Older Adults' Risk of Major Drug Interactions Falls, Study Finds
A new study shows the proportion of older Americans at risk for major drug interactions fell from 25.7% to 22.3% between 2015-2016 and 2021-2023.
The share of older U.S. Adults at risk for potentially major drug interactions declined from 25.7% to 22.3% between 2015-2016 and 2021-2023. Despite this improvement, Americans aged 62 and older are taking more medicines with antidepressants, statins, and aspirin-like drugs now posing the most frequent interaction dangers.
The analysis involved 2,754 individuals with a mean age of 70.2 years in the 2015-2016 period and 2,186 individuals with a mean age of 70.8 years in the 2021-2023 period. While the risk of dangerous combinations dipped, the underlying trend of polypharmacy, or taking multiple medications, grew significantly.
Specific drug classes drive both risks and improvements
Antidepressants, statins, and antiplatelet drugs were the classes most often involved in potentially major interactions in the latest period. The study found antidepressants were involved for 7.2% of older adults, statins for 5.2%, and antiplatelet drugs like aspirin for 4.5%.
Some high-risk combinations became less common. The share of older adults with opioids in a risky combination fell from 5.6% to 4.0%. The share with benzodiazepine sedatives dropped from 2.1% to 0.9%. In contrast, the involvement of muscle relaxants in risky combinations rose from 1.4% to 2.5%.
Polypharmacy increases across prescription and supplement use
Prescription polypharmacy, defined as taking five or more prescription drugs at once, rose from 31.0% to 35.7%. The share taking five or more dietary supplements increased from 12.6% to 16.7%. These jumps occurred even though the overall rates of using any prescription medication or any supplement remained stable.
| Metric | 2015-2016 | 2021-2023 | P-value |
|---|---|---|---|
| Any prescription medication use | 84.2% | 84.8% | 0.60 |
| Any dietary supplement use | 65.6% | 66.8% | 0.44 |
| Prescription polypharmacy (5+ drugs) | 31.0% | 35.7% | 0.003 |
| Supplement polypharmacy (5+ supplements) | 12.6% | 16.7% | 0.001 |
Experts urge medication reviews and deprescribing focus
Dr. Spencer Kroll, a physician with pharmacology expertise, noted that the flagged drug classes are essential for managing cardiovascular and mental health and cannot be simply avoided. He warned that interactions can lead to severe complications like increased bleeding or reduced drug metabolism. Kroll pointed to fragmented care as a key risk factor, where older patients see multiple physicians and use different pharmacies with non-communicating medical records.
The people most likely to face this risk are older adults taking five or more medicines, those who see several specialists, and those who combine prescriptions with over-the-counter drugs or supplements. Adults taking an antidepressant along with other drugs that affect serotonin have particular reason to ask questions. So do those taking blood thinners or aspirin with other medicines that raise bleeding risk.
Experts recommend a comprehensive medication review as a simple first step, gathering every pill bottle including vitamins, herbal products, and pain relievers. The study authors called on deprescribing programs to focus first on the interacting combinations that older adults use most. They urged that depression treatment guidelines for older adults prioritize reviewing antidepressant combinations.
NORC has continued collecting survey data since 2024, so a later round could show whether the share at risk keeps falling.
