A large-scale study of the effects of two promising anti-inflammatory painkillers in patients with Alzheimer's disease has come up empty. The results are discouraging, say researchers, who had hoped they were on the road to more effective treatments for the devastating disease. It remains unknown whether the drugs can prevent Alzheimer's disease in people who are at risk but are not yet ill.
A number of findings have led researchers to hope that nonsteroidal anti-inflammatory drugs (NSAIDs) might prevent Alzheimer's disease and even slow deterioration after disease has taken hold. The rationale is that brain inflammation contributes to impairment in Alzheimer's disease. Indeed, people who regularly take NSAIDs for illnesses such as arthritis have reduced risk for Alzheimer's disease. And laboratory experiments have shown that NSAIDs can reduce inflammation and break down protein fragments, known as b-amyloid plaques, that damage brain cells.
The new study is the first closely controlled, large-scale investigation of NSAIDs' effect on people who already have Alzheimer's disease. Georgetown University internist Paul Aisen and colleagues randomly assigned 351 patients with mild or moderate Alzheimer's disease to receive one of two NSAIDs, naproxen or rofecoxib, or a placebo. After a year, the researchers assessed patients' memory, attention, reasoning, language, orientation, and complex motor functioning. The results, published in the 4 June issue of the Journal of the American Medical Association, revealed no benefit of either drug over the placebo. Patients taking NSAIDs also experienced more side effects--such as fatigue, dizziness, and high blood pressure--than did those in the placebo group.
It's possible, Aisen notes, that other NSAIDs might be more effective in slowing Alzheimer's disease, or that taking the drugs in larger doses or for a longer period might make a difference. But for now, he says, "We have to conclude that treatment with this type of drug is not appropriate for Alzheimer's disease."
"It's disappointing to see that the drugs didn't have any effect," comments Lenore Launer, an epidemiologist at the National Institute on Aging in Bethesda, Maryland. But although NSAIDs may not be able to help Alzheimer's patients, she says, it's possible that the drugs can prevent the disease in people who do not yet show symptoms--a question that is currently under intense scrutiny.