The effect of anti-dementia drugs on Alzheimer disease-induced cognitive impairment: A network meta-analysis

BACKGROUND: Cognitive impairment is a principal manifestation of Alzheimer disease (AD). To provide a clinical reference for the treatment of AD, a network meta-analysis (NMA) was performed to evaluate the effects of different anti-dementia drugs on the cognitive impairment exhibited by patients with AD. METHODS: Relevant randomized controlled trials are found through the Pubmed database, Web of Science, Clinical Trials, Embase, Cohranne library, Chinese National Knowledge Infrastructure database, CBM databases, and Wanfang among others. A total of 33 articles were collected, with the earliest document collected having been published in February 2017. The included reports were screened for quality of papers by using strict inclusion and exclusion criteria. All analyses were based on previously published studies reporting de-identified data; thus, no ethical approval or patient consent were required. The Mini-Mental State Examination scores informed the classification of the 33 articles into a mild subgroup, which featured 11 articles, and 12 drugs (besides a placebo); a moderate subgroup, which featured 17 articles and 15 drugs (besides a placebo); and a severe subgroup, which featured 5 articles and 3 drugs (besides a placebo). RESULTS: While donepezil, galanthamine, and huperzine demonstrated the highest efficacy in the mild cognitive dysfunction subgroup (mean difference = 5.2, 2.5, and 2.4, respectively). Donepezil, huperzine A, and rivastigmine achieved the most significant effects in the moderate cognitive dysfunction subgroup (MD = 3.8, 2.9, and 3.0 respectively). In the severe subgroup, donepezil was demonstrably superior to memantine. Donepezil was thus found to effectively address cognitive impairment in patients with AD regardless of the degrees of cognitive decline. CONCLUSIONS: Evaluation of the clinically common anti-dementia drugs using NMA affirmed the utility of cholinesterase inhibitors, especially donepezil, in alleviating cognitive dysfunction of patients with AD. This study may therefore help to inform the clinical selection of pharmacotherapeutic interventions addressing cognitive dysfunction in patients with AD.