5. Certain Medicines Used for Parkinson’s Disease

Some older antiparkinson medicines have anticholinergic effects.

Examples include:

• Benztropine
• Trihexyphenidyl

These drugs can sometimes cause confusion and other cognitive side effects, particularly in older adults.

The JAMA study found an association between cumulative exposure to anticholinergic antiparkinson medications and dementia.

6. Certain Antiepileptic Medicines

Some medicines used to control seizures have anticholinergic properties or can affect cognition through other mechanisms.

The large observational study found an association between cumulative exposure to anticholinergic antiepileptic medicines and dementia.

However, seizure control is extremely important. Anyone taking an antiepileptic medication should never stop it independently because suddenly discontinuing some seizure medicines can be dangerous.

7. Certain Medicines Used for Motion Sickness or Vertigo

Some medicines used for motion sickness, nausea, or dizziness can have anticholinergic effects.

For example, meclizine and related medicines may cause drowsiness and confusion in susceptible people.

Occasional use is very different from prolonged cumulative exposure. If you regularly need these medications, particularly if you’re older, ask your pharmacist whether a lower-risk alternative is appropriate.

8. Some Medicines With Multiple Anticholinergic Effects

The biggest concern isn’t always a single medication.

A person may take several medicines that each have mild or moderate anticholinergic effects. Their combined anticholinergic burden can become substantial.

For example, an older adult might simultaneously use a nighttime allergy medicine, a bladder medication, and an antidepressant.

That is why a medication review can be extremely valuable.

Why Can Anticholinergic Medicines Affect the Brain?

Anticholinergic medicines block the action of acetylcholine, a chemical messenger involved in memory, attention, learning, and other functions.

Short-term anticholinergic effects can include:

• Dry mouth
• Blurred vision
• Constipation
• Urinary retention
• Drowsiness
• Confusion
• Memory difficulties

Older adults can be particularly sensitive to these effects.

Research has also found associations between higher cumulative exposure and dementia.

Does Taking One of These Medicines Mean You’ll Get Dementia?

No.

This is one of the most important points for readers.

Observational studies cannot establish that a particular medication directly caused an individual’s dementia.

People who need these medicines may already have other health conditions that influence dementia risk. Researchers attempt to account for such factors, but some confounding can remain.

The evidence is strong enough to encourage clinicians to review unnecessary long-term anticholinergic exposure, particularly in older adults, but it is not a reason for patients to abruptly discontinue necessary treatment.

What Should You Do If You Take One of These Medicines?

Don’t panic and don’t stop your medication on your own.

Instead, ask your doctor or pharmacist:

“Does this medicine have anticholinergic effects, and is there a safer alternative for me?”

A medication review can identify:

• Medicines that may no longer be necessary
• Duplicate treatments
• Over-the-counter products contributing to anticholinergic burden
• Possible alternatives
• Opportunities to reduce doses safely

Don’t Forget Over-the-Counter Medicines

Some people focus only on prescription medications and forget that common pharmacy products can also have anticholinergic effects.

Always tell your healthcare professional about:

• Allergy medicines
• Sleep aids
• Cold medicines
• Bladder medicines
• Antidepressants
• Herbal products
• Vitamins and supplements

Bring the actual medication packages to a medication review if possible.

What About Sudden Confusion?

Sudden confusion is not the same thing as dementia.

A rapid change in mental status can be delirium, which may be triggered by medications, infections, dehydration, metabolic problems, or other medical conditions.

Sudden confusion in an older adult deserves prompt medical assessment rather than being dismissed as normal aging.

The Bottom Line

The claim that “eight drugs cause dementia” is too simplistic.

A more accurate message is that long-term exposure to some medicines with strong anticholinergic effects has been associated with increased dementia risk, especially in older adults. Research has identified concerns involving certain antidepressants, bladder medications, antipsychotics, antiparkinson drugs, antiepileptic medicines, and other anticholinergic medications.

If you’re taking one of these medicines, don’t stop it without medical advice. The safest step is to ask a doctor or pharmacist to review your complete medication list and determine whether your treatment can be optimized.

Medical Disclaimer

This article is for educational purposes and does not replace individualized medical advice. Medication risks vary according to the specific drug, dose, duration of treatment, age, kidney and liver function, and other medicines being taken. Never stop a prescription medication abruptly without consulting your healthcare professional.