A new study suggests that the adverse effects of some dementia drugs could be placing the elderly patients at risk. Cholinesterase inhibitors (Aricept, Exelon and Reminyl) have been proven effective in managing some symptoms of dementia and Alzheimer’s disease. Medical professionals are aware of the possible side effects of this class of drugs. However, the impact of these effects has been brought to light only fairly recently when researchers of Queen’s University reported the result of their study.

As its name implies, a cholinesterase inhibitor works by blocking the enzyme cholinesterase. By doing so, the level of acetylcholine is increases. Acetylcholine is a neurotransmitter, when this substance is made more available to the brain cells, it translates to improvement of symptoms.

Queen’s University geriatrics professor Sudeep Gill and his colleagues carried out a population-based cohort study using health care databases from Ontario, Canada. The investigators identified 81,302 community-dwelling dementia patients, 19,803 of which are older adults who received cholinesterase inhibitors. The control group of 61,499 seniors did not use the said medicine.

The researchers discovered that the cholinesterase inhibitor users were hospitalized due to fainting almost twice as often as the control group. Moreover, the team found out that incidence of slowed heart rate was 69 percent more common among patients who took the dementia medicines, hence they have an increased chance for needing permanent pacemakers. Another significant finding is the increased risk of hip fractures in patients taking cholinesterase inhibitors.

Bradycardia or slow heart rate may cause a person to faint and suffer from injuries such as a broken hip which can largely debilitate people of advanced age. According to Dr. Gill, many physicians are not aware of the connection between such problems and dementia drug therapy.

The research team acknowledges the fact that anticholinesterase is among the few effective dementia drugs available at present. Dr. Gill suggests that people who are already at a higher risk, like those who have had episodes of fainting or slowed heart rate may consider asking their respective physicians to reevaluate the implications of cholinesterase inhibitor treatment. Dr Gill added that their findings does not suggest the discontinuation of the drug therapy, but rather increase the awareness of both caregivers and doctors of the potential side effects, and weigh these associated risks against the benefits of cholinesterase inhibitors.

Reference:
Syncope and Its Consequences in Patients With Dementia Receiving Cholinesterase Inhibitors
Sudeep S. Gill, MD, MSc; Geoffrey M. Anderson, MD, PhD;et al.
Arch Intern Med. 2009;169(9):867-873.

Queen’s University (2009, May 28). Dementia Drugs May Put Some Patients At Risk.

Tags: acetylcholine, alzheimer's, anticholinesterase, cholinesterase inhibitors, dementia, dementia treatment, fainting, syncope