September 17, 2013
Cognitive Enhancers Not Effective Against Minor Cognitive Impairment
redOrbit Staff & Wire Reports - Your Universe Online
Memory and concentration-improving drugs do not improve cognition or brain function, and may actually cause adverse health effects in people with mild cognitive impairment, according to research in Monday’s edition of the Canadian Medical Association Journal.These medications, which are known as cognitive enhancers, were found to be ineffective in treating patients suffering from mild cognitive impairment, a condition marked by memory complaints without significant limitations in everyday activity, Dr. Sharon Straus of St. Michael's Hospital in Toronto and her co-authors explained. Furthermore, they found that those using these drugs experienced significant negative side effects, including nausea, diarrhea, vomiting and headaches.
An estimated three to 42 percent of people are diagnosed with mild cognitive impairment each year, and between three and 17 percent of them will go on to develop dementia, the researchers explained. Experts have hypothesized that taking cognitive enhancers could delay the onset of dementia, spurring patients and their family members to increasingly request prescriptions for the medications. However, the efficacy of these drugs for patients suffering from mild cognitive impairment had not yet been firmly established.
Dr. Straus and her colleagues conducted a review of evidence to better understand the potential effectiveness and safety of cognitive enhancers in these men and women. They analyzed eight different randomized trials that compared one of four different cognitive enhancers (donepezil, rivastigmine, galantamine or memantine) to a placebo among patients diagnosed with mild cognitive impairment. While they found short-term benefits to using them on one congition scale, no long-term effects were observed after a period of 18 months.
“Our findings do not support the use of cognitive enhancers for mild cognitive impairment,” the study authors wrote. “These agents were not associated with any benefit and led to an increase in harms. Patients and their families should consider this information when requesting these medications. Similarly, health care decision-makers may not wish to approve the use of these medications for mild cognitive impairment, because these drugs might not be effective and are likely associated with harm.”
The study was funded by the Drug Safety and Effectiveness Network/Canadian Institutes of Health Research. Dr. Straus’ co-authors included scientists from the University of Calgary’s departments of Medicine and Community Health Sciences and the University of Toronto’s department of Geriatric Medicine. They reviewed a total of 15,554 titles and abstracts, as well as 1,384 full-text articles, as part of their research.