10 Drugs That May Cause Memory Loss
by Dr. Armon B. Neel Jr. for AARP: Are you having trouble remembering things? One of these meds may be the problem.For a long time doctors dismissed forgetfulness and mental confusion as a normal part of aging. But scientists now know that memory loss as you get older is by no means inevitable. Indeed, the brain can grow new brain cells and reshape their connections throughout life.Most people are familiar with at least some of the things that can impair memory, including alcohol and drug abuse, heavy cigarette smoking, head injuries, stroke, sleep deprivation, severe stress, vitamin B12 deficiency, and illnesses such as Alzheimer's disease and depression.But what many people don't realize is that many commonly prescribed drugs also can interfere with memory. Here are 10 of the top types of offenders.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).How they can cause memory loss: Benzodiazepines dampen activity in key parts of the brain, including those involved in the transfer of events from short-term to long-term memory. Indeed, benzodiazepines are used in anesthesia for this very reason. When they're added to the anesthesiologist's cocktail of meds, patients rarely remember any unpleasantness from a procedure. Midazolam (Versed) has particularly marked amnesic properties.Alternatives: Benzodiazepines should be prescribed only rarely in older adults, in my judgment, and then only for short periods of time. It takes older people much longer than younger people to flush these drugs out of their bodies, and the ensuing buildup puts older adults at higher risk for not just memory loss, but delirium, falls, fractures and motor vehicle accidents.If you take one of these meds for insomnia, mild anxiety or agitation, talk with your doctor or other health care professional about treating your condition with other types of drugs or nondrug treatments. If you have insomnia, for instance, melatonin might help. Taken before bedtime in doses from 3 to 10 mg, melatonin can help to reestablish healthy sleep patterns.Be sure to consult your health care professional before stopping or reducing the dosage of any benzodiazepine. Sudden withdrawal can trigger serious side effects, so a health professional should always monitor the process.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 drugsWhy 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. You might also want to explore lowering your dose (the side effects of antidepressants are often dose-related) or switching to a selective serotonin/norepinephrine reuptake inhibitor (SSRI/SNRI). Of the drugs in this category, I find venlafaxine (Effexor) to have the fewest adverse side effects in older patients.5. Narcotic painkillersWhy 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 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.Talk with your doctor or other health care provider about whether tramadol (Ultram), a nonnarcotic painkiller, might be a good choice for you. In my practice, I often recommend supplementing each 50 mg dose with a 325 mg tablet of acetaminophen (Tylenol). While there are prescription drugs that combine tramadol and acetaminophen, these products have only 37.5 mg of tramadol, and in my practice I've found that patients generally need the larger dose.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.