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Cholinesterase inhibitors in mild cognitive impairment: a meta-analysis of randomized controlled trials
Tomasz Sobów1, Iwona Kłoszewska
1Klinika Psychiatrii Wieku Podeszłego i Zaburzeń Psychotycznych, Uniwersytet Medyczny, Czechosłowacka 8/10, 92-216 Łódź. tmsobow@csk.umed.lodz.pl
Background And Purpose:
Despite being commonly regarded as an initial stage of dementia (particularly of Alzheimer's type, AD), mild cognitive impairment (MCI) is usually not treated and no recommendations for management have been established. Cholinesterase inhibitors have been proposed to halt the progression of MCI to AD and several randomized controlled studies (RCT) have been undertaken to prove this hypothesis. Here we have analyzed the results of RCT of ChEI in MCI.
Material And Methods:
Four long-term RCT of ChEI in MCI were identified. A meta-analysis was conducted with the Mantel-Haenszel method using a fixed model. We compared a major parameter of efficacy (the proportion of those who progressed to dementia within two years) and two parameters of safety, i.e. the total number of adverse events and the number of adverse events leading to drug discontinuation.
Results:
The use of ChEI resulted in approximately 24% reduction of risk of conversion from MCI to dementia at the cost of more than 50% increase of adverse events and more than 130% increase of adverse events leading to drug discontinuation, as compared to placebo. Moreover, in the case of galantamine a considerable increase in deaths was observed in the active treatment group; whether this outcome is a class effect of all ChEI or is limited to galantamine cannot be established due to the lack of data from donepezil and rivastigmine trials.
Conclusions:
Because of the questionable efficacy : risk ratio, we believe that it is too early to recommend ChEI in MCI. The sine qua non condition is to establish the factors that predict the risk of conversion from MCI to AD.
Insights
Cholinesterase inhibitors (ChEI) show a modest 24% reduction in mild cognitive impairment (MCI) to dementia progression but significantly increase adverse events. Current data suggests ChEI are not yet recommended for MCI management due to an unfavorable risk-benefit profile.
Area of Science:
- Neurology
- Pharmacology
- Clinical Trials
Background:
- Mild cognitive impairment (MCI) is often considered a precursor to Alzheimer's disease (AD).
- Currently, no established treatments or management guidelines exist for MCI.
- Cholinesterase inhibitors (ChEI) are being investigated for their potential to slow MCI progression to AD.
Purpose of the Study:
- To analyze the results of randomized controlled trials (RCTs) investigating the efficacy and safety of ChEI in patients with MCI.
- To evaluate the impact of ChEI on the conversion rate from MCI to dementia.
- To assess the safety profile of ChEI, including adverse events and discontinuation rates.
Main Methods:
- A meta-analysis of four long-term RCTs involving ChEI for MCI was performed.
- The Mantel-Haenszel method with a fixed model was employed for the analysis.
- Key outcomes included the proportion of patients progressing to dementia within two years, total adverse events, and adverse events leading to discontinuation.
Main Results:
- ChEI use was associated with a 24% reduction in the risk of MCI conversion to dementia compared to placebo.
- However, ChEI significantly increased adverse events by over 50% and those leading to discontinuation by over 130%.
- An increase in deaths was noted with galantamine, but a class effect for all ChEI could not be confirmed.
Conclusions:
- The efficacy-risk ratio of ChEI in MCI is currently questionable.
- It is premature to recommend ChEI for the management of MCI.
- Identifying predictive factors for MCI conversion to AD is crucial before considering treatment recommendations.
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