This is an observational study to systematically investigate domestic patients with Alzheimer's disease to figure out the safety under a situation of the use of Donepezil HCl 23mg. Additionally, if the dose of Donepezil HCl increase, there is need to examine the safety of Donepezil HCl 23mg in depth for patients with Alzheimer's disease by comparing aspects of occurring adverse events by the type of Donepezil HCl increase.
