Levonorgestrel: profile and news

Maryland's Plan B 07 Mar 2006
Available by prescription since 1999, Plan B is nothing more than two high-dosage pills of the drug levonorgestrel that can be taken up to 72 hours after ... - Baltimore Sun,

Going for Plan B Feb 27, 2006
Plan B is high dose of progesterone called Levonorgestrel (also used in the IUD Mirena). ... Plan B is given as a 0.75mg Levonorgestrel pill twice 12 hours apart. ... - Cavalierdaily.com,

Top editors fired at leading medical journal Feb 22, 2006
...its members to collect women's names, addresses, and sensitive personal information before dispensing the emergency contraceptive levonorgestrel (Plan B) - a ... - Ottawa Citizen,

Good reason for Plan B bill Mar 3, 2006
According to the AMA, Plan B is a Barr Laboratories drug that was first approved for use in 1999, and it contains levonorgestrel, "a synthetic hormone used in ... - Denver Post,

We Must Always Be Willing To Talk About Delicate Subjects Feb 28, 2006
...to explain the store's reluctance to stock the so-called morning-after pill, an emergency contraceptive that contains the hormone levonorgestrel, also found in ... - Hartford Courant,

Bills in General Assembly deal with Plan B Feb 3, 2006
Physicians soon legally could have the right to choose whether to sell Levonorgestrel, commonly known as Plan B. Plan B is a high ... - UM Maneater,

Emergency Contraceptive Methods Feb 10, 2006
WHO researchers found that a regimen using two 0.75 mg doses of levonorgestrel administered 12 hours apart, taken up to 72 hours after unprotected intercourse ... - AllAfrica.com,

The editorial autonomy of CMAJ Feb 22, 2006
...was compromised when a CMA executive objected strenuously to a news article we were preparing on behind-the-counter access to emergency levonorgestrel (Plan B ... - Ottawa Citizen,

Safety, user age questioned in morning after pill Feb 23, 2006
...prescription. Pharmacists must be certified under a state program. Plan B is the brand name of the drug, progestin levonorgestrel. It ... - Howard County Times,

'Plan B' recipients can remain anonymous: ombudsman Feb 3, 2006
Levonorgestrel, sold under the brand name Plan B and also known as the "morning-after pill," is kept behind the counter in pharmacies. ... - CBC Manitoba,

Morning-after privacy Feb 3, 2006
...with the recording," the document says. In April, Plan B, or levonorgestrel, first became available without prescription in Canada. - Winnipeg Sun,

Pill pains in 'Toba Feb 5, 2006
...lack of training. Levonorgestrel, or Plan B, can prevent pregnancy if taken within 72 hours of unprotected sex. But several Winnipeg ... - Winnipeg Sun,

Pharmacists’ Lawsuits Highlight ‘Right of Conscience’ Rift Feb 8, 2006
Since the drug’s active hormone, levonorgestrel, will only work within 72-hours of unprotected intercourse, its effectiveness gradually decreasing over that ... - The NewStandard,

Pharmacists won't sell abortion-causing pill Feb 1, 2006
But even in Winnipeg, about a quarter of the pharmacies contacted by the newspaper said they did not carry the drug levonorgestrel, or Plan B. ... - Today's Family News,

Wyeth Reports Earnings Results for the 2005 Fourth Quarter and ... Jan 31, 2006
In May, Wyeth submitted an application for LYBREL(TM) (levonorgestrel/ethinyl estradiol), a new oral contraceptive with a unique dosing regimen; in December ... - PR Newswire (press release),

Pharmacists’ Lawsuits Highlight ‘Right of Conscience’ Rift 09 Feb 2006
Since the drug’s active hormone, levonorgestrel, will only work within 72-hours of unprotected intercourse, its effectiveness gradually decreasing over that ... - The NewStandard,

Mirena, a Levonorgestrel-releasing intrauterine system, linked to ... Jan 28, 2006
The Levonorgestrel-releasing system Mirena, an intrauterine device ( IUD ), consists of a polyethylene T-shaped frame with a reservoir containing levonorgestrel ... - Xagena.it,

Editorial - No more questions Jan 30, 2006
WHETHER levonorgestrel is an abortion in a pill or a simple contraceptive is an issue that can be debated for years. It depends ... - Winnipeg Free Press (subscription),

Morning-after privacy Feb 3, 2006
...with the recording," the document says. In April, Plan B, or levonorgestrel, first became available without prescription in Canada. - Winnipeg Sun,

Pill pains in 'Toba Feb 5, 2006
...lack of training. Levonorgestrel, or Plan B, can prevent pregnancy if taken within 72 hours of unprotected sex. But several Winnipeg ... - Winnipeg Sun,

Some pharmacists reject 'abortion in a pill' Jan 29, 2006
Health Canada made Plan B, or levonorgestrel, available without a doctor's prescription in April. Pharmacists keep it behind the counter. ... - Winnipeg Free Press (subscription),

'Plan B' hits snag Jan 30, 2006
Health Canada made levonorgestrel, the Plan B drug, available without a doctor's prescription in April. Pharmacists keep it behind the counter. ... - Edmonton Sun,

NJ drugmaker hits roadblock on contraceptive Jan 30, 2006
It has been available by prescription since 1999, and Barr wants to sell Plan B - two high-dose pills of the contraceptive levonorgestrel - over the counter. ... - Philadelphia Inquirer,

Morning-after pill on sale in Juárez pharmacies Jan 28, 2006
It is a high dose of the contraceptive levonorgestrel which prevents pregnancy after contraceptive failure or unprotected intercourse by stopping ovulation ... - El Paso Times,

Drug maker Barr's Plan B efforts blocked Jan 22, 2006
Available by prescription since 1999, Barr wants to sell Plan B -- two high-dose pills of the contraceptive levonorgestrel -- over the counter. ... - BusinessWeek

Politics Trumps Science on Birth Control Jan 18, 2006
Also known as the morning-after pill, Plan B consists of two 0.75 milligrams doses of levonorgestrel, the synthetic hormone that has been used in birth control ... - Austin Chronicle,

Drugstore sex quiz probed Jan 19, 2006
Since "Plan B," or levonorgestrel, became available without prescription in April, pharmacists across Canada have asked would-be customers their names ... - Winnipeg Free Press (subscription),

EDITORIAL - Invasive questions Jan 20, 2006
The instructions included with the packaging of levonorgestrel ought to be sufficient for any teenager or woman wondering when it can be used. ... - Winnipeg Free Press (subscription),

Sexual history no longer taken for morning after pill Dec 8, 2005
The form was part of voluntary guidelines issued by the Canadian Pharmacists Association last April when the emergency contraceptive levonorgestrel, or Plan B ... - Toronto Star,

Jan FRYDENDAHL US must focus on helping own people Dec 9, 2005
In the abortion debate, Levonorgestrel — the drug that prevents conception — could have reduced our abortion rate by as much as 50 percent. ... - The Argus,

FDA ignores the science, folds to far-right dogma Dec 4, 2005
486). The pharmacy name for Plan B is levonorgestrel, a substance that has been used in birth control pills for more than 35 years. ... - In-Forum (subscription),

Privacy concerns raised about morning-after pill rules Dec 6, 2005
The drug levonorgestrel, sometimes known as Plan B, is 89 per cent effective at preventing pregnancy if women take the first of two doses within 72 hours of ... - CBC Saskatchewan,

» FDA fudging on Plan B, the drug that prevents conception Nov 14, 2005
Research has shown that levonorgestrel-only hormonal emergency contraception, such as Plan B, interferes with prefertilization events. ... - Media girl,

New Low Estrogen Contraceptive Patch Completes Phase 2 Study Nov 28, 2005
The Agile patch is designed to deliver levonorgestrel and ethinyl estradiol, the same hormone combination found in many oral contraceptives with well ... - Yahoo! News (press release)

Debate centers on pharmacists’ rights, state laws Dec 3, 2005
Both times Pace refused to fill a prescription for levonorgestrel, better known as emergency contraception, or the "morning-after pill" - actually two white ... - St. Louis Post-Dispatch,

Privacy and the `Plan B' pill Dec 2, 2005
Health Canada moved the emergency contraceptive levonorgestrel, or Plan B, from being a prescription to a behind-the-counter drug in April, making it available ... - Toronto Star,

FDA decision-making on emergency contraception 'unusual,' report ... Nov 14, 2005
Health Canada approved the sale of levonorgestrel, known as the Plan B morning-after birth control pill, without a prescription in April. ... - Canada.com,

US watchdog finds bias against morning-after pill Nov 23, 2005
Many critics suspected as much when over-the-counter access to Plan B (levonorgestrel) was denied in 2004 despite the recommendations of agency scientists and ... - Nature.com (subscription),

FDA Audited in Rejection of "Morning After Pill" for OTC use Nov 15, 2005
...the FDA by the Government Accounting Office (GAO) raises some troubling questions about just how they came to decide that "Plan B" (levonorgestrel .75mg) was ... - Medgadget.com,

Administration's Plan A for Plan B: Ignore science Nov 21, 2005
Plan B contains levonorgestrel, the same hormone found in many birth control pills, though in a larger dose, and contains no estrogen. ... - Modesto Bee,

Pro-life groups ask DOH to ban, stop use of IUDs Oct 10, 2005
...their petition their opposition to the application for the renewal of the Bureau of Food and Drug registration of Mirena (levonorgestrel-releasing intrauterine ... - Philippine Star,

Plan B FAQ Oct 2, 2005
Plan B is a brand name for Levonorgestrel (pronounced LEE-voe-nor-jes-trel), an emergency contraceptive used to prevent pregnancy following unprotected ... - Hartford Courant,

EC pills prevent pregnancy Sep 18, 2005
The different kinds of regimen available now are a 30, 50, 250, and 750 µg (microgram) of ethinyloestradiol and levonorgestrel pills. ... - Kathmandu Post,

FDA Safety Labeling Changes: Emtriva, FazaClo, Climara/Climara Pro Sep 14, 2005
...receiving clozapine therapy should be monitored regularly for granulopoietic suppression; and estradiol and estradiol/levonorgestrel transdermal therapies have ... - Medscape (subscription)

NCI Director Takes Second Job As FDA Commissioner Sep 26, 2005
...contentious confirmation process during which he was repeatedly pressed on the FDA's handling of Duramed Pharmaceutical's Plan B (levonorgestrel), an emergency ... - MedPage Today,

Plan B Casualties Oct 2, 2005
Consisting of two doses of the synthetic hormone levonorgestrel taken orally after unprotected sex, the medication prevents ovulation or fertilization, and it ... - Hartford Courant,

IUS a safer contraception method Sep 12, 2005
..."The special membrane of IUS controls the release of levonorgestrel (a type of progesterone) into the uterus at 20 micrograms per day. ... - New Straits Times,

‘Morning after’ pill now over the counter Sep 9, 2005
...of them suffer unwanted pregnancies. Two 0.75 mg pills of Levonorgestrel can prevent pregnancy in 95% of cases. They sell at Rs ... - Financial Express,

Contraceptive pills made easy Sep 9, 2005
The ministry, after 10 years of clinical trials, has also found the compound Levonorgestrel (the pure form of Progesterone) to be 95% effective on its own ... - Times of India,

Plan B predicament has FDA in hot water Sep 11, 2005
...by prescription since 1999. It consists of the hormone levonorgestrel, a common ingredient in birth-control pills. Plan B is effective ... - Houston Chronicle,

FDA Commissioner Quits Unexpectedly Sep 23, 2005
It consists pf two tablets of 0.75 mg of levonorgestrel to be taken 12 hours apart as soon as possible, and within 72 hours, after an act of unprotected or ... - MedPage Today,

Indian Health Ministry approves sale of Emergency contraceptives ... Sep 9, 2005
Emergency pills consist of a hormone levonorgestrel, which avoids pregnancy. Dr. Mittal said, “We have a drug which can prevent fertilization and conception. ... - MedIndia,

A Sad Day for Science at the FDA Sep 24, 2005
Plan B consists of two 0.75-mg levonorgestrel tablets to be taken 12 hours apart as soon as possible, and within 72 hours, after an act . . . ... - New England Journal of Medicine (subscription),

Emergency contraceptive pill now available over-the-counter Sep 9, 2005
Two 0.75 mg-pills of "levonorgestrel" (a kind of progestrone hormone which is produced in body) are taken within three days of sexual exposure, she said adding ... - Outlook (subscription),

Women should beware of morning-after pill's risks Sep 9, 2005
...(For example, the "Plan B" kit's two pills, to be taken 12 hours apart, contain the same amount of levonorgestrel that a birth control pill user would ingest ... - Tallahassee Democrat,

Other information

Indication
For use in menopausal and postmenopausal disorders and alone or in combination with other hormones as an oral contraceptive.

Pharmacology
L-Norgestrel is used as a female contraceptive. L-Norgestrel is a progestin or a synthetic form of the naturally occurring female sex hormone, progesterone. In a woman's normal menstrual cycle, an egg matures and is released from the ovaries (ovulation). The ovary then produces progesterone, preventing the release of further eggs and priming the lining of the womb for a possible pregnancy. If pregnancy occurs, progesterone levels in the body remain high, maintaining the womb lining. If pregnancy does not occur, progesterone levels in the body fall, resulting in a menstrual period. L-Norgestrel tricks the body processes into thinking that ovulation has already occurred, by maintaining high levels of the synthetic progesterone. This prevents the release of eggs from the ovaries.

Mechanism Of Action
Binds to the progesterone and estrogen receptors. Target cells include the female reproductive tract, the mammary gland, the hypothalamus, and the pituitary. Once bound to the receptor, progestins like L-Norgestrel will slow the frequency of release of gonadotropin releasing hormone (GnRH) from the hypothalamus and blunt the pre-ovulatory LH (luteinizing hormone) surge.

Drug Category
Contraceptives, Oral, Synthetic; Contraceptive Agents, Female; ATC:G03AC03

Brand Names/Synonyms
BRN 2391114; CCRIS 6525; D-Norgestrel; Follistrel; HSDB 6483; Jadelle; Levlen; Levlen Ed; Levonorgestrel; Levonorgestrel Implants; Levonorgestrel [Usan:Ban:Inn]; Levonorgestrelum [Inn-Latin]; Levonova; Levora-21; Levora-28; Logynon Ed; Malloside; Microgest Ed; Microgyn; Microgynon 21; Microgynon 28; Microgynon 30 Ed; Microgynon Cd; Microlution; Microval; Minivlar 30; Mirena; Monofeme 28; NORPLANT; Neogynon 21; Nordet; Nordette; Nordette 21; Nordette 28; Norplant 2; Norplant Ii; Norplant System in Plastic Container; Ovral-Lo; Ovranette; Ovrette; Plan B; Preven; Rigevidon 21+7; Stediril 30; Tri-Levlen; Tri-Levlen 21; Triagynon; Triciclor; Trifeme 28; Trigoa; Trinordiol 21; Trinordiol 28; Triphasil; Triphasil 21; Triphasil 28; Triquilar Ed; Trivora; Wy-5104

Dosage Forms
IMPLANT; INSERT (EXTENDED-RELEASE); TABLET

Absorption
Levonorgestrel is not subjected to a "first-pass" effect and is virtually 100% bioavailable.

Interactions
Interactions for L-Norgestrel: Changes in contraceptive effectiveness associated with coadministration of other products: Contraceptive effectiveness may be reduced when hormonal contraceptives are coadministered with antibiotics, anticonvulsants, and other drugs that increase the metabolism of contraceptive steroids. This could result in unintended pregnancy or breakthrough bleeding. Examples include rifampin, rifabutin, barbiturates, primidone, phenylbutazone, phenytoin, dexamethasone, carbamazepine, felbamate, oxcarbazepine, topiramate, griseofulvin, and modafinil. Several cases of contraceptive failure and breakthrough bleeding have been reported in the literature with concomitant administration of antibiotics such as ampicillin and other penicillins, and tetracyclines, possibly due to a decrease of enterohepatic recirculation of estrogens. However, clinical pharmacology studies investigating drug interactions between combined oral contraceptives and these antibiotics have reported inconsistent results. Enterohepatic recirculation of estrogens may also be decreased by substances that reduce gut transit time. Several of the anti-HIV protease inhibitors have been studied with coadministration of oral combination hormonal contraceptives; significant changes (increase and decrease) in the plasma levels of the estrogen and progestin have been noted in some cases. The safety and efficacy of oral contraceptive products may be affected with coadministration of anti-HIV protease inhibitors. Health-care professionals should refer to the label of the individual anti-HIV protease inhibitors for further drug-drug interaction information. Herbal products containing St. John's Wort (Hypericum perforatum) may induce hepatic enzymes (cytochrome P 450) and p-glycoprotein transporter and may reduce the effectiveness of contraceptive steroids. This may also result in breakthrough bleeding. During concomitant use of ethinyl estradiol containing products and substances that may lead to decreased plasma steroid hormone concentrations, it is recommended that a nonhormonal backup method of birth control be used in addition to the regular intake of Lo/Ovral. If the use of a substance which leads to decreased ethinyl estradiol plasma concentrations is required for a prolonged period of time, combination oral contraceptives should not be considered the primary contraceptive. After discontinuation of substances that may lead to decreased ethinyl estradiol plasma concentrations, use of a nonhormonal back-up method of birth control is recommended for 7 days. Longer use of a back-up method is advisable after discontinuation of substances that have led to induction of hepatic microsomal enzymes, resulting in decreased ethinyl estradiol concentrations. It may take several weeks until enzyme induction has completely subsided, depending on dosage, duration of use, and rate of elimination of the inducing substance. Increase in plasma levels associated with coadministered drugs: Coadministration of atorvastatin and certain oral contraceptives containing ethinyl estradiol increase AUC values for ethinyl estradiol by approximately 20%. The mechanism of this interaction is unknown. Ascorbic acid and acetaminophen increase the bioavailability of ethinyl estradiol since these drugs act as competitive inhibitors for sulfation of ethinyl estradiol in the gastrointestinal wall, a known pathway of elimination for ethinyl estradiol. CYP 3A4 inhibitors such as indinavir, itraconazole, ketoconazole, fluconazole, and troleandomycin may increase plasma hormone levels. Troleandomycin may also increase the risk of intrahepatic cholestasis during coadministration with combination oral contraceptives. Changes in plasma levels of coadministered drugs: Combination hormonal contraceptives containing some synthetic estrogens (eg, ethinyl estradiol) may inhibit the metabolism of other compounds. Increased plasma concentrations of cyclosporin, prednisolone and other corticosteroids, and theophylline have been reported with concomitant administration of oral contraceptives. Decreased plasma concentrations of acetaminophen and increased clearance of temazepam, salicylic acid, morphine, and clofibric acid, due to induction of conjugation (particularly glucuronidation), have been noted when these drugs were administered with oral contraceptives. Interactions With Laboratory Tests - Certain endocrine and liver-function tests and blood components may be affected by oral contraceptives: a. Increased prothrombin and factors VII, VIII, IX, and X; decreased antithrombin 3; increased norepinephrine-induced platelet aggregability. b. Increased thyroid-binding globulin (TBG) leading to increased circulating total thyroid hormone, as measured by protein-bound iodine (PBI), T4 by column or by radioimmunoassay. Free T3 resin uptake is decreased, reflecting the elevated TBG; free T4 concentration is unaltered. c. Other binding proteins may be elevated in serum ie, corticosteroid binding globulin (CBG), sex hormone-binding globulins (SHBG) leading to increased levels of total circulating corticosteroids and sex steroids respectively. Free or biologically active hormone concentrations are unchanged. d. Triglycerides may be increased and levels of various other lipids and lipoproteins may be affected. e. Glucose tolerance may be decreased. f. Serum folate levels may be depressed by oral-contraceptive therapy. This may be of clinical significance if a woman becomes pregnant shortly after discontinuing oral contraceptives.

Chemical 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

Chemical Formula
C21H28O2

Half Life
Not Available

Drug Type
Approved Drug

# Accession No
APRD00754

CAS Registry Number
17489-40-6