Donepezil, marketed under the trade name Aricept by its developer Eisai and partner Pfizer, is a centrally acting reversible acetylcholinesterase inhibitor. Its main therapeutic use is in the palliative treatment of mild to moderate Alzheimer's disease. Common side effects include gastrointestinal upset. It has an oral bioavailability of 100% and easily crosses the blood-brain barrier. Because it has a half-life of about 70 hours, it can be taken once a day.
Donepezil has also been studied in patients with mild cognitive impairment, schizophrenia, attention deficit disorder, post-coronary bypass cognitive impairment, cognitive impairment associated with multiple sclerosis, CADASIL syndrome, and Down syndrome. However at this time donepezil is not indicated for prevention of dementia.