Moderate
Probable
Description
Quetiapine's anticholinergic properties antagonize the pro-cholinergic mechanism of donepezil, potentially impairing cognitive benefits in dementia.
Mechanism
Donepezil inhibits acetylcholinesterase to increase synaptic acetylcholine; quetiapine's muscarinic receptor blockade directly opposes this effect, reducing cholinergic neurotransmission.
Clinical Significance
Pharmacodynamic antagonism may impair the cognitive benefits of donepezil; additionally, sedation and delirium risk increase.
Management
Use with caution; prefer antipsychotics with low anticholinergic burden for behavioral symptoms in dementia; monitor cognitive status closely.