Medications That Affect Memory


A variety of common medications can cause cognitive problems. If you or a loved one is experiencing such issues, be sure to evaluate all of your medications with a doctor (but don’t stop taking any of them before you do). Alternatives can be found for many of them.

In particular, a large group of medications with “anticholinergic” effects can pose a risk of cognitive impairment. These drugs block a chemical messenger called acetylcholine, which is involved in the transmission of nerve impulses in the brain. About half of the general population uses some type of medication with anticholinergic effects.

Some of these drugs, such as the common antihistamine diphenhydramine (Benadryl), are available over the counter; diphenhydramine is also an ingredient in many sleep aids such as Tylenol PM and most forms of Unisom. Other commonly used medications that have anticholinergic effects include certain treatments for anxiety, asthma, depression, overactive bladder, pain, inflammation, and Parkinson’s disease. Some sedatives and sleep medications also can cause memory problems or even accelerate cognitive decline among people with Alzheimer’s.

Risk of cognitive decline
In an older study published in The BMJ, researchers conducted cognitive assessments of 372 people over age 60 who had no signs of dementia. At the start of the study, about 14 percent were regularly using at least one anticholinergic medication.

After eight years, cognitive testing revealed that 80 percent of those taking an anticholinergic drug had signs of mild cognitive impairment, compared with 35 percent of those who weren’t. People who took anticholinergic drugs had slower reaction times and performed poorly on assessments of attention, nonverbal memory, narrative recall, language tasks, and visual-spatial construction. Overall, they were five times more likely to be mildly cognitively impaired than those who did not take the drugs.

However, when evaluated eight years after the start of the study, the two groups had similar rates of developing dementia. The researchers noted that older individuals who complain of memory or thinking problems are sometimes diagnosed with early dementia when their symptoms may actually be caused by their medication and thus may be reversible.

Your brain on sleeping pills
Sleeping pills have the potential to contribute to memory problems. This is particularly true with benzodiazepine sedatives, such as diazepam (Valium), temazepam (Restoril), lorazepam (Ativan), oxazepam, and alprazolam (Xanax). Benzodiazepines have the potential to impair episodic memory (responsible for learning new information and remembering recent events) and to slow working memory (responsible for attention, concentration, and short-term retention of information such as phone numbers or street addresses).

Other sleep medications, including zolpidem (Ambien), eszopiclone (Lunesta), and ramelteon (Rozerem), may be less likely to affect memory the next day if you get a full seven to eight hours of sleep. But some people have experienced effects such as walking, eating, or even driving while asleep during the first few hours after taking the medication—with no memory of it the next day. If you experience any of these events while taking a sleep medication, notify your doctor.

Possible good news: NSAIDs
Some evidence suggests that nonsteroidal anti-inflammatory drugs (NSAIDs) might help prevent Alzheimer’s disease. Scientists have observed that people with rheumatoid arthritis are much less likely to develop Alzheimer’s disease. Because most people with rheumatoid arthritis take NSAIDs such as ibuprofen (Advil and other brands) or naproxen (Aleve and others) to control their pain, some experts have hypothesized that these drugs might provide protection against Alzheimer’s disease by reducing inflammation in the brain.

Results from studies exploring whether such a connection exists have been mixed, however. And when NSAIDs have been given to people who already have cognitive decline, the drugs have had no effect.

Until more definitive research is done, doctors advise against taking NSAIDs in an attempt to prevent Alzheimer’s disease because the drugs can have potentially serious side effects.