Flumadine is an antiviral medicine used to treat or prevent influenza A in people who are at least 17 years old. This medicine is also used to prevent influenza A in children ages 1 to 16 years old.

Flumadine may not be effective during every flu season because certain strains of the virus may be resistant to Flumadine. This medicine should not be used in place of getting a yearly flu shot. The Centers for Disease Control recommends an annual flu shot to help protect you each year from new strains of influenza virus.

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

Do not receive a nasal flu vaccine while taking Flumadine, and for at least 48 hours after your last dose.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Start taking Flumadine within 24 to 48 hours after flu symptoms begin. Keep taking this medicine for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared.

Follow your doctor's dosing instructions very carefully.

Tell your doctor if the person taking this medicine has trouble swallowing the Flumadine tablet.

Call your doctor if your symptoms do not improve, or if they get worse.

Store at room temperature away from moisture and heat.

You should not use Flumadine if you are allergic to Flumadine or a similar medicine called amantadine.

Tell your doctor if you have ever had:

• a seizure; or

• liver or kidney disease.

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

You should not breastfeed while using this medicine.

Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose can be fatal.

Overdose symptoms may include agitation, hallucinations, or uneven heart rate.

Do not receive a nasal flu vaccine while using Flumadine, and for at least 48 hours after your last dose. The vaccine may not work as well during this time, and may not fully protect you from disease.

Do not drink alcohol. Dangerous side effects could occur.

Avoid driving or hazardous activity until you know how Flumadine will affect you. Your reactions could be impaired.

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

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

• extreme drowsiness, or if you fall asleep suddenly even after feeling alert;

• a light-headed feeling, like you might pass out;

• depression, agitation, aggression, behavior changes, hallucinations, thoughts of hurting yourself; or

• a seizure.

Side effects such as headache, dizziness, feeling weak or tired, anxiety, vomiting, and stomach pain may be more likely in older adults.

Common side effects of Flumadine may include:

• nausea, vomiting, loss of appetite, stomach pain;

• dry mouth;

• sleep problems (insomnia); or

• dizziness.

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.

Using Flumadine with other drugs that make you drowsy can worsen this effect. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

Other drugs may affect Flumadine, 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.