Amantadine is also an older medication that was initially developed to help prevent influenza Type A. It was subsequently found to have a mild but definite effect on Parkinson’s without worsening typical symptoms. More recently, it has been found to be helpful in reducing levodopa-induced dyskinesias and now is predominantly used in advanced Parkinson’s disease for this purpose. Furthermore, the use of amantadine followed by a dopamine agonist tends to lower the incidence of Levodopa-induced Dyskinesia (LID) compared to a dopamine agonist alone.
There are both on-label extended-release and off-label immediate-release options for amantadine. Adverse effects with amantadine are not uncommon and include swelling of the feet, dry mouth, constipation, vivid dreams, dizziness, and hallucinations. There is a once-daily extended-release, high-dose preparation given at bedtime that is specifically indicated for dyskinesias as well as OFF episodes. There is also an off-label variety of amantadine given twice daily but is not specifically FDA-approved for dyskinesia.
Discuss your options regarding the use of amantadine and its side effects with your doctor before implementing any new therapies into your routine.