Amantadine's role in the treatment of levodopa-induced dyskinesia

Levodopa-induced dyskinesia (LID) is one of the most common, frequently dose-limiting, complications of pharmacologic therapy for Parkinson disease (PD). These typically choreiform movements, usually occurring at the time of peak levodopa effect, occur in 40% to 50% of patients after 5 years of therapy, but have a reported incidence as high as 94% in a carefully conducted prospective study of patients under treatment for 15 years. When mild, LID often goes unnoticed by patients, but moderate or severe forms frequently constitute a major motor or emotional disability. This can lead to reduction or discontinuance of otherwise effective PD therapies, and may prompt implementation of more invasive treatments such as deep brain stimulation or direct intrajejunal infusion of levodopa gel. The need for a safe, effective, and enduring means of combating LID is clear. Although many drugs have been evaluated for this purpose, and others are currently under investigation, to date only one agent, amantadine, has been effective in an evidence-based medicine review.

Neurology 2013