Trio of Drugs May Improve Alzheimer's

Jan. 25, 2006 -- For people with mild to moderate Alzheimer's disease, three drugs -- Aricept, Razadyne, and Exelon -- may make some modest improvement in mental function.

The finding comes from a review of 13 studies of the drugs. The review appears in The Cochrane Library, a research journal.

Aricept, Razadyne, and Exelon seem equally effective at treating mild to moderate Alzheimer's disease, writes researcher Jacqueline Birks of England's University of Oxford.

The review also shows no way of predicting which patients would respond to the drugs.

Alzheimer's disease has no cure. It's the most common form of dementia for older adults, but Alzheimer's isn't part of the normal aging process.

How the Drugs Work

Aricept, Razadyne, and Exelon are cholinesterase inhibitors. They block the breakdown of a brain chemical called acetylcholine.

Acetylcholine levels are low in people with Alzheimer's disease and related conditions. By preventing acetylcholine from breaking down, acetylcholine levels rise. Though no one understands exactly how Alzheimer's works, boosting levels of acetylcholine appears to help mental function.

The new research review backs that up. The review included 13 studies with a combined total of nearly 7,300 patients. On average, the patients were 86 years old. Most had mild to moderate Alzheimer's disease.

The studies were done in the U.S., Europe, and Australia. Aricept, Razadyne, and Exelon have different makers; those companies sponsored most of the reviewed studies.

Small Improvements Noted

Modest gains in mental function were noted for all three drugs. "There is nothing to suggest the effects are less for patients with severe dementia or mild dementia, although there is very little evidence for other than mild-to-moderate dementia," Birks writes.

Most studies compared one of the cholinesterase inhibitors to a placebo, which contains no medicine. The medicines outperformed the placebos.

Four trials made head-to-head comparisons of cholinesterase inhibitors. The drugs worked slightly differently but were equally effective, the review shows.

Aricept appeared to have fewer side effects, perhaps because of the initial schedule of doses, notes Birks. She adds that if Razadyne and Exelon had been started in a similar fashion, they might have matched Aricept for tolerability.