Symmetrel FAQ
What is the brand and the generic name for this drug?
Symmetrel - brand; Amantadine - generic
What is Symmetrel (Amantadine) used for?
- Preventing and treating certain types of flu. It is used to treat Parkinson disease and uncontrolled muscle movements caused by some medicines. It may also be used for other conditions as determined by your doctor.
- Symmetrel (Amantadine) is an antiparkinson and antiviral agent. How Symmetrel (Amantadine) works against the flu is not known. It may block reproduction of the virus and decrease the ability of the virus to get into the cells. How Symmetrel (Amantadine) works against Parkinson disease is not known. It may increase a certain chemical in the brain.
When I should not use Symmetrel (Amantadine)?
Do NOT use Symmetrel (Amantadine) if:
- you are allergic to any ingredient in Symmetrel (Amantadine)
- you have uncontrolled narrow-angle glaucoma
Contact your doctor or health care provider right away if any of these apply to you.
What should I know before using Symmetrel (Amantadine)?
Some medical conditions may interact with Symmetrel (Amantadine). Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
- if you are pregnant, planning to become pregnant, or are breast-feeding
- if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
- if you have allergies to medicines, foods, or other substances
- if you have a history of heart problems (eg, congestive heart failure), swelling of your hands or feet, mental or mood problems, suicidal thoughts or actions, seizures, glaucoma, low blood pressure, dizziness when you stand or sit up, an eczema-like rash, or kidney or liver problems
What MEDICINES MAY INTERACT with Symmetrel (Amantadine)?
Tell your health care provider if you are taking any other medicines, especially any of the following:
- Thioridazine because tremors may be worsened in Parkinson patients
- Anticholinergics (eg, scopolamine), hydrochlorothiazide, quinidine, quinine, stimulants (eg, caffeine, methylphenidate, pseudoephedrine), or triamterene because they may increase the risk of Symmetrel (Amantadine) 's side effects
This may not be a complete list of all interactions that may occur. Ask your health care provider if Symmetrel (Amantadine) may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.
How should I use Symmetrel (Amantadine)?
Use Symmetrel (Amantadine) as directed by your doctor. Check the label on the medicine for exact dosing instructions.
- Take Symmetrel (Amantadine) by mouth with or without food.
- If you are using Symmetrel (Amantadine) for the flu, take it for the full course of treatment. Keep using Symmetrel (Amantadine) even if you feel better in a few days. This will help clear up your infection completely.
- If you miss a dose of Symmetrel (Amantadine) , take it as soon as possible. If it is almost time for your next dose, skip the missed dose. Go back to your regular dosing schedule. Do not take 2 doses at once.
Ask your health care provider any questions you may have about how to use Symmetrel (Amantadine).
Which is the most important safety information I should know about Symmetrel (Amantadine)?
- Symmetrel (Amantadine) may cause drowsiness, dizziness, or blurred vision. These effects may be worse if you take it with alcohol or certain medicines. Use Symmetrel (Amantadine) with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
- Symmetrel (Amantadine) may cause dizziness, lightheadedness, or fainting; alcohol, hot weather, exercise, or fever may increase these effects. To prevent them, sit up or stand slowly, especially in the morning. Sit or lie down at the first sign of any of these effects.
- Limit alcohol intake while you are taking Symmetrel (Amantadine). Talk with you doctor before you drink alcohol or use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using Symmetrel (Amantadine) ; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.
- Do not become overheated in hot weather or while you are being active; heatstroke may occur.
- Symmetrel (Amantadine) only works against certain types of the flu; it does not treat other viral infections (eg, the common cold).
- If you are taking Symmetrel (Amantadine) for the flu, be sure to use Symmetrel (Amantadine) for the full course of treatment. If you do not, the medicine may not clear up your infection completely. The virus could also become less sensitive to this or other medicines. This could make the infection harder to treat in the future.
- If you are taking Symmetrel (Amantadine) for Parkinson disease, increase physical activity slowly as your symptoms improve.
- Do not suddenly stop taking Symmetrel (Amantadine) without first checking with your doctor. Your dose may need to be lowered slowly to avoid side effects.
- Neuroleptic malignant syndrome (NMS) is a possibly fatal syndrome that can be caused by Symmetrel (Amantadine). Symptoms may include fever; stiff muscles; confusion; abnormal thinking; fast or irregular heartbeat; and sweating. Contact your doctor at once if you have any of these symptoms.
- If your symptoms do not get better or if they get worse, check with your doctor.
- Use Symmetrel (Amantadine) with caution in the ELDERLY; they may be more sensitive to its effects.
- Symmetrel (Amantadine) should be used with extreme caution in CHILDREN younger than 1 year old; safety and effectiveness in these children have not been confirmed.
- PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using this medicine while you are pregnant. Symmetrel (Amantadine) is found in breast milk. Do not breast-feed while taking Symmetrel (Amantadine).
- If you stop taking Symmetrel (Amantadine) suddenly, you may have WITHDRAWAL symptoms. These may include agitation, hallucinations, paranoia, anxiety, depression, confusion, or slurred speech.
Which are the possible side effects of Symmetrel (Amantadine)?
- All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:
- Appetite loss; blurred vision; constipation; diarrhea; dizziness; drowsiness; dry mouth or nose; headache; lightheadedness; nausea; strange dreams; tiredness; trouble sleeping.
- Seek medical attention right away if any of these SEVERE side effects occur:
- Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); agitation; aggression; confusion; depression; fainting; fast or irregular heartbeat; fever; hallucinations; memory loss; mental or mood changes; muscle problems (eg, spasms, uncontrolled movements); paranoid thoughts; personality changes; seizures; severe or persistent drowsiness or trouble sleeping; shortness of breath; swelling of hands, legs, feet, or ankles; thoughts of suicide; trouble urinating; unusual anxiety or irritability; vision changes.
What is the shelf life of the pills?
- The expiry date is mentioned on each blister. It is different for different batches. The shelf life is 2 years from the date of manufacture and would differ from batch to batch depending on when they were manufactured.


