Levonorgestrel

Levonorgestrelis is used to prevent pregnancy after unprotected sexual intercourse sex without any method of birth control or with a birth control method that failed or was not used properly. Levonorgestrel is in a class of medications called progestins. It works by preventing the release of an egg from the ovary or preventing fertilization of the egg by sperm (male reproductive cells). It also may work by chang ing the lining of the uterus (womb) to prevent development of a pregnancy. Levonorgestrel may prevent pregnancy, but it will not prevent the spread o f HIV and other sexually transmitted diseases. If it is taken together with drugs that induce the cytochrome liver enzyme, the levonorgestrel will be metabolized faster and have a decrease in effectiveness, thus a larger dose will be needed.
 * Levonorgestrel ** **is** a second generation synthetic progesterone used as an active ingredient in some hormonal contraceptives, including combined oral contraceptive pills, progesterone only pills,emergency contraceptive pills, intrauterine systems, and contraceptive implants.



How should this medicine be used?
Levonorgestrel comes as a tablet to take by mouth. If you are taking Plan B® One Dose, take one tablet as soon as possible within 72 hours after unprotected sexual intercourse. If you are taking Next Choice®, take one tablet as soon as possible within 72 hours after unprotected sexual intercourse and take a second dose 12 hours later. Levonorgestrel works best if it is taken as soon as possible after unprotected sexual intercourse. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take levonorgestrel exactly as directed. Levonorgestrel is available as a nonprescription medication for women 17 years of age and older, and by prescription only for women younger than 17 years of age. If you are younger than 17, you will need to talk to a doctor to get a prescription for levonorgestrel. If you are 17 years of age or older you can buy levonorgestrel at a pharmacy. Levonorgestrel is kept behind the pharmacy counter and you will need to show the pharmacist your driver's license or other government-issued identification that shows your age in order to purchase the medication. If you vomit less than 2 hours after you take a dose of levonorgestrel, call your doctor. You may need to take another dose of this medication. Because you can become pregnant soon after treatment with levonorgestrel, you should continue using your regular method of birth control or begin using regular birth control immediately. If you use hormonal contraceptives (birth control pills, patches, rings, implants, or injections), you should also use a barrier method (condom or diaphragm with spermicide) every time you have sex during the same menstrual cycle as you took levonorgestrel.

Other uses for this medicine
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?
Before taking levonorgestrel,
 * tell your doctor and pharmacist if you are allergic to levonorgestrel, any other medications, or any of the ingredients in levonorgestrel tablets. Ask your pharmacist for a list of the ingredients.
 * tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, and nutritional supplements, you are taking or plan to take. Be sure to mention any of the following: barbiturates such as phenobarbital or secobarbital (Seconal); bosentan (Tracleer); griseofulvin (Fulvicin-U/F, Grifulvin V, Gris-PEG); certain medications used to treat human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) including amprenavir (Agenerase), delavirdine (Rescriptor), efavirenz (Sustiva), etravirine (Intelence), fosamprenavir (Lexiva), nelfinavir (Viracept), nevirapine (Viramune), ritonavir (Norvir, in Kaletra), and saquinavir (Invirase); certain medications for seizures such as carbamazepine (Equetro, Tegretol), felbamate (Felbatol), oxcarbazepine (Trileptal), phenytoin (Dilantin, Phenytek), and topiramate (Topamax); and rifampin (Rifadin, Rimactane). Levonorgestrel may not work as well or may be more likely to cause side effects if it is taken with these medications.
 * tell your doctor what herbal products you are taking, especially St. John's wort.
 * tell your doctor if you have or have ever had any medical conditions.
 * tell your doctor if you are pregnant. Do not take levonorgestrel if you are already pregnant. Levonorgestrel will not end a pregnancy that has already begun.
 * tell your doctor if you are breast-feeding.
 * you should know that after you take levonorgestrel, it is normal for your next menstrual period to begin up to a week earlier or later than expected. If your next menstrual period is delayed for longer than 1 week after the expected date, call your doctor. You may be pregnant and your doctor will probably tell you to have a pregnancy test.

What special dietary instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.

What side effects can this medication cause?
Levonorgestrel may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
 * heavier or lighter than usual menstrual bleeding
 * spotting or bleeding between menstrual periods
 * nausea
 * vomiting
 * diarrhea
 * tiredness
 * headache
 * dizziness
 * breast pain or tenderness

Some side effects can be serious. If you experience the following symptom, call your doctor immediately:
 * severe lower abdominal pain (3 to 5 weeks after taking levonorgestrel)