone, Methyltestosterone, (see also anabolic steroids)
Antiandrogens: Bicalutamide, Cyproterone, Flutamide, Nilutamide, Spironolactone
Estrogens:
(receptor)		 ESTRADIOL, ESTRIOL, ESTRONE, Chlorotrianisene, Dienestrol, Diethylstilbestrol, Ethinylestradiol, Fosfestrol, Mestranol, Polyestradiol phosphate
Selective estrogen receptor modulator: Bazedoxifene, Clomifene, Fulvestrant, Raloxifene, Tamoxifen, Toremifene
Aromatase inhibitor: Aminogluthetimide, Anastrozole, Exemestane, Formestane, Letrozole, Vorozole
Gonadotropins:
(FSHR/LHCGR)		 ovulation stim.:Clomifene, Urofollitropin
Antigonadotropins: Danazol, Gestrinone
GnRH:
(receptor)		 agonist: Buserelin, Goserelin, Histrelin, Leuprorelin, Nafarelin, Triptorelin
antagonist: Abarelix, Cetrorelix, Ganirelix
Pills  This pharmacology-related article is a stub. You can help Wikipedia by expanding it.
Retrieved from "http://en.wikipedia.org../../../l/e/v/Levonorgestrel.html"
Advanced Search
Included Web Search Engines


Safe Search

close

Top Matching Results

Occasionally Search.com will highlight specialized results that are based on the context of your query. Examples of specialized results include specific links to news, images, or video.

Top Matching Results may highlight information from other Search.com pages, content from the CNET Network of sites, or third party content. The listings are based purely on relevance. Search.com does not receive payment for listings in this section but our partners that provide this data may get paid for listing these products.

Sponsored Links

This section contains paid listings which have been purchased by companies that want to have their sites appear for specific search terms and related content. These listings are administered, sorted and maintained by a third party and are not endorsed by Search.com.

Search Results

Search.com sends your search query to several search engines at one time and integrates the results into one list which has been sorted by relevance using Search.com's proprietary algorithm. You can customize the list of search engines included in your metasearch from the preferences.

The search engines that are used in your metasearch may allow companies to pay to have their Web sites included within the results. To view the Paid Inclusion policy for a specific search engine, please visit their Web site. Search.com does not accept payment or share revenue with any search engine partner for listings in this section.