July 30, 2007
Aricept, a drug commonly used to treat mild to moderate Alzheimer's, showed modest benefits for people with severe disease. People with advanced Alzheimer's showed modest improvements in memory and everyday function when given the drug, which goes by the generic name donepezil. The findings appeared in Neurology, the medical journal of the American Academy of Neurology.
The six-month study involved 343 people with severe Alzheimer's disease at clinics in the United States, Canada, France, the United Kingdom, and Australia. Half of the group received a daily dose of donepezil; the other half received a look-alike placebo pill. Study participants were given cognitive tests to assess memory and thinking skills at regular intervals.
The researchers found that cognitive function stabilized or improved in 63 percent of people taking Aricept, compared to 39 percent of people taking placebo. Compared to the placebo group, those taking Aricept showed improvement in memory, language, attention, and recognizing one's name. The group receiving the drug also showed less of a decline in social interaction, skills needed to complete a jigsaw puzzle, and arranging sentences compared to the placebo group.
"The effectiveness of donepezil in preserving cognitive and global function in people with severe Alzheimer's disease, as evidenced by this study and others, is encouraging," said study author Sandra Black, MD, Brill Professor of Neurology at Sunnybrook Health Sciences Centre, University of Toronto in Canada.
"People who progress to the severe stage of Alzheimer's disease have markedly diminished cognitive and global function, so preserving cognitive function is a worthwhile treatment goal," added Black. "It may help to keep patients at home longer, something that patients and caregivers often desire and which delays the costs of nursing home care."
It's important to note that Aricept and related drugs used to treat the cognitive symptoms of Alzheimer's disease, such as Exelon and Razadyne, do not work in all people with Alzheimer's. In addition, benefits may be modest. These drugs may provide a modest boost in memory and other functions, but they do nothing to stop the relentless downward progession of disease.
Black says the most common side effects reported in this study, namely diarrhea, insomnia, nausea, infection, and bladder problems, were mild to moderate and consistent with the known side effects of such drugs. "Our findings provide further evidence that donepezil is safe, effective, and benefits cognition and global function in people with severe Alzheimer's disease," she said.
As Alzheimer's disease progresses, people with advanced disease have marked diminishment in memory and the ability to carry out everyday tasks. They exhibit reduced social interactions, and the ability to carry out everyday functions like bathing and going to the bathroom become impaired, requiring continual, often 24-hour-a-day care.
Of the 4.5 million Americans with Alzheimer's, about one in five cases are severe. These numbers will increase in coming years as the population ages and baby boomers enter their golden years. The need for effective therapies to combat the downward spiral of Alzheimer's is more critical than ever.
In the United States, the first drug to be approved by the Food and Drug Administration for severe Alzheimer's was Namenda (generic name memantine). It works on different brain chemicals than Aricept, and was approved after studies showed that it produced benefits for people in the advanced stages of disease.
More recently, Aricept, too, was approved for the treatment of severe Alzheimer's. This study confirms earlier evidence that the drug provides modest benefits for treating advanced disease. Though the benefits may be modest for people with severe Alzheimer's, it may allow caregivers to keep loved ones with the disease at home longer, rather than moving them to more expensive nursing homes.
As Alzheimer's cases continue to mount, the need for an effective treatment for Alzheimer's continues to grow as well. The Fisher Center for Alzheimer's Research Foundation funds vital research into the root causes of Alzheimer's and the search for a cure. To learn more, visit www.ALZinfo.org.
S.E. Black, M.D.; R. Doody, M.D.; H. Li, Ph.D., et al: "Donepezil Preserves Cognition and Global Function in Patients with Severe Alzheimer's Disease." Neurology. Volume 69, July 3, 2007, pages 459-469.