Drugs That Cause Memory Loss (& what you can do)

Edited and medically reviewed by Patrick Alban, DC | Written by Deane Alban

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There are many kinds of prescription drugs and OTC medications that cause memory loss. See if any drugs you take are on our lists.

According to Harvard University, prescription drugs cause over 128,000 deaths per year in the United States. (1)

Shockingly, this does not count deaths in nursing homes — an estimated additional 350,000 deaths annually. (2)

Adverse drug reactions are now the fourth leading cause of death in the US and the fifth leading cause of death in Europe. (3, 4)

More emergency room visits result from prescription medications than from illicit drugs, alcohol, and recreational drug use combined. (5)

It’s very clear that medications carry significant risks and one of the most common risks is memory loss.

The 3 Worst Categories of Prescription Drugs for Memory Loss

If you are taking any prescription medication that is affecting your memory, it likely falls into one of three major categories of drugs known to cause memory loss and other cognitive problems: anticholinergics, sleeping pills, or cholesterol-lowering drugs.

Here’s an in-depth look at each.

1. Anticholinergics: The “Anti” Drugs

Acetylcholine is the primary neurotransmitter of memory and learning.

When you’re low in acetylcholine, you become forgetful and can’t concentrate.

You may struggle to find the right words when you speak.

Acetylcholine deficiencies are associated with dementia and Alzheimer’s; medications for these disorders work by preventing the breakdown of acetylcholine in the brain. (6)

Drugs that block the action of acetylcholine are known as anticholinergics.


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It’s easy to pick out many drugs that are anticholinergics because their common names start with “anti” as in:

  • antacids
  • antiarrhythmics
  • antibiotics
  • anticonvulsant
  • antidepressants
  • antiemetics
  • antihistamines
  • antihypertensives
  • antipsychotics
  • antispasmodics

Common side effects of anticholinergic drugs include:

  • blurred vision
  • confusion
  • constipation
  • difficulty urinating
  • dry mouth
  • lightheadedness
  • loss of bladder control

Low acetylcholine can lead to a cluster of symptoms that resembles dementia, including mental confusion, brain fog, incoherent speech, delirium, blurred vision, memory loss, and hallucinations.

Anticholinergic Drugs and Seniors

The side effects of anticholinergic drugs are more pronounced in seniors due to the natural decline in acetylcholine production that occurs with age.

The increased risk of dementia from anticholinergic drugs is significant — around 30%. (7)

Sadly, the use of anticholinergic drugs is known to increase the risk of falls and all-cause mortality (i.e., death) in the elderly. (8)

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Anticholinergic Drug Lists

Rather than list all of the drugs known to be anticholinergic here, we’ve assembled a few reputable anticholinergic drug lists.

You can take a look at the list created by PeoplesPharmacy.com or download a PDF created by the Indiana University Center for Aging Research.

Not all anticholinergic drugs are equally hazardous, so these lists rate drugs by their level of anticholinergic activity — mild, moderate, or severe.

Leo Galland, MD, a renowned functional medicine pioneer, has published an extensive list of anticholinergic substances that includes drugs and herbal remedies.

Additionally, you can check all the medications you are currently taking to determine your anticholinergic burden with this online calculator.

If your anticholinergic risk is high, we urge you to bring this to your doctor’s attention.

2. Sleeping Pills

Prescription sleeping pills like Ambien, Sonata, and Lunesta are notorious for causing memory problems.

Ever since these drugs came on the market, people have been reporting “Ambien amnesia” or “Ambien blackouts” during which they have walked, eaten, and even driven their car in their sleep with no recollection of it the following day! (9)

Kirk Parsley, MD, is a physician, former Navy SEAL, and a sleep expert for the US Navy.

He found a large number of Navy SEALs were using sleeping pills and made a startling discovery while studying EEGs of their brains. (10)

Brainwave patterns showed that, under the effect of sleeping pills, these men were unconscious but not actually asleep — as if they were drunk or in a coma.

According to Dr. Parsley, this means that these men were not experiencing the restorative sleep their brains needed to consolidate new memories and to maintain and repair itself. (11, 12, 1314)

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3. Cholesterol-Lowering Drugs

Cholesterol-lowering medications might just be the single worst group of drugs for your brain.

Memory loss is now required to be listed as a side effect on the label of cholesterol-lowering drugs, like Lipitor and Crestor, known as statins.

When researchers examined the medical records of nearly a million people, they found that statin use increased the risk of memory loss four-fold. (15)

And it’s not just statins, other kinds of cholesterol-lowering drugs are also strongly linked to increased forgetfulness.

Here’s why lowering cholesterol is a problem for your brain.

One-quarter of your brain is composed of cholesterol.

Cholesterol is necessary for memory, learning, and fast thinking.

It is needed to synthesize neurotransmitters, chemicals that brain cells use to communicate with each other. (16)

So it is not such a surprise that cholesterol-lowering drugs negatively affect the brain.

You’ll probably be surprised to learn that high total cholesterol has actually been found to reduce the risk of dementia in the elderly. (17)

You read that right.

Statins have been pushed on the public because they are among the most profitable prescription drugs in the world. (18)

One in two senior men and one in three senior women are prescribed these drugs. (19)

Related —
Cholesterol-lowering drugs are not the key to ending heart disease that we’ve been led to believe. Learn what to do if you currently take statins; read “The Link Between Statins, Memory Loss & Dementia.”

And if drug companies have their way, even more people will be prescribed statins in the future.

New guidelines recommend that everyone over the age of 40 take a statin drug even if they have no history of heart disease. (20)


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More Rx Drugs That Cause Memory Loss

Richard C. Mohs, PhD, is the Chief Scientific Officer for the Global Alzheimer’s Platform Foundation.

He is the author of more than 350 scientific papers, including those involving clinical trials that led to the approval of cholinergic drugs for treating Alzheimer’s disease.

According to Dr. Mohs, additional medications known to cause memory loss include: (21)

  • barbiturates (Amytal, Nembutal, Seconal, phenobarbital)
  • benzodiazepines (Valium, Xanax, Ativan, Dalmane)
  • beta blockers (especially those used for glaucoma)
  • chemotherapy drugs
  • insulin
  • interferons
  • lithium
  • methyldopa
  • naproxen
  • painkillers (heroin, morphine, codeine)
  • Parkinson’s (scopolamine, atropine, glycopyrrolate)
  • quinidine
  • steroids

12 Common OTC Remedies That Cause Memory Loss

Not all medications that cause memory loss are prescription-only.

Many popular over-the-counter (OTC) drugs also cause memory loss by blocking the neurotransmitter acetylcholine.

These are some common OTC remedies that are anticholinergic: (22, 23, 24)

  • Advil PM (for pain and insomnia)
  • Benadryl (for allergies)
  • Claritin (for allergies)
  • Dramamine (for motion sickness)
  • Excedrin PM (for pain and insomnia)
  • Nytol (for insomnia)
  • Pepcid AC (acid reflux)
  • Sominex (for insomnia)
  • Tagamet (acid reflux)
  • Tylenol PM (for pain and insomnia)
  • Unisom (for insomnia)
  • Zantac (acid reflux)

A large study found that seniors who take OTC medications like Benadryl are at significantly increased risk for developing dementia and Alzheimer’s. (25)


woman watering flower springing from her head

Does this sound like you?

Fuzzy thinking, foggy focus, forgetfulness?

Lack of energy and drive?

Struggle to learn and make decisions?

A quality brain supplement can make a big difference.

See our MIND LAB PRO review.

Dr. Pat | Be Brain Fit

Long-term use is not required.

Memory loss from these remedies was noticeable in as little as 60 days. (26)

This is bad news for the millions of people who rely on diphenhydramine — the generic name for Benadryl — to treat allergies, colds, and insomnia. (27)

Many OTC remedies for allergies, colds, cough, sinus problems, skin irritations, insomnia, headache, and pain contain diphenhydramine.

You can find a complete list of OTC medicines that contain diphenhydramine at Drugs.com.

Minimizing Medication-Induced Memory Loss: An Expert-Recommended Plan

Are you taking any of these prescription medications?

Do you believe they are affecting your memory?

Then we recommend following the advice of Armon B. Neel, Jr, PharmD, CGP, FASCP.

He is a geriatric pharmacist who has devoted his career to guiding health professionals and older adults in the appropriate use of medication.

He has been the author of AARP’s “Ask a Pharmacist” column and is the author of the eye-opening exposé Are Your Prescriptions Killing You?

Expert-Recommended Plan to Minimize Medication-Induced Memory Loss

Take Inventory

Take inventory of what you are taking.

Write down every medication, dosage, and when you started taking it.

Talk to Your Doctor

Talk to your doctor about what you are taking, how much you are taking, and why you are taking it.

If you have more than one physician, have this conversation with each of them.

Find Non-Drug Approaches

Ask if there are any non-drug approaches you can use instead.

Find out the consequences of stopping any medication.

Can Medications Be Eliminated?

If there are any medications that can be eliminated, discuss a plan for stopping them and follow the plan.

Talk to Your Pharmacist

You should always get all your medications filled by the same pharmacy.

Talk to your pharmacist about everything you take to make sure there are no known interactions.

In the meantime, you can check for interactions right now using one of the online drug interaction checkers in our Mental Health Resources Guide.

Read This Book

Read Are Your Prescriptions Killing You?.

Reviewers on Amazon call it “indispensable knowledge” and “a lifesaver.”

Find a Consultant Pharmacist

If you are a senior, consider enlisting the help of a senior care pharmacist.

Senior care pharmacists are specially trained to review their patient’s medications to ensure appropriate, effective, and safe use.

You can find one in your area through the American Society of Consultant Pharmacists.

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Lastly, use the lifestyle advice you find here on Be Brain Fit.

Even if you must stay on your medication, you can help your brain by taking proactive steps such as:

  • Getting the sleep and physical exercise your brain needs
  • Managing your stress
  • Taking the right brain supplements

If you regularly take an OTC medicine for allergies, pain, insomnia, or acid reflux, get serious about switching to natural remedies which can provide relief — without increasing your risk of dementia.

Give your brain the healthiest possible environment to stay mentally sharp — in spite of your medications.

Drugs That Cause Memory Loss: Take the Next Step

Prescription medications are a double-edged sword.

Obviously, they are sometimes needed, but doctors are often too eager to write prescriptions for drugs that can affect your memory and other cognitive skills.

Become an educated patient and understand exactly what you are taking, why you are taking it, and the risks involved.

Be proactive about talking to your doctor and your pharmacist if you believe your prescriptions, or OTC remedies, are causing your memory loss.