There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
The effectiveness of the 5 U.S. Food and Drug Administration-approved pharmacologic
therapies for dementias in achieving clinically relevant improvements is unclear.
To review the evidence for the effectiveness of cholinesterase inhibitors (donepezil,
galantamine, rivastigmine, and tacrine) and the neuropeptide-modifying agent memantine
in achieving clinically relevant improvements, primarily in cognition, global function,
behavior, and quality of life, for patients with dementia.
Cochrane Central Register of Controlled Trials, MEDLINE, PREMEDLINE, EMBASE, Allied
and Complementary Medicine Database, CINAHL, AgeLine, and PsycINFO from January 1986
through November 2006.
English-language randomized, controlled trials were included in the review if they
evaluated pharmacologic agents for adults with a diagnosis of dementia, did not use
a crossover design, and had a quality score of at least 3 on the Jadad scale.
Data were extracted on study characteristics and outcomes, including adverse events.
Effect sizes were calculated and data were combined when appropriate.
96 publications representing 59 unique studies were eligible for this review. Both
cholinesterase inhibitors and memantine had consistent effects in the domains of cognition
and global assessment, but summary estimates showed small effect sizes. Outcomes in
the domains of behavior and quality of life were evaluated less frequently and showed
less consistent effects. Most studies were of short duration (6 months), which limited
their ability to detect delay in onset or progression of dementia. Three studies directly
compared different cholinesterase inhibitors and found no differences in cognition
and behavior.
Limitations of available studies included short duration, inclusion of only patients
with mild to moderate Alzheimer disease, poor reporting of adverse events, lack of
clear definitions for statistical significance, limited evaluation of behavior and
quality-of-life outcomes, and limited direct comparison of different treatments.
Treatment of dementia with cholinesterase inhibitors and memantine can result in statistically
significant but clinically marginal improvement in measures of cognition and global
assessment of dementia.