Memantine, indicated for moderate to severe Alzheimer's, is frequently prescribed off label, either alone or with a cholinesterase
inhibitor, for mild Alzheimer's and mild cognitive impairment, but its effectiveness is questionable. U.S. and European manufacturers
of memantine have published meta-analyses claiming the beneficial effects of the drug for mild to severe cases of Alzheimer's.
But recently, Lon Schneider, M.D., of the University of Southern California Keck School of Medicine, and colleagues systematically
searched only manufacturer-sponsored meta-analyses, registries, presentations, and publications for randomized, placebo-controlled,
parallel-group clinical trials of memantine in those patients with mild to moderate Alzheimer's. The search identified three
trials that included 431 patients with mild Alzheimer's and 697 patients with moderate Alzheimer's. Using several scales,
the researchers assessed cognition, global change, functional activities, and behavior. They concluded that there were no
significant differences between memantine and placebo on any outcome for patients with mild Alzheimer's, either within any
trial or when data were combined.
"Despite its frequent off-label use, evidence is lacking for a benefit of memantine in mild Alzheimer's, and there is meager
evidence for its efficacy in moderate Alzheimer's," the authors concluded.
Schneider L, Dagerman K, Higgins J, et al.: Lack of Evidence for the Efficacy of Memantine in Mild Alzheimer Disease. Arch
Neurol. 2011 Apr 11. [Epub ahead of print]. An abstract is posted at <http://archneur.ama-assn.org/cgi/content/abstract/archneurol.2011.69>.