Clinical efficacy and safety of donepezil on cognitive and global function in patients with Alzheimer's disease. A 24-week, multicenter, double-blind, placebo-controlled study in Japan. E2020 Study Group

Dement Geriatr Cogn Disord. 2000 Nov-Dec;11(6):299-313. doi: 10.1159/000017259.


This study evaluated efficacy and safety of donepezil hydrochloride (donepezil) at 5 mg/day in patients with mild to moderately severe Alzheimer's disease for 24 weeks in a double-blind, placebo-controlled comparative trial. In this study, 268 patients were enrolled and 39 of these (15%) were withdrawn. In the evaluable population of efficacy, Protocol-Compatible (PC) analyzed patients (n = 228), better effects than that of placebo were confirmed using two primary efficacy measures: a cognitive performance test, the Japanese version of the Alzheimer's Disease Assessment Scale - cognitive subscale (ADAS-J cog, p = 0.003) and a clinical global assessment, the Japanese version of the Clinical Global Impression of Change (J-CGIC, p = 0.000). The superiority of donepezil was also shown by secondary measures: the Sum of the Boxes of the Clinical Dementia Rating (CDR-SB), the Mental Function Impairment Scale (MENFIS) and the caregiver-rated modified Crichton scale (CMCS). The same results were obtained in the intention-to-treat (ITT) analysis (n = 263). The incidence of drug-related adverse events was 10% (14/136) in the donepezil and 8% (10/131) in the placebo group; no significant difference was seen between the two groups. The main adverse events were gastrointestinal symptoms, and these were almost all mild, and they all disappeared with continued administration or temporary discontinuation of donepezil. These results indicate that the donepezil appears to be effective and well tolerated in patients with mild to moderately severe Alzheimer's disease.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / drug therapy*
  • Alzheimer Disease / psychology*
  • Caregivers
  • Cholinesterase Inhibitors / adverse effects
  • Cholinesterase Inhibitors / therapeutic use*
  • Cognition / drug effects*
  • Donepezil
  • Double-Blind Method
  • Endpoint Determination
  • Female
  • Humans
  • Indans / adverse effects
  • Indans / therapeutic use*
  • Japan
  • Male
  • Middle Aged
  • Nootropic Agents / adverse effects
  • Nootropic Agents / therapeutic use*
  • Piperidines / adverse effects
  • Piperidines / therapeutic use*
  • Psychiatric Status Rating Scales


  • Cholinesterase Inhibitors
  • Indans
  • Nootropic Agents
  • Piperidines
  • Donepezil