GENERIC NAME: amantadine
DISCONTINUED BRAND: Symmetrel
DRUG CLASS AND MECHANISM: Amantadine is a synthetic (man-made) anti-viral drug that can inhibit the replication of viruses in cells. To prevent a viral infection, the drug should be present before exposure to the virus. Clearly, this is not practical for most viral infections. It was initially used to prevent influenza A during flu season, and, if given within 24 to 48 hours of the onset of flu symptoms, to decrease the severity of the flu. Later amantadine was found to cause improvement in the symptoms of Parkinson's disease. Amantadine's mechanism of action in Parkinson's disease is not fully understood. Its effects may be related to its ability to augment (amplify) the effects of dopamine, a neurotransmitter in the brain, that is reduced in Parkinson's disease. Amantadine is less effective than levodopa in Parkinson's disease but can offer additional benefit when taken with levodopa. Amantadine was approved by the FDA in 1966.
PRESCRIBED FOR: Amantadine is used for the prevention or treatment of infections with influenza A, especially for individuals at high-risk such as immunosuppressed patients and nursing home residents. It should not be used as a substitute for vaccination for influenza. Amantadine also is used for control of the symptoms of Parkinson's disease and for treatment of drug-induced extrapyramidal symptoms.
SIDE EFFECTS: The most frequent side effects associated with amantadine that can appear after a few hours or several days of therapy include:
Less common side effects include:
- slurred speech,
- loss of appetite, and
- discolorations in the eye.
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