Gen-Amantadine

Brand Name:Symmetrel, Endantadine

Prescription needed: Yes

What is this drug used for?

Amantadine can be used to reduce the symptoms of the flu caused by Influenza A as well as prevent the start of flu symptoms, specifically in people who have been exposed to influenza A (e.g. in nursing homes). It can also be used to improve muscle control and decrease stiffness in people who have Parkinson’s Disease. As well, it may sometimes be used to treat the side effects (stiffness, shaking) of some medications.

Is there any reason not to take this drug?

You should not take this drug if you are allergic to amantadine. Before taking this medication, tell your doctor specifically if you have or have ever had:
  • eczema
  • problems with seizures
  • problems with your liver or kidney
  • problems with low blood pressure
  • swelling of the ankles or legs
  • congestive heart failure
  • problems with mental illness
  • angle closure glaucoma that is not being treated

What about possible side effects?

The most common side effects to this medication include:
  • nausea
  • dizziness
  • trouble falling or staying asleep
  • dry mouth/nose/throat
  • constipation
  • feeling agitated, irritable or anxious
  • feeling extremely tired
  • feeling confused
  • swelling of the ankles and feet
  • feeling lightheaded or off-balance when sit/stand up

These side effects are usually related to dose, the use of other medications and other factors (e.g. older age, other medical conditions). As well, the side effects may decrease with time. Discuss this with your doctor or pharmacist and always take as directed.

Other less common and possibly severe side effects include:

  • changes in vision
  • hallucinations
  • feeling depressed or thoughts of suicide - contact your doctor immediately
  • rash - stop the drug and contact your doctor immediately
  • a condition, called leukopenia or neutropenia - very rare, contact your doctor immediately if you experience unexplained sore throat, fever, chills, or other signs of infection
  • seizures

This is not a complete list of side effects. If you are concerned about these or other unusual symptoms while taking this medication, ask your doctor and/or pharmacist for more information and advice.

What if I am taking other drugs?

Always provide your doctor with a list of all other drugs you are taking (including over-the-counter medications and herbal/natural products) as they may interact with and/or may change the safety or effectiveness of either drug. Tell your doctor specifically if you are taking any of these drugs as he/she may need to make changes in your prescriptions or monitor you more closely:
  • amphetamine like drugs/ appetite suppressants (e.g. dexfenfluramine, methylphenidate, phenyephrine) - may increase your chances of having side effects
  • amitriptyline, imipramine, thioridizine, atropine, hyoscine, scopolamine, oxybutynin and other anti-cholinergic drugs (increases your chances for side effects)
  • trimethoprim, triamterene (can increase the amount of amantadine in the blood and increase the chances for side effects)

This is not a complete list of drug interactions. Ask your doctor or pharmacist to review your list of medications.

Other information:

If taking for Parkinson’s Disease:

It may take some time (up to two weeks) to see or feel the full effects of this drug. As well, amantadine may wear off or lose its effect after six to eight weeks. Sometimes the drug may need to be stopped and restarted to get it working again. However, your doctor may choose to change you to another drug.

Children: Can be used; lower doses are necessary.

Seniors: Can be used but lower doses are often required since this age group is more sensitive to the side effects.

Pregnancy: Generally not used; Safety not established. Talk to your doctor.

Women who are nursing: This medication passes through to breast milk. Talk to your doctor.

People who drive or operate machinery: Should not do so until they know the impact this drug has on them personally. Some people may have blurred vision, feel dizzy or be confused.

Overdose: If you experience any unusual reactions or if you seriously exceed the recommended dosage, call your doctor or 911.

Stopping the drug: Always talk to your doctor before stopping this drug. If you stop taking this drug symptoms may recur.

If you miss a dose: Take as soon as you remember, however if the next dose is due within two hours, take one dose now and skip the next dose. Do not double dose.

Storage conditions: Closed container; cool, dry location away from excess moisture (not in the bathroom); direct light, always out of reach of children. Do not allow liquid form of this medication to freeze.

Alcohol: Do not drink alcohol while taking this medication as it may increase a number of side effects including dizziness, lightheadedness, fainting and confusion.

Dietary Precautions: None