American Board of Internal Medicine (ABIM) Certification Practice Exam

What is a primary concern when using cholinesterase inhibitors?

1. Cardiac conduction abnormalities

2. Active thyroid disease

3. Chronic renal failure

4. Hypertension

The correct answer is: Cardiac conduction abnormalities

When considering the use of cholinesterase inhibitors, one primary concern is the potential for cardiac conduction abnormalities. Cholinesterase inhibitors, such as donepezil, rivastigmine, and galantamine, are commonly used in the management of conditions like Alzheimer's disease. These medications can increase levels of acetylcholine in the body, which can impact the heart's electrical conduction system. Increased acetylcholine can lead to bradycardia and other arrhythmias due to its cholinergic effects on the heart. Individuals with pre-existing cardiac issues or those taking other medications that affect heart conduction may thus be at heightened risk for adverse effects. While other options like active thyroid disease, chronic renal failure, and hypertension can certainly influence patient management or the overall health state of a patient receiving cholinesterase inhibitors, they are not as directly associated with the pharmacodynamics and potential side effects related to the medication's action on cholinergic receptors in the heart compared to cardiac conduction abnormalities. Therefore, monitoring heart rate and rhythm is essential when these medications are prescribed, especially in vulnerable populations.