Generic Name: amantadine (a MAN ta deen)
Brand Names: Symmetrel
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.
What is the most important information I should know about amantadine?
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.
Before taking amantadine, tell your doctor if you have epilepsy or other seizure disorder, congestive heart failure, kidney or liver disease, low blood pressure, eczema, glaucoma, or a history of mental illness, suicide attempt, or drug/alcohol addiction.
Amantadine can cause side effects that may impair your thinking, vision, or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly. If you are taking amantadine to treat influenza A, take the medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated. If you are taking amantadine to treat Parkinson symptoms, do not stop taking the medication without first talking to your doctor. If you stop taking amantadine suddenly, your condition may become worse.
You may have increased sexual urges, unusual urges to gamble, or other intense urges while taking this medication. Talk with your doctor if you believe you have any intense or unusual urges while taking amantadine.
What should I discuss with my healthcare provider before taking amantadine?
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 any of these other conditions, you may need a dose adjustment or special tests to safely take amantadine:
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.
How should I take amantadine?
Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.
Take this medicine with a full glass of water.
Measure the liquid form of amantadine with a special dose-measuring spoon or cup, not a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.
If you are taking amantadine to treat influenza A, start taking the medication within 24 to 48 hours after flu symptoms begin. Keep taking the medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated. If you are taking amantadine to treat Parkinson symptoms, do not stop taking the medication without first talking to your doctor. If you stop taking amantadine suddenly, your condition may become worse. Store amantadine at room temperature away from moisture and heat.
See also: Amantadine dosage (in more detail)
What happens if I miss a dose?
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.
What happens if I overdose?
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.
What should I avoid while taking amantadine?
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.
Amantadine 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.
Amantadine Dosing Information
Usual Adult Dose for Influenza:
On the basis of available antiviral testing results, the US Public Health Service Centers for Disease Control and Prevention (CDC) has provided an interim recommendation that amantadine not be used for the treatment or prophylaxis of influenza A in the United States for the remainder of the 2010 through 2011 influenza season. (During this period, oseltamivir or zanamivir should be selected if an antiviral medication is used for the treatment and prophylaxis of influenza.)
Normally recommended dose: 200 mg/day orally in 1 to 2 divided doses
For prophylaxis, 100 mg daily is an acceptable alternative in healthy adults who are not at risk for influenza-related complications. It is recommended for patients who cannot tolerate the 200 mg daily dosage because of central nervous system and other toxicities.
Usual Adult Dose for Influenza Prophylaxis:
On the basis of available antiviral testing results, the US Public Health Service Centers for Disease Control and Prevention (CDC) has provided an interim recommendation that amantadine not be used for the treatment or prophylaxis of influenza A in the United States for the remainder of the 2010 through 2011 influenza season. (During this period, oseltamivir or zanamivir should be selected if an antiviral medication is used for the treatment and prophylaxis of influenza.)
Normally recommended dose: 200 mg/day orally in 1 to 2 divided doses
For prophylaxis, 100 mg daily is an acceptable alternative in healthy adults who are not at risk for influenza-related complications. It is recommended for patients who cannot tolerate the 200 mg daily dosage because of central nervous system and other toxicities.
Usual Adult Dose for Parkinson's Disease:
100 mg orally twice a day when used alone or 100 mg once daily in patients with serious associated medical illnesses or receiving high dosages of other antiparkinson medications
After a minimum of one week, the dosage may be increased as needed and as tolerated. Some patients may require and tolerate 300 to 400 mg/day, in divided doses, with close supervision.
Amantadine's effectiveness can wane over time, in some cases after just a few months of use. If the patient is not already at the maximum tolerated dosage at that point, increasing the dosage may help. Alternatively, a temporary discontinuation of the drug for several weeks may help to recover some of the drug's effects when it is reinstated. The use of other antiparkinson drugs may be necessary.
If amantadine is initiated concurrently with levodopa, the dosage of amantadine should remain constant at the starting level while the dosage of levodopa is titrated to achieve optimal therapeutic response.
Usual Adult Dose for Extrapyramidal Reaction:
100 mg orally twice a day
After a minimum of one week, the dosage may be increased as needed and as tolerated. Some patients may require and tolerate 300 to 400 mg/day, in divided doses, with close supervision.
Usual Geriatric Dose for Influenza:
On the basis of available antiviral testing results, the CDC has provided an interim recommendation that amantadine not be used for the treatment or prophylaxis of influenza A in the United States for the remainder of the 2010 through 2011 influenza season. (During this period, oseltamivir or zanamivir should be selected if an antiviral medication is used for the treatment and prophylaxis of influenza.)
Normally recommended dose: 100 mg/day orally in 1 to 2 divided doses
Usual Geriatric Dose for Influenza Prophylaxis:
On the basis of available antiviral testing results, the CDC has provided an interim recommendation that amantadine not be used for the treatment or prophylaxis of influenza A in the United States for the remainder of the 2010 through 2011 influenza season. (During this period, oseltamivir or zanamivir should be selected if an antiviral medication is used for the treatment and prophylaxis of influenza.)
Normally recommended dose: 100 mg/day orally in 1 to 2 divided doses
Usual Pediatric Dose for Influenza:
On the basis of available antiviral testing results, the CDC has provided an interim recommendation that amantadine not be used for the treatment or prophylaxis of influenza A in the United States for the remainder of the 2010 through 2011 influenza season. (During this period, oseltamivir or zanamivir should be selected if an antiviral medication is used for the treatment and prophylaxis of influenza.)
Normally recommended doses:
1 to 9 years: 4.4 to 8.8 mg/kg orally per day, not to exceed 150 mg/day
10 to 12 years: 200 mg/day orally in 1 to 2 divided doses
To reduce the risk of toxicity, the Advisory Committee on Immunization Practices (ACIP) and the American Academy of Pediatrics (AAP) recommend that children 1 to 9 years of age receive 5 mg/kg/day (up to 150 mg/day). Children 10 years of age or older weighing less than 40 kg should also receive 5 mg/kg/day, while those weighing 40 kg or more may receive 200 mg/day. For prophylaxis, 100 mg daily is an acceptable alternative in children weighing more than 20 kg who are not at risk for influenza-related complications.
Usual Pediatric Dose for Influenza Prophylaxis:
On the basis of available antiviral testing results, the CDC has provided an interim recommendation that amantadine not be used for the treatment or prophylaxis of influenza A in the United States for the remainder of the 2010 through 2011 influenza season. (During this period, oseltamivir or zanamivir should be selected if an antiviral medication is used for the treatment and prophylaxis of influenza.)
Normally recommended doses:
1 to 9 years: 4.4 to 8.8 mg/kg orally per day, not to exceed 150 mg/day
10 to 12 years: 200 mg/day orally in 1 to 2 divided doses
To reduce the risk of toxicity, the Advisory Committee on Immunization Practices (ACIP) and the American Academy of Pediatrics (AAP) recommend that children 1 to 9 years of age receive 5 mg/kg/day (up to 150 mg/day). Children 10 years of age or older weighing less than 40 kg should also receive 5 mg/kg/day, while those weighing 40 kg or more may receive 200 mg/day. For prophylaxis, 100 mg daily is an acceptable alternative in children weighing more than 20 kg who are not at risk for influenza-related complications.
What other drugs will affect amantadine?
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.
More amantadine resources
- Amantadine Side Effects (in more detail)
- Amantadine Dosage
- Amantadine Use in Pregnancy & Breastfeeding
- Drug Images
- Amantadine Drug Interactions
- Amantadine Support Group
- 10 Reviews for Amantadine - Add your own review/rating
- amantadine Advanced Consumer (Micromedex) - Includes Dosage Information
- Amantadine MedFacts Consumer Leaflet (Wolters Kluwer)
- Amantadine Prescribing Information (FDA)
- Amantadine Hydrochloride Monograph (AHFS DI)
- Symmetrel Prescribing Information (FDA)
Compare amantadine with other medications
- ADHD
- Chronic Fatigue Syndrome
- Extrapyramidal Reaction
- Fatigue
- Influenza
- Influenza Prophylaxis
- Parkinson's Disease
- Post-Polio Syndrome
- Sexual Dysfunction, SSRI Induced
Where can I get more information?
- Your pharmacist can provide more information about amantadine.
See also: amantadine side effects (in more detail)
