title: Concentration of donepezil to the cognitive response in Alzheimer disease.
abstract: BACKGROUND
  Donepezil has been approved, and higher dosages are recommended for the treatment of Alzheimer disease (AD). However, a few studies have reported different cognitive responses in patients with AD treated with donepezil without measuring the concentration.
  
  
  METHODS
  We evaluated the relationships between the therapeutic responses and plasma concentrations of donepezil in various cognitive domains using the Cognitive Ability Screening Instrument among 37 patients with newly diagnosed mild stage AD taking donepezil 5 mg/d.
  
  
  RESULTS
  Among the 9 cognitive domains in the Cognitive Ability Screening Instrument, the long-term memory domain had the highest improvement ratio (81.1%) compared with the other domains. An increased donepezil plasma concentration [mean (SD), 75.14 (32.16) ng/mL] was significantly associated with the improvement of long-term memory (P = 0.045; odds ratio, 0.959; 95% confidence interval, 0.920-0.999) after adjusting for age, sex, education, and apolipoprotein E genotype.
  
  
  CONCLUSIONS
  Although there are some limitations in our study, these findings indicate that a higher concentration of donepezil improves long-term memory in patients with mild stage AD and imply the possible benefits in the advanced stage of AD for relatively preserved long-term memory.
authors.affiliation: Department of and Master's Program in Neurology, Faculty of Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. endless@kmu.edu.tw
authors.forename: Yuan-Han
authors.initials: YH
authors.lastname: Yang
authors.forename: Chun-Hung
authors.initials: CH
authors.lastname: Chen
authors.forename: Mei-Chuan
authors.initials: MC
authors.lastname: Chou
authors.forename: Chien-Hsun
authors.initials: CH
authors.lastname: Li
authors.forename: Ching-Kuan
authors.initials: CK
authors.lastname: Liu
authors.forename: Su-Hwei
authors.initials: SH
authors.lastname: Chen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000188:drug therapy* / Q000503:physiopathology; D003071:Cognition / Q000187:drug effects*; D000077265:Donepezil; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007189:Indans / Q000493:pharmacokinetics / Q000627:therapeutic use*; D008297:Male; D057567:Memory, Long-Term / Q000187:drug effects; D018697:Nootropic Agents / Q000493:pharmacokinetics / Q000627:therapeutic use*; D010880:Piperidines / Q000493:pharmacokinetics / Q000627:therapeutic use*; D011446:Prospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D007189:Indans; D018697:Nootropic Agents; D010880:Piperidines; D000077265:Donepezil