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Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.



COMMON BRAND NAME(S): Symadine, Symmetrel


This medication is used to treat or prevent infections of the respiratory tract caused by a certain virus. It acts by slowing the growth of the virus. Amantadine is also used to treat symptoms of Parkinson's disease and to treat the side effects caused by certain psychiatric drugs.

How To Use

This medication is best taken on an empty stomach, but may be taken with food or milk if stomach upset occurs. This medication works best when the amount of medicine in your body is kept at a constant level. Do this by taking the medication at evenly spaced intervals throughout the day and night. If you are taking amantadine for a viral infection, begin taking it as soon as possible. Continue to take until the full prescribed amount is finished even if symptoms disappear after a few days. Stopping the medication too early may result in a relapse of the infection. In Parkinson's disease, the effects of the medication may not be apparent for several weeks. Do not suddenly stop taking the medication as an increase in symptoms may occur. Your doctor may want to reduce your dose gradually. If after several months, you notice the drug may not be as effective, contact your doctor. Tolerance can develop after long-term use.

Side Effects

This medication may cause stomach upset, nausea, drowsiness, constipation, headache, dizziness, anxiety, or purplish-red blotchy spots on the skin during the first few days as your body adjusts to the medication. If these symptoms persist or become severe, inform your doctor promptly. Notify your doctor if you develop: slurred speech, shortness of breath, swelling of the arms or legs, vision disturbances, difficulty urinating, skin rash, mental/mood changes. If you notice other effects not listed above, contact your doctor or pharmacist.


Tell your doctor your medical history, including: allergies (especially drug allergies), swelling, heart problems. Because this medication may cause blurred vision or dizziness, use caution when driving or operating machinery while taking this medication. Limit use of alcoholic beverages. Amantadine should be used during pregnancy only if clearly needed. Since small amounts of the drug do appear in breast milk, consult with your doctor before breast-feeding.

Drug Interactions

Tell your doctor of all prescription and nonprescription drugs you may use, especially of: other drugs used for Parkinson's disease, stimulants (like decongestants commonly found in cough-and-cold products). Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include nausea, vomiting, slurred speech, blurred vision, drowsiness, memory loss, depression, excessive excitability, increased sensitivity to the sun, loss of consciousness, fast or irregular heartbeat.


Do not share this product with others.

Missed Dose

If you miss a dose, take as soon as remembered; do not take if it is almost time for the next dose, instead, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.


Store at room temperature away from sunlight and moisture.