ABSTRACT
Amantadine (Symmetrel®) was first introduced as an antiviral agent for the treatment of influenza. It was recognized as a potential treatment for Parkinson’s disease (PD) in 1968 when a woman treated for influenza noticed improvement in her parkinsonian symptoms and subsequent worsening of her PD symptoms when amantadine was discontinued.1 In an open-label study, it was subsequently shown that two-thirds of 163 PD patients had some improvement in rigidity, bradykinesia, and tremor with amantadine.1 Since this initial report, multiple studies have been conducted to examine the antiparkinsonian effects of amantadine as monotherapy in early PD, and as combination therapy in early and advanced PD. Currently, amantadine is the only antidyskinetic agent available for the treatment of levodopa induced dyskinsesia. The exact mechanism of action of amantadine is unknown, although it appears to have both dopaminergic and nondopaminergic properties. This chapter reviews the possible mechanisms of action, clinical studies, and safety of amantadine in PD.
