DSEN Abstract
Efficacy and Safety of Cognitive Enhancers for Mild Cognitive Impairment – A Systematic Review and Meta-analysis

This research was funded by the Drug Safety and Effectiveness Network (DSEN) and conducted by the following investigators: Tricco AC, Soobiah C, Berliner S, Ho J, Ng C, Ashoor H, Straus SE. The statements made herein are those of the stated authors, who are independent researchers.

What is the current situation of cognitive enhancers?

Mild cognitive impairment (MCI) is characterized by memory and cognitive deficits, and increases with age. Between 3% and 17% of MCI cases progress to dementia, a serious public health burden with over 4.6 million new cases a year. Cognitive enhancers, used to treat dementia, are a possible strategy to prevent the progression of MCI, but their efficacy in MCI patients is unclear.

Highlights and Implications

  • A systematic review and meta-analysis of 8 randomized controlled trials and 3 companion reports.
  • No improvements in cognition, function or mortality were identified among patients who used cognitive enhancers.
  • Numerous harms (nausea, diarrhea, vomiting, headaches) were associated with taking cognitive enhancers.
  • Careful consideration needs to be made when determining whether to cover these agents for patients with MCI, given lack of evidence of effectiveness and risk of potential harms.

For more information, please contact Dr. Andrea Tricco: Andrea.Tricco@unityhealth.to.

What was the aim of the study?

This study examines the efficacy and safety of cognitive enhancers for patients with MCI.

How was the study conducted?

  • A systematic review and meta-analysis was conducted; twoindependent reviewers completed the screening, data abstraction and risk of bias appraisal.
  • Selected studies examined MCI patients prescribed donepezil,rivastigmine, galantamine, and/or memantine compared to placebo, other cognitive enhancers and/or supportive care. Outcomes included cognition, function, mortality, and potential harms.

What did the study find?

  • Of the 15, 556 titles and abstracts and 1,386 full-text articles, 8 RCTs(4 examining donepezil 5-10 mg, 2 examining galantamine 16-24 mg, 1 each examining memantine 10-20 mg and rivastigmine 3-12 mg) and 3 companion reports were included.
  • No statistically significant differences were found between cognitiveenhancers and placebo across cognition, function, and mortality outcomes.
  • Patients taking cognitive enhancers experienced significantly more nausea, diarrhea, vomiting, and headaches compared to those on placebo. There were no differences in major adverse events between those taking cognitive enhancers and placebo.

Links to publications: Tricco et al, 2013; Tricco et al, 2012; Tricco et al, 2017

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