What is amantadine?

Amantadine is an antiviral medication. It blocks the actions of viruses in your body.

Amantadine is used to treat and to prevent influenza A (a viral infection). There may be some flu seasons during which amantadine is not recommended because certain flu strains may be resistant to this drug.

Amantadine is also used to treat Parkinson’s disease and "Parkinson-like” symptoms such as stiffness and shaking that may be caused by the use of certain drugs.

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

Precautions

You should not use this medication if you are allergic to amantadine, or if you have received a nasal flu vaccine (FluMist) within the past 14 days.

If you have certain conditions, you may need a dose adjustment or special tests to safely take this medication. Before you take amantadine, tell your doctor if you are allergic to any drugs, or if you have:

  • epilepsy or other seizure disorder;
  • congestive heart failure;
  • kidney disease;
  • liver disease;
  • low blood pressure or fainting;
  • eczema;
  • glaucoma; or
  • a history of mental illness, suicide attempt, or drug/alcohol addiction.

You may have increased sexual urges, unusual urges to gamble, or other intense urges while taking amantadine. It is not known whether the medicine actually causes this effect. Talk with your doctor if you believe you have any intense or unusual urges while taking amantadine.

Some people taking medicines for Parkinson’s disease have developed skin cancer (melanoma). However, people with Parkinson's disease may have a higher risk than most people for developing melanoma. Talk to your doctor about your specific risk and what skin symptoms to watch for. You may need to have regular skin exams.

FDA pregnancy category C. It is not known whether this medication is harmful to an unborn baby. Before taking amantadine, tell your doctor if you are pregnant or plan to become pregnant during treatment.

Amantadine can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Do not use FluMist nasal influenza "live vaccine” while you are being treated with amantadine and for at least 48 hours after you stop taking amantadine. The nasal vaccine may not be as effective if you receive it while you are taking amantadine. Before taking amantadine, tell your doctor if you have received a nasal flu vaccine within the past 14 days.

Amantadine can cause side effects that may impair your vision, thinking, or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.

Avoid drinking alcohol. It can increase some of the side effects of amantadine.

Avoid taking diet pills, caffeine pills, or other stimulants (such as ADHD medications) without your doctor’s advice. Taking a stimulant together with amantadine can increase your risk of unpleasant side effects.

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Instructions

Seek emergency medical attention if you think you have used too much of this medicine. An overdose of amantadine can be fatal.

Overdose symptoms may include fever, anxiety, severe headache, confusion, hallucinations, agitation, aggression, personality changes, tremor, problems with balance or walking, fast or uneven heart rate, urinating less than usual or not at all, trouble breathing, seizure (convulsion), or fainting.

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at your next regularly scheduled time. Do not take extra medicine to make up the missed dose.

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Side Effects

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

Call your doctor at once if you have any of these serious side effects:

  • feeling short of breath, even with mild exertion;
  • swelling, rapid weight gain;
  • feeling depressed, agitated, or aggressive;
  • behavior changes, hallucinations, thoughts of hurting yourself;
  • urinating less than usual or not at all;
  • high fever, stiff muscles, confusion, sweating, fast or uneven heartbeats, rapid breathing, feeling like you might pass out;
  • restless muscle movements in your eyes, tongue, jaw, or neck; or
  • tremor (uncontrolled shaking).

Less serious side effects may include:

  • dizziness, drowsiness, headache;
  • sleep problems (insomnia), strange dreams;
  • feeling nervous;
  • nausea, diarrhea, constipation, loss of appetite;
  • dry mouth, dry nose; or
  • loss of balance or coordination.

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. You may report side effects to FDA at 1-800-FDA-1088.

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Interactions

Before taking amantadine, tell your doctor if you are using any of the following drugs:

  • atropine (Atreza, Sal-Tropine, and others);
  • dicyclomine (Bentyl);
  • glycopyrrolate (Robinul);
  • hyoscyamine (Anaspaz, Levbid, Levsin, Nulev, and others);
  • mepenzolate (Cantil);
  • methscopolamine (Pamine);
  • propantheline (Pro-Banthine);
  • scopolamine (Maldemar, Scopace, Transderm-Scop).
  • quinine (Qualaquin);
  • quinidine (Cardioquin, Quinaglute);
  • a diuretic (water pill) such as triamterene (Dyrenium), hydrochlorothiazide (HCTZ, Dyazide, HydroDiuril, Hyzaar, Lopressor, Vasoretic, Zestoretic), and others; or
  • phenothiazines such as prochlorperazine (Compazine), thioridazine (Mellaril), and others.

This list is not complete and there may be other drugs that can interact with amantadine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Other Names

Symmetrel and amantadine

Available Strengths & Dosages


Route Form Strength
oral capsule 100 mg
oral syrup 50 mg/5 mL
oral tablet 100 mg

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Disclaimer

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2004 Cerner Multum, Inc. Version 2.05. Revision date 8/23/04

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