Many Drugs Impair Memory, Know Which Ones
Problems with memory are common among the elderly, a population that also tends to take multiple medications. Many of the drugs older adults take also impair memory, which may compound existing memory challenges or even cause them.
Which drugs can cause memory problems?
When you consider the scores of over-the-counter (OTC) and prescription drugs that can interfere with memory, it may seem like an easier question to ask is, "Which drugs don't cause memory problems?" because it might be a shorter list.
Let's explore two reasons why these two questions need to be asked. One is the finding of a new international study headed by Dr. Cara Tannenbaum, associate professor of medicine and pharmacy at the University of Montreal.
The team examined which medications are most likely to have an impact on amnestic (memory) or non-amnestic (attention, concentration, performance) brain activities from four drug classes. A total of 162 experiments on drugs with the potential to cause such brain problems were investigated.
Overall, the authors found the following:
- Episodic use of various medications can cause amnestic or non-amnestic deficits. Memory or cognitive problems associated with such drug use typically is not considered in people who are otherwise in good health.
- Use of benzodiazepines (e.g., Ativan, Halcion, Librium, Valium, Xanax, and dozens more) were consistently associated with memory and concentration impairment
- Antihistamines and tricyclic antidepressants were shown to be associated with deficits in information processing and attention
The findings support the 2012 American Geriatrics Society recommendation that seniors should avoid use of all sleeping pills, first-generation antihistamines, and tricyclic antidepressants. Tannenbaum also noted that individuals have a right "to make an informed choice based on preference and a thorough understanding of the effects the medications may have on their memory and function."
Another reason why questions about drug use and memory should be asked is that much of the focus on any association between medication use and memory problems is on those known as anticholinergics.
Most of the medications that cause mild cognitive impairment, a condition characterized by short-term memory impairment and forgetfulness, also inhibit the activity of acetylcholine, a substance with a critical role in memory and brain function. Such drugs are said to have anticholinergic properties.
According to Leo Galland, MD, few drugs are officially categorized as being anticholinergics (typically antispasmodics for bladder irritation and intestinal cramps). However, "there are 17 additional types of drugs used for many other purposes that may also have anticholinergic effects," and Galland warned that "many doctors and pharmacists [and also patients] are unaware of the anti-cholinergic properties of these medications."
In Galland's list are two drug categories explored in the University of Montreal study (antihistamines and antidepressants), but there are more. Some of them are available OTC and may be combined with other drugs, most often in headache and cold and flu remedies.
Below is a partial list of drugs that may have an impact on memory or cognitive function. This list includes mostly brand names and should be viewed as a starting point to investigate whether drugs you or a loved one may be taking could have an effect on the brain.
- Antacids: Axid, Pepcid, Tagamet, Zantac
- Antiarrythmics: digoxin (generic), Norpace, Quinaglute
- Antidepressants: Aventyl, Celexa, Cymbalta, Elavil,Lexapro, Paxil, Prozac, Tofranil
- Antiemetics (to suppress nausea and vomiting): Compazine, Phenergan, Tigan
- Antihistamines: Atarax, Benadryl, Clarinex, Claritin, Contact, Tavist
- Antiparkinsonian: Artane, Cogentin, Kemadrine, Symmetrel
- Antipsychotics: Clopine, Mellaril, Serentil, Zyprexa
- Antispasmotics: Atropine, Detrol, Ditropan, Levsin, ProBanthine, VesiCARE
- Muscle relaxants: Flexeryl, Norflex, Robaxin, Soma
- Others: These drugs have an anticholinergic effect if taken at high doses or when used by people with compromised kidney function or with hypersensitivity to anticholinergic side effects. They can include antibiotics (e.g., amoxicillin, Levaquin), seizure medication (e.g., Dilantin, Tegretol), anti-inflammatory (e.g., Celebrex), narcotics (e.g., Duragesic, hydrocodone), sleeping pills (e.g., Restoril), and antidiabetes medication (e.g., Glucophage).
The bottom line
As a precaution, anyone who is taking either OTC or prescription medication (and especially anyone taking multiple drugs) should consult their healthcare provider or other knowledgeable professional about the possibility of an impact on memory or other brain functions. Many drugs can impair memory, and it pays to know them.
Galland, Leo MD. Memory loss can be caused by over-the-counter drugs.
University of Montreal