Levonorgestrel
From DrugPedia: A Wikipedia for Drug discovery
Levonorgestrel (or l-norgestrel or D-norgestrel) is a synthetic progestogen used as an active ingredient in some hormonal contraceptives.
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Chemistry
Chemically, it is a hormonally active levorotatory enantiomer of the racemic mixture norgestrel. It is a gonane progestin derived from 19-nortestosterone.<ref>Edgren RA, Stanczyk FZ (1999). "Nomenclature of the gonane progestins". Contraception 60 (6): 313. doi:. PMID 10715364.</ref>
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.<ref>Sitruk-Ware R (2006). "New progestagens for contraceptive use". Hum Reprod Update 12 (2): 169–78. doi:. PMID 16291771.</ref>
Usage
Oral contraceptives
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.
Emergency contraception
Levonorgestrel is used in emergency contraceptive pills (ECPs), both in a combined Yuzpe regimen which includes estrogen, and as a levonorgestrel-only method. The levonorgestrel-only method uses levonorgestrel 1500 μg (as a single dose or as two 750 μg doses 12 hours apart) taken within 3 days of unprotected sex. There are many brand names of levonorgestrel-only ECPs, including: Escapelle, Plan B, Levonelle, NorLevo, Postinor-2, and 72-HOURS.<ref name="ecp worldwide">Template:Cite web</ref>
IUD
Levonorgestrel is the active ingredient in Mirena.
Contraceptive implants
Levonorgestrel is the active ingredient in Norplant and Jadelle.
References
External links
- Levonelle manufacturer's product information from Schering
- Monograph for levonorgestrel - Uk Medicines Information
Template:Sex hormonesTemplate:Pharma-stub
Levonorgestrel Pubchem(13109)
A synthetic progestational hormone with actions similar to those of PROGESTERONE and about twice as potent as its racemic or (+-)-isomer (NORGESTREL). It is used for contraception, control of menstrual disorders, and treatment of endometriosis.
KEGG(C08149,C08153,D00950,D00954)
Activity Progestin
| Physical Property | Value | Units | Temp (deg C) | Source |
|---|---|---|---|---|
| Melting Point | 240 | deg C | EXP | |
| Water Solubility | 2.050 | mg/L | 25 | EST |
| Vapor Pressure | 3.93E-10 | mm Hg | 25 | EST |
| Henry's Law Constant | 7.70E-10 | atm-m3/mole | 25 | EST |
| Atmospheric OH Rate Constant | 1.14E-11 | cm3/molecule-sec | 25 | EST |
