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.

Contents 1 Chemistry 2 Usage 2.1 Oral contraceptives 2.2 Emergency contraception 2.3 IUD 2.4 Contraceptive implants 3 References 4 External links

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:10.1016/S0010-7824(99)00101-8. 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:10.1093/humupd/dmi046. PMID 16291771. </ref>

Usage

Main article: birth control

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

Physiochemical properties of Estradiol:

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