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Amantadine (Symmetrel™)

Medications such as amantadine (Symmetrel) is a mild agent that is used in early PD to help tremor. In recent years, amantadine has also been found useful in reducing dyskinesias that occur with dopamine medication.

What Are the Facts?

  • Initially developed as an antiviral medication to treat influenza in the 1960s, and was coincidentally realized to be a treatment for PD.
  • Used in combination with levodopa to treat dyskinesias.
  • Usually provides only mild relief and is seldom used in early stages of PD.
  • Most commonly available in 100 mg capsules, although liquid and tablet forms can also be obtained.

What are the side effects?

  • Nausea
  • Lightheadedness
  • Insomnia
  • Confusion
  • Hallucinations
  • Swelling of the ankles
  • Livedo reticularis — a lacey, purplish discoloration of the skin on the legs with some leg swelling. Occurs in less than 1 percent of people with PD who take this medication.

Caution: PD medications may have interactions with certain foods, other medications, vitamins, herbal supplements, over the counter cold pills and other remedies. Anyone taking a PD medication should talk to their doctor and pharmacist about potential drug interactions.


Available Doses

Initial Dosing

Side Effects*





100 mg

100 mg 2-3 X/day

Dizziness, weakness, dry mouth, anxiety, confusion, constipation, skin blotches

Secondary medication for tremor and muscle rigidity

Cogentin® (benztropine), Disipal® (orphenadrine), Artane® (trihexyphenidyl), amphetamines, alcohol

* Please note that the side effects listed in the tables that accompany each class of medication are the most commonly experienced. Not all individuals will experience such side effects. For many people who do experience side effects, they can often be effectively limited or eliminated with careful adjustments to dosage or the timing of the individual doses.

Speak to the treating physician immediately if any side effects are experienced. For a complete description of each drug and its possible side effects, please request a “package insert” from your pharmacist for each drug used. It is recommended that all prescriptions be filled at the same pharmacy to avoid interactions between medications. Interactions can be dangerous and even life-threatening, so make sure the pharmacist knows of all medications and supplements being taken, including over-the-counter medications and supplements.

Page reviewed by Dr. Chauncey Spears, Movement Disorders Fellow at the University of Florida, a Parkinson’s Foundation Center of Excellence.

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