How to Prevent Drug-Drug Interactions in Elderly Patients

Every year, nearly 35% of hospital admissions for people over 65 are caused by medication problems. And more than half of those could have been avoided. The biggest culprit? Drug-drug interactions. When an elderly person takes five, six, or even ten different pills, the chance of harmful overlaps skyrockets. It’s not just about taking too many drugs-it’s about which ones are mixed together, how the body changes with age, and who’s managing the list.

Why Older Adults Are at Higher Risk

As we age, our bodies don’t process drugs the same way. The liver slows down. Kidneys filter less efficiently. Fat and muscle ratios shift. These changes mean medications stick around longer, build up in the system, and can turn from helpful to harmful. An older adult might be just as sensitive to a drug as a child, even if they’re taking the same dose.

Take blood pressure meds and NSAIDs like ibuprofen. Together, they can crash kidney function. Or consider a statin and a common antibiotic-both processed by the same liver enzyme. Add them up, and you get muscle damage, not just lower cholesterol. These aren’t rare mistakes. In fact, 38.7% of serious drug interactions in seniors involve heart and blood pressure drugs. Another 29.4% hit the brain, causing dizziness, confusion, or falls.

And it’s not just prescriptions. Nearly 70% of older adults don’t tell their doctor about the vitamins, herbs, or over-the-counter painkillers they’re taking. Garlic pills, St. John’s wort, melatonin-they all interact. One study found that 68% of seniors hide their supplement use because they think it’s “not medicine.” But it is.

Polypharmacy: The Silent Crisis

Polypharmacy-taking five or more medications-isn’t just common. It’s normal for many seniors. About 40% of older adults in the U.S. are on five or more prescriptions. Some are managing diabetes, heart disease, arthritis, depression, and insomnia-all at once. Each doctor sees one piece. The cardiologist prescribes a beta-blocker. The neurologist adds a sleep aid. The primary care doc adds a diuretic. No one sees the full picture.

And when someone switches doctors or moves to a new pharmacy, the risk spikes. More than two-thirds of seniors see multiple providers and use different pharmacies. That means no single person has the full list. Pills get duplicated. Doses get doubled. Dangerous combos slip through.

It’s not just about quantity-it’s about quality. The American Geriatrics Society’s Beers Criteria, updated in 2023, lists 30 medications that should be avoided in older adults because the risks outweigh the benefits. Examples include long-acting benzodiazepines like diazepam (too sedating), anticholinergics like diphenhydramine (causes confusion), and certain NSAIDs (bad for kidneys). There are also 40 more drugs that need lower doses because of reduced kidney function.

Tools That Actually Work

There are proven tools to catch these problems before they hurt someone. Two stand out: the Beers Criteria and the STOPP criteria.

STOPP stands for Screening Tool of Older Persons’ Potentially Inappropriate Prescriptions. It’s a checklist with 114 red flags-like prescribing a diuretic to someone with low sodium, or using a sleeping pill with a history of falls. When hospitals used STOPP during discharge planning, they cut inappropriate prescribing by 34.7% and reduced readmissions by 22.1%.

Another tool, called NO TEARS, gives doctors a step-by-step way to review every medication:

• Need: Is this drug still necessary?
• Optimization: Is the dose right for age and kidney function?
• Trade-offs: Do the benefits still outweigh the risks?
• Economics: Can the patient afford it?
• Administration: Are they taking it correctly?
• Reduction: Can we stop one or two?
• Self-management: Do they understand why they’re taking it?

One clinic in Minnesota used NO TEARS in every visit for patients on seven or more drugs. Within six months, they cut unnecessary medications by 27% and reduced ER visits by 31%.

What Doctors Should Do

It’s not enough to just check a box. Prevention requires time, communication, and follow-up.

Doctors should spend at least 15 minutes per visit reviewing medications with seniors on five or more drugs. For those on seven or more, add another 10 minutes. That’s not optional-it’s essential. And no, you can’t do it in five minutes while typing on a computer.

Never start two new medications at the same time. If a patient gets a new painkiller and a new antidepressant in the same visit, and they get dizzy the next day-how do you know which one caused it? Start one. Wait two weeks. Then add the next. That’s how you find the culprit.

And don’t rely on electronic alerts alone. Most systems flag every possible interaction-even ones that are harmless or irrelevant. That creates alert fatigue. Doctors start ignoring them. The best systems combine automated flags with human review.

What Families and Patients Can Do

You don’t have to wait for your doctor to fix this. You can help.

Bring a complete list of everything you take to every appointment. Include:

• Prescriptions
• Over-the-counter pills (Tylenol, ibuprofen, antacids)
• Vitamins and supplements (fish oil, magnesium, ginkgo)
• Herbs and teas (turmeric, chamomile, ginseng)
• Topical creams and patches (lidocaine, fentanyl)

Use one pharmacy if you can. It’s easier for the pharmacist to spot conflicts. If you use multiple pharmacies, ask them to share your list with each other.

Ask these three questions at every visit:

1. Can any of these be stopped?
2. Is this still helping me, or just adding risk?
3. What happens if I don’t take this anymore?

Don’t be afraid to say, “I think I’m taking too much.” Many seniors don’t speak up because they think their doctor knows best. But doctors don’t know what you’re not telling them.

The Bigger Picture

The system is broken-not because of bad people, but because it wasn’t built for aging bodies. Clinical trials for new drugs rarely include older adults. Less than 5% of participants in Phase 3 trials are over 65, even though they make up 40% of the people who will use those drugs. That means we’re guessing how they’ll react.

The FDA is trying to fix this. Their 2022 guidance asks drug makers to test medications in older adults and report how age affects metabolism. But only 18% of new drug applications between 2018 and 2022 included that data. That’s not progress-it’s a gap.

Meanwhile, AI tools are starting to help. Hospitals using artificial intelligence to flag dangerous interactions saw adoption jump from 22% in 2020 to 47% in 2023. These systems can scan hundreds of interactions in seconds, cross-check with Beers and STOPP, and suggest safer alternatives.

But technology can’t replace human judgment. No algorithm knows if your grandmother can afford her pills. Or if she’s swallowing them correctly. Or if she’s scared to stop something her doctor told her to take 10 years ago.

What’s Next

The 2025 update to the Beers Criteria will add more drug-disease interactions and 15 new medications requiring kidney-based dose adjustments. That’s good. But real change needs more than updated lists.

Medical schools still don’t teach enough about geriatric pharmacology. Only 38% of U.S. medical schools have a dedicated course. That number is rising-projected to hit 65% by 2026-but it’s too slow.

Medicare’s Medication Therapy Management program has helped 11.2 million people since 2020, reducing hospitalizations by 15.3%. But it’s underused. Many seniors don’t even know it exists.

The solution isn’t one magic fix. It’s a system of checks: better labeling, smarter tools, trained providers, informed families, and patients who ask questions. Every pill matters. Every interaction counts. And in older adults, the stakes are life or death.

Final Thoughts

Preventing drug interactions in older adults isn’t about cutting pills. It’s about clarity. It’s about asking the right questions. It’s about making sure every medication still has a reason to be there. The goal isn’t to take fewer drugs-it’s to take the right ones, at the right dose, for the right reason. And that takes time, teamwork, and a willingness to challenge the status quo.