BiomedExperts: Donepezil for dementia due to Alzheimer's disease. BACKGROUND: 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. However, some (like tacrine) are associated with adverse effects such as hepatotoxicity, but donepezil (E2020, Aricept) is safer. 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 9 October 2002. 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 weighted mean differences or Peto odds ratios (95%CI) estimated. MAIN RESULTS: Sixteen trials are included, involving 4365 participants. The trials were of 12, 24 or 52 weeks duration in selected patients. Available outcome data cover domains including cognitive function and global clinical state, but data on several important dimensions of outcome are unavailable.For cognition there is a statistically significant improvement for both 5 and 10 mg/day of donepezil at 24 weeks compared with placebo (-2.02 points on the ADAS-Cog scale WMD, 95%CI -2.77 to -1.26, p 0.00001; -2.92 points on the ADAS-Cog scale WMD 95% CI -3.74 to -2.10, p 0.
