React

React is used to prevent pregnancy after unprotected sex or if other forms of birth control fail (for example, if a condom breaks or if you miss 2 or more birth control pills).

React may also be used for reasons not mentioned in this medication guide.

Use exactly as directed on the label, or as prescribed by your doctor.

React must be taken as soon as possible after unprotected sex (no later than 72 hours afterward).

Call your doctor right away if you vomit within 2 hours after taking React. Do not take a second dose without first asking your doctor.

If your period is late by 1 week or longer after the expected date, you may be pregnant. Get a pregnancy test and contact your doctor if you are pregnant. React will not terminate pregnancy if the fertilized egg has attached to the uterus.

Within 3 weeks after taking React, a doctor should confirm that you are not pregnant, and that this medicine has not caused any harmful effects.

Store at room temperature away from moisture and heat.

React will not end a pregnancy if the fertilized egg has already attached to the uterus.

Before taking levonorgestrel, ask a doctor or pharmacist if you regularly use medication for seizures, tuberculosis, or HIV/AIDS. Some other medicines can make levonorgestrel less effective.

React is not meant to be used as a regular form of birth control. Talk to your doctor about the different types of birth control options available.

Do not use this medicine if you are already pregnant. React will not end a pregnancy that has already started (when the fertilized egg has attached to the uterus).

Not approved for use by anyone younger than 17 years old.

You should not use levonorgestrel if you are allergic to it.

Ask a doctor or pharmacist before taking levonorgestrel if you regularly take medication for seizures, tuberculosis, or HIV/AIDS. Some medications can make levonorgestrel less effective as an emergency contraceptive.

Levonorgestrel may reduce breast milk production. Let your doctor know if you are breastfeeding.

Get emergency medical help if you notice signs of an allergic reaction: hives; trouble breathing; swelling of your face, lips, tongue, or throat.

Call your doctor or get emergency medical help if you feel severe pain in your lower stomach or side. This could mean you have a tubal pregnancy (a pregnancy that grows in the fallopian tube instead of the uterus). A tubal pregnancy is a medical emergency.

Common side effects of React may include:

• stomach pain;
• breast pain or tenderness;
• nausea, vomiting, diarrhea;
• headache, dizziness;
• feeling tired; or
• changes in your menstrual periods.

This is not a complete list of side effects and others may happen. Call your doctor for medical advice about side effects. You can report side effects to the FDA at 1-800-FDA-1088.

Since React is taken as a single dose, it does not have a daily dosing schedule.

Because React comes as one tablet in a specific strength, it is unlikely that you will overdose when using the levonorgestrel as instructed. Do not take more than one tablet at the same time.

React will not protect you from sexually transmitted diseases--including HIV and AIDS. Using a condom is the only way to protect yourself from these diseases. Avoid having unprotected sex.

Certain other medications can make React less effective, which may lead to pregnancy. Ask a doctor or pharmacist if React is safe to use if you are taking any of the following medications:

• efavirenz;
• rifampin; or
• seizure medication--carbamazepine, felbamate, fosphenytoin, phenobarbital, phenytoin, primidone.

This list is not complete. Other drugs may affect levonorgestrel, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.