- Subject receiving a Monoamine Oxidase (MAO)-B Inhibitor (eg, Selegiline or Rasagiline), an n-Methyl-d-Aspartate Antagonist (eg, Amantadine), or allowed anti-Parkinson medications and has been on a stable dose for at least 21 days prior to starting Parkinson's diaries and is anticipated to be maintained on that dose for the duration of the study