Medications That Can Affect Memory

Common prescription and over-the-counter medicines—including sleep aids, allergy pills, bladder drugs and anxiety medicines—can cloud memory in older adults. Here's what to know and what to ask.

Last reviewed: October 2026

If you or someone you love has become more forgetful, foggy or confused, it's worth looking in the medicine cabinet. Some of the most commonly used medicines can affect memory and thinking, especially in older adults. The good news: medication-related memory problems are often reversible once the cause is found.

The National Institute on Aging (NIA) advises doctors evaluating memory problems to review all prescription and over-the-counter medicines and supplements, and to reassess the need for anticholinergics, antihistamines, narcotics, sedatives and benzodiazepines. Families can help by bringing a complete list to every appointment.

Why older adults are more sensitive

With age, the liver and kidneys clear drugs more slowly, body composition changes, and the brain becomes more sensitive to medicines that affect brain chemicals. Many older adults also take several medicines at once, which raises the chance of side effects and interactions. A dose that was fine at 50 may cause confusion at 80.

Medicines to know about

The American Geriatrics Society (AGS) Beers Criteria—a widely used guide listing medicines that may be inappropriate for older adults—highlights several groups that can affect thinking.

1. Strongly anticholinergic medicines

These block acetylcholine, a brain chemical important for memory. Examples include:

Some allergy and sleep aids, such as diphenhydramine (found in many "PM" products) and chlorpheniramine
Some bladder-control drugs for overactive bladder, such as oxybutynin
Older tricyclic antidepressants, such as amitriptyline
Some muscle relaxants and stomach or nausea medicines

The Beers Criteria notes that diphenhydramine is highly anticholinergic, and that cumulative exposure to anticholinergic drugs is associated with an increased risk of falls, delirium and dementia. It recommends considering a person's total anticholinergic burden.

2. Benzodiazepines

Medicines such as alprazolam, lorazepam, diazepam and temazepam, used for anxiety or sleep. According to the Beers Criteria, older adults are more sensitive to these drugs, and all benzodiazepines increase the risk of cognitive impairment, delirium, falls, fractures and car crashes in older adults.

3. "Z-drug" sleeping pills

Zolpidem, eszopiclone and zaleplon have side effects similar to benzodiazepines in older adults—delirium, falls and fractures—with only minimal improvement in sleep, per the Beers Criteria.

4. Opioid pain medicines

Opioids can cause drowsiness and confusion, and MedlinePlus lists overuse of medicines such as opioids, barbiturates and sleeping pills among causes of memory loss. Pain still needs treatment—untreated pain can also worsen thinking—so this is a balance to discuss with a doctor.

5. Other medicines that can contribute

Depending on the person, these may also play a role:

Some antipsychotics and anti-seizure drugs
Corticosteroids (like prednisone) at higher doses
Certain blood pressure medicines if they drop blood pressure too low, causing dizziness and fogginess
Diabetes medicines if they cause low blood sugar
Long-term acid reducers or metformin, which can lower vitamin B12—see Vitamin B12 Deficiency and Memory

Warning signs

Talk with a doctor or pharmacist if memory or thinking changes:

Started or worsened after a new medicine or dose change
Come with drowsiness, dizziness, unsteadiness or falls
Appear suddenly—sudden confusion can be delirium, which needs prompt medical attention
Include dry mouth, constipation, blurred vision or trouble urinating (common anticholinergic effects)

What to do: a "brown bag" review

Gather everything—prescriptions, over-the-counter medicines, vitamins, herbal supplements, eye drops, creams and sleep aids—into a bag.
Bring it to the doctor or pharmacist and ask for a full review.
Ask these questions:
Could any of these be affecting memory or thinking?
Is each medicine still needed? Is the dose right for my age and kidney function?
Are there safer alternatives?
Do any of these interact with each other?
Use one pharmacy when possible, so interactions are easier to catch.
Keep an updated medication list in your wallet or phone.

Never stop medicines suddenly

Do not stop or change any prescribed medicine on your own. Some drugs—especially benzodiazepines, certain antidepressants, seizure medicines and blood pressure medicines—can cause dangerous withdrawal or rebound effects if stopped abruptly. Your doctor can create a safe plan to taper, switch or reduce doses.

Safer approaches to common problems

Sleep: Good sleep habits and cognitive behavioral therapy for insomnia (CBT-I) often work better long-term than sleeping pills—see Sleep and Memory.
Allergies: Ask about non-sedating options rather than diphenhydramine.
Anxiety: Counseling, exercise and other medicines may be options—see Stress, Anxiety and Memory.
Overactive bladder: Ask whether there are alternatives with less effect on the brain.

Bottom line

Many common medicines—especially anticholinergics, benzodiazepines and sleeping pills—can affect memory in older adults, and the effects are often reversible. If memory changes appear, ask for a full medication review. Talk with your doctor or pharmacist before making any changes.

Sources

Not medical advice. This article is general information, not a diagnosis or treatment plan for any individual. Talk with a doctor about your situation.

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