Popular Drugs Linked To Dementia Even At Low Dosage

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A new study in the University of Washington provides strong evidence that certain popular drugs may increase the risk of dementia in older adults. The drugs share some common mechanisms within key areas of the brain but are used primarily as ingredients in over-the-counter sleep, cough, cold, and allergy medicines as well as in the treatment of an overactive bladder and depression.

Drugs And Dementia

The most commonly used drug linked to dementia is diphenhydramine, which is used in many popular products such as Benadryl, Nytol Sominex, Theraflu, Triaminic Allergy, etc. It is also implicated in drugs containing chlorpheniramine (Aller-Chlor); oxybutynin (Ditropan) and tolterodine (Detrol) for overactive bladder; and tricyclic antidepressants, such as doxepin or amitriptyline.1

Background Data

Acetylcholine is a critical brain chemical involved in the transmission of nerve impulse and is especially important for proper memory and cognitive function. For example, Alzheimer’s disease is associated with a severe reduction in acetylcholine levels due to reduced activity of the enzyme that manufactures acetylcholine (choline acetyltransferase).2

Given the link between low acetylcholine levels and poor brain function, including dementia, previous studies have linked drugs to reduced acetylcholine activity as well as mild cognitive impairment. These drugs include the ones mentioned earlier.

While discontinuation of the drugs is thought to reverse the mental deficit, there is evidence that anticholinergic drugs may produce permanent changes leading to irreversible dementia.

These drugs are known to cause short-term drowsiness or confusion, which is included in the prescribing information, but the long-term effects these drugs have on mental function are generally not known by physicians or the people taking them.3 4 5

Other drugs, like sedative hypnotic drugs (sleeping pills) and antihistamines, have also been linked to an increased risk of dementia. All of these drugs, both prescription and over-the-counter, are used at an alarming rate by the elderly population, putting them at significant risk for dementia.

New Data

To evaluate whether cumulative anticholinergic use is associated with a higher risk of incident dementia, researchers examined medical records from 3,434 participants 65 years or older with no dementia at study entry. Initial recruitment occurred from 1994 through 1996 and from 2000 through 2003 and data through September 30, 2012 were also included in these analyses.6

Exposure to anticholinergic drugs was determined from computerized pharmacy records. Cumulative exposure was updated as participants were followed up over a 10-year period. About 20% of the population was found to be using anticholinergic drugs.

During the evaluation period, 797 participants (23.2%) developed dementia, with 637 of these (80%) developing Alzheimer’s disease. A 10-year cumulative dose-response relationship was observed for dementia and Alzheimer’s. In other words, the higher the cumulative anticholinergic use, the greater the risk of dementia. The highest risk threshold was taking the minimum daily effective dose of one of the anticholinergic agents every day for 3 years.

Even at low dosage or recommended levels, chronic use of these drugs should be avoided.

Based upon these results, the authors of the study propose efforts to increase awareness among health care professionals and older adults about the risk of the use of these drugs over time.

Bottom Line

The results from this study highlight the importance of avoiding long-term use of such drugs, including diphenhydramine and over-the-counter sleeping pills. What this research further establishes is that the human brain can be adversely affected by minor pharmacological agents, highlighting the importance of using natural approaches that not only address the key issue (e.g., insomnia, allergies, etc.) but also have a positive effect on brain function. For example, the natural compound enzymatically modified isoquercitrin (EMIQ) has demonstrated significant anti-allergy effects and also has been shown to block the formation of beta-amyloid, a protein that is linked to causing the brain damage in Alzheimer’s disease.

References   [ + ]

1. Basu, Ranita, Hiroko Dodge, Gary P. Stoehr, and Mary Ganguli. “Sedative-hypnotic use of diphenhydramine in a rural, older adult, community-based cohort: effects on cognition.” The American journal of geriatric psychiatry 11, no. 2 (2003): 205-213.
2. Richter, Judith A., Elaine K. Perry, and Bernard E. Tomlinson. “Acetylcholine and choline levels in post-mortem human brain tissue: preliminary observations in Alzheimer’s disease.” Life sciences 26, no. 20 (1980): 1683-1689.
3. Starr, John M., and Lawrence J. Whalley. “Drug-induced dementia.” Drug safety 11, no. 5 (1994): 310-317.
4. Ancelin, Marie L., Sylvaine Artero, Florence Portet, Anne-Marie Dupuy, Jacques Touchon, and Karen Ritchie. “Non-degenerative mild cognitive impairment in elderly people and use of anticholinergic drugs: longitudinal cohort study.” Bmj 332, no. 7539 (2006): 455-459.
5. Mintzer, Jacobo, and Alistair Burns. “Anticholinergic side-effects of drugs in elderly people.” Journal of the Royal Society of Medicine 93, no. 9 (2000): 457.
6. Gray, Shelly L., Sascha Dublin, Onchee Yu, Rod Walker, Melissa Anderson, Rebecca A. Hubbard, Paul K. Crane, and Eric B. Larson. “Benzodiazepine use and risk of incident dementia or cognitive decline: prospective population based study.” bmj 352 (2016): i90.
Michael T. Murray

Michael T. Murray ND is a naturopathic physician regarded as one of the world's top authorities on natural medicine. An educator, lecturer, researcher, and health food industry consultant, he is the author of more than 30 books, including his new book, The Complete Book of Juicing, Revised and Updated: Your Delicious Guide to Youthful Vitality (Clarkson Potter, 2014). Learn more at www.DrMurray.com.

Michael T. Murray

Michael T. Murray ND is a naturopathic physician regarded as one of the world's top authorities on natural medicine. An educator, lecturer, researcher, and health food industry consultant, he is the author of more than 30 books, including his new book, The Complete Book of Juicing, Revised and Updated: Your Delicious Guide to Youthful Vitality (Clarkson Potter, 2014). Learn more at www.DrMurray.com.

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Wendy Goddard
Wendy Goddard 5pts

Yep, heard this from my mom's doctor about Benedryl. Good to know if you're older and having trouble sleeping, not your best choice on a regular basis

Ann Small
Ann Small 5pts

Starting to worry I am on 3 a day Amitriptyline a day for nerve  pain in my hands has been on that for couple of years i am nearly 63 years old  think a  visit to doctor  to speak about this but they claim that pill only one that will help.

Jude Sergeant
Jude Sergeant 5pts

If this had been proven beyond any doubt, after multiple long controlled trials, the medications would become prescription only or withdrawn from sale indefinitely.

Felicia L Jones
Felicia L Jones 5pts

You are right Barbara Anthony, but the problem is people don't know there are natural alternatives to OTC and pharmaceuticals, so they just keep taking them.

Barbara Anthony
Barbara Anthony 5pts

I wish people would know this, too important to just have it sit on fb!!

piezdescalzos 5pts

Sleep deprivation and anxiety left me no alternative but to use Diphenhydramine for almost 30 years.  Add fibromyalgia 10 years ago (Lyrica}, and an autoimmune disease and condition horrible painful and itchy blisters for which I  was prescribed a very potent drug, Dapsone..  Dapsone is a very potent drug also used to treat leprosy. So it is also an antibacterial drug.  Dapsone is also used at times as an organ transplant.  It is very toxic.  I had no alternative.  As an aside to Lyrica which has the added non benefit of peripheral neuropathy.  Lucky me.  Please bury me sooner rather than later.

Alicia P
Alicia P 5pts

@piezdescalzos  That sounds terrible and very familiar to people who found out after years and numerous doctors that they had one or more tick diseases. Please see the lyme disease documentary and look at ilads. org or talk to people in Lyme groups. There are numerous tick diseases and they don't have a good test or any test for them. 

Joy St John
Joy St John 5pts

See a homeopath! Homeopathy works by reversing the damages from one med back to the damage from the previous med and so on back to the original reason you started meds.I was raised in a full on allopathic mileu with a physician father, med tech brother, RN sister...went pre-med, nursing school myself working in medicine 25 yrs then medical model mental health for another 25. Homeopathic medicine still rocks my empirical credulity but I see it working & that evidentiary enough. Meds very low cost & safe.

AndrewDiseker 5pts

Yeah, I can either constantly sneeze and have other allergy symptoms for 6 months of the year, or I can rot my brain.  I can't say I disbelieve you, but I disbelieve you.

Alicia P
Alicia P 5pts

@AndrewDiseker  It was good they referred to at least one natural remedy. Quercetin may help and there are others, look or ask around for natural products for allergies. Vitamin C and ashwagandha may be two others.   Allergy shots?

JimMataczynski 5pts

If you are not willing to cite the actual work, post a link to the paper or give contact information to the researchers, then you are misinformed, misinterpreting, have other gains in mind, a liar, a damned liar, a politician or a quack.

SarahLoftin 5pts

Where are the references/work sited information to this research? Nothing like instilling fearinto people that normally do not know what to look for as a means of "proof" to this information. Garbage. Shame on you.


Dionne Johnson
Dionne Johnson 5pts

I dn't think any elderly person shuld take these drugs, for Dementia, it's a sign of Agisim

Ashley Nicole
Ashley Nicole 5pts

Benadryl cough and allergy, otc smh \U0001f440\U0001f440

Maryservs 5pts

Not if they weren't /aren't married....

Susan Omiak
Susan Omiak 5pts

My dad had dementia, didn't take any of these.

Gooden Sharon
Gooden Sharon 5pts

Ashley Nicole. Read this !!!!!see what meds has this in it to cause dementia

Saroj Ojha
Saroj Ojha 5pts


Ayurveda 5pts

Sorry to hear that Connie Wasik

Connie Wasik
Connie Wasik 5pts

My Mom never took any of those drugs, she had it progressively bad for almost 10 yrs.

Jay Rogers
Jay Rogers 5pts

All we will need comes right out of the ground. Quest: why treat the symptoms & not the root cause. Ans: money & lack of courage.

Brenda Jenkins
Brenda Jenkins 5pts

Thank you Ayurveda! I have learned so much from social media how to live a healthy lifestyle!

Ayurveda 5pts

Thank you Lynda Cannon :)

Ayurveda 5pts

That's great Brenda Jenkins :)

Brenda Jenkins
Brenda Jenkins 5pts

I dont take any medicine! Only natural remedies for me!

Ladell Dodge
Ladell Dodge 5pts

Thank the Lord that none of my doctors have prescribed any of these drugs.

Zhaqueline Walker
Zhaqueline Walker 5pts

I can't take statins and I am apart of the small percent that can't take Benadryl.