Over-the-counter pills could raise risk of Alzheimer’s: study

Anti-allergy medication Benadryl is just one of the over-the-counter drugs that could raise the risk of Alzheimer's, according to a new study. Photo: Getty Images

Some over-the-counter hay fever pills and sleeping aids could raise the risk of Alzheimer’s disease, a US study has found.
Sleep remedy Nytol, anti-allergy meds Benadryl and Piriton, and some older antidepressants are among the products associated with an increased risk of the dementia disease, researchers found, the Daily Mail reported.
The drugs affect the brain by blocking acetylcholine, a key chemical messenger, the report found.
The risk of dementia is the highest when the so-called anticholinergic drugs are taken in high doses over several years.
“Health-care providers should regularly review their older patients’ drug regimens, including over-the-counter medications, to look for chances to use fewer anticholinergic medications at lower doses,” said Professor Shelly Gray of the University of Washington School of Pharmacy, the study’s leader.
Gray emphasized that people should talk to their doctors before they stop taking any of the drugs.
The connection between anticholinergic drugs and mental impairment among the elderly was shown in research last year.
The latest study — published in the journal JAMA Internal Medicine — is the first that links higher doses with higher risks of dementia.
A group of 3,434 men and women age 65 and older were monitored for about seven years as they used anticholinergic meds. Of the group, 637 developed Alzheimer’s disease and 160 others were affected by other kinds of dementia.
The risk of dementia was 54 percent higher for those who took the highest doses of the drugs than for those who took none, the study found. The risk of Alzheimer’s was 63 percent greater.
A higher risk of dementia was seen in those who took at least 10mg a day of the antidepressant doxepin, 4mg a day of diphenhydramine, which is in Nytol and Benadryl, or 5mg a day of oxybutynin (Ditropan) — used for an overactive bladder — for at least three years.
Anticholinergic drugs lead to side effects including drowsiness and poor memory. Alzheimer’s sufferers also are known to lack acetylcholine, which is blocked by the drugs.
“This large study adds to some existing evidence linking anticholinergic drugs to a small increased risk of dementia, but the results don’t tell us that these drugs cause the condition,” said Dr. Simon Ridley of Alzheimer’s Research UK, adding that more research is needed.