Plan B

Generic name: Levonorgestrel

What is Plan B?

Plan B is an emergency contraception. Emergency contraception is a backup method of preventing pregnancy and is not for routine use. Drugs used for emergency contraception are called postcoital pills, or morning after pills. Plan B can reduce your chance of pregnancy after unprotected sex (if your regular birth control method fails or if you have had sex without birth control). For example, if you were using a condom and it broke, or if you forgot to take 2 or more of your birth control pills in a month, or if you did not use any birth control method, Plan B may work for you.

This drug works mainly by preventing ovulation (egg release). It may also prevent fertilization of a released egg (joining of sperm and egg) or attachment of a fertilized egg to the uterus (implantation).

What is the most important information I should know about Plan B?

Plan B is used as an emergency contraceptive. The first tablet should be taken as soon as possible following unprotected intercourse. The first dose must taken within 72 hours of intercourse; the second tablet must be taken 12 hours later. (For women age 17 and younger, Plan B is a prescription only medication.)

Plan B does not protect against the AIDS virus (HIV) or other sexually transmitted diseases (STDs). Plan B should not be used as a regular birth control method. It does not work as well as most other forms of birth control when they are used consistently and correctly. Plan B is not effective in terminating an existing pregnancy. Plan B is a backup or emergency method of contraception.

Do not drive or perform other possibly unsafe tasks until you know how you react to Plan B; this medication may cause dizziness. This effect may be worse if you take Plan B with alcohol or certain medicines.

Plan B may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.

Who should not take Plan B?

Do not take Plan B if you are already pregnant (because it will not work), or you are allergic to levonorgestrel or any of its ingredients.

What should I tell my doctor before I take the first dose of Plan B?

Tell your doctor about all prescription, over-the-counter, and herbal medication you are taking before taking Plan B. Also, talk to your doctor about your medical history especially if you have diabetes, a history of ectopic pregnancy (when the fertilized egg implants anywhere other than the uterine wall) or you are premenstrual.

What is the usual dosage?

The information below is based on the dosage guidelines your doctor uses. Depending on your condition and medical history, your doctor may prescribe a different regimen. Do not change the dosage or stop taking your medication without your doctor's approval.

Adults: The usual dosage of Plan B (for women 18 years and older) is to take the first tablet as soon as possible but not later than 72 hours (3 days) after unprotected sex, then take the second tablet 12 hours after you take the first tablet. If you vomit within 1 hour of taking either dose of medication, call your doctor to discuss whether to repeat the dose. A prescription is necessary only for patients 17 years and younger (see your doctor for more information).

How should I take Plan B?

Take Plan B as soon as possible after suspected birth control failure or after you have unprotected sexual intercourse. The first dose must be taken within 72 hours. Take the second tablet 12 hours after the first tablet. However, your doctor may instruct you to take Plan B in a different way. Follow the directions provided by your doctor.

Plan B can be used any time during the menstrual cycle.

If vomiting occurs within 1 hour after taking either tablet of Plan B, talk with your health care provider to discuss whether to repeat that dose.

What should I avoid while taking Plan B?

Try to avoid vomiting within 1 hour of taking Plan B. If you happen to vomit within 1 hour of taking either dose, call your doctor to discuss if you should repeat the dosage.

Do not drive or perform other possibly unsafe tasks until you know how you react to Plan B; this medication may cause dizziness. This effect may be worse if you take it with alcohol or certain medicines.

What are possible food and drug interactions associated with Plan B?

If Plan B is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Plan B with the following: anticoagulants such as warfarin; antifungals such as ketoconazole; barbiturates such as Phenobarbital; beta-adrenergic blockers such as metoprolol; carbamazepine; corticosteroids such as prednisone; felbamate; HIV protease inhibitors such as indinavir; hydantoins such as Phenytoin; Lamotrigine; modafinil; nevirapine; penicillins such as amoxicillin; Rifampin; selegiline; St. John's wort; tetracyclines such as doxycycline; theophylline; and topiramate.

What are the possible side effects of Plan B?

Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking this drug.

Side effects may include: breast pain or tenderness, diarrhea, dizziness, headache, menstrual changes, nausea, stomach pain, tiredness, vomiting, lower stomach pain, spotting during your usual menstrual cycle

Can I receive Plan B if I am pregnant or breastfeeding?

Plan B does not end existing pregnancies. Do not use Plan B if you are pregnant. Plan B is found in breast milk; contact your doctor if you are breastfeeding and have currently taken Plan B.

What should I do if I miss a dose of Plan B?

If you miss a dose of Plan B, contact your doctor immediately to find out the best way to prevent pregnancy.

How should I store Plan B?

Store at room temperature away from heat, moisture, and light. Do not store in the bathroom.