These are common medicines…
I might have mentioned that I am studying Mental Health Science. While it is very interesting it has thrown up some worrying issues that I wasn’t aware of.
One of them is something called the ‘anticholinergic burden’ and the link it seems to have with the risk of developing dementia.
The word anticholinergic refers to a type of medication which blocks a specific neurotransmitter in the nervous system called acetylcholine. This neurotransmitter plays a very important role in several functions, including muscle activation, heart rate regulation, and brain health and cognition. Anticholinergic drugs are widely prescribed for conditions such as depression, allergies, urinary incontinence, and gastrointestinal disorders. They are very common. Here are some you may have heard of:
Antihistamines (e.g., diphenhydramine, chlorpheniramine)
Tricyclic antidepressants (e.g., amitriptyline, imipramine)
Medications for overactive bladder (e.g., oxybutynin, tolterodine)
Sleeping pills (e.g., doxylamine, diphenhydramine)
Many people have found these drugs really useful. But when anticholinergic drugs are prescribed at high doses or in combination, they can become cumulative and lead to significant health risks, particularly for the elderly. Research has shown that these medications can have detrimental effects on cognitive function, particularly when used over long periods or in high doses. The cumulative effect is referred to as the ‘anticholinergic burden’ and can lead to symptoms such as confusion, memory loss, and overall cognitive decline.
So, this is concerning for older adults who are already at an increased risk of dementia.
The cumulative effects of these drugs have been such a concern that there is a specific anticholinergic burden calculator [ABC] which gives a number to each drugs – the point of this is so that the clinician can make sure that the burden doesn’t rise about three. Shall we do some adding up, because a score of 3+ is considered high risk and a score of 6+ is associated with significant cognitive decline risk.
[Taken from: https://www.acbcalc.com/?form=MG0AV3]Antihistamines:
- Diphenhydramine: 3 points
- Chlorpheniramine: 3 points
Tricyclic antidepressants:
- Amitriptyline: 3 points
- Imipramine: 3 points
Overactive bladder medications:
- Oxybutynin: 3 points
- Tolterodine: 3 points
Sleeping pills:
- Doxylamine: 3 points
- Diphenhydramine: 3 points (already counted above)
Total burden: 21 points
This is a very high anticholinergic burden.
It is not in the realms of fantasy to imaging an elderly person on a diuretic, and antihistamines, or possibly an antidepressant. Is it?
The cumulative effects of these drugs could include:
Severe confusion/Memory problems/Blurred vision/Severe dry mouth/Urinary retention/ Increased fall risk…
And;
Potential increased risk of dementia with long-term use.
How?
All these drugs compete for and block the same acetylcholine receptors in the body.
In the Central Nervous System:
i] Each drug blocks acetylcholine in the brain
ii] This disrupts the cholinergic pathways crucial for memory and cognition
iii] When multiple drugs block these pathways, the effect multiplies rather than just adds
Peripheral Nervous System:
Anticholinergic drugs block receptors throughout the body
This affects:
i]Salivary glands (causing dry mouth)
ii] Smooth muscle in the bladder (causing retention)
iii] Eyes (causing pupil dilation and blurred vision)
Compounding Factors:
Each drug has a different half-life so that some, like amitriptyline, have long-acting metabolites which means that the effects can build up over time. We know that the blood-brain barrier becomes more permeable with age, so that may increase effects on cognition.
Why the ‘burden’ multiplies:
i] These drugs often compete for the same metabolic pathways
ii] This can slow the breakdown of each drug
iii] The delayed clearance means more drug accumulation
iv] Higher concentrations lead to more receptor blockade
Even though these risks are known, anticholinergic drugs are often prescribed to the elderly without sufficient consideration of the cumulative burden. It is not uncommon for a patient in a nursing home to receive multiple prescriptions leading to a high anticholinergic load. Of course this polypharmacy significantly increases the risk of adverse cognitive outcomes. Studies have indicated that even moderate anticholinergic use can double the risk of developing dementia over a decade.
The link between anticholinergic burden and dementia risk has become increasingly evident through scientific studies.* Long-term use of anticholinergic medications, especially in high doses, has been associated with an increased risk of developing Alzheimer’s disease and other forms of dementia. The mechanisms underlying this association are not entirely understood, but it is believed that the disruption of acetylcholine signalling may contribute to the neurodegenerative processes.
*Talwar, A., Chatterjee, S., Sherer, J., Abughosh, S., Johnson, M., Aparasu, R. (2024) Cumulative Anticholinergic Burden and its Predictors among Older Adults with Alzheimer’s Disease Initiating Cholinesterase Inhibitors. Drugs & Aging 41:339–355.
I don’t want to scare anyone. I just think we must be aware of what we [and our vulnerable elderly] are taking. It wouldn’t hurt to inquire about the anticholinergic burden of medications and do a bit of adding up ourselves using the ABC calculator link above.
If you would like to chat about natural medications that you can out in your body without increasing the risk of dementia, then come and join my HerbWorks membership for £9.99 a month. There are videos on the membership site which are being added to month by month, plus an hour live group chat/Q&A each month. Hope to see you there…
