Robert Howard, M.D. Donepezil and Memantine for Moderate-to-Severe Alzheimer’s Disease : NEJM 2012 ;366:10 893-903
Clinical trials have shown the benefits of cholinesterase inhibitors for the treatment of mild-to-moderate Alzheimer’s disease. It is not known whether treatment benefits continue after the progression to moderate(MMSE5~9)-to-severe(MMSE10~13) disease.
Design was multicenter, double-blind, placebo-controlled, clinical trial with two-by-two factorial design. The researchers assigned 295 community-dwelling patients who had been treated with donepezil for at least 3 months and who had moderate or severe Alzheimer’s disease (a score of 5 to 13 on the Standardized Mini?Mental State Examination [SMMSE, on which scores range from 0 to 30, with higher scores indicating better cognitive function]) to continue donepezil, discontinue donepezil, discontinue donepezil and start memantine, or continue donepezil and start memantine. Patients received the study treatment for 52 weeks. The coprimary outcomes were scores on the SMMSE and on the Bristol Activities of Daily Living Scale (BADLS, on which scores range from 0 to 60, with higher scores indicating greater impairment). The minimum clinically important differences were 1.4 points on the SMMSE and 3.5 points on the BADLS.
①D○ M× = D10mg + placebo M
②D× M× = D5mg(week1?4) → placebo D(week5?) + placebo M
③D× M○ = D5mg(week1?4) → placebo D(week5?) + M5mg→5mg up/wk →20mg max
④D○ M○ = D10 mg + M5mg→5mg up/wk →20mg max
The baseline characteristics of the participants in four treatment groups were broadly similar.
Patients assigned to continue donepezil, as compared with those assigned to discontinue donepezil, had a score on the SMMSE that was higher by an average of 1.9 points (95% confidence interval [CI], 1.3 to 2.5) and a score on the BADLS that was lower (indicating less impairment) by 3.0 points (95% CI, 1.8 to 4.3) (P<0.001 for both comparisons). Patients assigned to receive memantine, as compared with those assigned to receive memantine placebo, had a score on the SMMSE that was an average of 1.2 points higher (95% CI, 0.6 to 1.8; P<0.001) and a score on the BADLS that was 1.5 points lower (95% CI, 0.3 to 2.8; P=0.02). The efficacy of donepezil and of memantine did not differ significantly in the presence or absence of the other. There were no significant benefits of the combination of donepezil and memantine over donepezil alone. ※The minimum clinically important difference in scores on the SMMSE was 1.4 points, on the BADLS was 3.5 points. ＜Conclusions＞ In patients with moderate or severe Alzheimer’s disease, continued treatment with donepezil was associated with cognitive benefits that exceeded the minimum clinically important difference and with significant functional benefits over the course of 12 months. 【開催日】 2012年3月14日