Donepezil plus memantine versus donepezil alone for treatment of concomitant Alzheimer’s disease and chronic obstructive pulmonary disease: a retrospective observational study

Objective To assess the clinical outcomes of donepezil plus memantine (DM) and donepezil (DO) alone in Asian patients with a concomitant diagnosis of moderate-to-severe Alzheimer’s disease and mild-to-moderate chronic obstructive pulmonary disease (AD-COPD). Methods We conducted a retrospective analysis of patients with AD-COPD who received either DM or DO for 6 months, or until the occurrence of unacceptable adverse events or disease progression, between June 2012 and May 2016. The primary endpoint was the score on the Standardized Mini-Mental State Examination (SMMSE). Secondary endpoints were scores on the caregiver-rated Bristol Activities of Daily Living Scale, Neuropsychiatric Inventory, Dementia Quality of Life (DEMQOL)-Proxy, and General Health Questionnaire 12. Results In total, 154 eligible patients received DM, whereas 156 received DO. Compared with patients who received DO, patients who received DM had significantly higher mean scores on the SMMSE by 2.1 points (95% confidence interval, 1.3–2.5). Significant between-group heterogeneity was not detected in outcomes over time. The benefits of treatment with DM were greater than those of treatment with DO, in terms of the primary endpoint. Significant differences were also detected in terms of secondary endpoints. Conclusion DM is more effective than DO alone for Asian patients with AD-COPD.