Uses

What is amantadine used for?

Amantadine is commonly used for the following conditions.

Amantadine may not be appropriate for treating or preventing all cases of the flu, depending on which virus is causing the infection. Amantadine does not work against all influenza viruses. Influenza A viruses in some locations may have developed resistance to amantadine, which will make it less effective.

Amantadine may also be used for other conditions as determined by your healthcare provider.

How does amantadine work (mechanism of action)?

Amantadine works as an antiviral by blocking the activity of a specific protein in certain viruses they need to multiply and spread in the body. Amantadine may help relieve Parkinson’s symptoms or treat drug-induced movement problems by acting like dopamine in the brain to control movements.

How is amantadine supplied (dosage forms)?

Brands and other names

  • Gocovri

Dosage forms and strengths

  • 100 mg oral capsules
  • 100 mg oral tablets
  • 50mg/5mL oral solution
  • 68.5 mg, 137 mg extended-release oral capsules 

How should I store amantadine?

Amantadine should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C), for shorter periods of time, such as when transporting it. Store in a cool, dry place.

Side Effects

What are the most common side effects of amantadine?

The most common side effects of amantadine are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Nausea
  • Dizziness or lightheadedness
  • Falls
  • Trouble sleeping
  • Hallucinations (see below)
  • Dry mouth
  • Swelling of the hands, feet, or legs
  • Constipation
  • Low blood pressure upon standing  (orthostatic hypotension) (see below)

There may be other side effects of amantadine that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of amantadine?

While less common, the most serious side effects of amantadine are described below, along with what to do if they happen.

Severe Allergic Reactions. Amantadine may cause allergic reactions, which can be serious. Stop taking amantadine and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Suicidal Thoughts or Actions. Amantadine may cause suicidal thoughts or actions in a small number of people. This may occur even if you do not have a history of mental health problems. If you are about to harm yourself, call 911 or call or text 988, the Suicide & Crisis Lifeline. Call your healthcare provider right away if you, your family, or your caregivers notice that you have any of the following symptoms.

  • New or increased thoughts of suicide or death
  • Suicide attempt
  • New or increased feelings of anxiety, depression, or other unusual changes in mood or behavior

Sleepiness or Falling Asleep. Amantadine can make some people fall asleep, even without feeling sleepy. This can happen while doing simple daily tasks, like while eating or talking with someone. Call your healthcare provider right away if this happens to you. Do not drive or do other activities that require alertness or coordination until you know how amantadine affects you.

Hallucinations. Amantadine may cause hallucinations or worsen existing psychotic-like behavior. Tell your healthcare provider right away if you have any of the following symptoms, or if you have been told by others you have these symptoms.

  • Hearing, seeing, smelling, tasting, or otherwise perceiving things that others do not
  • Delusional thoughts, such as false beliefs that you are being controlled
  • Feeling paranoid

Low Blood Pressure Upon Standing (Orthostatic Hypotension). Amantadine may cause a sudden drop in blood pressure when standing up from a seated or lying position. To help prevent this, be careful not to get up too quickly. If you feel dizzy, sit or lie down right away until the dizziness stops, then take your time getting up again. Tell your healthcare provider right away if you have any of the following symptoms of orthostatic hypotension.

  • Dizziness, feeling lightheaded, or fainting upon standing
  • Blurred vision
  • Confusion
  • Feeling weak

Unusual or Compulsive Behaviors. Amantadine can cause some people to have strong unusual and uncontrolled urges (compulsions), including gambling, sex, shopping, or eating. Talk to your healthcare provider right away if you or someone you know notices that you have new or worsening strong urges or behaviors.

Neuroleptic Malignant Syndrome (NMS). Do not lower your dose or stop taking amantadine without talking to your healthcare provider. Stopping amantadine too quickly may cause a serious side effect, called neuroleptic malignant syndrome (NMS), which can lead to death. Call your healthcare provider if you need to lower your dose or stop taking amantadine. Call your healthcare provider right away if you experience any of the following symptoms when stopping amantadine or lowering your dose.

  • High fever
  • Muscle stiffness or rigidity, where it is hard to move
  • Changes in your breathing or heart rate
  • Increased sweating
  • Confusion

Warnings & Precautions

Who should not use amantadine?

Allergies to Ingredients. People who are allergic to any of the following should not take amantadine products.

  • Amantadine
  • Gocovri
  • Symmetrel
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific amantadine products they stock.

Kidney Problems. Amantadine extended-release capsules should not be taken if your kidneys are not working as well as they should be. If there is a concern about the health of your kidneys, your healthcare provider may do tests to determine if they are working well enough to take this medicine.

What should I know about amantadine before using it?

Do not take amantadine unless it has been prescribed to you by a healthcare provider. 

Do not share amantadine with other people, even if they have the same condition as you. It may harm them.

Keep amantadine out of the reach of children.

Do not chew, cut, or crush amantadine extended-release capsules. They should be swallowed whole. If you have trouble swallowing the extended-release capsule, you can open them and pour the contents on a spoonful of  applesauce. You should then swallow the applesauce right away without chewing.

If you are taking amantadine for Parkinson’s disease, do not stop taking it without talking to your healthcare provider. Stopping suddenly can lead to serious problems, including worsening of Parkinson’s disease, agitation, depression, and hallucinations. Contact your healthcare provider if you think you need to stop taking amantadine.

Use an accurate measuring device to measure your dose of amantadine liquid. A household spoon is not an accurate measuring device and may cause you to take the wrong dose. Ask your pharmacist to recommend an appropriate measuring device.

Amantadine can affect your alertness or coordination and may cause blurry vision. Do not drive or do other activities that require alertness or coordination until you know how amantadine affects you.

People who are 65 years of age and older can be at a greater risk for some side effects of amantadine. Talk to your healthcare provider about your risks if you are in this age group.

You should monitor your skin for changes while taking amantadine. Keep any appointments to have your skin checked.

What should I tell my healthcare provider before using amantadine?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if amantadine is right for you.

In particular, make sure that you discuss any of the following.

Vaccines. Talk with your healthcare provider about any vaccines that you may need. You should not receive certain vaccines right before or while using amantadine. Tell your healthcare provider about any vaccines you have recently received or have scheduled.

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

  • Heart problems, including heart failure
  • Kidney problems, including renal tubular acidosis
  • A severe infection of the bladder or kidney
  • Liver problems
  • Seizures
  • Sleep problems
  • Glaucoma
  • Mental health problems, including depression, mood problems, or psychosis
  • A history of skin problems
  • Low blood pressure, even if it only happens when you stand up
  • Swelling of arms, legs, hands, or feet
  • Substance use disorder

Other Medicines and Supplements. Amantadine may interact with other medicines and supplements. Before taking amantadine, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how amantadine could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant. Your healthcare provider will advise you if you should take amantadine while you are pregnant or trying to get pregnant.

Breastfeeding. Amantadine passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should take amantadine while breastfeeding.

Interactions

Does amantadine interact with foods or drinks?

There are no known interactions between amantadine and foods or drinks.

Do not drink alcohol while taking amantadine. Drinking alcohol may change how quickly amantadine gets into your blood. The risk of dizziness, confusion, and sleepiness may be increased if you drink alcohol while taking amantadine.

Does amantadine interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking amantadine.

  • An anticholinergic medicine, which includes antihistamines and medicines commonly used for overactive bladder, Parkinson’s disease, or stomach problems
  • A carbonic anhydrase inhibitor, such as zonisamide (Zonegran), acetazolamide (Diamox), or methazolamide
  • Sodium bicarbonate, which is in some over-the-counter (OTC) and prescription medicines (Zegerid, Zegerid OTC, and Alka-Seltzer) used for heartburn and stomach ulcers
  • Thioridazine, which is a medicine used for certain mental health conditions
  • Triamterene/hydrochlorothiazide, which is a medicine used to treat high blood pressure and edema (fluid retention)
  • Quinidine, which is a medicine used for an irregular heart rhythm
  • Any other medicine that causes dizziness and sleepiness, such as prescription pain medicines, sleep medicines, or medicines for anxiety

This may not be a complete list of medicines that can interact with amantadine. Always check with your healthcare provider.

Does Amantadine interact with other drugs you are taking?
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Overdose/Missed Dose

What should I do if I accidentally use too much amantadine?

If you or someone else has taken too much amantadine, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of amantadine?

If you miss a dose of an amantadine tablet, liquid, or capsule, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose as scheduled. Do not take double or extra doses.

If you miss a dose of an amantadine extended-release capsule, skip the missed dose. Take your next dose when you normally would. If you have missed several doses in a row, ask your healthcare provider what to do. Do not take extra or double doses. 

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