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What happens if I miss a dose (Symmetrel)?
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 (Symmetrel)?
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 (Symmetrel)?
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.
What other drugs will affect amantadine (Symmetrel)?
Before taking amantadine, tell your doctor if you are using any of the following drugs:
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.
Where can I get more information?
Your pharmacist can provide more information about amantadine.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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