Can Too Many Medications Cause Reversible Symptoms of Dementia?

Polypharmacy and Drug-Induced Cognitive Impairment

Confused, dazed and can't remember things? While these symptoms can be caused by Alzheimer's and other types of dementia, there could be another, possibly reversible, cause: medication. Too many medicines, called polypharmacy, can affect your ability to think clearly, remember, and make appropriate decisions.

Different prescription pills in pile
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Drug-Induced Cognitive Impairment

According to one study, cognitive impairment was present in 22 percent of those taking five or fewer medications, while that rate increased to 33 percent in people who took more than five medications and 54 percent in those taking 10 or more medications. A second study from that 12 percent of dementias may be related to polypharmacy. A third study found that the risk of developing delirium was more than doubled in those who were taking more than five medicines. Symptoms of mild cognitive impairment or delirium that develop when a person is taking multiple medications should always be thoroughly investigated.

High-Risk Drugs Classes

According to the journal Clinical Geriatrics, "classes of drugs with the potential to impair cognition and function in the elderly include anticholinergic drugs, psychotropic drugs, analgesics, sedative-hypnotics, and drugs with a narrow therapeutic window."

What Is Polypharmacy?

The word poly means many, and pharmacy refers to medicines. So, polypharmacy is when too many (defined as more than five in some sources and more than six in others) medications are used to treat a person. There are certainly many situations in which multiple medications are necessary and appropriate, but the use of multiple medications, especially in older adults, also has the potential for unintended negative effects.

There are several contributing factors for polypharmacy, including the following.

1. Multiple Physicians

Often, people will go to more than one doctor, such as a specialist, for different concerns. If you don't clearly communicate which medicines are being prescribed by the other doctors, or if your medical records are not accurately sent to the next physician, too many medications might be prescribed.

2. Herbs and Supplements

You should report any herbs or supplements that you're taking to your doctor. Even though they may be completely natural, they can still affect how your body absorbs the medicine and pose the possibility of interaction with medicines.

3. Self-Medicating

Some people feel that if two pills are good, four are better. Or, they borrow medicines from their neighbors for various aches and pains. Remember that mixing and self-prescribing medications can have negative results, both of not helping the problem you're hoping to address, and of causing harmful drug interactions.

4. Medicine-Dependent Culture

Particularly in our culture, it's common to look for a medicine for everything. Feeling anxious? Take a pill. Your knee hurts? Have some medicine. High cholesterol? Here's another pill. Of course, there are wonderful medicines available — and they might be the exact remedy you need. But, for some situations, there are other approaches that could be tried first, such as counseling, physical therapy or a healthier diet and exercise regimen.

5. Medication Administration Errors

For some people, taking medication properly is a challenge. It's not uncommon for people to forget that they took their medication and then take another dose, take it at the wrong time of day, take it with food when it should be without, or get the names of medications confused and take the wrong pill.

Sometimes, a medication administration system can help prevent these types of errors.

6. Over-the-Counter Medicine Usage

There are so many over-the-counter medications available without a prescription, but just like herbs and supplements, you can still take too many of these medicines, and they can also interact negatively with other medicines.

7. Hospitalizations

Sometimes extra medications are prescribed when someone is hospitalized, and they're intended for a temporary condition. But, as time goes on, those medications may never be discontinued. When you go to a follow-up doctor's appointment after a hospital stay, ask your physician to review the medications you're taking to ensure that they're all still appropriate.

8. Treating Medication Side Effects With Other Medications

This is a very common problem. For example, if a medicine has a side effect of causing constipation, a doctor may prescribe another pill instead of recommending that you exercise more, drink plenty of water and eat lots of fiber. Based on your condition, that medicine might be exactly what you need to prevent a serious complication like a bowel obstruction. But, it's also possible that for some people, non-drug approaches may resolve the problem just as effectively.

Older Adults and Medication

According to a study published in 2005 in Pharmacotherapy, 40% of older adults take more than five medications a week, and 10% take more than 10 a week.

Additionally, care must be taken with prescribing medications for older adults, because their bodies tend to respond more sensitively to medicines. Specifically, older people tend to metabolize, absorb, distribute and excrete drugs more slowly, which is why there's often a different set of guidelines and dosage recommendations for the elderly than the general population.


Maintain a personal health record with all of your medications listed, as well as a diagnosis for each medicine. If you don't know why you're taking a medicine, ask your doctor. When you go to a physician, bring your record with you.

Medical practitioners are encouraged to "start low and go slow" with medications, as well as to pay attention to medicines that are on the Beers list, a compilation of drugs that can be potentially inappropriate for older adults.

A Word From Verywell

While medications can be very helpful and appropriate to treat certain conditions, remember that each mediation potentially has side effects the can interact with other medicines. Being aware that too many medications can create confusion and memory problems may help you identify this concern in yourself or someone you love. Don't hesitate to ask your physician about each medicine you're taking so that you both are clear on why they're necessary for your health and well-being.

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