Which medication is used to treat Parkinson disease tremor via anticholinergic mechanism?

• A. Benztropine
• B. Levodopa
• C. Selegiline
• D. Amantadine

Answer: (A)

Tremor in Parkinson disease often comes from an imbalance where acetylcholine activity in the striatum is relatively high because dopamine is deficient. Blocking acetylcholine with an anticholinergic reduces this overactive cholinergic signaling and directly helps diminish tremor and rigidity.

Benztropine is a central anticholinergic that antagonizes muscarinic receptors in the brain. By calming that cholinergic overactivity, it specifically targets tremor and rigidity driven by the dopamine-acetylcholine imbalance, making it especially helpful for tremor-dominant Parkinson disease and for drug-induced parkinsonism.

Other options work through different mechanisms—dopamine replacement or promotion (levodopa), MAO-B inhibition to boost dopamine (selegiline), or Dopamine modulation with amantadine—not via anticholinergic effects. Therefore they don’t address the tremor through the anticholinergic pathway the way benztropine does. Note that anticholinergics can cause dry mouth, constipation, urinary retention, blurred vision, and cognitive issues, especially in older patients.