IRCT138812183518N1 IRCT 2010-05-20 Isfahan University of Medical Sciences, Isfahan, Iran Evaluating the effect of Donepezil on Cerebral Blood Flow Velocity in Alzheimer's disease Evaluating the effect of Donepezil on Cerebral Blood Flow Velocity in Alzheimer's disease 2008-04-03 anticipated 30 Complete https://irct.ir/trial/3621 interventional Randomization: Not randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Other, Purpose: Treatment, Other design features: In this study, 19 patients with AD were initially allocated to the case group. Out of the 19 patients, five did not continue participating in the study after four weeks of treatment with Donepezil, one patient in the second round of follow up did not cooperate to perform TCD and two were excluded due to discontinuation of the drug because of agitation side effect and finally 11 patients remained in the case group. Also, 11 patients with AD were allocated to the control group. The case group comprised patients who were treated with Donepezil; and TCD was performed every four weeks. The control group consisted of Alzheimer's disease patients who did not use any medication; and inclusion and exclusion criteria similar to those for the case group were applied to this group, and TCD was performed only once for them. N/A Condition 1: Alzheimer's disease. Condition 2: Alzheimer's disease. Intervention 1: In control group no drug was used and only one time carry out TCD. Intervention 2: Donepazil(oral) tab with dose of 5mg/d for 1 month and then 5mg/d every 12 hours for another 1 month.