The average American over 60 takes 4.5 prescription medications. Add over-the-counter drugs and supplements, and it's closer to 8 daily substances. Each one was prescribed or chosen for a reason — but nobody's checking how they work together. Adverse drug interactions send 1.3 million Americans to the emergency room every year, and adults over 60 account for more than half of those visits.
The Fragmented Prescriber Problem
Here's why dangerous interactions happen: your cardiologist prescribes one drug, your primary care doctor prescribes another, your orthopedist adds a third, and your dentist gives you an antibiotic — and none of them see the full picture. Your pharmacy software catches obvious conflicts, but it misses roughly 30% of clinically significant interactions, especially involving supplements and OTC drugs.
The Most Dangerous Common Interactions
High-Risk Drug Combinations After 60
| Drug A | Drug B | What Happens | Risk Level |
|---|---|---|---|
| Blood thinners (Eliquis, Xarelto) | NSAIDs (ibuprofen, naproxen) | Internal bleeding risk doubles | CRITICAL |
| Statins (Lipitor, Crestor) | Certain antibiotics (clarithromycin) | Severe muscle damage (rhabdomyolysis) | HIGH |
| Blood pressure meds (ACE inhibitors) | Potassium supplements | Dangerously high potassium, cardiac arrest risk | HIGH |
| SSRIs (Lexapro, Zoloft) | Tramadol or migraine triptans | Serotonin syndrome (potentially fatal) | HIGH |
| Metformin (diabetes) | Contrast dye (CT scans) | Kidney damage, lactic acidosis | MODERATE |
| Thyroid meds (levothyroxine) | Calcium or iron supplements | Thyroid medication rendered ineffective | MODERATE |
How to Do a Medication Audit
Your Complete Medication Review Process
Supplements That Interfere With Medications
This is the blind spot most people miss. Your doctor probably doesn't ask about supplements, and supplement labels don't warn about drug interactions.
- St. John's Wort — reduces effectiveness of blood thinners, birth control, statins, antidepressants, and dozens more. This herb is a wrecking ball for medication levels.
- Fish oil (high dose) — increases bleeding risk with blood thinners. Low-dose (1-2g) is usually fine; high-dose (4g+) is risky.
- Ginkgo biloba — increases bleeding risk, interferes with blood thinners and blood pressure medications.
- Calcium — blocks absorption of thyroid medication, certain antibiotics, and iron. Take calcium 4 hours apart from these drugs.
- Vitamin K (including in green vegetables) — directly counteracts warfarin (Coumadin). Consistency matters more than avoidance.
- CBD oil — inhibits liver enzymes that metabolize many common drugs, potentially raising drug levels to dangerous ranges.
- Turmeric/curcumin — increases bleeding risk with anticoagulants and may increase effects of diabetes medications.
The Brown Bag Review
Every six months, put every medication and supplement in a brown paper bag and bring it to your primary care doctor. Say: "Can we review everything I'm taking and make sure it all still makes sense?" Medication needs change. A drug that was appropriate at 55 may be inappropriate at 65 due to changing kidney function, new diagnoses, or better alternatives. The goal isn't fewer pills for the sake of fewer pills — it's the right pills at the right doses with no harmful overlaps.