Which drug should be avoided in patients with syncope due to bradycardia risk?

Which drug should be avoided in patients with syncope due to bradycardia risk?

• A. Donepezil
• B. Memantine
• C. Rivastigmine
• D. Galantamine

Answer: (A)

The drugs in question are cholinesterase inhibitors used for dementia, which increase acetylcholine at muscarinic receptors and boost parasympathetic (vagal) tone. This can slow the heart rate and lower blood pressure, raising the risk of bradycardia and related syncope in susceptible patients. Among these options, donepezil is the one most commonly associated with clinically significant bradycardia and fainting due to excessive vagal stimulation of the heart. Rivastigmine and galantamine are also cholinesterase inhibitors but tend to have a lower bradycardia risk, while memantine works via NMDA receptor antagonism and does not typically provoke bradycardia. Therefore, in a patient with syncope risk from bradycardia, avoiding donepezil is prudent; consider alternatives like memantine or other non-bradycardia–related approaches, and review other medications that could contribute to bradycardia.

The drugs in question are cholinesterase inhibitors used for dementia, which increase acetylcholine at muscarinic receptors and boost parasympathetic (vagal) tone. This can slow the heart rate and lower blood pressure, raising the risk of bradycardia and related syncope in susceptible patients. Among these options, donepezil is the one most commonly associated with clinically significant bradycardia and fainting due to excessive vagal stimulation of the heart. Rivastigmine and galantamine are also cholinesterase inhibitors but tend to have a lower bradycardia risk, while memantine works via NMDA receptor antagonism and does not typically provoke bradycardia. Therefore, in a patient with syncope risk from bradycardia, avoiding donepezil is prudent; consider alternatives like memantine or other non-bradycardia–related approaches, and review other medications that could contribute to bradycardia.