A new research has identified a considerable connection between high use of anticholinergic medicines, which includes well-known OTC sleep aids and the antihistamine Benadryl (diphenhydramine) and enhanced risk of developing dementia and Alzheimer’s condition in older adults.
Anticholinergics drugs are a type of drug that prevents the action of the neurotransmitter acetylcholine in the brain and body.
This can result in many side effects, such as drowsiness, retaining urine, constipation and dry mouth and eyes.
The investigators, lead by Shelly Gray, publish their results in JAMA Internal Medicine.
Prof. Gray states that:
“Older people must be conscious that many drugs – which includes some accessible without a prescription, like as over-the-counter sleep aids – have powerful anticholinergic effects.”
Individuals shouldn’t stop their treatment but discuss to their doctor
Prof. Gray urges individuals not to quit their treatment dependent on the results of this study – they must talk to their doctor, and also tell them about all their OTC drug use.
“Health care providers must consistently evaluate their older sufferers’ drug regimens – which include OTC drugs – to look for possibilities to use less anticholinergic drugs at reduced doses,” she says.
If providers have to recommend anticholinergics to their sufferers to provide the best therapy, then “they must use the lowest effective dose, keep track of the therapy consistently to make sure it’s working, and end the treatment if it’s ineffective,” she adds.
Even though the connection between increased threat of dementia and anticholinergics has been identified before, the new research uses more extensive methods – such as above 7 years of follow-up – to set up the strength of the connection. By obtaining pharmacy records, the investigators were also capable to include non-prescription use of anticholinergics in their details.
It is also the initial research to display a dose-response effect, note the authors. That is, the greater the cumulative amount of drug taken, the greater the risk of developing dementia.
And another first for the research is that it also reveals that dementia threat connected to anticholinergics may persist even after individuals stop taking the drugs.
Using anticholinergics for over 3 years connected to greater dementia risk
For their research, Prof. Gray and colleagues monitored almost 3,500 men and women aged 65 and above with no dementia signs at the start of the research. The individuals were part of the Adult Changes in Thought (ACT) research in Group Health, an incorporated health care delivery system in Seattle.
To evaluate how much exposure the individuals had to anticholinergic drugs, the scientists used computer data from the pharmacies that dispensed them.
From the pharmacy information they added up all the regular daily doses and worked out the collective anticholinergic exposure for each individual over the last 10 years. This was up to date as individuals were followed up for an average of 7 years.
Over the period of the research, almost 800 individuals developed dementia.
The outcomes revealed that the most frequently used drugs were first-generation antihistamines, tricyclic antidepressants, and antimuscarinics for bladder control.
The investigators approximated that individuals taking minimum of 10 mg of doxepin, 4 mg of chlorpheniramine, or 5 mg of oxybutynin daily for over 3 years would be at higher risk for developing dementia.
Prof. Gray states that there are alternate non-anticholinergic medicines for doxepin and chlorpheniramine. For instance, to deal with depression there are the selective serotonin re-uptake inhibitors (SSRIs) and there are second generation antihistamines to treat allergies.
However, while there are not several choices to oxybutynin for improving bladder control, she indicates behavioral modifications may be an option.
Some of the ACT participants have decided to have their brains autopsied after they die. This may show if using anticholinergic medicines is more probably to result in brain modifications that are characteristic of individuals who develop Alzheimer’s.
Finances for the research came from the NIH’s National Institute on Aging and the Branta Foundation.