Amantadine was originally developed in the mid 1960s as an anti-viral drug used to treat Influenza-A. Now largely withdrawn for use against 'flu due to widespread drug-resistance concerns.

It was subsequently found to be of use in treating the dyskinesia (faulty movements) and rigidity of Parkinson's diseaseplugin-autotooltip__plain plugin-autotooltip_bigParkinson's disease

Also known as Parkinson disease, Parkinson's, idiopathic Parkinsonism, primary Parkinsonism, PD, or paralysis agitans - is a degenerative disorder of the central nervous system resulting from the death of dopamine-containing cells in the. It's now sold under the brand names Gocovri, Wiregyt, Amanta, Amixx, Inflex, Tregor and others, and often used alongside other drugs such as Levodopa.

The mechanisms of its effects in movement disorders are not well understood but probably reflect an increase in synthesis and release of dopamine, with perhaps some inhibition of dopamine uptake.

Source : NCBI MeSH