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Could medications contribute to dementia?

November 3, 2020


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Robert Shmerling
June 4, 2018

Regarding whether the PDR is correct: I don’t think we can be absolutely sure any particular source is correct – but the PDR is well-respected and generally considered a reliable source of drug information. On the other hand, it’s true that there are bigger “offenders” than bupropion when it comes to anti-cholinergic effects.

This study did not assess whether any particular drug contributes to dementia; rather, it found an association with a particular drug effect. And even drugs with low anti-cholinergic effects may matter in this regard since many people take more than one drug with anti-cholinergic effects.

Anne Thompson
June 1, 2018

Just to add–my understanding is that the ACB scale assigns a score of 1 (mild) to bupropion.

Has this changed?

Thank you.

Anne Thompson
June 1, 2018

Are you sure the PDR is correct in saying bupropion has moderate anticholinergic effects? Even this health letter has stated that its anticholinergic effects are very low. Perhaps there are new studies/analyses? You may be right, but I wonder if you could give some references to studies or analyses other than the PDR.

It is an important question since bupropion has been thought to be one antidepressant not causing this particular problem for seniors.

Looking forward to hearing about evidence. If you provided a link to something above, it’s not functional on my computer.

Thank you!

May 28, 2018

I think you underestimate the causality of the relationship of anticholinergics to the underlying protein biochemistry and evolution of the dementia process. Yes, it is difficult to extrapolate from human population studies to causality, but the “entire body of work” which includes animal studies that can’t be done ethically in humans (even with PET antibody and receptor imaging techniques or fMRI protocols), indicates cholinergic receptor agonists and antagonists induce specific directional changes in post receptor neuronal protein turnover and accumulation that are pathognomonic for dementia. Furthermore, OTC diphenhydramine- containing meds are ubiquitous in the allergy, pain, and sleep aid aisles and come in a variety of liquid forms for children. The basal forebrain cholinergic nuclei project to the cognitive and memory areas of importance in dementia, and specific centrally acting anti cholinesterase drugs temporarily benefit people with dementia. Why then is there such a gap between late incorporation and early incorporation in human drug consumption behavior, clinical guidelines, and basic science ? The apparent fear of “upsetting the public with science” in the midst of a terrible epidemic reminds me of the 60 years of tobacco and public health policy. Having spent 13 years in basic neuroscience research before medical school and 25 years in general practice since, I must say there is a surprising significant gap between the two disciplines and a seeming lack of urgency in the mission statements of both.

Anne Thompson PhD
May 25, 2018

Are you sure bupropion is anticholinergic? Please doublecheck this claim for accuracy.

Nancy Ferrari
May 27, 2018

Dear Anne,

Surprising but the answer is yes, though mildly so. From the PDR section on mechanism of action: “….Bupropion does exhibit moderate anticholinergic effects, and produces a sensation of mild local anesthesia on the oral mucosa. Antidepressant activity is usually noted within 1—3 weeks of initiation of bupropion treatment; full effects may not be seen until 4 weeks of therapy.”

You can see how the study investigators ranked anticholinergic effects for the medications by going to the study link in the blog.

May 24, 2018

Be cautious. The symptoms you describe could also be due to residual depression. It will not be hard to figure out which it is eg. begin to reduce the dose and see if you are worse or better. Good luck.

Joanne E. Bucci
May 24, 2018

Is Claratin and Zertex in that mix…Jb

Patricia B.
May 23, 2018

I believe this is true, at least in my case. I have depression and have been on bupropion (though I was unaware that this drug had any anticholinergic effects) 450mg along with escitalopram 20mg daily for about a year and a half after a life crisis, and have noticed a very noticeable difference in my ability to think or recall things in that time. I am getting quite annoyed by this, and it is also noticeable to my family. To me the mood regulation is definitely not worth the sensation of days passing without the ability to engage daily in real life. Hence I intend to address this with my psychiatrist at my upcoming appt. As he is very attuned to my opinion on how I’m handling my medications I know he will be willing to test how lowering them will or will not improve my cognitive issues. It will be interesting.

May 23, 2018

All of these medications can certainly increase problems with severe side effects for people who already have Lewy Body Dementia.

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