Side effects from common medications like blood pressure drugs and iron supplements can lead to unnecessary additional prescriptions in older adults, according to a new study. Led by researchers from Sinai Health and the University of Toronto, the study analyzed patient data from nearly 2.3 million adults in Ontario ages 66 and older to identify side effects from drugs that could unintentionally lead to new prescriptions, with those side effects being mistaken for new health problems. The research team included scientists from the United States, Belgium, Italy, Israel and Ireland and initially created a list of 65 such drug combinations, which they called “potentially inappropriate prescribing cascades.” From there, each drug was compared against three factors: how common the first drug was in the population, how often it preceded the second drug and how strong the link was between both medications. The study, published this month in the BMJ medical journal ultimately pinpointed 24 of the most common and harmful instances of prescribing cascades. Cardiovascular drugs topped the list as users were shown to turn to other prescriptions to treat side effects like nausea vomiting, depression, water retention and constipation. Following cardiovascular drugs, like those used to treat high blood pressure, the most prevalent prescribing cascades observed were iron supplements leading to laxatives, statins for high cholesterol leading to pain relievers, and cholinesterase inhibitors for neurodegenerative conditions like Alzheimer’s leading to medications to aid sleep. “These sequences of events are common but often missed in clinical practice,” corresponding author and University of Toronto medical professor Dr. Paula Rochon said in a news release on Friday. “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.” Rochon – who is also a senior clinician scientist and the director of research at the Weston and O’Born Centre for Mature Women’s Health at Sinai Health in Toronto – says it’s important for physicians to take a closer look at their patients’ medication history, especially when it comes to older adults, because they’re more likely to have multiple conditions and multiple medications. “Our concern is that so often these conversations between the health-care prescriber and the patient are being missed, so people don’t recognize the sequences of events and that they are connected to one another,” Rochon said. The researchers hope their findings inform next steps, including digital tools that can help physicians flag potential prescribing cascades as well as involving pharmacists to leverage their expertise in the prescribing process.
