Why is this medication prescribed?

Amantadine is used to treat Parkinson's disease and conditions similar to those of Parkinson's disease. It also is used to prevent and treat respiratory infections caused by influenza A virus.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Amantadine comes as a capsule and liquid to take by mouth. It is usually taken once or twice a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take amantadine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. Do not stop taking amantadine without talking to your doctor.

If this medication causes insomnia (difficulty sleeping), take the last dose several hours before bedtime.

What special precautions should I follow?

Before taking amantadine,

• tell your doctor and pharmacist if you are allergic to amantadine or any other drugs.

• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially benztropine (Cogentin), hydrochlorothiazide with triamterene (Maxzide, Dyazide), medication for depression, other medication for Parkinson's disease, medication for spasms of the stomach or intestines, stimulants, trihexyphenidyl (Artane), and vitamins.

• tell your doctor if you have epilepsy or any other type of seizures, or have ever had heart, kidney, or liver disease, heart failure, low blood pressure, recurring skin rash, or mental illness.

• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking amantadine, call your doctor immediately. Amantadine may cause harm to the fetus.

• this medicine may cause blurred vision; be careful when driving or doing things requiring alertness.

What special dietary instructions should I follow?

Amantadine may cause an upset stomach. Take amantadine with food or milk.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?

Amantadine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• blurred vision

• dizziness

• lightheadedness

• faintness

• trouble sleeping

If you experience any of the following side effects, call your doctor immediately:

• depression or anxiety

• swelling of the hands, legs, or feet

• difficulty urinating

• shortness of breath

• rash

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].

What storage conditions are needed for this medicine?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Do not freeze. Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What other information should I know?

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your response to amantadine.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription. If you still have symptoms of infection after you finish the amantadine, call your doctor.

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.