People with mild, moderate or severe dementia due to Alzheimer's disease treated for periods of 12, 24 or 52 weeks with donepezil experienced benefits in cognitive function, activities of daily living and behaviour. Study clinicians rated global clinical state more positively in treated patients, and measured less decline in measures of global disease severity. There is some evidence that use of donepezil is neither more nor less expensive compared with placebo when assessing total health care resource costs. Benefits on the 10 mg/day dose were marginally larger than on the 5 mg/day dose. Taking into consideration the better tolerability of the 5 mg/day donepezil compared with the 10 mg/day dose, together with the lower cost, the lower dose may be the better option. The debate on whether donepezil is effective continues despite the evidence of efficacy from the clinical studies because the treatment effects are small and are not always apparent in practice.
Efficacy of donepezil in early-stage Alzheimer disease: a randomized placebo-controlled trial.
To evaluate the efficacy of donepezil in patients with early-stage Alzheimer disease.
                Multicenter, randomized, double-blind, 24-week, placebo-controlled study that enrolled patients with early-stage Alzheimer disease. Patients were randomized in an approximately 2:1 ratio to donepezil, 5 mg/d, for the first 6 weeks, with a forced escalation to 10 mg/d thereafter (n = 96), or placebo (n = 57). The primary efficacy measure was the modified Alzheimer Disease Assessment Scale-cognitive subscale. Secondary efficacy measures included the Mini-Mental State Examination, the Computerized Memory Battery Test, the Clinical Dementia Rating Scale-Sum of the Boxes, the Patient Global Assessment Scale, and the Apathy Scale.
                Improvements favoring donepezil on the Alzheimer Disease Assessment Scale-cognitive subscale were found at weeks 12 and 24 and at the end point (last observation carried forward); treatment differences were 1.9 (P = .03), 2.3 (P = .008), and 2.3 (P = .001) points, respectively. Improvements favoring donepezil on the Mini-Mental State Examination were found at weeks 6, 12, and 24 and at the end point (last observation carried forward); treatment differences were 1.4 (P = .02), 1.2 (P = .04), 1.4 (P = .03), and 1.8 (P = .002) points, respectively. Donepezil-treated patients showed greater mean improvement compared with placebo-treated patients on the following Computerized Memory Battery Test subscales: facial recognition (P = .007 in the intent-to-treat population and P = .04 in the fully evaluable population), first and last name total acquisition (P = .02), and name-face association delayed recall (P = .04). Donepezil was safe and well tolerated in this population; serious adverse events occurred in similar numbers of donepezil- and placebo-treated patients.
                These data suggest significant treatment benefits of donepezil in early-stage Alzheimer disease, supporting the initiation of therapy early in the disease course to improve daily cognitive functioning.