Rapivab works by preventing an enzyme in the body from releasing virus from infected cells.

Rapivab is used to treat influenza in adults and children who are at least 2 years old, who have had flu symptoms for up to 2 days.

Rapivab may also be used for purposes not listed in this medication guide.

Before you receive Rapivab, tell your doctor about all your medical conditions and allergies. Also make sure your doctor knows if you are pregnant or breast-feeding.

Rapivab is given as an infusion into a vein. A healthcare provider will give you this injection.

Rapivab is usually given as a single dose. The medicine should be given within the first 2 days of when flu symptoms start.

Rapivab will not treat an infection caused by bacteria or fungus.

Call your doctor if your symptoms do not improve, or if they get worse after you have received this medicine.

Tell your doctor if you have ever had:

• kidney disease (or if you are on dialysis); or

• if you have received a nasal flu vaccine (FluMist) within the past 2 weeks.

It is not known whether Rapivab will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It may not be safe to breast-feed while using this medicine. Ask your doctor about any risk.

Since Rapivab is used as a single dose, it does not have a daily dosing schedule.

Since Rapivab is given by a healthcare professional in a medical setting, an overdose is unlikely to occur.

Avoid getting the nasal flu vaccine (FluMist) within 48 hours after you are treated with Rapivab, unless your doctor tells you to.

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning in your eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling).

Rapivab may cause serious side effects. Call your doctor at once if you have:

• new or worsening flu symptoms; or

• confusion, hallucinations, unusual thoughts or behavior.

Common side effects of Rapivab may include:

• diarrhea;

• constipation; or

• sleep problems (insomnia).

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

Other drugs may affect Rapivab, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.