["alzheimer's disease"]
['donepezil']

        Inclusion Criteria:

          -  dementia according to Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV
             criteria

          -  probable Alzheimer's disease dementia according to National Institute on
             Aging-Alzheimer's Association (NIAAA) criteria

          -  Mini-Mental State Examination (MMSE) score of 20 or less

          -  General Deterioration Scale (GDS) score of 4 or more / Clinical Dementia Rating (CDR)
             score of 2 or more

          -  stable dose of 10mg donepezil at least 3 months before screening

          -  caregiver who can come together at every visit and give informations about side
             effects profiles should exist

          -  patients and caregivers accepted the study

        Exclusion Criteria:

          -  patients receiving other concomitant acetylcholinesterase inhibitor

          -  uncontrolled psychiatric disorders

          -  drug overuse or alcohol abuse history within 5 years

          -  significant uncontrolled or active medical conditions

          -  uncontrolled epilepsy

          -  patients who cannot come at scheduled visits
      