Immediate-release 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. In 2017, an extended-release form of amantadine (Gocovri) was the first drug approved by the FDA specifically to treat dyskinesia in Parkinson's.
What Are the Facts?
- Amantadine was initially developed as an antiviral medication to treat influenza in the 1960s; later it was realized that it can be used as a treatment for PD, and this use was confirmed in clinical trials.
- It is used in combination with levodopa to treat dyskinesias.
- Immediate-release amantadine is most commonly available in 100 mg capsules, although liquid and tablet forms can also be obtained. Most people take multiple doses per day.
- Extended-release amantadine is a once per day treatment option. People who are doing well on multiple doses per day of generic amantadine will likely not benefit from switching to one-a-day Gocovri, but people who experience side effects from amantadine now have another option.
- No trial has been done comparing immediate- and extended-release amantadine, but many trials show that amantadine in any formulation can be effective at suppressing dyskinesia.
What Are the Side Effects?
- 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.
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.