8 Medications That May Affect Memory and Cognitive Function

Memory lapses can happen for many reasons. Stress, lack of sleep, aging, medical conditions, nutritional problems, and even certain medications may affect the way the brain works.

For some people, a new medication or a change in dosage may be followed by forgetfulness, mental fog, confusion, drowsiness, or difficulty concentrating. These effects can be especially noticeable in older adults, who may be more sensitive to certain medicines and are also more likely to take several medications at the same time.

That does not mean these medicines are necessarily unsafe. Many of them are important treatments for anxiety, pain, allergies, insomnia, depression, bladder problems, and other health conditions. The goal is not to stop taking a medication without medical advice, but to recognize when a medication could potentially be contributing to changes in memory or thinking.

Here are eight types of medications that may affect memory and cognitive function.

1. Benzodiazepines

Benzodiazepines are prescription medications commonly used to treat anxiety, panic disorders, insomnia, muscle spasms, and certain seizure disorders.

Examples include:

• Alprazolam
• Lorazepam
• Diazepam
• Clonazepam
• Temazepam

These medications work by slowing activity in the central nervous system. This can produce a calming and sedating effect.

While that effect can be useful, benzodiazepines may also cause sleepiness, slowed reactions, difficulty concentrating, and problems with short-term memory in some people.

Older adults may be particularly sensitive to these effects. A person may feel unusually sleepy during the day, have difficulty remembering conversations, or appear less alert than usual.

Long-term or frequent use may require particularly careful monitoring.

If you have been taking a benzodiazepine regularly, do not stop suddenly. These medications can cause withdrawal symptoms, and discontinuing them often requires a gradual reduction under medical supervision.

2. Certain Sleeping Medications

Prescription sleeping medications can help people who struggle with insomnia, but some can also affect alertness and cognitive function.

Examples include medications such as:

• Zolpidem
• Zaleplon
• Eszopiclone

These medicines are intended to promote sleep, but their effects may sometimes continue into the following morning.

A person may wake up feeling groggy, have difficulty concentrating, or experience temporary memory problems.

The risk can be greater when a sleeping medication is taken at a higher dose, used with other sedating substances, or taken by an older adult.

If you regularly need medication to sleep, it is worth discussing the long-term plan with your healthcare professional. Improving sleep habits and addressing the underlying cause of insomnia may also be important.

3. First-Generation Antihistamines

Antihistamines are commonly used to relieve allergy symptoms such as sneezing, itching, runny nose, and watery eyes.

Some older antihistamines can cross into the brain and cause considerable drowsiness.

Examples include:

• Diphenhydramine
• Chlorpheniramine
• Hydroxyzine

These medications may cause sleepiness, slowed thinking, dizziness, and difficulty concentrating.

Some also have anticholinergic effects, meaning they interfere with the action of acetylcholine, a chemical messenger involved in several brain functions, including memory and attention.

Diphenhydramine deserves special attention because it is found in many over-the-counter allergy, cold, and nighttime products.

Because these medicines are available without a prescription, people may not realize they could contribute to cognitive symptoms.

Always check the active ingredients in combination products, particularly if you are already taking other medications that cause drowsiness.

4. Some Antidepressants

Antidepressants are widely used to treat depression and anxiety, and some are also prescribed for chronic pain, migraine prevention, or other conditions.

Certain older antidepressants, particularly some tricyclic antidepressants, can have anticholinergic and sedating effects.

Examples include:

• Amitriptyline
• Imipramine
• Doxepin

Depending on the medication and dose, side effects may include drowsiness, dizziness, dry mouth, constipation, blurred vision, confusion, or difficulty concentrating.

Amitriptyline, for example, is sometimes prescribed for nerve pain rather than depression.

This does not mean that all antidepressants cause memory problems. Different medications have very different effects.

If you notice new cognitive symptoms after beginning an antidepressant or increasing its dose, tell your healthcare professional. They can determine whether the medication may be contributing and whether an adjustment is appropriate.

5. Anticholinergic Medications for Bladder Problems

Certain medications used to treat overactive bladder can affect the nervous system because they have anticholinergic properties.

Examples include:

• Oxybutynin
• Tolterodine
• Solifenacin
• Darifenacin

These medications work by reducing involuntary bladder contractions, which can help decrease urgency and frequent urination.

However, anticholinergic activity can also affect the brain.

Possible side effects include confusion, difficulty concentrating, drowsiness, and memory problems, particularly in people who are more sensitive to these effects.

Not every person taking these medications will experience cognitive problems, and the effects can differ between drugs.

If you notice changes in memory after starting treatment for an overactive bladder, discuss the symptoms with your healthcare professional. Depending on your situation, there may be alternative treatments or approaches worth considering.

6. Some Muscle Relaxants

Muscle relaxants are commonly prescribed for muscle spasms, back pain, neck pain, and other musculoskeletal problems.

Examples include:

• Cyclobenzaprine
• Methocarbamol
• Carisoprodol
• Tizanidine

Many muscle relaxants can cause drowsiness and dizziness.

Some may also make a person feel mentally slowed or less focused.

These effects can become more noticeable when a muscle relaxant is combined with other medicines that cause sedation.

For example, taking a muscle relaxant together with a sleeping medication or certain pain medicines may increase overall drowsiness.

Older adults may be particularly vulnerable to dizziness and confusion, which can also increase the risk of falls.

If you feel unusually sleepy, confused, or mentally foggy while taking a muscle relaxant, contact your healthcare professional rather than changing the dose yourself.

7. Opioid Pain Medications

Opioids are powerful pain-relieving medicines used for certain types of moderate to severe pain.

Examples include:

• Oxycodone
• Hydrocodone
• Morphine
• Codeine
• Tramadol
• Fentanyl

Opioids can affect the central nervous system and may cause sleepiness, dizziness, slowed thinking, confusion, and impaired attention.

These effects may be more pronounced when opioids are combined with other sedating medications.

For people who need opioids for significant pain, the medications can provide important benefits. The goal is to use them carefully and under appropriate medical supervision.

Combining opioids with alcohol or other sedating substances can be particularly dangerous.

If you experience unusual confusion, extreme sleepiness, or difficulty staying awake while taking an opioid, seek medical advice promptly.

8. Some Antipsychotic Medications

Antipsychotic medications are used to treat conditions such as schizophrenia, bipolar disorder, and certain severe psychiatric symptoms.

Examples include:

• Quetiapine
• Risperidone
• Olanzapine
• Haloperidol

These medications can cause drowsiness, slowed reactions, dizziness, and changes in alertness.

In some situations, antipsychotic medicines are prescribed to older adults experiencing severe behavioral symptoms associated with dementia. Such use requires careful consideration because older adults with dementia can face increased risks from these medications.

These drugs should be taken exactly as prescribed.

If a person develops significant confusion, excessive sedation, unusual movements, or a noticeable change in behavior after starting or changing an antipsychotic medication, the prescribing healthcare professional should be contacted.

Why Medications May Affect Memory

Different medications can influence cognitive function in different ways.

Some directly slow activity in the brain. Others affect neurotransmitters involved in memory and attention. Some cause sleepiness or dizziness, making it harder to concentrate.

Anticholinergic medications are one important example.

Acetylcholine is a chemical messenger involved in memory, attention, learning, and other nervous system functions. Medications that block acetylcholine can therefore sometimes contribute to cognitive problems.

The effect is not the same for everyone.

Age, health conditions, dosage, kidney and liver function, medication combinations, and individual sensitivity can all influence how strongly a person reacts to a medicine.

Multiple Medications Can Increase the Risk

Taking several medications at the same time can make cognitive side effects more noticeable.

This is particularly important for older adults, who may take medications for blood pressure, diabetes, pain, sleep, allergies, bladder problems, and other conditions.

Even if each medication causes only mild drowsiness, their effects can sometimes add together.

For example, a person might take a sedating allergy medicine during the day and a sleeping medication at night while also using a prescription pain reliever.

The combined effects may contribute to daytime fatigue, poor concentration, dizziness, or confusion.

This is why a regular medication review can be helpful.

Signs a Medication May Be Affecting Your Memory

Medication-related cognitive changes can appear in several ways.

Possible signs include:

• Increased forgetfulness
• Difficulty concentrating
• Mental fog
• Unusual sleepiness
• Confusion
• Trouble finding words
• Slower thinking
• Difficulty following conversations
• Problems completing familiar tasks
• Increased dizziness
• Changes in alertness

The timing can provide an important clue.

If symptoms begin shortly after starting a new medication, increasing a dose, or adding another drug, mention this to your doctor or pharmacist.

However, timing alone does not prove that the medication is responsible.

Other Causes of Memory Problems

Medication is only one possible explanation for changes in memory.

Other potential causes include:

• Poor sleep
• Depression
• Anxiety
• Severe stress
• Dehydration
• Vitamin deficiencies
• Thyroid problems
• Infections
• Alcohol use
• Hearing problems
• Vision problems
• Neurological conditions
• Other medical conditions

Because there are so many possibilities, persistent memory problems should be evaluated rather than automatically blamed on medication.

What to Do If You Notice Cognitive Changes

If you think a medication may be affecting your memory, do not stop taking it on your own.

Instead, make an appointment with your doctor or speak with a pharmacist.

It can be helpful to write down:

• The medication name
• The dosage
• When you started taking it
• When the symptoms began
• Any recent dosage changes
• Other prescription medicines you take
• Over-the-counter medicines you use
• Vitamins or supplements you take

This information can help your healthcare professional identify possible medication-related problems.

Depending on the situation, they may recommend continuing the medication, changing the dosage, switching to another treatment, or investigating other causes of the symptoms.

Never Stop Certain Medications Suddenly

Some medications require gradual dose reduction.

This is particularly important with medicines such as benzodiazepines and certain other drugs that can cause withdrawal symptoms when stopped abruptly.

Stopping a medication suddenly can sometimes be more dangerous than the side effect you are trying to prevent.

Always ask your healthcare professional how a medication should be reduced or discontinued.

How to Lower the Risk of Medication-Related Memory Problems

There are several simple steps you can take to make medication use safer.

Keep a Current Medication List

Maintain an up-to-date list of everything you take, including prescriptions, over-the-counter products, vitamins, and supplements.

Bring the list to medical appointments.

Review Your Medicines Regularly

Ask your doctor or pharmacist whether every medication is still necessary and whether the current dose remains appropriate.

This is particularly important if you take multiple medications.

Be Careful With Over-the-Counter Products

Some allergy, cold, and sleep products contain ingredients that can cause drowsiness or confusion.

Read labels carefully and ask a pharmacist if you are unsure.

Avoid Mixing Sedating Substances

Combining alcohol with certain medications can increase drowsiness and impair thinking.

Likewise, combining several sedating medicines without professional guidance can increase the risk of serious side effects.

Report New Symptoms

If you develop confusion, unusual sleepiness, dizziness, or memory problems after starting a medication, tell your healthcare professional.

Do not assume that the symptoms are simply part of aging.

When Confusion Requires Urgent Medical Attention

Medication-related cognitive symptoms can sometimes develop gradually, but sudden confusion requires particular attention.

A person who suddenly becomes severely confused, difficult to wake, unusually agitated, or unable to think clearly may need urgent medical evaluation.

Emergency care may be necessary if confusion occurs alongside:

• Difficulty breathing
• Loss of consciousness
• Seizures
• Severe weakness
• Sudden difficulty speaking
• Sudden facial drooping
• Sudden loss of balance
• A severe or unusual headache

Sudden cognitive changes can have many causes, some of which require immediate treatment.

Frequently Asked Questions

Can medications cause memory loss?

Yes. Certain medications can cause confusion, drowsiness, difficulty concentrating, or memory problems. The risk depends on the medication, dosage, duration of treatment, age, health conditions, and other medicines being taken.

Which medications are most likely to affect memory?

Medications with strong sedating or anticholinergic effects are among those that may interfere with memory and concentration. Examples include certain benzodiazepines, sleeping medications, older antihistamines, some antidepressants, bladder medications, muscle relaxants, opioids, and antipsychotics.

Should I stop taking my medication if I notice memory problems?

No. Do not stop a prescription medication without speaking with your doctor or pharmacist. Some medications need to be reduced gradually, and suddenly stopping them can cause withdrawal symptoms or worsen the condition being treated.

Can over-the-counter medicines affect memory?

Yes. Some nonprescription allergy, cold, and sleep medications can cause drowsiness or cognitive problems, especially in older adults.

Can medication-related memory problems be reversed?

Sometimes. If a medication is contributing to cognitive symptoms, the problem may improve after a healthcare professional adjusts the dose, changes the medication, or safely discontinues it. However, improvement depends on the individual and the underlying cause.

Does taking several medications increase the risk?

It can. When multiple medicines have sedating or anticholinergic effects, their effects may add together and increase the likelihood of confusion, drowsiness, or difficulty concentrating.

Are memory problems always caused by medications?

No. Memory changes can result from many conditions, including poor sleep, depression, anxiety, nutritional deficiencies, infections, thyroid problems, and neurological disorders.

Final Thoughts

Certain medications can affect memory and cognitive function, particularly those that cause sedation or have anticholinergic effects. Benzodiazepines, some sleeping pills, older antihistamines, certain antidepressants, bladder medications, starting a medication or changing its dosage, talk with your doctor or pharmacist. A careful medication review can help determine whether the medicine is contributing to muscle relaxants, opioids, and antipsychotic medicines are among the drug groups that may contribute to confusion, forgetfulness, or difficulty concentrating in some people.

However, a medication that can affect memory is not automatically a medication that should be avoided. Many of these medicines provide important benefits and may be the best treatment for a particular condition.

If you notice new memory problems after starting a medication or changing its dosage, talk with your doctor or pharmacist. A careful medication review can help determine whether the medicine is contributing to the problem or whether another health issue may be responsible.