Donepezil for dementia due to Alzheimer's disease. [Cochrane Database Syst Rev. 2006] - PubMed Result University of Oxford, Department of Clinical Geratology, Radcliffe Infirmary, Woodstock Road, Oxford, UK, OX2 6HE. jacqueline.birks@geratol.ox.ac.ukBACKGROUND: Alzheimer's disease is the most common cause of dementia in older people. One of the aims of therapy is to inhibit the breakdown of a chemical neurotransmitter, acetylcholine, by blocking the relevant enzyme. This can be done by a group of chemicals known as cholinesterase inhibitors. OBJECTIVES: The objective of this review is to assess whether donepezil improves the well-being of patients with dementia due to Alzheimer's disease. SEARCH STRATEGY: The Cochrane Dementia and Cognitive Improvement Group's Specialized Register was searched using the terms 'donepezil', 'E2020' and 'Aricept' on 12 June 2005. This Register contains up-to-date records of all major health care databases and many ongoing trial databases.Members of the Donepezil Study Group and Eisai Inc were contacted. SELECTION CRITERIA: All unconfounded, double-blind, randomized controlled trials in which treatment with donepezil was compared with placebo for patients with mild, moderate or severe dementia due to Alzheimer's disease. DATA COLLECTION AND ANALYSIS: Data were extracted by one reviewer (JSB), pooled where appropriate and possible, and the pooled treatment effects, or the risks and benefits of treatment estimated. MAIN RESULTS: 23 trials are included, involving 5272 participants. Most trials were of 6 months or less duration in selected patients. Available outcome data cover domains including cognitive function, activities of daily living, behaviour , global clinical state and health care resource costs.For cognition there is a statistically significant improvement for both 5 and 10 mg/day of donepezil at 24 weeks compared with placebo on the ADAS-Cog scale (-2.01 points MD, 95%CI -2.69 to -1.34, p 0.00001); -2.80 points, MD 95% CI -3.