Do Not Use List: Medications to Avoid and Why

When it comes to your health, not all medications are created equal. Some drugs carry risks so high that doctors and pharmacists actively avoid prescribing them—especially for certain patients. This is what’s known as the Do Not Use list, a collection of medications flagged by medical guidelines for dangerous side effects, poor safety profiles, or high risk of harm when used in specific populations. Also known as contraindicated drugs, these aren’t always banned—they’re just too risky for many people to use safely. The list isn’t about illegal drugs or street substances. It’s about common prescriptions and even over-the-counter pills that can quietly cause strokes, kidney failure, falls, or deadly interactions.

Take NTI drugs, narrow therapeutic index medications like warfarin, phenytoin, and cyclosporine that require very precise dosing. Also known as narrow window drugs, even tiny changes in blood levels can lead to overdose or treatment failure. Switching from brand to generic versions of these drugs might seem harmless—but studies show it can cause dangerous spikes or drops in effectiveness. That’s why many hospitals and clinics have strict rules against automatic substitution for NTI drugs.

Then there’s the group of medications that increase fall risk in older adults, including benzodiazepines, sleep aids, antidepressants, and even common OTC antihistamines like diphenhydramine. Also known as sedating medications, they don’t just make you drowsy—they throw off your balance, slow your reflexes, and turn a simple trip to the bathroom into a fracture waiting to happen. One study found that seniors on these drugs were twice as likely to end up in the ER from a fall. And it’s not just the elderly. People with kidney disease should avoid antacids like Tums and Milk of Magnesia—those calcium and magnesium salts can build up to toxic levels, damaging the heart and bones.

These aren’t theoretical concerns. Real people get hurt every day because these drugs are still sold over the counter or prescribed without proper warnings. The Do Not Use list exists because the data is clear: some medications do more harm than good for large groups of patients. What you’ll find in the posts below are deep dives into exactly which drugs belong on this list, why they’re dangerous, who’s most at risk, and what safer alternatives actually work. From antihistamines that cause dizziness to blood thinners that need careful monitoring, this collection gives you the facts you need to ask the right questions—and protect yourself or someone you care about.