Want to keep your brain — or the brain of someone you love — as healthy as possible?
Then it’s essential to know which commonly used medications affect brain function.
In this article, I’ll go into details regarding a type of medication that I wish all older adults knew about: anticholinergic drugs.
How Anticholinergics Affect the Aging Brain and Body
Anticholinergics are drugs that block acetylcholine, a key neurotransmitter in the body. This leads to lower brain function, which people often experience as drowsiness.
Sometimes that sedation is why people take the drugs, and a little sleepiness might sound benign. But when the brain is older, or otherwise vulnerable, these drugs can be problematic.
In fact, these literally have the opposite effect of the drugs often used to treat Alzheimer’s and other dementias. Donepezil, rivastigmine, and galantamine (brand names Aricept, Exelon, and Razadyne), for example, are designed to increase acetylcholine by blocking the brain enzyme that breaks it down.
Research has linked anticholinergic drugs to increased risk of Alzheimer’s disease, and also to hospitalizations in older adults. And the American Geriatrics Society has warned about them for years; anticholinergics are definitely on the Beer’s List of medications older adults should avoid or use with caution.
Acetylcholine is a neurotransmitter used in many other parts of the body, including the eyes, mouth, bowels, and bladder. So anticholinergic drugs commonly cause side-effects such as dry eyes, dry mouth, and constipation.
These drugs are in everything from allergy medicines to muscle relaxants to painkillers. They are in many over-the-counter (OTC) medications, and they are often prescribed for a variety of common health complaints.
7 Common Types of Medication that are Anticholinergic
Here are seven common types of anticholinergic medication that older adults should avoid, or use with caution:
1. Sedating antihistamines. The prime example is diphenhydramine (brand name Benadryl), which is available over-the-counter and has strong anticholinergic activity. Non-sedating antihistamines, such as loratadine (brand name Claritin) are less anticholinergic and are safer for the brain.
2. PM versions of over-the-counter (OTC) painkillers. Most OTC painkillers, such as acetaminophen and ibuprofen (brand names Tylenol and Motrin, respectively) come in a “PM” or night-time formulation, which means a mild sedative — usually an antihistamine — has been mixed in. Ditto for night-time cold and cough medications such as Nyquil.
3. Medications for overactive bladder. These include bladder relaxants such as oxybutynin and tolterodine (brand names Ditropan and Detrol, respectively).
4. Medications for vertigo or motion sickness. Meclizine (brand name Antivert) is often prescribed to treat benign positional vertigo. It’s also used to treat motion sickness.
5. Medications for itching. These include the strong antihistamines hydroxyzine (brand name Vistaril) and diphendyramine (brand name Benadryl), which are often prescribed for itching or hives.
6. Medications for nerve pain. An older class of antidepressant known as “tricyclics” isn’t used for depression that much any longer, but it’s still used to treat pain from neuropathy. (These are also prescribed to reduce the chance of chronic nerve pain after shingles.) Commonly-used tricyclics include amitriptyline and nortriptyline.
7. Muscle relaxants. These include drugs such as cyclobenzaprine (brand name Flexeril) and they are often prescribed for back or neck pain.
Also anticholinergic is the SSRI-type anti-depression/anxiety drug paroxetine (brand name Paxil), which is why geriatricians almost never prescribe this particular SSRI. However, other SSRIs, including escitalopram, citalopram, and sertraline (brand names Lexapro, Celexa, and Zoloft, respectively) are not anticholinergic, which is why SSRIs aren’t on the list above.
Many more medications have strong anticholinergic effects, but they tend to be prescribed less often. Ask your doctor or pharmacist if you want help spotting all anticholinergics you might be taking.
Who Should Avoid Anticholinergics?
You should especially avoid or minimize anticholinergics if you:
- Are worried about your memory,
- Have been diagnosed with mild cognitive impairment or dementia such as Alzheimer’s disease, or
- Want to reduce your risk of developing Alzheimer’s.
How to Reduce Brain Risk Due to Anticholinergics
For a longer list of anticholinergics that your older relative might be taking, I recommend this list, which specifies whether the drugs have “definite” anticholinergic activity versus “possible.” You’ll want to focus on identifying and minimizing drugs in the “definite” category.
To date, several research studies have reported a concerning association between cumulative lifetime dosing of anticholinergics and dementia risk. (See Anticholinergic Drug Exposure and the Risk of Dementia and here’s one specific for bladder drugs.)
For more help identifying and reducing anticholinergic drugs, you can also ask your doctor or pharmacist.
If you find that you or your older relative is taking an anticholinergic drug, don’t panic. But do plan on reviewing the benefits and risks with the doctor soon. You may be able to reduce the dosage of these risky drugs, switch to a safer medication, or try a non-drug treatment instead.
For more on medications that affect brain function, see 4 Types of Medication to Avoid if You’re Worried About Memory.
I also provide more on reducing risky medications here: Deprescribing: How to Be on Less Medication for Healthier Aging.
Hi Leslie thank you for your wonderful articles. Can any memory/neurological damage from cholinergics be reversed? I am a 52 year old and have been taking benadryl regularly for 20 years for idiopathic anaphylaxis and have recently noticed a marked decline in my memory, can i reverse some of the damage done?
Thank you
Congrats on being proactive in addressing your brain health. I’m not aware of any proven ways to reverse the “damage” from taking anticholinergics during one’s 30s and 40s, I don’t even know that we have a lot of research on the long-term effects of anticholinergics on the brain at that age.
What we do know is that the hormonal changes associated with perimenopause and menopause do affect women’s memory, and may have implications for later cognitive aging or other more significant forms of cognitive decline. There has also been a lot of research done on the effect of estrogen on cognition, but for now, it’s not clear to me how one might determine whether to give a woman estrogen (what kind of estrogen is given gets tricky) to protect and improve cognition:
Estradiol and cognitive function: Past, present and future
I don’t personally provide medical care to women who are as young as you are, but if you are concerned about your memory, you may want to consult with someone who does specialize in menopause and women’s health, they might be able to give you more specific advice, or perhaps even enroll you in a trial. I would also recommend getting evaluated for other common contributors to subjective and objective memory problems in people your age, as there are other medical problems that can affect memory and brain function.
If you can manage without taking benadryl, or with less of it, that’s probably safer for your brain. Good luck!
I hope you are still getting notifications on this comment. I’m 57 now and took Benadryl intermittently in my 20s and 30, but began taking it daily when I started taking care of an elderly relative who was a smoker. That made my allergies go wild. I’ve been having problems with recall and short term memory. I’ve cut out 3/4ths of my Benadryl but just replaced it with Claritin. I’d also been taking Trazadone at night, but I just cut that in 1/2. I also take Seroquel but stopped that 2 months ago now. My mood has brightened and I can think and remember things better already. My guess is that my brain functions better just from having more choline active. I started researching this subject in December which was the first time I learned about the dangers of anticholinergics such as Benadryl. I have chronic pain and major depressive disorder and when I’m depressed I can’t sleep. That’s why I take Trazadone, Seroquel, and Benadryl nightly. My Dr is aware I’ve been taking these meds long term but hasn’t warned me. I hope you’re doing well and can give an update.
Hi Brandon, I’m glad you found the article informative. It’s great that you are taking an interest in your medications and your brain health, which is important at any age.
I see many patients in my practice that are living with pain and major depression, and the medications used to treat these conditions can have anticholinergic side effects. Despite that, many people need to be on some anticholingeric medications long term, in order to be able to manage their symptoms.
The approach that I use in working with my patients is:
1. Try to find an alternative to an anticholinergic medication that has more favourable properties
2. Try to use the lowest dose possible of an anticholinergic medication
3. When symptoms have been well controlled for a while, try to reduce the dose or discontinue the medication
4. Optimize other treatment modalities, such as exercise, counselling, developing a strong support network, and eating healthy foods
Thanks again for reading the article, and best of luck to you.
Hello, my father of 74yrs old was walking perfect and holding a cup perfectly three months ago. He had a shoulder replacement 4 months ago. Now he has no sensation in his hands, and not hold a cup, or be able to eat properly. He can not even stand up by himself or walk he has fallen 15 times. He suffers from mild Dementia and is on Donepezil. He also suffers from arthritis and recently had an Mri of his back and fold some sciatic on his lower back. Our main concern is why did all of a sudden in a short period of time he lose his ability to walk and use his hands. We are worried and sadden that he is going through this. We have little sources 🙁
Sorry to hear about your father’s condition. It does sound worrisome. It is quite common for older adults to experience some delirium and confusion related to surgery, and this can take weeks or months to fully clear up. Being bedbound for a few weeks can also leave older adults with very diminished strength, which can lead to falls.
However, all of this isn’t usually associated with losing sensation in the hands or becoming unable to hold a cup. Those are true neurological changes, and so I would recommend asking your usual health provider for help evaluating them. It might also make sense to see a neurologist. Good luck!
Thank you so much. We are planning to talk to his MD and suggest and refer my dad to see a neurologist. Thank you again. Have a beautiful day.
R. Santos
I am a 73 year-old physically active male. My only prescription medicationI is 100mg/25 mg of Lozartan HCTZ in the morning, After discovering the risks of dementia from anticholinergics four months ago I weaned myself off of 50 mg of Doxepin after taking it for 25 years for insomnia. I’ve tried several “natural sleep aids” and followed the gamut of environmental and behavioral strategies, but still can’t remain asleep more than 4-5 hours. No problem getting to sleep, but pain from chronic sciatica and the need to urinate contribute to awakening me. The only thing that seems to help me get back to sleep is 25 mg of acetaminaphen PM. Yes, another anticholinergic, the very thing I’m trying to avoid (although I worry that the the damage is already baked in). I feel like I’m caught between a rock and a hard place, because I need my sleep. Any suggestions?
Hi Dale. Dr Kernisan has a great article about sleep which you can read here. It is natural for older adults to need less sleep, in general, than younger adults.
Another helpful site about sleep is mysleepwell.ca, which has a lot of information about Cognitive Behavioural Therapy for Insomnia, which can be very effective, without medication.
If a person is being woken up by pain, then it’s probably more of a pain problem than a sleep problem, and talking to your MD about pain management might be more effective than trying to find the ideal sleeping pill. Good luck.