Chinese Medicine for Alzheimer's Disease: A Meta-Analysis of Randomized Controlled Trials

To evaluate the effificacy of oral Chinese medicine (CM) in comparison with donepezil, a cholinesterase inhibitor (ChEI), for the treatment of Alzheimer's disease (AD).

Randomized controlled trials (RCTs) have been searched, and the effect of CM compared with donepezil in AD has been investigated. An electronic search of MEDLINE, Excerpta Medica Database (EMBASE), Cochrane Library, Chinese Biological Medicine Database (CBMdisc), and China National Knowledge Infrastructure (CNKI) to identify articles in English and Chinese from the inception of the database until October 18, 2015. A modifified Jadad score (7-points) to judge the methodological quality of studies, comprehensive meta-analysis was performed with Cochrane Collaboration Revman 5.3. Dichotomous data were analyzed by relative risk (RR) with a 95% confifidence interval (CI), while continuous variables were analyzed by using mean differences (MD) with 95% CI for effect size.

Six studies involving 596 AD patients through Jadad assessment with low bias were included in the meta-analysis. No signifificant difference was observed in cognitive improvement and daily abilities of patients using the Mini Mental State Examination (MMSE) (MD: 0.69, 95% CI:-0.17 to 1.56) and Activities of Daily Living (ADL) scale (MD: 0.94, 95% CI:-1.54 to 3.43). There were no signifificant differences in status of illness or MD for mild-moderate AD patients at 24 weeks (MD: 0.62, 95% CI:-2.99 to 4.23) and 48 weeks (MD:-0.73, 95% CI:-5.02 to 3.56). Severe AD patients were also assessed at 24 weeks (MD: 3.13, 95% CI:-6.92 to 13.18) and 48 weeks (MD: 4.23, 95% CI:-6.38 to 14.84). Furthermore, compared with donepezil, Xin (Heart)-regulating CM and Shen (Kidney)-tonifying groups were observed (MD:-1.50, 95% CI:-3.08 to 0.08; MD:-1.92, 95% CI:-3.50 to-0.33; respectively). CM had fewer side effects in AD patients.

Compared with donepezil, oral CM showed no signifificant difference in effectiveness in AD patients, and more evidence is needed to verify the fifindings.