What is Amantadine? Amantadine hydrochloride is an antiviral medication that inhibits overactive nerve signals in the central nervous system (CNS). This occurs by antagonizing N-methyl-D-aspartate (NMDA) receptors in the nervous system which commonly transmits pain signals. Typically, when these pain pathways become overstimulated the animal will have a hypersensitivity to pain. Amantadine works to ‘reset’…