Tacrine for Alzheimer's disease

Area of Science:

• Neurology
• Pharmacology
• Geriatrics

Background:

• Alzheimer's disease (AD) is a progressive neurodegenerative disorder.
• Tacrine (tetrahydroaminoacridine, THA) is a cholinesterase inhibitor investigated for AD symptom management.

Purpose of the Study:

• To determine the clinical efficacy of tacrine for Alzheimer's disease symptoms.

Main Methods:

• Systematic search of the Cochrane Dementia Group Register of Clinical Trials for randomized, double-blind, placebo-controlled trials of tacrine in Alzheimer's disease.
• Independent data extraction by two reviewers, with pooled analysis of odds ratios and average differences where possible.
• Prioritization of intention-to-treat data for analysis.

Main Results:

• No clear evidence of tacrine efficacy for overall clinical improvement, behavioral disturbance, or cognitive function compared to placebo.
• Tacrine showed a barely statistically significant benefit for cognitive function on the Alzheimer's Disease Assessment Scale-cognitive scale (SMD -0.22; 95%CI -0.32 – -0.13).
• Withdrawal due to adverse events, particularly raised serum liver enzymes and gastrointestinal issues, was significantly higher in the tacrine group.

Conclusions:

• Current evidence does not convincingly support tacrine as an effective treatment for Alzheimer's disease symptoms.
• Limited data suitability for pooling necessitates further independent meta-analysis of individual-patient data.
• Additional searches did not yield further eligible data to alter the review's conclusions.