Donepezil and Memantine-Induced Second-Degree Atrioventricular Block: A Case Report

Donepezil and memantine are second-generation antipsychotics widely used in the management of mild to moderate Alzheimer's disease. These drugs are highly selective for the central nervous system, targeting different neural pathways to mitigate cognitive decline. Donepezil is a reversible and specific acetylcholinesterase inhibitor, while memantine is an NMDA receptor antagonist which modulates glutamatergic activity. Although these medications are safe, they are associated with adverse effects, and cardiovascular complications are rare. The reported cardiac adverse drug reactions include bradycardia, atrioventricular block, and prolonged QT interval. We are reporting a case of an 81-year-old male patient with schizophrenia, Alzheimer's disease and bilateral sensorineural deafness receiving oral donepezil and memantine presented with second-degree atrioventricular block. The patient's atrioventricular block recovered completely in 2 to 3 weeks after the discontinuation of donepezil-memantine and with a short course of sympathomimetic drugs.