BCHE and Alzheimer disease: Donepezil hydrochloride is a second-generation cholinesterase inhibitor that reversibly inhibits acetyl choline degradation in the brain and thereby indirectly increases the level of choline in the cerebral cortex, delaying the development of AD and vascular dementia.[11,12] The drug is safe in terms of the cardiovascular health of elderly patients.[13] According to the current researches, the safe dosage scale of donepezil is no more than 23 mg/day.[14,15] However, excessive cholinergic action can cause gastrointestinal and neurological adverse reactions.