8 Medications That May Affect Memory: What to Know

Forgetting a name, misplacing your keys, or struggling to remember why you walked into a room can happen occasionally to anyone. But when memory problems become more frequent, it is natural to wonder what might be causing them.

Age, stress, poor sleep, certain medical conditions, nutritional deficiencies, and other factors can contribute to changes in memory. One factor that is sometimes overlooked is medication.

Some medicines can affect the brain and nervous system in ways that may cause temporary confusion, drowsiness, difficulty concentrating, or problems with memory. The risk can be greater in older adults, particularly when several medications are taken together.

This does not mean that everyone who takes one of these medicines will develop memory problems. Many of these medications are useful and necessary for treating specific health conditions. The important point is to recognize that medications can sometimes contribute to cognitive symptoms and that a healthcare professional can help determine whether a particular medicine may be involved.

Here are eight medication groups that may affect memory or other aspects of thinking.

1. Antihistamines

Antihistamines are commonly used to relieve allergy symptoms such as sneezing, itching, runny nose, and watery eyes. Some are also found in over-the-counter products used for sleep or cold symptoms.

Older, first-generation antihistamines can have anticholinergic effects. These effects may interfere with certain brain processes and can contribute to drowsiness, confusion, and problems with concentration or memory, particularly in older adults.

Examples include medications containing diphenhydramine, doxylamine, chlorpheniramine, or hydroxyzine.

One reason these medications can be easy to overlook is that some are available without a prescription. People may therefore not realize that an over-the-counter product could potentially contribute to changes in alertness or thinking.

If you regularly use an antihistamine and have noticed unusual confusion or memory problems, talk with a healthcare professional before making changes.

2. Benzodiazepines

Benzodiazepines are prescription medications commonly used for conditions such as anxiety, certain seizure disorders, and sometimes severe sleep problems. Examples include diazepam, lorazepam, alprazolam, clonazepam, and temazepam.

These medicines affect the central nervous system and can cause sedation and slowed thinking. Memory difficulties may occur in some people, particularly during or after taking the medication.

Older adults can be more sensitive to benzodiazepines. Long-term use can also lead to physical dependence, meaning that suddenly stopping the medication may cause withdrawal symptoms.

For this reason, anyone who has been taking a benzodiazepine regularly should not stop it suddenly without medical guidance. A healthcare professional can determine whether the medication remains appropriate and, if necessary, develop a gradual reduction plan.

3. Certain Antidepressants

Antidepressants are important treatments for depression, anxiety, and several other conditions. However, some antidepressants have stronger anticholinergic effects than others.

Older tricyclic antidepressants such as amitriptyline, imipramine, and nortriptyline can produce effects such as drowsiness, dry mouth, blurred vision, and cognitive changes in some people.

Not all antidepressants affect memory in the same way. The specific medication, dosage, age of the person taking it, other medications, and underlying health conditions all matter.

It is also important to remember that depression and anxiety themselves can affect concentration and memory. Therefore, noticing memory problems while taking an antidepressant does not automatically mean that the medication is responsible.

A healthcare professional can help distinguish medication effects from symptoms related to the underlying condition.

4. Sleeping Pills

Some prescription sleeping medications can affect alertness, concentration, and memory.

A commonly discussed group includes medicines known as “Z-drugs,” such as zolpidem, zaleplon, and eszopiclone. These medications are designed to promote sleep, but they can also affect the central nervous system.

Some people may experience next-day drowsiness, impaired alertness, or unusual behaviors while taking certain sleep medications.

The risk can be particularly important for older adults because sedation and impaired coordination can also increase the risk of falls.

If you regularly depend on a sleeping medication and are experiencing memory problems, discuss the situation with your doctor rather than stopping the medicine on your own.

Improving sleep habits, treating an underlying sleep disorder, and reviewing medications may sometimes be part of a broader approach to better sleep.

5. Certain Medications for Bladder Problems

Some medications used to treat an overactive bladder or urinary incontinence work by blocking acetylcholine, a chemical messenger involved in several body functions.

These medicines are sometimes referred to as anticholinergic or antimuscarinic medications.

Examples include oxybutynin, tolterodine, and similar medicines. Because acetylcholine also plays an important role in brain function, medications with anticholinergic activity can sometimes cause confusion or cognitive difficulties.

Older adults may be especially sensitive to these effects.

This does not mean that people with bladder problems should stop their medication. Instead, it may be worthwhile to have the medication list reviewed periodically, especially if new memory or concentration problems appear.

A healthcare professional may be able to discuss alternative treatments depending on the person’s symptoms and medical history.

6. Some Medications Used for Pain

Certain pain medicines can affect alertness and mental clarity.

Opioid pain medications, for example, act on the central nervous system and may cause sleepiness, dizziness, confusion, or difficulty concentrating. These effects can become more noticeable when opioids are combined with other medicines that cause sedation.

Other medications used for nerve-related pain, including some anticonvulsant medicines, can also cause drowsiness or cognitive side effects in some people.

Pain itself can interfere with sleep, concentration, and memory, so it is not always easy to determine whether a cognitive problem comes from the medication, the pain, poor sleep, or another factor.

If you experience new confusion or significant changes in alertness after starting or increasing a pain medication, contact your healthcare professional.

7. Some Antipsychotic Medications

Antipsychotic medicines are used to treat certain psychiatric and neurological conditions. Depending on the specific medication and situation, they may cause sedation, slowed thinking, or other effects on the central nervous system.

In older adults with dementia, the use of antipsychotic medications requires particular caution because this group has been associated with important risks.

However, these medicines can be appropriate and necessary for certain conditions. They should never be stopped simply because of concerns about memory without discussing the situation with the prescribing clinician.

If a person taking an antipsychotic medication develops new confusion, excessive sleepiness, or noticeable changes in thinking, a medication review may be appropriate.

8. Certain Medications for Nausea, Dizziness, or Motion Sickness

Some medications used for nausea, dizziness, or motion sickness have anticholinergic effects and can cause drowsiness or confusion.

Examples include certain medicines containing meclizine or promethazine.

These effects may be more noticeable in older adults or in people who are taking several medications with similar effects.

Because some of these products are available without a prescription, it is important to include them when telling your healthcare professional about all the medicines you take.

Even medications used only occasionally can be relevant when investigating sudden changes in alertness or memory.

Why Medication Combinations Matter

One medication may not be the only factor affecting memory. Sometimes the problem is related to the combined effects of several medicines.

Many medications can cause some degree of drowsiness or cognitive slowing. When multiple central nervous system medications are taken together, these effects may become more pronounced.

Anticholinergic medications are another important example. Taking multiple medicines with anticholinergic properties can increase the overall anticholinergic burden.

This is one reason medication reviews are particularly useful for older adults and people taking several prescription or over-the-counter products.

Other Things Can Affect Memory Too

Before assuming that medication is responsible for memory problems, it is important to consider other possible causes.

Memory and concentration can be affected by:

• Poor sleep

• Stress or anxiety

• Depression

• Dehydration

• Alcohol use

• Certain infections

• Thyroid problems

• Vitamin deficiencies

• Changes in blood sugar

• Head injuries

• Other medical or neurological conditions

Sometimes several factors occur at the same time.

For example, someone may begin sleeping poorly because of pain, take a sedating medication for the pain, and then notice that concentration is worse during the day. The medication may be part of the picture, but it may not be the only cause.

What Should You Do If You Notice Memory Problems?

If you suspect that a medication is affecting your memory, don’t immediately stop taking it.

Instead, make a list of everything you take, including:

• Prescription medications

• Over-the-counter medicines

• Vitamins

• Herbal products

• Sleep aids

• Allergy medicines

• Pain relievers

Take the list to your doctor or pharmacist and explain when the memory problems started.

It can also be helpful to note whether symptoms occur shortly after taking a particular medicine, whether they improve at certain times of the day, and whether the symptoms appeared after a dose was increased.

A healthcare professional may determine that a medication is contributing to the problem, or they may identify another underlying cause.

Never Stop Certain Medicines Suddenly

One of the most important things to remember is that stopping a medication without medical advice can sometimes be dangerous.

Certain medicines, particularly benzodiazepines and some other drugs that affect the nervous system, may cause withdrawal symptoms if stopped abruptly.

Other medications may cause health problems if treatment is suddenly interrupted.

If a medicine needs to be reduced or discontinued, a healthcare professional can determine the safest approach.

When Memory Problems Need Prompt Attention

Occasional forgetfulness is not necessarily a sign of a serious problem. However, sudden or severe changes in memory or thinking deserve medical attention.

Seek urgent medical care if confusion develops suddenly, particularly when it occurs along with symptoms such as difficulty speaking, weakness on one side of the body, severe headache, loss of consciousness, or other sudden neurological changes.

For gradual memory changes, schedule an appointment with a healthcare professional. A medication review can be an important part of the evaluation.

Final Thoughts

Medications can sometimes affect memory, concentration, alertness, or other aspects of thinking. Antihistamines, benzodiazepines, certain antidepressants, sleeping medicines, bladder medications, some pain medicines, antipsychotics, and certain medicines for nausea or dizziness are among the groups that may contribute to cognitive symptoms in some people.

The risk depends on many factors, including the particular medication, dose, duration of treatment, age, other medicines being taken, and overall health.

The goal is not to avoid every medication that could potentially affect memory. Many of these medicines are valuable treatments when used appropriately. Instead, the important step is to recognize possible side effects and have medications reviewed when new cognitive symptoms appear.

If you or someone you care for has noticed unexplained changes in memory, concentration, or alertness, speak with a qualified healthcare professional. A careful medication review may help identify whether a medicine is contributing to the problem and what options may be available.
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