Safety and efficacy of acetylcholinesterase inhibitors for Alzheimer’s disease: A systematic review and meta-analysis

Alzheimer's disease (AD) affects millions of people worldwide. The most commonly used drugs are acetylcholinesterase inhibitors, i.e., donepezil, galantamine and rivastigmine, which increase levels of acetylcholine. However, the exact efficacy and safety of acetylcholinesterase inhibitors in the treatment of AD is still unclear. The main objective of the current study was to determine the exact safety and efficacy profile of acetylcholinesterase inhibitors in the treatment of AD by conducting a systematic review and meta-analysis of clinical trials according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We conducted a web-based literature search of PubMed and clinical trial websites using relevant keywords. Data were extracted from eligible records and pooled as mean difference (MD) or risk ratio (RR) values with their 95% confidence interval (95% CI) using Review Manager software (v. 5.3 for Windows). Heterogeneity was calculated using χ2 and I2 tests. The standard mean difference (SMD) was -0.33 [-0.52, -0.13] for donepezil, -0.48 [-0.58, -0.38] for galantamine and -0.65 [-1.06, -0.23] for rivastigmine, indicating a significant effect of these drugs on cognitive outcomes. Here we show the significant effects of all available acetylcholinesterase inhibitors on cognitive function in patients with AD. However, further studies are needed to draw valid conclusions about the effects of acetylcholinesterase inhibitors on functional outcomes and adverse events.