Optimal Dose Escalation Strategy to Successful Achievement of High Dose Donepezil 23mg

This study evaluates the side effects of dose escalation in the treatment of donepezil 23mg for patients with Alzheimer's disease. Investigators randomly divide participants into three groups according to the dose escalation method; no titration, 15mg of donepezil for a month before escalation to 23mg, and alternating of 10mg and 23mg for a month before escalation to 23mg.

High dose of donepezil is currently prescribed for patients with Alzheimer's disease who showed poor response in lower dose, however the side effect profiles according to dose titration method were not clarified yet. This study aims to confirm which titration method would show better safeties and tolerabilities in the high dose donepezil treatment. Investigators include patients with moderate to severe dementia who were diagnosed as probable Alzheimer's disease and treated with donepezil 10mg at least 3 months before the study. The study duration is for 12 weeks and the titration duration is the first 4 weeks of the study. Investigators evaluate the side effects profiles and vital signs at every 4 weeks and measure blood laboratory tests at screening and the last visit.