The drugs naproxen and celecoxib did not reduce risk for Alzheimer’s disease in an analysis of data from a clinical trial sponsored by the National Institute on Aging (NIA), part of the National Institutes of Health. The trial researchers noted that the results are contrary to those of earlier observational studies on non-steroidal anti-inflammatory drugs (NSAIDs) and Alzheimer’s risk, and that more time may be needed to see protective effects in this trial.
The findings, published today in Neurology, come from the Alzheimer’s Disease Anti-inflammatory Prevention Trial (ADAPT) which was designed to test whether long-term use of naproxen or celecoxib can prevent Alzheimer’s disease in individuals at risk for the disease because of a family history of Alzheimer’s. ADAPT is a multicenter trialadministered through the University of Washington, with clinical centers in Baltimore, Boston, Rochester, N.Y., Sun City, Ariz., Tampa and Seattle, and a coordinating center in Baltimore. The trial began enrolling volunteers in 2001. Treatment was suspended in December 2004 (see statement at www.nia.nih.gov/newsroom/2006/11/nia-statement-data-published-safety-review-anti-inflammatory-drugs-adapt-alzheimers ).
Researchers have continued to follow participants closely since that time to assess whether the medications produced any changes in their risk for Alzheimer’s and to further evaluate their risk for cardiovascular disease.
Although this early analysis suggests that naproxen and celecoxib do not reduce risk for developing Alzheimer’s disease, the researchers note that a different picture could emerge after following the ADAPT participants for a few more years. They recommend continued follow-up to see whether the timing of the drug treatments relative to onset of dementia has important bearing on their effect.
In the Neurology paper, the ADAPT investigators consider possible explanations for the differences in treatment effects in ADAPT and earlier observational studies. They note that protection against AD might be limited to certain NSAIDs that were not the drugs used in ADAPT. But they also speculate that NSAIDs’ influence on Alzheimer’s disease could differ with the stage of disease progression, noting that the drugs might have a protective effect only if given several years before symptoms appear. By the time symptoms begin to emerge, NSAIDs appear to have no effect, or may even inhibit the brain’s ability to clear abnormal protein deposits.
An analysis of the cardiovascular risks of the ADAPT study medications appeared in the Nov. 17, 2006, issue of PLoS Clinical Trials, a journal of the Public Library of Science. Additional information on ADAPT is available on the ADAPT web site, www.jhucct.com/adapt/default.htm .
Reference: ADAPT Research Group. Naproxen and celecoxib do not prevent AD in early results from a randomized controlled trial. Neurology, DOI:10.1212/01.wnl.0000260269.93245.d2
NIA leads the federal effort supporting and conducting research on aging and the medical, social and behavioral issues of older people, including Alzheimer’s disease and age-related cognitive decline. For information on dementia and aging, please visit the NIA’s Alzheimer’s Disease Education and Referral Center at www.nia.nih.gov/alzheimers , or call 1-800-438-4380. For more general information on research and aging, go to www.nia.nih.gov. 
The National Institutes of Health— the Nation's Medical Research Agency — includes 27 institutes and centers and is a component of the U. S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov .