MONDAY, Sept. 28, 2026 (HealthDay News) — More than 1 in 5 seniors are at risk for a potentially dangerous drug interaction from the medications they’ve been prescribed, a new study says.
About 22% of U.S. adults between 62 and 85 years of age had a drug regimen that put them at high risk for a harmful interaction in 2021-2023, researchers reported Sept. 24 in the Journal of the American Medical Association.
That’s actually a slight improvement from 2015-2016, when nearly 26% of seniors were at risk for a drug interaction, researchers noted.
But it still leaves a large number of older people at risk, the team said.
“These findings underscore the need for continuing efforts to improve medication safety among older adults,” lead researcher Dima Mazen Qato, a senior fellow at the University of Southern California, said in a news release.
Polypharmacy — taking five or more prescription medications at the same time — is an ongoing health concern for seniors, researchers said. That many drugs increase the risk that one will interact with another in a way that could harm a person’s health.
For example, the heartburn drug cimetidine (Tagamet) can inadvertently boost the effects of the blood thinner warfarin, increasing a person’s risk of bleeding and stroke, according to Harvard Medical School.
For the new study, researchers compared 2015-2016 and 2021-2023 data gathered during two separate waves of a national study on health and aging. The two waves involved nearly 5,000 seniors.
Between the two periods, polypharmacy increased from 31% to nearly 36% of seniors, the study found.
More seniors also were taking five or more dietary supplements, rising from under 13% to nearly 17%.
Antidepressants, statins and blood thinners were the most commonly used drugs that increased the risk of major interactions, researchers found.
“Efforts to reduce polypharmacy and harmful drug interactions should focus on commonly used interacting regimens, particularly those involving antidepressants,” Qato said.
More information
Harvard Medical School has more on polypharmacy.
SOURCE: University of Southern California, news release, Sept. 24, 2026