Amantadine: the journey from fighting flu to treating Parkinson disease

To explore how amantadine transitioned from an anti-flu drug to antiparkinsonian agent.

A review of the historical literature on the use of amantadine from 1966 to the present was performed.

Amantadine was originally introduced and utilized as an antiviral medication. A single patient noticed relief in her Parkinson disease (PD) symptoms after taking amantadine for a flu infection, and this observation sparked an interest, and several important studies that eventually led to a new drug indication.

Amantadine has over the years fallen out of favor as a drug to address influenza infection; however, it has become part of the arsenal utilized for early symptomatic treatment of PD, as well an option for treating dyskinesia.