Can Dementia Meds Delay Mild Mental Decline?

Mild cognitive impairment not helped by cognitive enhancers used for dementia treatment

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Adults are living longer lives, which means more people will be living with some level of mental decline. Can that decline be delayed?

A recent review was conducted on the effectiveness and safety of cognitive enhancers for treating mild cognitive impairment (mild yet noticeable mental decline that does not affect basic day-to-day activities).

Cognitive enhancers are medications that help improve basic mental function such as memory, attention, concentration and understanding, and are usually used to treat dementia (serious mental decline that affects the ability to do everyday activities).

The authors found that cognitive enhancers offered no benefit to patients with mild cognitive impairment in this study. These medications were also found to put patients at risk for internal injury, especially of the stomach and intestines.

The authors concluded that their findings did not support the use of cognitive enhancers in patients with mild cognitive impairment.

"Talk to a doctor if you are experiencing loss of mental function."

This review was conducted by Sharon Straus, MD, MSc, from the Li Ka Shing Knowledge Institute and the Department of Geriatric Medicine at the University of Toronto in Ontario, Canada, and colleagues.

These researchers searched electronic databases for studies on the safety and effectiveness of four cognitive enhancers: donepezil (brand name Aricept), rivastigmine (Exelon), galantamine (Razadyne) or memantine (Namenda). The authors only included studies that involved patients with a diagnosis of mild cognitive impairment who were given one of these cognitive enhancers and compared it to the effects of a placebo (fake medication).

The authors chose 10 articles to review — three of which were other study reviews on eight different studies, and seven of which were primary publications. All of the studies used in this review were randomized clinical trials conducted between 1999 and 2007.

The average age of the study participants was between 66 and 73 years old. The number of participants in each study ranged from 51 to 1,058.

Each study reported measurements of general cognition (basic mental processes such as attention, memory, decision making, etc.), ability to function in everyday activities, behavior and deaths or physical harm.

The authors of this review compared data from each study at six weeks, 12 weeks and 24 weeks of follow-up, as well as the longest length of follow-up time in each study.

After almost every follow-up period, the researchers found that there was no significant difference in the effects of the cognitive enhancers versus the placebos.

The authors discovered that after an average of 126 weeks, participants using these cognitive enhancers reported significantly more issues with nausea, diarrhea, vomiting and headaches when compared to the participants taking the placebo.

These review findings suggest that cognitive enhancers may have no benefit to patients with mild cognitive impairment, and that they may pose a risk for issues in the gastrointestinal system (stomach, intestines, etc.). The authors believe that both patients and any healthcare decision makers should be aware that these medications may not be effective and can be very harmful.

The authors mentioned a few limitations of their study.

First, there were not many studies or much information on this subject, so the authors did not get to examine a variety of study designs, and were not able to do as wide of comparison as they would have liked.

Second, most of the studies included in the review did not include information on whether or not the study participants had any other conditions at the same time as mild cognitive impairment.

Third, the definition of mild cognitive impairment was not uniform across all studies. Fourth, many of the studies used very short follow-up periods. Lastly, the authors believe that many of the studies had poor reporting of the results.

This review was published in the September edition of the Canadian Medical Association Journal.

The Drug Safety and Effectiveness Network and the Canadian Institutes of Health Research provided funding.

Review Date: 
September 17, 2013
Last Updated:
September 17, 2013