Amantadine is used to treat Parkinson's disease and "Parkinson-like" symptoms such as stiffness or tremors, shaking, and repetitive uncontrolled muscle movements that may be caused by the use of certain drugs.

Amantadine is also used to treat or prevent influenza A in adults and children. Amantadine may not be effective during every flu season because certain strains of the virus may be resistant to this medicine. Amantadine should not be used in place of getting a yearly flu shot. The Centers for Disease Control recommends an annual flu shot to help protect you each year from new strains of influenza virus.

Amantadine may also be used for purposes not listed in this medication guide.

You should not use amantadine if you are allergic to it, or if:

• you have severe kidney disease; or
• you received a "live" nasal flu vaccine (FluMist) within the past 14 days.

Tell your doctor if you have ever had:

• kidney disease;
• daytime drowsiness (caused by a sleep disorder or taking certain medicines);
• congestive heart failure;
• eczema;
• glaucoma;
• liver disease;
• a seizure;
• low blood pressure, fainting spells;
• alcoholism or drug addiction; or
• mental illness, psychosis, or suicidal thoughts or actions.

People with Parkinson's disease may have a higher risk of skin cancer (melanoma). Talk to your doctor about this risk and what skin symptoms to watch for.

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

You should not breast-feed while using this medicine.

Amantadine is not approved for influenza in a child younger than 1 year old. Gocovri is not approved for use by anyone younger than 18 years old.

Use Osmolex ER (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction: 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 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.

Do not receive a nasal flu vaccine while using amantadine, and for at least 48 hours after your last dose. The vaccine may not work as well during this time, and may not protect you from influenza.

Do not drink alcohol. Dangerous side effects could occur.

Avoid driving or operating machinery until you know how this medicine will affect you. Amantadine may impair your thinking or reactions. Some people taking amantadine have fallen asleep during normal daytime activities such as working, talking, eating, or driving. You may fall asleep suddenly, even after feeling alert. Be careful if you drive or do anything that requires you to be alert.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

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.