Amantadine, Oral Capsule

• Suicide warning: Some people who have taken amantadine tried to die by suicide, even some without a history of psychiatric illness. Also, amantadine can worsen mental health problems in people who have psychiatric problems or substance abuse problems. When people attempt suicide, they usually show abnormal behaviors beforehand. These may include confusion, depression, personality changes, agitation, aggressive behavior, hallucinations, paranoia, excessive sleepiness, or insomnia.
• Vision problems warning: If you have blurry vision or other confusion after taking amantadine, you should not drive or work in a situation in which you need to be alert or be able to move well.
• Warning about stopping the drug too quickly: If you’re taking amantadine for Parkinson’s disease, do not abruptly stop taking it. If you do, you may experience serious side effects, including agitation, hallucinations, slurred speech, and stupor depression.

Amantadine is a prescription drug. It comes in five forms: immediate-release capsule, extended-release capsule, immediate-release tablet, extended-release tablet, and syrup. All forms are oral (taken by mouth).

Amantadine extended-release oral capsule is available as the brand-name drug Gocovri. Amantadine immediate-release oral capsule is available as a generic drug. Generic drugs usually cost less than the brand-name version. In some cases, they may not be available in every strength or form as the brand-name drug.

Why it’s used

Amantadine oral capsule is used to treat a variety of movement disorders caused by Parkinson’s disease. It can also be used to treat movement disorders caused by certain drugs (drug-induced movement disorders).

In addition, this drug is used to prevent and treat influenza A virus infection. Amantadine is not a substitute for annual flu shots.

When used to treat Parkinson’s disease, this drug may be used as part of a combination therapy. This means you may need to take it with other medications.

How it works

Amantadine belongs to a class of drugs called antivirals. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.

It’s not fully understood how amantadine works as an antiviral or anti-Parkinson’s disease drug. Amantadine can block the multiplying of influenza A virus in the body. In patients with Parkinson’s disease and drug-induced movement disorders, amantadine increases the effect of a chemical in your brain called dopamine. This helps your body better control your movements.

Amantadine oral capsule doesn’t cause drowsiness, but it can cause other side effects.

More common side effects

Some of the more common side effects that can occur with use of amantadine include:

• nausea
• dizziness and lightheadedness
• insomnia

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious side effects

Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

• Hallucinations
• Abnormal thoughts
• Coma
• Intense urges, such as new or increased urges to gamble, have sex, or go on impulsive shopping sprees
• Skin cancer (melanoma) for people with Parkinson’s disease. If you take this drug to treat Parkinson’s, you should have a healthcare provider check your skin regularly.
• Heart failure. Symptoms can include:
• fluid buildup (edema) in your legs
• fluid buildup in your chest
• shortness of breath
• getting more easily out of breath
• irregular heartbeat or faster heartbeat or both
• Neuroleptic malignant syndrome. This is a rare but sometimes fatal reaction caused by increased dopamine in a certain part of the brain. Symptoms can include:
• fever
• rigid muscles
• involuntary movements
• altered consciousness
• mental status changes
• fast pulse
• fast and shallow breathing
• high or low blood pressure

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.

Amantadine oral capsule can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Examples of drugs that can cause interactions with amantadine are listed below.

Central nervous system stimulants

If you take these drugs with amantadine, you may experience increased nervousness, irritability, insomnia, seizures, or irregular heart rhythms (arrhythmias). Examples of central nervous system stimulants include:

• dextroamphetamines
• atomoxetine
• methylphenidate

Anticholinergic drugs

Taking amantadine with anticholinergic medications can increase side effects of both drugs, such as dry mouth, urinary retention, blurred vision, and drowsiness. Examples of anticholinergic drugs include:

• diphenhydramine
• scopolamine
• tolterodine
• benztropine

Heart drugs

Taking certain heart drugs with amantadine can increase the level of amantadine in your body. This can increase your risk of side effects such as nausea, dizziness, or insomnia. This can also increase your risk of death or other serious side effects from overdose of amantadine. Examples of these heart drugs include:

• triamterene-hydrochlorothiazide

Malaria drugs

Taking certain malaria drugs with amantadine can increase the level of amantadine in your body. This can increase your risk of side effects such as nausea, dizziness, or insomnia. This can also increase your risk of death or other serious side effects from overdose of amantadine. Examples of these malaria drugs include:

• quinine
• quinidine

Influenza vaccine

Receiving live attenuated influenza vaccine while you’re taking amantadine can make the influenza vaccine less effective. People who take amantadine should receive this vaccine either 2 weeks before taking amantadine or 48 hours after taking it. If that is not possible, you should receive a different type of flu vaccine called an inactivated vaccine.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.

This drug comes with several warnings.

Allergy warning

Amantadine can cause a severe allergic reaction. Symptoms can include:

• trouble breathing and swallowing
• swelling of the face, such as around the eyes and the mouth
• fever
• hives
• rash

If you develop these symptoms, a call 911 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).

Alcohol interaction warning

Drinking alcohol can increase your risk of side effects from this drug. These side effects can include dizziness, confusion, lightheadedness, and positional low blood pressure (low blood pressure when you stand). If you drink alcohol, talk to your doctor.

Warnings for people with certain health conditions

For people with epilepsy or seizures: Taking amantadine can increase the severity and number of seizures you have.

For people with kidney disease: Deaths have been reported in people with kidney disease who took more than the recommended dosage of amantadine. This can happen with doses as low as 1 g and can cause heart failure, breathing failure, kidney failure, and central nervous system failure.

For people with heart disease: People with a history of congestive heart failure or peripheral edema (swelling of legs or arms) are at increased risk of heart failure when they take amantadine.

For people with glaucoma: People with certain types of glaucoma should not use amantadine because it can cause the pupils to dilate.

For people with recurring eczema-type rash: Taking amantadine can increase the severity of the rash or number of rashes you get.

For people with psychiatric disorders: Taking amantadine can make your disorder become more severe. You may also have increased suicidal thoughts or behaviors.

Warnings for other groups

For pregnant women: Amantadine is a category C pregnancy drug. That means two things:

1. Research in animals has shown adverse effects to the fetus when the mother takes the drug.
2. There haven’t been enough studies done in humans to be certain how the drug might affect the fetus.

Talk to your doctor if you’re pregnant or planning to become pregnant. This drug should be used only if the potential benefit justifies the potential risk to your pregnancy.

If you become pregnant while taking this drug, call your doctor right away.

For women who are breastfeeding: Amantadine passes into breast milk and may cause side effects in a child who is breastfed. Talk to your doctor if you breastfeed your child. You may need to decide whether to stop breastfeeding or stop taking this drug.

All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:

• your age
• the condition being treated
• how severe your condition is
• other medical conditions you have
• how you react to the first dose

Dosage for Parkinson’s disease

Generic: Amantadine

• Form: immediate-release oral capsule
• Strength: 100 mg

Brand: Gocovri

• Form: extended-release oral capsule
• Strength: 68.5 mg, 137 mg

Immediate-release capsule

Adult dosage (ages 18 to 64 years)

• Typical starting dosage: 100 mg, taken twice per day, when not used with other drugs for Parkinson’s disease.
• In some cases: Some people may need to start with 100 mg, taken once per day, if they have certain serious medical illnesses or are taking high doses of other drugs to treat Parkinson’s disease.
• Maximum dosage: 200 mg, taken twice per day.

Child dosage (ages 0 to 17 years)

It has not been confirmed that amantadine is safe and effective for use in people younger than 18 years.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, a higher amount of a drug stays in your body for a longer time. This increases your risk of side effects.

Extended-release capsule

Adult dosage (ages 18 to 64 years)

• Typical starting dosage: 137 mg, taken once a day at bedtime.
• Dosage increases: After one week, your doctor will likely increase your dosage to 274 mg (two 137-mg capsules) once a day at bedtime.

Child dosage (ages 0 to 17 years)

It has not been confirmed that amantadine is safe and effective for use in people younger than 18 years.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, a higher amount of a drug stays in your body for a longer time. This increases your risk of side effects, such as falls and hallucinations.

Dosage for drug-induced movement problems

Generic: Amantadine

• Form: immediate-release oral capsule
• Strength: 100 mg

Adult dosage (ages 18 to 64 years)

• Typical dosage: 100 mg, taken twice per day. However, some people may need to take 300 mg per day in divided doses.

Child dosage (ages 0 to 17 years)

It has not been confirmed that amantadine is safe and effective for use in people younger than 18 years.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, an increased amount of a drug stays in your body for a longer time. This raises your risk of side effects.

Dosage for prevention and treatment of influenza A virus infection

Generic: Amantadine

• Form: immediate-release oral capsule
• Strength: 100 mg

Adult dosage (ages 18 to 64 years)

• Typical dosage: 200 mg taken once per day, or 100 mg taken twice per day.

Child dosage (ages 9 to 12 years)

• Typical dosage: 200 mg taken once per day, or 100 mg taken twice per day.

Child dosage (ages 1 to 8 years)

Dosage is based on weight. It should not exceed 150 mg per day.

Child dosage (ages 0 to 11 months)

It has not been confirmed that amantadine is safe and effective for use in people younger than 1 year.

Senior dosage (ages 65 years and older)

• Typical dosage: 100 mg per day.

Special dosage considerations

For people with kidney disease: Your dosage will depend on the severity of your kidney disease. You may take 200 mg of amantadine on the first day, then 100 mg per day thereafter. However, you may take 200 mg on the first day, then 100 mg every other day. If you have very severe kidney disease or are on dialysis, you shouldn’t take any more than 200 mg once per week.

Dosage warnings

Death from overdose has been reported in a person who ingested 1 g (1,000 mg) of amantadine. There is no antidote for this type of overdose, so it’s extremely important to take amantadine exactly as your doctor prescribed it.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always speak with your doctor or pharmacist about dosages that are right for you.

Amantadine is used for short-term treatment of influenza. It’s used for long-term treatment of Parkinson’s disease and drug-induced movement problems. This drug comes with risks if you don’t take it as prescribed.

If you stop taking the drug or don’t take it at all: If you stop taking the drug suddenly, this might cause delirium, agitation, delusions, hallucinations, paranoia, anxiety, depression, or slurred speech. If you don’t take the drug at all, your condition will not get better.

If you miss doses or don’t take the drug on schedule: Your medication may not work as well or may stop working completely. For this drug to work well, a certain amount needs to be in your body at all times.

What to do if you miss a dose: Take your dose as soon as you remember. But if you remember just a few hours before your next scheduled dose, take only one dose. Never try to catch up by taking two doses at once. This could result in dangerous side effects.

If you take too much: You could have dangerous levels of the drug in your body or you could die. Symptoms of overdose include:

• trouble breathing
• fast or irregular heart rhythm
• high blood pressure
• confusion
• hallucinations
• fluid buildup (edema) in your legs

If you think you’ve taken too much of this drug, call your doctor or local poison control center. If your symptoms are severe, call 911 or go to the nearest emergency room right away.

How to tell if the drug is working: If you’re taking amantadine for Parkinson’s disease, you should have fewer tremors. You should also feel less rigid and be able to move more smoothly.

If you’re taking this drug for drug-induced movement problems, you should be able to move more smoothly and control your movements better.

If you’re taking this drug for influenza A infection, you should have fewer flu symptoms or flu that doesn’t last very long.

Keep these considerations in mind if your doctor prescribes amantadine for you.

General

• You can take amantadine with or without food.
• You should not open the capsule.

Storage

• Store amantadine at room temperature between 68°F and 77°F (20°C and 25°C). It can be temporarily stored in temperatures from 59°F to 86°F (15°C to 30°C).
• Don’t store this medication in moist or damp areas, such as bathrooms.

Refills

A prescription for this medication is refillable. You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.

Travel

When traveling with your medication:

• Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
• Don’t worry about airport X-ray machines. They can’t harm your medication.
• You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled container with you.
• Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Clinical monitoring

Your doctor will test you while you take this drug. Your doctor will check your kidney function. If you take this drug for Parkinson’s disease, you will need to see a dermatologist periodically. This is to check your skin for possible melanoma.

Availability

Not every pharmacy stocks this drug. When filling your prescription, be sure to call ahead to make sure your pharmacy carries it.

Prior authorization

Many insurance companies require a prior authorization for this drug. This means your doctor will need to get approval from your insurance company before your insurance company will pay for the prescription.

There are other drugs available to treat your condition. Some may be better suited for you than others. Talk to your doctor about other drug options that may work for you.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.