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Aricept No Better Than Sugar Pills in Slowing Progression of Disease, Research Shows
June 24, 2004 -- In the longest study to date, the world's most-prescribed drug to treat Alzheimer's disease proved no more effective than sugar pills in nearly all areas assessed.
During the course of the five-year trial, researchers say there was no difference in "worthwhile improvements" -- rates of disease progression, the rate at which people with Alzheimer's disease were placed in nursing homes, caregiver time, or behaviour decline -- among 565 people with mild to moderate Alzheimer's disease given a daily dose of Aricept or a placebo.
Significant improvements in these areas were not seen even among patients who got a higher dose of the popular drug compared with placebo.
During the first two years of the study, patients taking Aricept did slightly better in tests gauging thinking and functional ability. But those improvements waned and were no different than placebo, say researchers.
'Better Value' Elsewhere
"Realistically, patients are unlikely to derive much benefit from this drug," the study's lead researcher, Richard Gray, PhD, tells WebMD. "If cost is not a consideration, then any slight benefit may be considered worth buying it. But, on a societal level, better value for money is likely to be obtained from social support than (Aricept)."
Gray's findings, published in this week's issue of The Lancet, differs from previous studies of Aricept. The drug is one of a group of medications called cholinesterase inhibitors. These medications, which also include Reminyl, Exelon, and Cognex, increase the level of acetylcholine, a brain chemical that is decreased in Alzheimer's patients. It's believed that boosting acetylcholine levels could slow mental decline in people with Alzheimer's disease.
Those previous studies have suggested that Aricept could benefit patients with mild to moderate Alzheimer's symptoms, usually modestly improving their memory and other abilities. Last November, a study in the American Journal of Psychiatry found that Aricept protected "brain structure" in Alzheimer's patients for at least six months.
But there are two likely explanations for the difference between Gray's research and other studies, says one expert not involved in any of the studies.
Longer Study, 'Everyday Patients'
The studies finding a positive impact from Aricept were all shorter than Gray's research -- rarely lasting longer than one year and often only six months.
"Patients typically stay on Aricept an average of 16-20 weeks," says Lon S. Schneider, MD, director of the Alzheimer Disease Research Center of California at the University of Southern California.
But since the drug may cause side effects such as nausea, muscle ache, and other problems, "many can't tolerate the medication for very long or don't continue to use it," he tells WebMD. "You just don't see that in a six-month study."
More importantly, perhaps, Gray's study included "everyday patients" rather those meeting the selection criteria in many pharmaceutical company-sponsored studies.
"What this study does is take patients who are ordinary patients of GPs, picked really on basis that physicians were uncertain they would benefit from medications," says Schneider, who wrote an editorial in The Lancet applauding Gray's study. "These are everyday patients who are representative of the general Alzheimer's population.
"In designing a study for a trial, you often want a patient who is a pure example of the illness," says Schneider, professor of psychiatry, neurology, and gerontology at USC's Keck School of Medicine. As a general rule, that means "younger and healthier" Alzheimer's patients who are more likely to respond favorably to the tested drug. That means people in earlier stages of the disease and without other conditions or taking other medications that could "compromise the study medication."
Modest Benefits for Some
Still, Schneider says that Aricept and other cholinesterase inhibitors do have a role in Alzheimer's disease treatment, but perhaps not as significant as marketers might lead you to believe.
"Pharmaceutical companies have been saying the amount of cognition improvement (demonstrated in studies they sponsor) can be projected to a delay in nursing home placement of two to five years," he says. "What Gray is showing is that when you do the studies properly, you don't see anything of the sort. This is an experiment that tempers our expectations on the extent to which these drugs may prevent nursing home placement.
"We prescribe Aricept for the vast majority of people with Alzheimer's," Schneider says. "But when we prescribe the drug, we don't prescribe it with the expectation that it will keep people out of nursing homes or it will cure them. We'll keep the drug going for people who seem to be stable and are tolerating it. If they continue to deteriorate, we'll stop it."
SOURCES: AD2000 Collaborative Group, The Lancet, June 26, 2004; vol 363: pp 2105-2115. Richard Gray, PhD, professor of medical statistics; director, University of Birmingham Clinical Trials Unit, United Kingdom. Lon S. Schneider, MD, professor of psychiatry, neurology, and gerontology, University of Southern California Keck School of Medicine
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