An editorial discusses several important limitations of the study:
• There was no active comparison with immediate-release amantadine.• There was an early and unexpected termination of the study.• The study did not shed light on responders to amantadine therapy vs non-responders.• There was also an underrepresentation in the sample of patients with young-onset Parkinson’s disease (PD) who in general tend to have more severe LID (mean age at onset for PD in study was ~56 years).
It notes however that the findings of relatively low incidence of adverse effects and the reversible nature of cognitive adverse effects in an older sample of patients with PD are encouraging. It concludes that despite the many advantages of this pill, until a true comparison with a generic amantadine pill is performed, it remains unclear whether the potential benefits justify the cost.