Millions of people worldwide have Alzheimer disease (AD), a progressive neurodegenerative disorder, according to background information in the article. Various chemical and other processes in the brain may contribute to the development of the condition. Memantine appears to act on one of those pathways, which involves the neurotransmitter glutamate, the authors report. The drug was approved in the United States in 2003 and also is available in the European Union and Australia.
Barry Reisberg, M.D., from the New York University School of Medicine, and colleagues conducted a 24-week open-label extension trial. In this type of trial, participants who had previously been part of a double-blind study--where some were taking an active drug and some were taking a placebo--were all given the same amount of the active drug. For this study, 175 patients with moderate to severe AD who completed the previous 28-week study received 20 mg of memantine daily for an additional 24 weeks.
The authors report that during the study, cognitive tests, reports from caregivers and observations by clinicians all indicated that memantine was beneficial to AD patients. "The benefits of memantine seen in the double-blind phase were again observed when patients treated with placebo were switched to memantine treatment in the open extension," they write. "For the patients who were randomized to memantine treatment during the double-blind phase, these clinically relevant benefits also appeared to be maintained in sum." The completion rate for the extension phase was high (78 percent) and the adverse event profile for memantine was similar to that observed in the double-blind study.
(Arch Neurol. 2006;63:49-54. Available pre-embargo to the media at www.jamamedia.org)
Editor's Note: This study was funded by Merz Pharmaceuticals GmbH, Frankfurt, Germany. Development of measurements used in this study was supported by grants from the National Institute of Aging and the U.S. National Institutes of Health. Please see Archives of Neurology study for authors' financial disclosures.
Editorial: What Researchers Have Learned about Memantine
In an accompanying editorial, Jeffrey L. Cummings, M.D., of the David Geffen School of Medicine at the University of California, Los Angeles, comments on the current study on memantine and the overall benefits of this type of trial.
"Previous studies support the use of memantine to improve cognitive function or delay its decline, reduce the rate of loss of activities of daily living and reduce or decrease the emergence of new behavioral symptoms in patients with AD," Dr. Cummings writes. "These new data from Reisberg and coworkers provide additional reassurance to prescribing physicians that long-term use of memantine is safe, continues to have a low rate of adverse effects and may have continuing beneficial clinical effects."
(Arch Neurol. 2006;63:18-19. Available pre-embargo to the media at www.jamamedia.org)
Editor's Note: Dr. Cummings has served as a consultant or performed research for AstraZeneca, Avanir, Bristol Myers-Squibb, Eisai Forest, Janssen, Lilly, Lundbeck, Memory, Merz, Neurochem, Novartis, Ono, Pfizer, Praecis, Takeda, Sanofi-Aventis, Sepracor and Wyeth.