The National Institutes of Health (NIH) announced that research investigators suspended, until further notice, the use of two drugs, naproxen (220 mg twice a day) and celecoxib (200 mg twice a day), in a large, three-arm, national Alzheimer's disease prevention trial sponsored by the National Institute on Aging (NIA), a part of the NIH. The trial, called the Alzheimer's Disease Anti-Inflammatory Prevention Trial (or ADAPT) was designed to assess the potential benefit of long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) -- naproxen (Aleve) and the COX-2 inhibitor celecoxib (Celebrex) in decreasing the risk of developing Alzheimer's Disease in people 70 years of age or older who were considered to be at increased risk because of family history, but did not have symptoms of the disease.

Approximately 2400 volunteer participants were randomly assigned to receive naproxen, celecoxib, or placebo for periods of time up to three years. Although no significant increase in risk for celecoxib was found in this trial, the use of these drugs in the study was suspended in part because of findings reported last week from a National Cancer Institute (NCI) trial to test the effectiveness of celecoxib in preventing colon cancer. In addition, however, data from the ADAPT trial indicated an apparent increase in cardiovascular and cerebrovascular events among the participants taking naproxen when compared with those on placebo.

"This step is being taken as a precautionary measure to ensure the safety of the study's participants," said NIH Director, Elias A. Zerhouni, M.D. "The investigators made their decision based on the risk/benefit analysis specific to this trial," added Dr. Zerhouni.

The ADAPT trial began in 2001 and was conducted at six sites across the US -- Tampa, FL; Rochester, NY; Baltimore, MD; Sun City, AZ; Seattle, WA; and, Boston, MA. The principal investigator for the study is John Breitner, M.D., of the Veterans Affairs Medical Center Puget Sound and the University of Washington.

Investigators and NIH scientists will continue to review this and other NSAIDs studies sponsored by NIH in the light of these findings. It should be pointed that the cancer prevention trials and the ADAPT study are among the first long-term, clinical trials to test these classes of drugs. These studies are examining these compounds for uses very different from the uses for which these medications are currently approved. NIH and FDA will work together to provide the public with information they need to make informed health decisions.