Most people assume that if they begin to have memory problems it is either “natural” aging or bad luck. If a relative had Alzheimer’s disease, forgetfulness and dementia are blamed on genetic factors. But what if medications could be contributing to the epidemic of cognitive impairment that is affecting millions of people? This reader wants to know if such side effects are reversible:
Q. I’ve begun having some memory problems and they’ve made it difficult at times to function. Sometimes I forget how to use equipment I’ve used hundreds of times, or I have trouble with math that has always been easy for me.
I’ve taken many anticholinergic drugs over the years (antidepressants, tranquilizers, incontinence drugs, allergy drugs). I am just learning that these drugs could lead to cognitive difficulties.
There is a strong history of dementia in my mother’s family, and I have fears that some of the damage may be irreversible. Do you have any information that will help?
A. You need a thorough work-up to rule out obvious contributors to mild cognitive impairment such as thyroid problems or vitamin deficiency. This should also include a review of your current medications to minimize exposure to drugs that could affect your mental clarity.
Medications That Can Cause Memory Problems:
It has come as a great shock to both health professionals and patients to learn that some of the most commonly prescribed drugs in the pharmacy can cause cognitive impairment or dementia. As this reader notes, anticholinergic drugs can include allergy medications, antidepressants, anti-anxiety agents (benzodiazepines), and incontinence drugs. But that is only a partial list. Here is a quick overview:
Researchers call the chemicals that make nerve cells function, neurotransmitters. Acetylcholine (ACh) is one of those crucial neurochemicals. It is responsible for muscle contraction. Without adequate amounts of ACh you wouldn’t be able to type on a keyboard, hold a pencil, breathe or blink. ACh is also essential for cognitive functioning and memory.
Medical students, pharmacy students, nursing students and physician assistants are all taught about anticholinergic drugs. Sadly, the training is often woefully inadequate.
Classic Anticholinergic Medications:
When health professionals are taught about classic anticholinergic drugs they learn about deadly nightshade, i.e., belladonna. Chemical cousins, atropine, hyoscyamine and scopolamine were all derived from the plant Atropa belladonna. These drugs dry up secretions throughout the body by blocking the action of ACh on neurons. They also slow or diminish muscle contractions.
Atropine has been used to slow digestive tract motility and ease symptoms of diarrhea. You may recognize the brand name Lomotil which contains both atropine and diphenoxylate. Doctors have prescribed anticholinergic drugs for gastritis, colitis and diverticulitis.
Incontinence and Overactive Bladder:
A side effect of anticholinergic drugs like atropine and scopolamine is urinary retention. In other words, it becomes harder to empty the bladder when someone is taking an anticholinergic medication. Drug companies have turned this side effect into a “benefit” by developing a number of medications with anticholinergic activity and promoting them for overactive bladder. Such drugs include oxybutynin (Ditropan), tolterodine (Detrol) and fesoterodine (Toviaz).
Asthma, Bronchitis, COPD (chronic obstructive pulmonary disease):
Remember that we said anticholinergic drugs dry up secretions. They also ease some respiratory symptoms by opening constricted airways. Healers have used the smoke from plants containing atropine to help people with breathing problems for hundreds, if not thousands, of years. Learn more about the old-timey uses of marijuana, stramonium and belladonna to treat asthma at this link. Examples of modern anticholinergic drugs include ipratropium (Atrovent) and tiotropium (Spiriva).
Another common side effect of anticholinergic drugs is drowsiness. People who take Benadryl (diphenhydramine) for allergies or Dramamine (dimenhydrinate) for motion sickness are familiar with this common complication. Drug companies have taken advantage of this adverse reaction by putting diphenhydramine in lots of OTC sleeping pills and PM pain relievers. Here is just a partial list of OTC drugs that may contain diphenhydramine:
Advil PM, Aleve PM, Bayer PM, Excedrin PM, Nytol, Simply Sleep, Sominex, Tylenol PM and Unisom.
Unexpected Sources of Anticholinergic Activity:
As mentioned above, most health professionals should know by now that drugs like atropine, scopolamine (for motion sickness) and diphenhydramine have strong anticholinergic activity that can affect memory and cognitive function. What they may not realize is that there are great many other drugs that also affect ACh action at nerve endings.
There are a number of antidepressants that have significant anticholinergic activity (amitriptyline, desipramine, doxepin, imipramine, nortriptyline, paroxetine, etc). The antihistamine chlorpheniramine is found in dozens of allergy medications.
Antipsychotic drugs such as chlorpromazine, prochlorperazine and olanzapine (Zyprexa) also have anticholinergic activity. Drugs for dizziness like meclizine (Antivert) are included in this category along with the codeine, cimetidine (Tagamet) and the diuretic furosemide (Lasix). People with heart problems should NEVER stop Lasix because it can lead to a life-threatening buildup of fluid.
The Anticholinergic Body Burden:
You may not be able to avoid all such drugs, but the more medicines someone is taking with anticholinergic activity the greater the risk of memory problems. The longer such drugs are taken the greater the risk of memory problems.
It is not known whether the anticholinergic effect is totally reversible. A new study published in the journal Cerebral CORTEX (online, June 16, 2016) gives us pause. The researchers studied the impact of “cholinergic dysfunction” on the brains of mice. By blocking the action of ACh in an effort to mimic the impact of anticholinergic drugs the researchers wanted to see what happened in their rodent model. They found that without adequate ACh, brain cells died and that learning and memory were affected.
A primary author of the study was quoted:
“We demonstrated that in order to keep neurons healthy you need acetylcholine…So if acetylcholine actions are suppressed, brain cells respond by drastically changing their messenger RNAs and when they age, they show signs of pathology that have many of the hallmarks of Alzheimer’s disease.”
You can listen to a short interview with Dr. Shelly Gray as she describes her research on this topic that was published in JAMA Internal Medicine. Here is a link to the free streaming audio of the show or the MP3 or CD.
You need to make sure your physician knows which of your medications has anticholinergic activity so you can lower the anticholinergic burden that is being placed on your brain.
To help you with that process, here is a link to our Guide to Older People with a list of anticholinergic drugs and other medications that are considered inappropriate for older people. You may want to take it with you to your next doctor’s appointment.