The nurse reviews a client's history before the first dose of donepezil. Which finding requires priority clarification with the prescriber?
1Mild constipation that is controlled with dietary fiber and adequate fluid intake
2Corrected visual acuity with prescription glasses and no new visual symptoms
3A family history of Alzheimer disease without personal cardiac symptoms
4A resting heart rate of 48/min with second-degree atrioventricular block and near-syncope✓ Correct answer
Explanation
Donepezil and other cholinesterase inhibitors can have vagotonic effects on the sinoatrial and atrioventricular nodes, causing bradycardia or heart block, and syncope has been reported. Baseline symptomatic bradycardia with second-degree AV block therefore requires priority clarification before the first dose. The other findings do not present the same immediate labeled conduction risk.
Clinical reasoning Donepezil increases cholinergic activity and can slow sinoatrial and atrioventricular conduction. Existing bradycardia, heart block, or syncope raises immediate safety concern.
Decision rule Clarify clinically significant conduction disease before starting a cholinesterase inhibitor and monitor for dizziness, syncope, or pulse slowing.
Scenario 78-year-old male, moderate Alzheimer disease, starting donepezil 5 mg PO HS. Baseline assessment: resting HR 48, history of second-degree AV block.
Cholinesterase inhibitor — A medication class that increases acetylcholine and may temporarily support cognition in Alzheimer disease while also increasing cholinergic adverse effects.
Vagotonic conduction effect — Slowing at the sinoatrial or atrioventricular node that can manifest as bradycardia, heart block, or syncope.