Get emergency medical help if you have signs of an allergic reaction to amantadine: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
extreme drowsiness, falling asleep suddenly even after feeling alert;
a light-headed feeling, like you might pass out;
shortness of breath (even with mild exertion), swelling in your hands or feet;
painful or difficult urination;
depression, agitation, aggression, behavior changes, hallucinations, thoughts of hurting yourself;
a seizure; or
severe nervous system reaction - very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors.
You may have increased sexual urges, unusual urges to gamble, or other intense urges while taking this medicine. Talk with your doctor if this occurs.
Side effects may be more likely in older adults.
Common amantadine side effects may include:
dizziness, falls;
dry mouth;
swelling in your legs or feet;
nausea, constipation; or
sleep problems (insomnia).
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Amantadine side effects (more detail)
