Uses
Levonorgestrel 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 [e.g., a condom that slipped or broke or birth control pills that were not taken as scheduled]). Levonorgestrel should not be used to prevent pregnancy on a regular basis. This medication is to be used as an emergency contraceptive or backup in case regular birth control fails or is used incorrectly. 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 changing the lining of the uterus (womb) to prevent the development of a pregnancy. Levonorgestrel may prevent pregnancy, but it will not prevent the spread of human immunodeficiency virus (HIV, the virus that causes acquired immunodeficiency syndrome [AIDS]) and other sexually transmitted diseases.
Side Effects Of Levonorgestrel
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)
- Levonorgestrel may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
Warnings & Precautions
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; bosentan (Tracleer); griseofulvin (Grifulvin V, Gris-PEG); certain medications used to treat HIV including atazanavir (Reyataz). darunavir (Prezista, in Prezcobix), delavirdine (Rescriptor), efavirenz (Sustiva), etravirine (Intelence), fosamprenavir (Lexiva), indinavir (Crixivan), lopinavir (in Kaletra), nelfinavir (Viracept), nevirapine (Viramune), rilpivirine (Edurant, in Complera), ritonavir (Norvir, in Kaletra), saquinavir (Invirase), and tipranavir (Aptivus); certain medications for seizures such as carbamazepine (Carbatrol, Equetro, Tegretol), felbamate (Felbatol), oxcarbazepine (Oxtellar XR, Trileptal), phenytoin (Dilantin, Phenytek), and topiramate (Qudexy XR, Topamax, Trokendi XR, in Qsymia); and rifampin (Rifadin, Rimactane). Levonorgestrel may not work as well or maybe 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.
- 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.
Levonorgestrel Dosage
Levonorgestrel comes as a tablet to take by mouth. If you are taking levonorgestrel as a single tablet product, take one tablet as soon as possible within 72 hours after unprotected sexual intercourse. If you are taking levonorgestrel as a two tablet product, 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.
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.
Other
Keep all appointments with your doctor.
Ask your pharmacist any questions you have about levonorgestrel.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Source
All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.
