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Common anticholinergic drugs like Benadryl linked to increased dementia risk

January 19, 2022
  • By Harvard Health Publishing Staff, Harvard Health

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Harvard Health Publishing Staff, Harvard Health

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March 27, 2015

Took a look at the study
The diffence between the people that were in the non users and heavy users is massively different. 3x higher on EVERY risk factor stroke, obese, etc.. Odd this would get so much traction with the press.. Borderline irresponsible of Harvard to publish this on their blog. Nothing here even hints at causality

March 26, 2015

here is what the experts say. Also people have been taking bendryl for 70 years, over the counter for 30 years. If this was causing dementia the rates would be increasing..
Dr. Knopman said that it was “highly unlikely” that the drugs themselves were the direct cause of the dementia, adding that the ultimate underpinnings of the article have a strong biologic basis.
Anticholinergic drugs “affect the area of the brain that facilitates learning and memory, and that’s the basis of the cholinergic model of Alzheimer’s,” he said. “That pharmacologic profile probably has negligible impact on people under 60, but with people with incipient dementia, the drug probably exacerbates the symptoms.”
Dr. Knopman said the main limitation with a prospective study is an indication bias. He suggested that the use of these drugs might be because of incipient dementia, rather than the drugs themselves causing the dementia.

March 12, 2015

Trouble sleeping, especially past middle age?

Worth considering: your body makes as much melatonin as it needs but only starts to do it after the last blue light goes away in the evening — if you let it.

Blue light has a dark side – Harvard Health

You can find yellow “bug light” bulbs cheap, or amber “turtle safe” lights.

(The blue light ‘wakeful/attention’ switch is evolutionarily very, very old. Daytime sky light color — Florida protects baby turtles so they go toward the ocean instead of toward the freeway)
— or any automotive supplier has 12-volt “clearance” amber LED lights. Remember there’s a spike of blue in even “warm white” lights. You can see it.

That’s what drives the phosphor that emits the rest of the color.

Harvard University
May 1, 2012 – Light at night is bad for your health, and exposure to blue light emitted by electronics and energy-efficient lightbulbs may be especially so.

March 22, 2015

My mother has taken these drugs and she has made such a turnaround since being off of them that it amazes me…..

March 8, 2015

I’ve been taking diphenhydramine for three years, and have been noticing a definite decline in short-term memory and the ability to retrieve the word I need. Have been blaming it on the job being more stressful than it seems. Stopped taking it around Valentine’s Day when I first came across the info being discussed here. Have just in the past day or so noticed a little lifting of the fog, but I also take supplements specifically for brain, and meditate. Maybe has something to do with quicker recovery. Experience has shown me DHA has the most noticeable effect, at least at short-term. For brain I also take B Vites and ginkgo. So I don’t know that everyone would feel some recovery that quickly, or that I’ll recover completely. But I think I will, and will use my newly recovered mental powers to search out ways to enhance that recovery. So good luck all; you’re on a computer here, won’t find a more convenient way to research what you need now.

Political Cynic
March 4, 2015

May I just point out that this article, as presented, is meaningless.

54 percent increase FROM WHAT? Without knowing the relative distributions of people in control and non-control groups this tells us nothing.

Was the risk 1/100 increased to 1.5 in 100? Was it 25/100 increased to 37.5/100?

Learn how NOT to lie with statistics please…

March 8, 2015

Obviously, it was not 1/100 with an increase to 1.5/100. Far more than 1% of the population acquires dementia. You make a valid point though. I was thinking the same thing you were. If 17% of the population acquired dementia without taking the suspected drugs, and 26% of those who took the suspected drugs acquired dementia, it does lead to some suspicion though. Like you said, we need to see the exact numbers.

February 28, 2015

Hi, thanks for the informative research link. There is always the risk of any medication, and it is challenging to know which poses the greater risk-allergicic reaction, untreated depression, or insomnia.

I have read too that Melatonin is also not without risk as the hormonal effects for older folks causes problems, and that is best used as a short term reset for sleep disorders.

Gloves, face masks, good sleep hygiene, and increasing activities that improve our quality of life seem all the more necessary when faced with damage from the pharmacopeia approach to allergies, sleep disorders depression, and lack of physical conditioning. Just a thought.

Thanks for a great discussion

February 26, 2015

Recently I lost my COBRA coverage. It was very expensive but they kicked me out and the only insurance I could get is MediCal. Today I met my new primary care MD (newly minted Resident). I asked for a refill of oxazepam that I have taken for 15 years without any problem. The doctor did not want to fill it. He recommended melatonin, benadryl and Elavil. So he wanted to give me a combo of anitcholinergics. I told him I have tried each in the past with poor results. I also mentioned this research as a concern. His reply, “I have read the information”. End of discussion. He suggested I might need to find another doctor unless I want to take his Rx. Disappointing.

elizabeth kang
February 24, 2015

I believe I have an early s/s of dementia caused by the benadryl and I am scared to death at this point 2/24/15. I took 200mg Benadryl for allergies in Texas (lots, lots of allergies in TX) for about 15 years. The prescription was read, Benadryl 50mg po qid. My husband is a physician, and his friend who also is a physician whote the prescription for me after seeing an horrible allergy attack and the trip to the ER for anaphylactic episode. About 5 to 6 years later I started to noticed that I was forgeting names (but could see the face of the person in mind’s eye, just can’t bring the names up), often can’t find the things. I often don’t remember what I have done minutes before I start another project thus running the car in the garage for hours… it just wanted to warm up the car before take off but changed mind to do another project. I also left house while the eggs were boiling in the kitchen… when I came home after having a lunch with friends, the house was full of the smoke… I also not showing up at the dinner party which was for my honor. They said a week before and I agreed to be there.

My family has no history of dementia.
No one told me about long term use of the dementia effect from the Benadryl. I told my FPs & other specialists (when I see them for other reasons, but they do the medication inventory on new pt); they never questioned me taking such a high doeses of the Benadryl for all these years… now what should I do? I understand this is a permanent state. No way to cure it. Please help me.

March 8, 2015

What you are experiencing is not necessarily early signs of dementia. Talk to your husband more about this. I did similar things as you when I was in my twenties and thirties. I am not in my fifties and am not any worse. There can be many reasons for forgetting. Stress, fright, ADD, and medications to name a few, can all cause this to happen. I think 200 mg of benedryl is too much though. I have severe allergies myself. The allergist said I am one of his ten worst patients. I limit the benedryl to 25 mg a day though.

February 20, 2015

I’m a White Male age 77. I’ve been taking one Benadryl and 10 mg Melatonin for sleep for the last 27 years and haven’t noticed any dementia although I do read slower to fully comprehend what I read.

February 17, 2015

I have been taking Benedryl for years for insomnia. Occasionally I will take Ambien or Melatonin. I never take more than 1/2 tablet and probably average 2-3 Tylenol PM/Alieve PM a week. Any suggestions as to what to take instead? And, at 52 years, will there still be long term affects if I stop now?

February 16, 2015

Thank you for the informative article. I am worried about the medications my husband (age 81) is taking. Both over the counter (Advil PM, contains diphenylhydramine) and the prescription drugs you mentioned. He has complained about brain fog. Will double check all his medications for interactions and/or anticholinergic actions.

February 15, 2015

I have panic attacks and allergies and the best alternative to some drugs (xanax and 12/24hr. allergy pills that didn’t work). I have been taking Benedryl almost regularly for the past 5 yrs. I would take up to 4 doses a day during my allergy season and at least 1 or 2 doses every other day! My question is since I quit taking it about 2 wks ago…..will the effects be reversed or am I simply keeping the dimentia symptoms from coming on faster and harder or whatever. Will I get better and be back to me? Or am I screwed!!!!

February 12, 2015

Where does one find ACB scores for specific drugs?

February 21, 2015

Hello. The article has a link to most drugs that can be categorized A, B or C in the last paragraph. The point is that all of these drugs have some degree of “anti-muscarinic” effect. They are all anticholinergics. If your meds are not on this list, they are probably not anticholinergics. You can google your specific drugs and just read to see if any of them are anticholinergics. This is the key word: anticholinergic.

February 10, 2015

Your information is really useful and interesting..Thanks for sharing this great article…

February 1, 2015

These results and understandings on the detriment to memory by many commonly prescribed and over the counter medicines is just beginning to be written up in medical literature. Your family physician might not be aware of the information. Print this and other articles and bring them with you to the doctor. Ask your doctor to look into these findings. Changing medications is a viable alternative, and in some cases discontinue using others. You are your own best advocate for health and well being. Doctors are well learned and intelligent- but that doesn’t mean they always know what is best for you and your loved ones. In the end you are in charge of your own body and possibly the body of someone who relies on you to be their eyes and ears.

February 3, 2015

And I like to find the physician that will take the time to actually go through this bag of meds. We are lucky to get face to face time with the physician for more than 8 minutes and to answer one or two of our questions…..

January 31, 2015

I still believe that it’s Diabetes of the brain.
January 30, 2015

I would like to promote my Video on Vimeo about water scarcity around the world and the humanitarian crises in Sudan.
HALEEMA was screened on countless festivals and is now available on Vimeo.

Mont. E. Python
February 8, 2015

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January 29, 2015

Do the researchers have any advice for those already suffering from dementia? My wife has dementia, and just last week I questioned her urologist about the medications she was taking. He said they were standard and effective drugs to help control her bladder. After seeing this article, I checked lists of anticholinergic drugs and found imiprimine, one of the drugs she takes, on the list. Is this likely to make her mental condition worse?

February 1, 2015

I don’t know about researchers, but I know from my own experience about my mother suffering dementia and being on lots of anticholinergic drugs (including oxibutinine, an incontinnece drug), for many many years, that discontinuing the drugs can ameliorate dementia symptoms and in some extent halt its progress. Doctors are however reluctant to admit this and to advice drug discontinuation (I discontinued all of my mom drugs and found out they were doing no good at all: actually incontinence problems were caused by another anticholinergic drug from the benzodiazepines family. I am not in the US or Europe where probbaly I could face legal problems by not following Drs instructions).

February 1, 2015

Posted a reply but I don’t see it

Haym Solomon
January 29, 2015

Perhaps one should consider that Parkinson’s and other Dementia- spectrum diseases have an early symptom of not being able to get to sleep. That being said, did the research consider that study participants might self medicate for insomnia ….years before the onset of Dementia , or recognition and diagnosis by a health care provider? Cart or the Horse?

March 8, 2015

Yes, that’s mentioned in the sixth paragraph.

January 29, 2015

The information is useless unless the specific drugs are named. My husband has Parkinson’s, which drug should he not be taking and what is the substitute? Is there any place other than Harvard where I could find out more?

John Traylor
January 30, 2015

My wife has parkinsons disease also. Would you mind sharing with me what you might have learned about which medications to take and not to take. Would appreciate your sharing any other data or experiences, or anything that might be helpful.
Thank you,
John Athens, Ga.

MH White
February 1, 2015

You can probably find out about specific drugs by asking your pharmacist. A good one may be more up-to-date about the side effects of particular drugs than physicians have time to be. Also, check the website for “The People’s Pharmacy,” the radio show. I believe they have a list in one of their books.

January 29, 2015

Scary article considering I have been using benedryl every night for sleep for the past ten years. My primary care doctor told me it’s fine and that’s why most people take the drug. My question is whether stopping will reverse the damage.

February 1, 2015

I have been taking them for sleep also for years…my doctor knew this and did not warn me of dementia side -effects either. I wonder if the damage will subside some if we stop taking them..or is the damage permanent?

February 6, 2015

I too have been taking Benadryl to help me sleep for about two years. I only take half a caplet but still very scary. Need to find something else or just not sleep, better than the alternative. Thanks for your post.

Taufiq Zuhdi
January 29, 2015

Thanks for sharing. I will wait for your writing again.

Malcolm Kyle
January 29, 2015

All of these dangerous medications can be replaced with a far healthier alternative, marijuana.

Researchers have found that there are no differences between daily marijuana users and those using no marijuana in their use of the emergency room, in hospitalizations, medical diagnoses, or their health status.

”Researchers from Boston Medical Center (BMC) and Boston University School of Medicine (BUSM) studied 589 adults who screened positive for drug use at a primary care visit. Those patients were asked about their drug use, their emergency room use and hospitalizations, and their overall health status. In addition, information about other medical diagnoses was obtained from their medical records. They found the vast majority of the study sample (84 percent) used marijuana, 25 percent used cocaine, 23 percent opioids and eight percent used other drugs; 58 percent reported using marijuana but no other drugs. They also found no differences between daily marijuana users and those using no marijuana in their use of the emergency room, in hospitalizations, medical diagnoses or their health status.”

February 21, 2015

Hi Malcolm. I don’t doubt that you have found an article supporting your use of marijuana and it may indeed have veracity. However, chronic smoking of marijuana can have detrimental effects on the lungs; and of course smoking it can make it difficult to control the dose. I know of anecdotal accounts of marijuana helping with insomnia but I’m not sure that has been proven and paranoia is a known side effect which would, of course, inhibit sleep. I’m all for the drug being legal, but we need more data.

Commenting has been closed for this post.

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