Which medication is used to treat dyskinesia related to Parkinson's disease therapy?

• A. Selegiline
• B. Amantadine
• C. Tolcapone
• D. Carbidopa-levodopa

Answer: (B)

Dyskinesias arising from Parkinson’s therapy are best managed with amantadine because it works differently from dopaminergic drugs. Amantadine blocks NMDA receptors, which reduces abnormal glutamatergic activity in the basal ganglia that contributes to peak-dose dyskinesias from long-term levodopa use. This helps smooth out involuntary movements without increasing dopaminergic stimulation that can worsen dyskinesias. Other options either boost dopamine to improve symptoms (selegiline) or extend levodopa’s effect without addressing the dyskinesia itself (tolcapone and carbidopa-levodopa), and can even worsen dyskinesias over time. So amantadine specifically targets the dyskinesia mechanism, making it the best choice.