The clinical trial, conducted at six dementia research clinics across the United States, involved more than 2,100 people over age 70 with no signs of dementia, but a family history of Alzheimer's disease. The participants were randomly assigned daily doses of naproxen, celecoxib, or placebo for up to four years, but most participants had received the treatments for less than two years.

The study found neither treatment was associated with a reduction in Alzheimer's disease or dementia.

"Although our study was conducted to test the hypothesis that celecoxib or naproxen would reduce the incidence of Alzheimer's disease, these results indicate no such effect, at least within the first few years after treatment begins," said study author Constantine Lyketsos, MD, MHS, with Johns Hopkins Bayview Hospital and Johns Hopkins School of Medicine in Baltimore, Maryland.

The findings appear to be inconsistent with other studies suggesting reduced risk of Alzheimer's disease among people who take NSAIDs over a long period of time. "One possible explanation for this inconsistency is that our findings relate specifically to celecoxib and naproxen, but not to other commonly used NSAIDs, such as ibuprofen. Or the drugs may not prevent the progression of disease in people who have advanced Alzheimer's pathology without symptoms – the very people most likely to develop symptoms within a year or two," said study author John C. S. Breitner, MD, with VA Puget Sound Health Care.

"While long-term follow-up of our study's participants is essential, for now we suggest celecoxib and naproxen not be taken to primarily prevent Alzheimer's disease," urged Lyketsos.

Source: American Academy of Neurology