Dementia is an overall term for diseases and conditions characterized by a decline in memory, language, problem-solving and other thinking skills that affect a person’s ability to perform everyday activities. Memory loss is an example. Alzheimer’s is the most common cause of dementia.
Causes Of Dementia
Dementia is caused by damage to brain cells. This damage interferes with the ability of brain cells to communicate with each other. When brain cells cannot communicate normally, thinking, behavior and feelings can be affected.
The brain has many distinct regions, each of which is responsible for different functions (for example, memory, judgment, and movement). When cells in a particular region are damaged, that region cannot carry out its functions normally.
Different types of dementia are associated with particular types of brain cell damage in particular regions of the brain. For example, in Alzheimer’s disease, high levels of certain proteins inside and outside brain cells make it hard for brain cells to stay healthy and to communicate with each other. The brain region called the hippocampus is the center of learning and memory in the brain, and the brain cells in this region are often the first to be damaged. That’s why memory loss is often one of the earliest symptoms of Alzheimer’s.
While most changes in the brain that cause dementia are permanent and worsen over time, thinking and memory problems caused by the following conditions may improve when the condition is treated or addressed:
- Depression
- Medication side effects
- Excess use of alcohol
- Thyroid problems
- Vitamin deficiencies
10 Drugs That May Cause Memory Loss
1. Antianxiety drugs
2. Cholesterol drugs
3. Antiseizure drugs
4. Antidepressant drugs
5. Narcotic painkillers
6. Parkinson’s drugs
7. Hypertension drugs
8. Sleeping aids
9. Incontinence drugs
10. Antihistamines
1. Antianxiety drugs (Benzodiazepines)
Why they are prescribed: Benzodiazepines are used to treat a variety of anxiety disorders, agitation, delirium and muscle spasms, and to prevent seizures. Because benzodiazepines have a sedative effect, they are sometimes used to treat insomnia and the anxiety that can accompany depression.
Examples: Alprazolam (Xanax), chlordiazepoxide (Librium), clonazepam (Klonopin), diazepam (Valium), flurazepam (Dalmane), lorazepam (Ativan), midazolam (Versed), quazepam (Doral), temazepam (Restoril) and triazolam (Halcion)
2. Cholesterol-lowering drugs (Statins)
Why they are prescribed: Statins are used to treat high cholesterol.
Examples: Atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor), pravastatin (Pravachol), rosuvastatin (Crestor) and simvastatin (Zocor).
How they can cause memory loss: Drugs that lower blood levels of cholesterol may impair memory and other mental processes by depleting brain levels of cholesterol as well. In the brain, these lipids are vital to the formation of connections between nerve cells — the links underlying memory and learning. (The brain, in fact, contains a quarter of the body’s cholesterol.)
A study published in the journal Pharmacotherapy in 2009 found that three out of four people using these drugs experienced adverse cognitive effects “probably or definitely related to” the drug. The researchers also found that 90 percent of the patients who stopped statin therapy reported improvements in cognition, sometimes within days. In February 2012, the Food and Drug Administration ordered drug companies to add a new warning label about possible memory problems to the prescribing information for statins.
Alternatives: If you’re among the many older Americans without known coronary disease who are taking these drugs to treat your slightly elevated LDL (“bad”) cholesterol and low HDL (“good”) cholesterol), ask your doctor or other health care provider about instead taking a combination of sublingual (under-the-tongue) vitamin B12 (1,000 mcg daily), folic acid (800 mcg daily) and vitamin B6 (200 mg daily).
3. Antiseizure drugs
Why they are prescribed: Long used to treat seizures, these medications are increasingly prescribed for nerve pain, bipolar disorder, mood disorders, and mania.
Examples: Acetazolamide (Diamox), carbamazepine (Tegretol), ezogabine (Potiga), gabapentin (Neurontin), lamotrigine (Lamictal), levetiracetam (Keppra), oxcarbazepine (Trileptal), pregabalin (Lyrica), rufinamide (Banzel), topiramate (Topamax), valproic acid (Depakote) and zonisamide (Zonegran).
How they can cause memory loss: Anticonvulsants are believed to limit seizures by dampening the flow of signals within the central nervous system (CNS). All drugs that depress signaling in the CNS can cause memory loss.
Alternatives: Many patients with seizures do well on phenytoin (Dilantin), which has little if any impact on memory. Many patients with chronic nerve pain find that venlafaxine (Effexor) — which also spares memory — alleviates their pain.
4. Antidepressant drugs (Tricyclic antidepressants)
Why they are prescribed: TCAs are prescribed for depression and, increasingly, anxiety disorders, eating disorders, obsessive-compulsive disorder, chronic pain, smoking cessation and some hormone-mediated disorders, such as severe menstrual cramps and hot flashes.
Examples: Amitriptyline (Elavil), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Sinequan), imipramine (Tofranil), nortriptyline (Pamelor), protriptyline (Vivactil) and trimipramine (Surmontil).
How they can cause memory loss: About 35 percent of adults taking TCAs report some degree of memory impairment and about 54 percent report having difficulty concentrating. TCAs are thought to cause memory problems by blocking the action of serotonin and norepinephrine — two of the brain’s key chemical messengers.
Alternatives: Talk with your health care provider about whether nondrug therapies might work just as well or better for you than a drug.
5. Narcotic painkillers
Why they are prescribed: Also called opioid analgesics, these medications are used to relieve moderate to severe chronic pain, such as the pain caused by rheumatoid arthritis.
Examples: Fentanyl (Duragesic), hydrocodone (Norco, Vicodin), hydromorphone (Dilaudid, Exalgo), morphine (Astramorph, Avinza) and oxycodone (OxyContin, Percocet). These drugs come in many different forms, including tablets, solutions for injection, transdermal patches, and suppositories.
How they can cause memory loss: These drugs work by stemming the flow of pain signals within the central nervous system and by blunting one’s emotional reaction to pain. Both these actions are mediated by chemical messengers that are also involved in many aspects of cognition. So the use of these drugs can interfere with long- and short-term memory, especially when used for extended periods of time.
Alternatives: In patients under the age of 50 years, nonsteroidal anti-inflammatory drugs (NSAIDs) are the frontline therapy for pain. Unfortunately, NSAID therapy is less appropriate for older patients, who have a much higher risk of dangerous gastrointestinal bleeding. Research shows the risk goes up with the dosage and duration of treatment.
6. Parkinson’s drugs (Dopamine agonists)
Why they are prescribed: These drugs are used to treat Parkinson’s disease, certain pituitary tumors and, increasingly, restless legs syndrome (RLS).
Examples: Apomorphine (Apokyn), pramipexole (Mirapex) and ropinirole (Requip).
How they can cause memory loss: These meds activate signaling pathways for dopamine, a chemical messenger involved in many brain functions, including motivation, the experience of pleasure, fine motor control, learning, and memory. As a result, major side effects can include memory loss, confusion, delusions, hallucinations, drowsiness and compulsive behaviors such as overeating and gambling.
Alternatives: If you are being treated for RLS, ask your doctor or pharmacist whether one of your prescription or over-the-counter medications may be the trigger. Potential culprits include many antinausea and antiseizure medications, antipsychotic drugs with tranquilizing effects, some antidepressants, and some cold and allergy medications. In this case, your RLS — and memory problems — could potentially be resolved by simply replacing the offending medication with another drug.
7. Hypertension drugs (Beta-blockers)
Why they are prescribed: Beta-blockers slow the heart rate and lower blood pressure and typically are prescribed for high blood pressure, congestive heart failure and abnormal heart rhythms. They’re also used to treat chest pain (angina), migraines, tremors and, in eyedrop form, certain types of glaucoma.
Examples: Atenolol (Tenormin), carvedilol (Coreg), metoprolol (Lopressor, Toprol), propranolol (Inderal), sotalol (Betapace), timolol (Timoptic) and some other drugs whose chemical names end with “-olol.”
How they can cause memory loss: Beta-blockers are thought to cause memory problems by interfering with (“blocking”) the action of key chemical messengers in the brain, including norepinephrine and epinephrine.
Alternatives: For older people, benzothiazepine calcium channel blockers, another type of blood pressure medication, are often safer and more effective than beta-blockers. If the beta-blocker is being used to treat glaucoma, I recommend talking with your health care professional about potentially using a carbonic anhydrase inhibitor, such as dorzolamide (Trusopt), instead.
8. Sleeping aids (Nonbenzodiazepine sedative-hypnotics)
Why they are prescribed: Sometimes called the “Z” drugs, these medications are used to treat insomnia and other sleep problems. They also are prescribed for mild anxiety.
Examples: Eszopiclone (Lunesta), zaleplon (Sonata) and zolpidem (Ambien).
How they can cause memory loss: Although these are molecularly distinct from benzodiazepines (see No. 1 above), they act on many of the same brain pathways and chemical messengers, producing similar side effects and problems with addiction and withdrawal.
The “Z” drugs also can cause amnesia and sometimes trigger dangerous or strange behaviors, such as cooking a meal or driving a car — with no recollection of the event upon awakening.
Alternatives: There are alternative drug and nondrug treatments for insomnia and anxiety, so talk with your health care professional about options. Melatonin, in doses from 3 to 10 mg before bedtime, for instance, sometimes helps to reestablish healthy sleep patterns.
Before stopping or reducing the dosage of these sleeping aids, be sure to consult your health care professional. Sudden withdrawal can cause serious side effects, so a health professional should always monitor the process.
9. Incontinence drugs (Anticholinergics)
Why they are prescribed: These medications are used to relieve symptoms of overactive bladder and reduce episodes of urge incontinence, an urge to urinate so sudden and strong that you often can’t get to a bathroom in time.
Examples: Darifenacin (Enablex), oxybutynin (Ditropan XL, Gelnique, Oxytrol), solifenacin (Vesicare), tolterodine (Detrol) and trospium (Sanctura). Another oxybutynin product, Oxytrol for Women, is sold over the counter.
How they can cause memory loss: These drugs block the action of acetylcholine, a chemical messenger that mediates all sorts of functions in the body. In the bladder, anticholinergics prevent involuntary contractions of the muscles that control urine flow. In the brain, they inhibit activity in the memory and learning centers. The risk of memory loss is heightened when the drugs are taken for more than a short time or used with other anticholinergic drugs.
Older people are particularly vulnerable to the other adverse effects of anticholinergic drugs, including constipation (which, in turn, can cause urinary incontinence), blurred vision, dizziness, anxiety, depression, and hallucinations.
Alternatives: As a first step, it’s important to make sure that you have been properly diagnosed. Check with your doctor or other health professionals to see if your urinary incontinence symptoms might stem from another condition (such as a bladder infection or another form of incontinence) or a medication (such as a blood pressure drug, diuretic or muscle relaxant).
10. Antihistamines (First-generation)
Why they are prescribed: These medications are used to relieve or prevent allergy symptoms or those of the common cold. Some antihistamines are also used to prevent motion sickness, nausea, vomiting and dizziness, and to treat anxiety or insomnia.
Examples: Brompheniramine (Dimetane), carbinoxamine (Clistin), chlorpheniramine (Chlor-Trimeton), clemastine (Tavist), diphenhydramine (Benadryl) and hydroxyzine (Vistaril).
How they can cause memory loss: These medications (prescription and over-the-counter) inhibit the action of acetylcholine, a chemical messenger that mediates a wide range of functions in the body. In the brain, they inhibit activity in the memory and learning centers, which can lead to memory loss.
Alternatives: newer-generation antihistamines such as loratadine (Claritin) and cetirizine (Zyrtec) are better tolerated by older patients and do not present the same risks to memory and cognition.
Important Information
Information contained in this article is intended to help individuals and their families become more informed about medication usage and interactions, and be better health care consumers. Any advice or information provided should not be followed in lieu of a personal consultation with a trained medical professional.
