Which drug in the described regimen is used to treat Parkinson's disease?

• A. Dalteparin
• B. Metoclopramide
• C. Sinemet
• D. Co-codamol

Answer: (C)

Parkinson’s symptoms come from a deficiency of dopamine in the brain, so treatments that increase brain dopamine are used. Sinemet is a combination of levodopa and carbidopa. Levodopa is the direct precursor to dopamine and can cross into the brain, where it is converted to dopamine to replenish losses and improve motor symptoms like slowness and stiffness. Carbidopa blocks the enzyme that breaks down levodopa outside the brain, so more levodopa reaches the brain and side effects such as nausea are reduced. That makes Sinemet the best option for addressing the core motor issues in Parkinson’s.

Dalteparin is an anticoagulant used to prevent clots; metoclopramide is an antiemetic that can worsen Parkinsonian symptoms by blocking dopamine in the brain; co-codamol provides analgesia (paracetamol with codeine) and does not treat Parkinson’s.