Jim was starting to worry about the problems he was having with his memory. At 64, he seemed far too young to be experiencing dementia, but he was starting to forget to turn off the stove or unplug the coffeepot. When he complained to his family doctor, he was told to come in for an exam and to bring any medications he was taking with him. Jim needed a shopping bag to gather up all of the supplements, vitamins, drugs, and herbs he took each day -- several of which he learned were interacting with each other and almost certainly causing his memory problems.
Your local pharmacy's shelves are lined with purported "miracle" drugs, but a surprising number of them can turn your sharp memory into mush. In fact, about five percent of all memory problems are related to medication interactions. It's a serious problem, especially among older Americans, who are more likely to be taking several medications and supplements at once.
Many of the drugs typically taken by people over 50 can cause subtle thinking problems by themselves, but when several are taken at once, significant Alzheimer's-like problems can appear. These problems may include memory loss, absentmindedness, confusion, disorientation, and emotional outbursts. Alcohol abuse will worsen drug-related memory problems.
Opiate painkillers and drugs that act on the brain are the most common drugs that cause memory problems. Other often-used drugs that may cause or aggravate memory problems include anticholinergic medications, which are used to treat movement disorders, allergic reactions, or stomach problems, and drugs used to treat cardiovascular problems such as high blood pressure. And the Food and Drug Administration recently required makers of the popular new sleep medications to warn patients about the possibility of rare side effects including sleep-driving and sleep-eating -- in which patients who have taken one of these medications unknowingly get up and drive or eat while they are asleep but have no memory of having done so when they wake up -- after multiple reports of such effects hit the news. Even if you suspect that your memory problems may be linked to prescribed medication, however, do not discontinue use of the medication without first discussing it with your doctor.
Anticholinergic Drugs (scopolamine, atropine, glycopyrrolate)
These drugs block acetylcholine and are used to treat movement disorders (such as Parkinson's disease), irritable bowel syndrome, asthma, certain types of urinary incontinence, and other problems. Scopolamine in particular is a strong memory blocker.
Anti-epilepsy Drugs (phenytoin/Dilantin)
Drugs that are used to treat brain problems such as epilepsy are considered to be harmful to memory, as are derivatives of atropine, which typically induce amnesia. In particular, large doses of Dilantin can interfere with memory, reaction time, and thinking.
Opiates (heroin, morphine, codeine)
Natural opiates come from the opium poppy Papaver somniferum. Narcotics are made from opium and are used legally as prescription painkillers. Many of the opiates are quite capable of interfering with both short- and long-term memory and learning. Experts think these drugs interfere with memory by affecting brain chemicals including acetylcholine and norepinephrine.
While many psychoactive medications interfere with memory, different drug classes within this broad category may cause different types of memory problem. In fact, the type and extent of memory loss may vary even among the drugs within the same class. For example, one type of antidepressant that interferes with certain brain chemicals may improve memory, compared to another group of antidepressants (such as the tricyclics) that interferes with memory. Some of the psychoactive drugs that cause memory problems include:
- benzodiazepines (Valium, Xanax, Ativan, Dalmane, many others)
- neuroleptics (also known as antipsychotics: Haldol, Mellaril, etc.)
- tricyclic antidepressants
- barbiturates (Amytal, Nembutal, Seconal, phenobarbital)
ChemotherapyMild memory loss may be a potential side effect of chemotherapy. How significant a problem it is, which drugs cause it, how long it lasts, and what you can do to combat it are questions scientists are trying to answer. One Canadian study found that half of all women taking or finished with chemotherapy showed mild problems with cognition and memory. The women taking chemotherapy during the study had more significant memory problems than those who had already finished chemotherapy.
Other Chemicals and DrugsMany other drugs can cause memory problems, including:
- antibiotics (quinolones)
- high blood pressure drugs
- beta blockers (especially those used for glaucoma)
- seasickness patches
- carbon monoxide
- carbon disulfide
- excessive amounts of manganese
To learn more about the various aspects of memory, see:
ABOUT THE AUTHOR:
Richard C. Mohs, Ph.D., has been vice chairman of the Department of Psychiatry at the Mount Sinai School of Medicine and associate chief of staff for research at the Bronx Veterans Affairs Medical Center. The author or co-author of more than 300 scientific papers, Dr. Mohs has conducted numerous research studies on aging, Alzheimer's disease, and cognitive function.