A new study from the JAMA Internal Medicine journal has linked commonly used medicines, including over-the-counter treatments for conditions such as insomnia and hay-fever, to dementia.
Medical experts say that people do not need to panic or stop taking their prescriptions. The medication types in questions are all drugs with an “anticholinergic” effect.
Researchers at the University of Washington looked at the health of 3,434 people aged 65 and older who had no signs of dementia at the start of the study. Looking at medical and pharmacy records, they determined how many of the participants were given drugs with anticholinergic effects, and compared their use with subsequent dementia diagnoses over the next decade.
The study confirmed that higher doses and prolonged use of these were linked to higher dementia risk, particularly in elderly people, and researchers found the increased risk only appeared when people took drugs every day for three years or more.
Over the course of the study, 797 of the participants developed dementia.
All medicines can have side-effects and anticholinergic-type drugs that block a neurotransmitter called acetylcholine are no exception, according to the report.
Dementia is a loss of brain function that affects cognitive memory, judgment, language, and normal behavior.
While the study does not name specific drug brands to look out for, it does outline the types of treatments investigated, including anti-depressants, antihistamines (for hay-fever and allergies), and antimuscarinics (for treating urinary incontinence). Most of these commonly-used drugs were given on prescription, rather than bought at the pharmacy over-the-counter.
Information leaflets accompanying these certain drugs warn of the possibility of reduced attention span and memory problems, as well as a dry mouth. People should also be aware that these medications may be linked to increased risk of developing dementia.
Researchers say that doctors and pharmacists might want to take a precautionary approach, and offer different treatments instead, if not lowering the recommended doses for shorter periods of time.
“It is still unclear whether this is the case and if so, whether the effects seen are a result of long-term use or several episodes of short-term use,” said Dr. Doug Brown from the UK’s Alzheimer’s Society. “More robust research is needed to understand what the potential dangers are, and if some drugs are more likely to have this effect than others.
“We would encourage doctors and pharmacists to be aware of this potential link and would advise anyone concerned about this to speak to their GP before stopping any medication.”
(With reports from BBC News)