American Board of Internal Medicine (ABIM) Certification Practice Exam

What type of medication may provide benefit for Parkinson's patients with prominent tremors?

1. Beta-blockers

2. Anticholinergics

3. Monoamine oxidase inhibitors

4. Dopamine agonists

The correct answer is: Anticholinergics

Anticholinergics are particularly effective in managing prominent tremors in Parkinson's disease due to their action on the neurotransmitter acetylcholine. In Parkinson's disease, there is a relative deficiency of dopamine in the brain, which leads to an imbalance between acetylcholine and dopamine levels. The exacerbation of tremors is often due to this imbalance, where acetylcholine activity is unopposed. Anticholinergic medications work by blocking the effects of acetylcholine, thereby correcting the imbalance that contributes to the motor symptoms, including tremors. These medications, such as trihexyphenidyl and benztropine, can help reduce tremors effectively, especially in younger patients or those who have not yet developed significant bradykinesia or rigidity. While other classes of medications, such as dopamine agonists and monoamine oxidase inhibitors, can help with a broader range of Parkinson's symptoms, they are primarily beneficial for improving overall motor function rather than targeting tremor specifically. Beta-blockers can be used for tremors but are not first-line agents in Parkinson's disease for this purpose. Thus, anticholinergics stand out as the correct choice for addressing prominent tremors in this context.