What is/are Ethinyl Estradiol and Levonorgestrel?
Levonorgestrel (or l-norgestrel or D-norgestrel) (Plan B, Next Choice, Postinor, and others[1]) is a second generation synthetic progestogen used as an active ingredient in some hormonal contraceptives, including combined oral contraceptive pills, progestogen only pills, emergency contraceptive pills, intrauterine systems, contraceptive implants, and hormone replacement therapy.
Medical uses
Oral contraception
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 1.5 mg (as a single dose or as two .75 mg doses 12 hours apart) taken within 3 days of unprotected sex, with one study indicating that beginning as late as 120 hours (5 days) after intercourse could be effective.
There are many brand names of levonorgestrel-only ECPs, including: Escapelle, Plan B, Levonelle, Glanique, NorLevo, Postinor-2, i-pill, "Next Choice" and 72-HOURS.
The primary mechanism of action of levonorgestrel as a progestogen-only emergency contraceptive pill is to prevent fertilization by inhibition of ovulation. The International Federation of Gynecology and Obstetrics (FIGO) has issued a statement that: "review of the evidence suggests that LNG [levonorgestreol] ECPs cannot prevent implantation of a fertilized egg. Language on implantation should not be included in LNG ECP product labeling." In June 2012, a New York Times editorial called on the FDA to remove from the label the unsupported suggestion that levonorgestrel emergency contraceptive pills inhibit implantation.
Intrauterine system
Levonorgestrel is the active ingredient in the Mirena & Skyla intrauterine system.
Contraceptive implants
Levonorgestrel is the active ingredient in Norplant and Jadelle.
Hormone replacement therapy
Levenorgestrel is combined with 17-beta estradiol in the Climara Pro hormonal patch.
Adverse effects
Possible side effects of levonorgestrel include nausea, vomiting, stomach pain, dizziness, breast tenderness, tiredness and weakness, headache, menstrual changes, and diarrhea.
It decreases total and free testosterone, androstenedione, dehydroepiandrosterone sulfate (DHEAS), dihydrotestosterone (DHT) and sex hormone–binding globulin (SHBG), but has no effect on sexual function or markers of androgen bioactivity.
This article uses material from the Wikipedia article Ethinyl Estradiol and Levonorgestrel, which is released under the Creative Commons Attribution-Share-Alike License 3.0.
