The pill your parent started for cholesterol may have led to an iron supplement.
The one they take for arthritis pain may have led to a blood pressure drug.
That chain, where a side effect of one medicine is treated with another medicine instead of a change to the first, is called a prescribing cascade, and it is far more common in older adults than most patients realize.
A population-level study published in The BMJ on September 10, 2026, identified the 24 potentially inappropriate prescribing cascades most likely to affect older adults.
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The team analyzed Ontario prescription records and, with an international panel of 12 experts in internal medicine, geriatric medicine, and clinical pharmacology, narrowed an initial list of 65 possible cascades down to the 24 with the greatest population-level impact.
One everyday example the researchers flagged is nonsteroidal anti-inflammatory drugs (NSAIDs), commonly prescribed for pain, which can raise blood pressure and lead to a new prescription for hypertension rather than a second look at the original painkiller.
Statins and iron supplements are named as another pairing that shows up in the data.
Why cascades slip past patients and doctors
The problem is that the second prescription usually feels like a fresh diagnosis rather than a reaction to the first pill.
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A patient's blood pressure creeps up, or a new symptom appears, and a new drug goes on the list without anyone stepping back to ask whether the first drug caused the change.
Dr. Paula Rochon, director of research at the Weston and O'Born Centre for Mature Women's Health at Sinai Health in Toronto and the lead author, said the pattern often goes unspoken during clinic visits.
"These sequences of events are common but often missed in clinical practice. Knowing what medications, you are taking, when they were started and for what indication is important in order to identify possible prescribing cascades that may be problematic," she said in a summary of the findings from news-medical.net.
Rochon also noted that the risk is highest in patients who already take many medicines.
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Older women, who tend to live with more chronic conditions and are prescribed more drugs on average, appear to be hit hardest.
Polypharmacy sets the stage
The concern lands in a country where taking a handful of pills a day is the norm after 65.
According to CDC data on prescription drug use in adults, 34.5 percent of Americans aged 60 to 79 had used five or more prescription drugs in the previous 30 days.
A later JAMA analysis of national trends found that more than 4 in 10 adults aged 65 and older reported using five or more prescription medications between 2017 and 2020.
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The more drugs on the list, the greater the chance that a side effect of one is being treated by another.
That is why researchers now urge clinicians to review the full medication list, including over-the-counter products and supplements, at every visit, and to consider whether a new symptom might be traceable to a recent prescription before adding another.
How to spot a possible cascade
The most useful signal for a caregiver or patient is timing.
A new symptom that appears in the weeks or months after starting a new medication, followed by a second prescription to treat that symptom, is the classic pattern the researchers describe.
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Common triggers to watch for include swelling in the ankles after a calcium channel blocker, a persistent dry cough after an ACE inhibitor, tremor or stiffness after certain antipsychotics or antinausea drugs, and constipation after opioid painkillers.
A practical step is to bring every bottle, including supplements, to the next appointment and ask the prescriber or pharmacist to review them together, noting when each was started and why.
If any drug on the list appears to be treating the side effect of another, that is the conversation to have before the next refill.
Rochon and her coauthors also called for automated tools inside electronic prescribing systems that would flag a likely cascade at the moment a new drug is ordered, and for expanded pharmacist involvement in medication reviews, so a fresh set of eyes catches sequences the original prescriber may miss.
The team's list of 24 high-priority cascades is intended to guide those tools and reviews.
The next Medicare Annual Wellness Visit is a natural place to ask for a full medication review, since it already includes a check of current prescriptions at no cost to the patient.
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.