Pain medications such as naproxen and celecoxib do not prevent Alzheimer's disease, new research has claimed.
This contradicts earlier studies which suggested nonsteroidal anti-inflammatory drugs (NSAIDs) may protect against Alzheimer's disease.
The study involved 2,100 people who were given the drugs or a placebo over four years, but most received the drugs for not more than two years.
Constantine Lyketsos, lead author of the study, said: "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."
John Breitner, an author on the study, explained why the contradiction might have occurred: One possible explanation… is that our findings relate specifically to celecoxib and naproxen, but not other commonly used NSAIDs, such as ibuprofen.
"Or the drugs may prevent the progression of the disease in people who have advanced Alzheimer's pathology without symptoms – the very people likely to develop symptoms within a year or two."