Oral dosage forms comprising donepezil or a pharmaceutically acceptable salt thereof (e.g., donepezil hydrochloride) alone or in combination with a second active ingredient (e.g., memantine hydrochloride or a pharmaceutically acceptable salt thereof) for the treatment of Alzheimer's disease are provided. The oral dosage forms comprise donepezil granules that may be sprinkled on food and can significantly improve compliance in patients with swallowing difficulty.