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Medications: How Many is Too Many?

Joseph Gerald (Jerry) Reves, M.D.
May 24, 2023
Person examining the label on a medicine bottle.

This month, we tackle a challenging question about the many medicines we take as we age. How many should we be taking? The answer depends on exactly which ones are necessary. That’s the easy answer.

Often, several “right” treatments are available for a person’s particular problem or condition. Choosing one is between you and your physician. And once the correct drug is selected and the right dosage for you is determined, then you’re all set. Or are you? What if you have more than one condition or illness?

As We Age, We Have Multiple Problems

Even normal aging can bring medical problems and/or acute or chronic conditions. Each one may require one or more specific medications. This is how, as we age, we accumulate multiple medications.

It has been reported that more than a third of adults between 75 and 85 years of age take at least five prescription medications a day. As each medication is added, the risk for diminished effectiveness or appropriateness goes up along with the chance of negative interactions with the other medications you’re taking. This is particularly true with sedatives and anticoagulants. Over-the-counter medications can also affect the prescription drugs we are taking. For example, cold remedies and decongestants can interfere with sleep medications.

You and your physician must be acutely aware of the risk of taking multiple medications without close monitoring.

Polypharmacy and Aging

“Polypharmacy” is the term that describes patients’ multiple medications. Sometimes the word is used to convey the use of unnecessary medications. I would like to keep the term simple, however, and define polypharmacy as the use of multiple medicines by one person.

This brings us to the question and title of the column: “How Many Medications is Too Many?” The question can be further refined: “Does aging affect the answer to that question?”

As we age, our bodies undergo changes that can alter our reactions to prescription and over-the-counter medications.

A change in metabolism can keep our kidneys from clearing certain drugs efficiently, posing a risk of toxicity. This means that the dose needs to be reduced to avoid toxicity. An example of increased sensitivity as we age is the effect that some classes of drugs have on their receptors.

Drugs work by occupying a cell receptor, and this causes the cell to react. The same dose in a young person can have a significantly greater effect on an older person; thus, the dose must be lowered for the older patient.

Common Problems of Polypharmacy in Older Patients

The most common problems encountered with multiple prescriptions for the elderly are listed below.

Diet can affect medications. The most prominent is Coumadin’s interaction with green vegetables, which reduces Coumadin’s effectiveness. It’s important for you and your prescribing doctor to discuss your diet and potential interactions with your medications. 

One of the most common problems as we age is confusion about the medications that we’re taking. We can forget to take them or take the wrong one at the wrong time. Keeping all your medicine in one place and making a list of your medications, what they’re for, when to take them, and the dosage are essential. Checking each one as you take it can help prevent over- or under-dosing.

Anticholinergic Medications – A Special Risk

Anticholinergic medications block and inhibit the activity of acetylcholine, a neurotransmitter in the central and peripheral nervous system. Drugs with this action are used to treat a variety of conditions, including insomnia, urinary incontinence, Parkinson’s disease, gastrointestinal disorders, respiratory disease, cardiovascular disease, and motion sickness.

A large group of drugs, including over-the-counter medications, have anticholinergic effects that pose a particular risk to the elderly. Some are listed below, but there are many others. The brain and some muscles are significantly more sensitive to anticholinergic medicines, causing the medicines to have more pronounced side effects in older patients. These side effects are potentially serious in the elderly and include loss of memory, confusion, drowsiness, blurred vision, increased heart rate, urinary retention, constipation, reduced sweating, and increased falls and risk for fractures.

There is some scientific research showing that people taking anticholinergics over time (years) have major problems with the complications, including the appearance and erroneous diagnosis of dementia.

It is important to limit or eliminate the use of anticholinergic medications in the elderly. Doctors have been advised not to prescribe anticholinergic medications to geriatric patients and certainly no more than one. These medicines, however, are ubiquitous and used in the treatment of many problems in the elderly.

Many over-the-counter medicines used for itching (antihistamines) and sleep have anticholinergic effects. Thus, when one consults a physician about new or old medications, be sure to mention any of the non-prescription drugs you routinely take, especially if you’re experiencing any of the side effects mentioned above.

More information is available on this website.

The Bottom Line

As we age and begin to take multiple medications, we must be alert to the potential side effects of each new one. Every time you visit your doctor it is essential to review all medicines, including over-the-counter ones and any dietary changes to minimize the problems of polypharmacy.

Common Problems of Multiple Drugs in Older Patients

Overdose (the medicine is unexpectedly stronger in patient)

Underdose (the medicine is unexpectedly weaker in patient)

Drug-Drug Interaction (drugs acting together can cause over or underdose)

Over-the-counter Medicines (over-the-counter medicines can cause drug-drug interactions)

Diet (the actions of some medicines are augmented or diminished by diet)

Failure to Take as Directed (medicines must be taken as directed and not omitted or increased)

Trade Names of Some Commonly Used Anticholinergic Medicines*

Karbinal or Palgic

Vistaril or Atarax

*See for a more complete list of anticholinergic medicines.