Donepezil has the following mechanism of action

Donepezil: cerebro selective and reversible anti-AchE produces improvement in several cognitive as well as non cognitive (activities of daily living) scores in Alzheimer's Dementia. The benefit is ascribed to elevation of Ach level in the coex, especially in the surviving neurons that project from basal forebrain to cerebral coex and hippocampus. Therapeutic doses produce only weak peripheral AchE inhibition: cholinergic side effects are mild. Because of long t 1/2 (~70 hr), donepezil is administered once daily at bedtime It is generally well tolerated and is not hepatotoxic.