The efficacy of donepezil in the treatment of neuropsychiatric symptoms in Alzheimer disease

OBJECTIVE: To determine the efficacy of donepezil in the treatment of neuropsychiatric symptoms in patients with Alzheimer disease (AD) in a randomized withdrawal study. METHOD: Patients with mild to moderate AD with marked neuropsychiatric symptoms at baseline (Neuropsychiatric Inventory [NPI] > 11 points) were treated openly with donepezil 5 mg daily for 6 weeks followed by 10 mg daily for a further 6 weeks. Patients were then randomized (60:40) to either placebo or 10 mg donepezil daily. All patients were assessed at 6 weeks and provided there was no marked cognitive deterioration their blinded treatment was continued for a further 6 weeks. NPI and carer distress were assessed at 6 weekly intervals throughout the study. RESULTS: A total of 134 patients participated. Following randomization patients who continued on donepezil 10 mg for 12 weeks had improvements in NPI compared with the placebo group (mean change -2.9 vs 3.3 points; ITT-LOCF p = 0.02) and in NPI-Distress scores (median change -2.0 vs 1.0 points; ITT-LOCF p = 0.01). During the open-label phase the total NPI and NPI-Distress scores were lower after 12 weeks treatment with open label donepezil compared with baseline (total NPI 22 points vs13 points; ITT-LOCF p < 0.0001; NPI-Distress 13.5 vs 7.9 points; ITT-LOCF p < 0.0001). In the open-label phase all domains of the NPI (with the exception of elation) were improved (all p < 0.05 after Bonferroni correction). CONCLUSIONS: Donepezil has significant efficacy in the treatment of neuropsychiatric symptoms in patients with mild to moderate AD.