Fall Risk in Older Adults on Sedating Antihistamines: Prevention Strategies

Every year, nearly one in four older adults in the U.S. falls. For many, the cause isn’t just slippery floors or poor lighting-it’s a medication they picked up at the drugstore without a second thought. Diphenhydramine, the active ingredient in Benadryl and many sleep aids, is one of the most common culprits. It’s cheap, easy to find, and marketed as harmless. But for people over 65, it’s a hidden danger. These first-generation antihistamines don’t just relieve allergies-they slow down the brain, blur vision, throw off balance, and increase the chance of a fall by more than half. And the worst part? Most older adults-and even their doctors-don’t realize how risky they are.

Why Sedating Antihistamines Are Dangerous for Older Adults

First-generation antihistamines like diphenhydramine, chlorpheniramine, and brompheniramine were designed decades ago to block histamine and stop sneezing. But they also cross the blood-brain barrier easily. That’s why they make you drowsy. In younger people, that’s fine. In older adults, it’s a recipe for disaster.

As we age, our liver and kidneys don’t process drugs as quickly. Diphenhydramine, which lasts about 8.5 hours in a healthy 30-year-old, can stick around for over 13 hours in someone over 65. That means drowsiness, dizziness, and poor coordination last longer-often into the morning. A 2025 study of nearly 200,000 older adults found that 8% of those who filled a prescription for a sedating antihistamine fell and needed medical care within two months. That’s not rare. That’s predictable.

These drugs also have strong anticholinergic effects. That means they interfere with acetylcholine, a brain chemical critical for memory, attention, and muscle control. The American Geriatric Society lists diphenhydramine as a potentially inappropriate medication for older adults in its Beers Criteria. Side effects aren’t just annoying-they’re life-threatening: confusion, dry mouth, constipation, blurred vision, and orthostatic hypotension (a sudden drop in blood pressure when standing). All of these increase fall risk.

The Clear Difference Between First- and Second-Generation Antihistamines

Not all antihistamines are the same. Second-generation options like loratadine (Claritin), cetirizine (Zyrtec), and fexofenadine (Allegra) were developed to avoid the brain. They barely cross the blood-brain barrier. That means they treat allergies without making you sleepy.

Here’s the numbers: First-generation antihistamines carry an anticholinergic burden score of 3 or 4 (high risk). Second-generation ones score 0 or 1 (low risk). A 2025 study showed that people taking first-generation antihistamines had an 87% higher risk of falling compared to those who didn’t. Those taking second-generation ones? No increased risk at all. Fexofenadine, in particular, causes drowsiness in only 6% of older adults-less than the placebo group in some trials.

Even among second-generation options, there’s variation. Cetirizine can still cause mild drowsiness in up to 14% of older users. Fexofenadine and loratadine are the safest bets. If you need an antihistamine, fexofenadine is the top choice. It’s just as effective for allergies, with almost zero sedation.

Why Doctors Keep Prescribing Them

It’s not because they don’t know better. They do. The problem is inertia. First-generation antihistamines are still sold over the counter without strong warnings. Many older adults self-medicate for allergies, insomnia, or even nausea, thinking it’s harmless. A 2019 study found that 12.7% of older adults were prescribed these drugs-almost the same rate as younger adults. That’s like giving a 90-year-old the same painkiller dosage as a 30-year-old. It doesn’t make sense.

Primary care doctors, dermatologists, and even pharmacists sometimes default to diphenhydramine because it’s familiar and cheap. But sales data tells a different story: diphenhydramine is the third most bought OTC sleep aid in the U.S., with over 28 million units sold annually to people 65 and older. That’s $142 million in revenue from a drug known to increase fall risk.

There’s also a lack of awareness among patients. Many don’t realize that Benadryl isn’t just for allergies-it’s also in nighttime cold medicines, sleep aids, and even some stomach remedies. A single bottle can contain multiple sedating ingredients. Without a full medication review, the danger flies under the radar.

How to Prevent Falls: The CDC’s Three-Step Plan

The CDC’s STEADI initiative gives a clear roadmap: STOP, SWITCH, REDUCE.

• STOP using first-generation antihistamines unless absolutely necessary. If someone is taking diphenhydramine for sleep, it’s not a long-term solution-it’s a fall waiting to happen.
• SWITCH to safer alternatives. Fexofenadine, loratadine, or even nasal saline sprays are better choices. For allergies, allergen-proof bedding and HEPA filters reduce triggers without drugs. One study showed HEPA filters cut airborne allergens by 99.97%.
• REDUCE doses if switching isn’t possible. If diphenhydramine must be used, start with 12.5 mg instead of 25 mg. Give it at night, not in the morning. Never combine it with alcohol, benzodiazepines, or opioids.

Pharmacists play a key role. A simple “brown bag” review-where patients bring all their pills, supplements, and OTC meds to the pharmacy-can uncover 3.2 high-risk medications per person. One study found pharmacist-led reviews cut fall risk by 26%.

Non-Drug Alternatives That Actually Work

You don’t need a pill to manage allergies or sleep better. In fact, non-drug options are often safer and more effective.

• Nasal saline irrigation reduces allergy symptoms by 35-40%, according to JAMA Otolaryngology. It’s cheap, easy, and has no side effects.
• Allergen-proof bedding cuts dust mite exposure by 83%. That’s a huge win for people with seasonal allergies.
• HEPA air filters remove nearly all airborne allergens. Place one in the bedroom for the best results.
• For sleep: Stick to a regular bedtime, avoid caffeine after noon, keep the room cool and dark, and try relaxation techniques like deep breathing. These are more effective than diphenhydramine-and they don’t make you fall.

Environmental changes matter too. Install grab bars in the bathroom (cuts falls by 28%), improve lighting (cuts falls by 32%), remove loose rugs, and keep walkways clear. These fixes cost little but save lives.

What to Do If You’re Already Taking a Sedating Antihistamine

If you or a loved one is taking diphenhydramine, don’t quit cold turkey. Talk to a doctor or pharmacist first. Suddenly stopping can cause rebound symptoms like worse allergies or insomnia.

Instead, create a plan:

1. Write down every medication, including OTC and supplements.
2. Ask: Is this drug on the Beers Criteria list? Is there a safer alternative?
3. Switch to fexofenadine or loratadine if possible.
4. If switching isn’t an option, lower the dose and take it only at night.
5. Monitor for dizziness, confusion, or unsteadiness after the change.
6. Schedule a follow-up in 2-4 weeks.

Medicare now requires providers to review high-risk medications during the Annual Wellness Visit. Use that appointment to ask: “Am I on any drugs that could make me fall?”

The Future Is Safer-But We Need to Act Now

There’s hope on the horizon. Two new antihistamines designed specifically for older adults are in Phase II trials. Early results show an 89% reduction in drowsiness compared to diphenhydramine. But they’re years away from market.

In the meantime, change is possible. Every time a doctor switches a patient from diphenhydramine to fexofenadine, they prevent a potential fall. Every time a pharmacist catches an unsafe combo, they save a life. And every time a family member asks, “Is this really safe for Dad?” they become part of the solution.

The data is clear. The tools are available. The only thing missing is action.