Specifically, the Food and Drug Administration (FDA) has approved amantadine oral capsule to:
This article describes possible side effects of amantadine oral capsule. You can explore this overview article to learn more about amantadine, including the drug’s uses, ways to save on cost, and more.
Amantadine oral capsule is a generic medication. It isn’t available in a brand-name version. Amantadine also comes in other forms that you swallow, but these forms aren’t described in this article. To learn more about these forms, talk with your doctor.
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More common side effects of amantadine
Amantadine oral capsule may cause mild or serious side effects. Below are some of the more common side effects of this medication.
Commonly reported side effects of amantadine oral capsule include:
- nausea
- dizziness or lightheadedness
- insomnia
Mild side effects of amantadine
Amantadine may cause certain mild side effects. Usually, mild side effects are temporary and can be easily managed. Tell your doctor or pharmacist if you have side effects that don’t go away or become bothersome.
Mild side effects of amantadine oral capsule that occurred in studies include:
- loss of appetite
- confusion
- constipation or diarrhea
- dizziness or lightheadedness
- dry mouth
- fatigue
- feeling agitated or irritable
- fluid retention in arms, legs, feet, or hands
- headache
- insomnia or sleepiness
- nausea
- mild allergic reaction*
Amantadine oral capsule may cause more mild side effects than those listed above. For details, see the drug’s prescribing information.
* To learn more about this side effect, see the “Side effects of amantadine in detail” section below.
Serious side effects of amantadine
Amantadine may cause certain serious side effects. If you have any serious side effects from amantadine oral capsule, call your doctor right away. But if you think you’re having a medical emergency or your side effects feel life threatening, take immediate action. Call 911 or a local emergency number, or go to the nearest emergency room.
After the FDA approves a drug, it tracks and reviews side effects of the medication. Visit MedWatch’s website if you’d like to notify the FDA about a side effect you’ve had with amantadine.
Serious side effects of amantadine oral capsule that occurred in studies include:
* To learn more about this side effect, see the “Side effects of amantadine in detail” section below.
Suicide prevention
If you or someone you know is in crisis and considering suicide or self-harm, please seek support:
If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.
If you are not in the same household, stay on the phone with them until help arrives.
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Common questions about side effects of amantadine
Here are answers to some common questions about side effects of amantadine oral capsule. If you have other questions, talk with your doctor or pharmacist.
Can amantadine be used in dogs? If so, what side effects do dogs experience from the drug?
Amantadine oral capsule is approved for use in people. It should not be used in dogs or pets without talking with their veterinarian. Talk with a veterinarian to learn more.
Is amantadine safe for older adults?
Yes. Older adults (ages 65 years and older) aren’t expected to experience different side effects than younger adults when taking amantadine oral capsule, according to studies of the drug.
Older adults are more likely to have weakened kidney function, which can increase the risk for side effects of amantadine. For this reason, doctors may prescribe a lower amantadine dose when starting treatment in older adults. They may also order kidney function tests before prescribing amantadine oral capsule.
Does amantadine cause long-term side effects?
Yes, in some cases amantadine oral capsule may cause long-term side effects. These can occur if you take the drug for a long time, or they may last for a while after you’ve stopped taking the drug.
Examples of long-term side effects reported with amantadine oral capsule include:
- heart failure
- mental health side effects*
*To learn more about this side effect, see the “Side effects of amantadine in detail” section below.
Talk with your doctor to learn more about these side effects and how to manage them. Ask your doctor for more information about how long these side effects of amantadine may last.
Side effects of amantadine in detail
Below you’ll find details on some of the side effects of amantadine oral capsule.
Mental health side effects
In studies, mental health side effects were rare in people taking amantadine oral capsule. These side effects may be serious.
Mental health side effects reported with amantadine include:
These effects are possible even when amantadine is used short term.
Certain factors can increase the risk of mental health side effects with amantadine oral capsule. These include having an existing mental health condition or a history of mental health problems.
Ways to manage
If you experience symptoms of a mental health side effect, immediately tell your doctor. They’ll recommend the best treatment for you based on your symptoms. This will vary depending on the type of symptoms you’re experiencing.
However, if your symptoms feel severe, seek immediate medical help. If you’re having thoughts of harming yourself, call the 988 Suicide and Crisis Lifeline at 988. You can also call 911 or your local emergency services number if you feel safe to do so.
Eye and vision problems
In studies, eye and vision problems were rare in people taking amantadine oral capsule. These side effects may be serious.
Eye and vision problems reported with amantadine include:
Certain factors can increase the risk of eye and vision problems with amantadine oral capsule. These include having an existing eye condition, such as glaucoma. Doctors typically won’t prescribe amantadine to people with closed-angle glaucoma due to this risk, for example.
Ways to manage
If you experience symptoms of an eye or vision problem, tell your doctor. They’ll likely recommend making an eye exam to review your symptoms. The results of this exam will dictate the recommended treatment, which may involve temporarily or permanently stopping amantadine treatment.
For some people, amantadine oral capsule can cause an allergic reaction.
Symptoms can be mild or serious, and they may include:
- itchiness
- skin rash
- swelling under the skin, usually affecting eyelids, lips, hands, or feet
- swelling of the mouth, tongue, or throat, which can make it hard to breathe
- flushing (temporary warmth, redness, or deepening of skin color)
Ways to manage
For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.
For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to amantadine oral capsule, your doctor may recommend taking a different medication instead.
Warnings for amantadine
Below are some factors you may want to discuss with your doctor before taking amantadine oral capsule.
Warnings
It may not be safe for you to take amantadine oral capsule if you have specific health conditions. These are sometimes called drug-condition interactions. Other things may also affect whether amantadine oral capsule is a safe treatment option for you.
Before taking amantadine oral capsule, tell your doctor about your health and medications you take. Things to consider include:
Amantadine and pregnancy
It’s not known whether amantadine oral capsule should be taken during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking this medication.
Amantadine and breastfeeding
Amantadine oral capsule should not be taken while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking this medication. Your doctor may recommend other ways to feed your child during treatment with amantadine.
Amantadine oral capsule is known to interact with alcohol. Consuming alcohol increases the risk for certain side effects of amantadine, including dizziness, confusion, and orthostatic hypotension (dizziness on standing up).
If you drink alcohol, talk with your doctor about whether it’s safe to consume it during your treatment with amantadine oral capsule.
What to ask your doctor
This article describes common and serious side effects of amantadine oral capsule. If your doctor prescribes this medication, they can discuss possible side effects with you. Let your doctor know if you have concerns or questions about treatment with this medication.
Here’s a list of some possible questions you may want to ask your doctor:
- How do side effects of amantadine compare with those of other medications that can treat my condition?
- Does my risk of mental health side effects depend on the dosage of amantadine oral capsule I take?
- Does my risk of heart failure depend on the length of amantadine treatment?
Disclaimer: Optum Perks 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 another 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.
