Donepezil is a medicine used to treat symptoms of dementia in people with Alzheimer’s disease, including mild, moderate and severe stages, by helping with memory, thinking and daily functioning. It belongs to a group of drugs called cholinesterase inhibitors, which work by increasing levels of the neurotransmitter acetylcholine in the brain, supporting communication between nerve cells. Donepezil does not cure Alzheimer’s disease or stop it from progressing, but it can modestly slow symptom worsening and improve or stabilize cognition and behavior for some patients.