The side effects from several drugs commonly prescribed for Alzheimer's disease may be putting some elderly Canadians at risk, finds a new study.
Queen's University geriatrics professor Sudeep Gill studied Ontario-wide data, looking at 19,803 older adults with dementia who were prescribed drugs called cholinesterase inhibitors, which include Aricept, Exelon and Reminyl. They compared them to 61,499 patients who did not take the meds.
The research team found that elderly patients on the dementia drugs were hospitalized for fainting twice as often as dementia patients who did not take those drugs.
Patients taking the drugs also had an 18 per cent increased risk of having a hip replacement because of damage sustained during fainting spells.
In addition, people taking the dementia drugs were 69 per cent more likely to experience a slowed heart rate, and had a 49 per cent increased chance of having permanent pacemakers implanted.
The findings were published recently in the journal Archives of Internal Medicine.
Cholinesterase inhibitors are often prescribed for people with Alzheimer's disease and related dementias. They work by increasing the levels of a chemical in the brain that seems to help memory, but can also lead to a slowing of the heart rate, which may cause a person to faint.
Although such drugs are known to provoke fainting episodes, the magnitude of these risks has not been clear until now.
"This is very troubling, because the drugs are marketed as helping to preserve memory and improve function," says Dr. Gill, who is an Ontario Ministry of Health and Long-term Care Career Scientist.
"But for a subset of people, the effect appears to be the exact opposite."
Gill notes that fainting episodes can cause significant injury for seniors, such as a broken hip -- an often debilitating and sometimes fatal injury for seniors.
What's more, some doctors may not connect the drugs to slower heart rates in their patients and may prescribe a permanent pacemaker, which involves an invasive procedure that can cause serious complications for seniors.
While acknowledging that the drugs do have an important role in managing dementia, Gill suggests people who are already at a higher risk for fainting because of previous episodes should ask their doctors to reassess whether they should be using the drugs.
"This study does not suggest that dementia patients shouldn't take these drugs," says Gill. "What's critical is that patients, caregivers and physicians be aware of the potential side effects, and weigh these risks carefully against the potential for beneficial effects."
