Treatment effects between monotherapy of donepezil versus combination with memantine for Alzheimer disease: A meta-analysis

BACKGROUND: This is the first meta-analysis to compare the treatment effects and safety of administering donepezil alone versus a combination of memantine and donepezil to treat patients with moderate to severe Alzheimer Disease, particularly regarding cognitive functions, behavioral and psychological symptoms in dementia (BPSD), and global functions. METHODS: PubMed, Medline, Embase, PsycINFO, and Cochrane databases were used to search for English and non-English articles for inclusion in the meta-analysis to evaluate the effect size and incidence of adverse drug reactions of different treatments. RESULTS: Compared with patients who received donepezil alone, those who received donepezil in combination with memantine exhibited limited improvements in cognitive functions (g = 0.378, p < .001), BPSD (g = -0.878, p < .001) and global functions (g = -0.585, p = .004). Gradual titration of memantine plus a fixed dose and gradual titration of donepezil as well as a fixed dose and gradual titration of memantine resulted in limited improvements in cognitive functions(g = 0.371, p = .005), BPSD(g = -0.913, p = .001), and global functions(g = -0.371, p = .001). CONCLUSION: Both in the 24th week and at the final evaluation point, the combination of donepezil and memantine led to greater improvement in cognitive functions, BPSD, and global functions than did donepezil alone in patients with moderate to severe Alzheimer Disease.