Every year, more than one in four older adults falls. For many, the cause isn’t just slippery floors or poor lighting-it’s a medication they took without realizing the danger. First-generation antihistamines like diphenhydramine (Benadryl), chlorpheniramine, and brompheniramine are still widely used by older adults for allergies, colds, or sleep. But these drugs aren’t harmless. They’re a hidden trigger for falls, fractures, and hospitalizations-and the risk grows with every pill taken.

Why Sedating Antihistamines Are Dangerous for Older Adults

First-generation antihistamines work by blocking histamine to stop sneezing and runny noses. But they also cross the blood-brain barrier, where they interfere with acetylcholine, a key brain chemical. This causes drowsiness, dizziness, slowed reaction time, and blurred vision-all of which wreck balance in older adults.

Age changes how the body handles drugs. Older adults process these medications slower. Diphenhydramine’s half-life jumps from 8.5 hours in young adults to 13.5 hours in those over 65. That means sedation lasts longer. Peak effects hit 1-3 hours after taking it-and can linger for 6-8 hours. Even a single dose can leave someone unsteady for most of the day.

Studies show these drugs don’t just cause drowsiness-they raise fall risk by 54%. One 2025 study of nearly 200,000 older adults found that 8% of those who filled a prescription for a first-generation antihistamine fell within 60 days. That’s not a small number. It’s a pattern. The American Geriatric Society calls these drugs “potentially inappropriate” for older adults in their Beers Criteria, a trusted guide for safe prescribing.

The Clear Difference: First-Gen vs. Second-Gen Antihistamines

Not all antihistamines are the same. Second-generation options like loratadine (Claritin), cetirizine (Zyrtec), and fexofenadine (Allegra) were designed to stay out of the brain. They don’t cross the blood-brain barrier the same way. That’s why they’re far safer.

Here’s the real difference:

• Diphenhydramine: Causes drowsiness in 15-20% of users, dizziness in 10%, and has a strong anticholinergic score of 3-4 on the Anticholinergic Cognitive Burden Scale.
• Loratadine: Drowsiness in under 6% of older adults, anticholinergic score of 0.
• Fexofenadine: Drowsiness in just 6%, minimal anticholinergic effects, no significant increase in fall risk.

A 2025 study found that people taking first-generation antihistamines had an 87% higher chance of falling compared to those not taking them. Those on second-generation drugs? No increased risk at all. Even cetirizine, often thought of as “mild,” causes drowsiness in 14% of older adults-twice the rate of fexofenadine.

When it comes to safety, fexofenadine is the clear winner. It’s just as effective for allergies, with almost no sedation. And it’s available over the counter, just like Benadryl.

Why Are These Dangerous Drugs Still So Common?

It’s not because doctors are ignoring the science. It’s because the drugs are easy to get-and people don’t know any better.

Diphenhydramine is the third most bought OTC sleep aid in the U.S. among people over 65. In 2024, 28.7 million units were sold to older adults. That’s more than 1 in 4 older Americans using it for sleep or allergies. Labels warn about urinary issues or glaucoma-but not about falling. The FDA required a warning in 2020, but it doesn’t mention balance, dizziness, or fall risk.

Doctors still prescribe them. A 2019 study found that 12.7% of older adults were prescribed first-generation antihistamines-almost the same rate as younger patients. That’s a “one-size-fits-all” approach that ignores aging physiology. Pharmacists see it too. In “brown bag” reviews-where patients bring all their meds to the pharmacy-on average, each older adult had 3.2 high-risk medications. Antihistamines were among the top three.

How to Prevent Falls: A Practical 4-Step Plan

Stopping falls isn’t about installing grab bars alone. It’s about fixing the medication first.

1. Review all medications-prescription, OTC, and herbal-every year. Ask: “Is this drug still needed?” Especially if it causes drowsiness. The CDC’s STEADI initiative says this is non-negotiable.
2. Switch to safer alternatives. If you need an antihistamine, choose fexofenadine (Allegra) or loratadine (Claritin). Avoid cetirizine (Zyrtec) if you’re already unsteady. Fexofenadine has the lowest sedation risk.
3. Use the lowest dose. If you must keep diphenhydramine, use 12.5mg instead of 25mg-and take it at night, not in the morning. Even then, it’s still risky.
4. Try non-drug options. Nasal saline rinses reduce allergy symptoms by 35-40%. Allergen-proof bedding cuts dust mite exposure by 83%. HEPA filters remove 99.97% of airborne allergens. These work. And they don’t make you dizzy.

Pharmacist-led medication reviews reduce fall risk by 26%. That’s huge. If you’re seeing a doctor or pharmacist, ask for a full med review. Bring your pill bottles. Don’t assume they know what you’re taking.

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

If you’ve been taking diphenhydramine for sleep or allergies, don’t stop cold turkey. Talk to your doctor. Withdrawal can cause rebound symptoms-like worse allergies or insomnia.

Here’s how to do it safely:

• Replace it with fexofenadine or loratadine first.
• Gradually reduce the dose over 1-2 weeks.
• Use non-drug allergy or sleep strategies while transitioning.
• Monitor for dizziness or confusion. If symptoms worsen, contact your provider.

For sleep, ditch the pill. Try sleep hygiene: go to bed and wake up at the same time, avoid caffeine after noon, keep the bedroom cool and dark, and get light exposure in the morning. Studies show these work better than sedating pills-and they don’t increase fall risk.

Environmental Fixes That Save Lives

Medication changes alone aren’t enough. Combine them with home safety.

• Install grab bars in the bathroom. Reduces fall risk by 28%.
• Improve lighting, especially on stairs and hallways. Reduces falls by 32%.
• Remove loose rugs, cords, and clutter. Most falls happen at home.
• Use non-slip mats in the shower.
• Wear shoes with good grip-no socks or slippers.

These aren’t luxuries. They’re necessities for anyone on sedating meds. And if you’re reducing antihistamine use, these changes make the transition safer.

What’s Changing in 2025 and Beyond

Things are starting to shift. The CDC updated its STEADI toolkit in January 2025 to include a new medication risk module. Medicare now requires doctors to review high-risk medications during the Annual Wellness Visit. That includes antihistamines.

The American Academy of Neurology just issued new guidance: avoid vestibular suppressants-including first-gen antihistamines-in anyone with a history of falls. And two new antihistamines (AGS-2025-01 and FEX-AGE-101) are in Phase II trials. Early results show 89% less drowsiness than diphenhydramine. These could be game-changers.

But until then, the safest choice is clear: stop using diphenhydramine and similar drugs. Switch to safer options. Talk to your pharmacist. Make your home safer. These steps don’t just prevent falls-they prevent death.

Next Steps: What to Do Today

Take 10 minutes right now. Look at your medicine cabinet. Find any bottle with diphenhydramine, chlorpheniramine, or brompheniramine. Write down the name and dose. Then call your doctor or pharmacist. Ask: “Is this safe for someone my age? Is there a non-sedating alternative?”

If you’re caring for an older relative, do the same for them. Don’t wait for a fall to happen. Prevention starts with one question: “Why am I taking this?”