You’ve probably heard the word “anticholinergic” on TV, or in one of my other articles, and mentally checked out because it sounds technical. Don’t. It’s actually simple. It just means the drug blocks acetylcholine, a chemical messenger that your body uses all day, every day.
That’s it.
No mystery. But the consequences of blocking it? That’s where it gets interesting.
So let me boil this down into 7 things you should know about acetylcholine before you take a drug that blocks it:
-
Acetylcholine keeps your brain sharp and your body regulated.
-
Blocking it can mimic aging.
-
Some medications are strong blockers and cross into the brain.
-
Even mild drugs can add up when stacked together.
-
Older adults are especially vulnerable.
-
Anticholinergic burden is linked to increased dementia risk. Statins have been studied in relation to memory and depression. I break down how it impacts your memory in THIS ARTICLE.
-
Dryness is your biggest clue.
Now let’s unpack that.
What Acetylcholine Actually Does
Acetylcholine helps you:
Think clearly.
Form memories.
Produce saliva and tears.
Move your intestines.
Empty your bladder.
Contract muscles.
Maintain focus.
It’s not a minor player. It’s like the Wi-Fi signal for your nervous system. When it’s strong, things connect. When it’s blocked, you start buffering.
And here’s the tricky part — when it’s blocked, the symptoms look suspiciously like “getting older.” It oculd impact your ability to get things done. I’m big on protecting independence. Reviewing your medications is one piece of that. Small environmental supports are another. I wrote about some of my favorite simple gadgets that make aging safer and easier — you might enjoy this next: 33 Gadgets That Quietly Protect Your Independence.
Dry mouth.
Dry eyes.
Constipation.
Blurred vision.
Urinary retention.
Faster heart rate.
Brain fog.
Memory lapses.
Sometimes that’s aging.
Sometimes it’s pharmacology wearing an aging costume.
Blocking acetylcholine is one piece of the puzzle. Supporting your brain so it can make what it needs is another. Certain B vitamins are directly involved in neurotransmitter production and brain energy. If you’re working on clarity and resilience, that’s something to consider.
7 Things You Should Know
Let me boil this down into 7 things you should know about acetylcholine before you take a drug that blocks it:
- Acetylcholine keeps your brain sharp and your body regulated.
- Blocking it can mimic aging.
- Some medications are strong blockers and cross into the brain.
- Even mild drugs can add up when stacked together.
- Older adults are especially vulnerable.
- Anticholinergic burden is linked to increased dementia risk.
- Dryness is your biggest clue.
The Dementia Connection (Yes, There Is Research)
This isn’t theoretical.
A large study published in JAMA Internal Medicine in 2019 followed nearly 300,000 adults and found that higher cumulative anticholinergic use was associated with an increased risk of dementia.
Association is not causation, but when biology makes sense and the data lines up, I pay attention.
And remember, Alzheimer’s medications like donepezil actually work by increasing acetylcholine. So chronically blocking it while trying to preserve cognition is… contradictory at best.
Why Stacking Is the Real Problem
Most people aren’t on “one giant anticholinergic.”
They’re on for example:
One allergy pill.
One bladder medication.
One nighttime sleep aid.
Maybe something for mood.
Each one seems reasonable. But receptors don’t care about intentions. They respond to load. It’s like putting tiny weights on a shelf. One is fine. Five? Still fine. Ten? Now the shelf bows.
That bowing? That’s brain fog.
Who Should Be Extra Careful
Older adults.
People with dementia.
Men with prostate enlargement.
Anyone with chronic constipation.
Babies and toddlers (who can actually get paradoxically wired from sedating antihistamines).
Acetylcholine is central to the hippocampus — your memory center. If that area is already vulnerable, blocking this neurotransmitter doesn’t help.
The Biggest Clue: Dryness
If you feel:
Dry mouth
Dry eyes
Dry skin
Constipation
Before assuming hormones, dehydration, or “just aging,” look at your medication list.
Acetylcholine stimulates secretions.
Block it — and things dry up.
It’s not poetic. It’s physiology.
The Medication List (Common Offenders)
This is not exhaustive. But it gives you a feel for how widespread this problem is. Check your medications and see ifyou take anything here:
Strong Anticholinergic Effect (High Brain Penetration)
These are the big hitters. Many cross the blood-brain barrier and can significantly impair thinking in some people.
Diphenhydramine (Benadryl)
Doxylamine (Unisom)
Amitriptyline
Nortriptyline
Imipramine
Oxybutynin
Tolterodine
Solifenacin
Trospium
Cyclobenzaprine
Paroxetine
Chlorpheniramine
Hydroxyzine
Promethazine
Scopolamine (the travel patch)
Moderate Anticholinergic Effect
These may seem milder, but stacking matters.
Cetirizine (Zyrtec)
Loratadine (Claritin)
Desipramine
Olanzapine
Quetiapine
Risperidone
Meclizine (Antivert)
Dicyclomine
Hyoscyamine
Trazodone
Minimal to Low (But Not Zero)
These generally have low central anticholinergic activity — but again, combinations change the picture.
Sertraline (Zoloft)
Escitalopram
Fluoxetine (Prozac)
Fexofenadine
Venlafaxine
Mirtazapine
Metoprolol
Propranolol
Cimetidine
What I Tell My Patients
If you need an antihistamine during peak allergy season, okay. Just don’t live on it for weeks. Use it short term. If the tablet is scored, sometimes half is enough.
Add the basics. Saline rinses. A good HEPA filter. Shower after high-pollen days so you’re not sleeping in what you just walked through. If dry mouth kicks in, xylitol lozenges can stimulate saliva. Magnesium can help if constipation develops.
Drink water, but understand hydration does not override receptor blockade. Your physiology does not care what the drug is “for.” Allergy. Bladder. Sleep. Depression. It responds to total chemical load. Anticholinergic means the drug blocks acetylcholine.
Sometimes that’s appropriate.
Sometimes it’s necessary.
And sometimes it quietly creates brain fog, dryness, constipation and slowdown that gets blamed on aging.
Aging already gets blamed for enough things it didn’t do.
If you’re over 60, review your medication list once a year. Ask specifically about anticholinergic burden. It’s a real concept.
If you want a deeper dive and tools to evaluate your prescriptions, that’s exactly why I built this site HERE so you can review your own medication list.
Suzy Cohen, has been a licensed pharmacist for over 30 years and believes the best approach to chronic illness is a combination of natural medicine and conventional. She founded her own dietary supplement company specializing in custom-formulas, some of which have patents. With a special focus on functional medicine, thyroid health and drug nutrient depletion, Suzy is the author of several related books including Thyroid Healthy, Drug Muggers, Diabetes Without Drugs, and a nationally syndicated column.
