April 04, 2026

#151 - What Allergists Think About Antihistamines

18 minutes

If you have ever taken an antihistamine labeled "non-drowsy" and still ended up foggy and tired, you are not imagining it. Allergists have a lot to say about that label and about the foggy feeling that comes with allergy season in general.

In part two of our live recordings from the AAAAI conference in Philadelphia, Kortney and Dr. Payel Gupta talk to allergists from across the US about what they actually think about antihistamines.

What we cover in this episode about antihistamines:

Non-drowsy does not mean the same thing for every antihistamine. Zyrtec, Claritin, and Allegra are all labeled non-drowsy, but some are more likely to make you sleepy than others.

Why allergists have moved away from Benadryl. First-generation antihistamines cross into the brain more easily, causing drowsiness and a range of other side effects that are far less common with newer antihistamines.

The foggy feeling might not be your medication. Congestion from untreated allergies disrupts your sleep, and poor sleep creates its own fog. Sometimes it is the disease, not the drug.

Timing your antihistamine makes a real difference. Taking it before you head out gives it the best chance to work. And if it makes you drowsy, switching to a nighttime dose is a simple fix.

Not all second-generation antihistamines are approved for pilots. Fexofenadine has the lowest penetration into the brain of any antihistamine tested, which is why the FAA cleared it as the only option pilots can take while flying.

Second-generation antihistamines (non-sedating or minimally sedating)

Cetirizine — Zyrtec

Loratadine — Claritin, Alavert

Fexofenadine — Allegra

Levocetirizine — Xyzal

Desloratadine — Clarinex (prescription only)

First-generation antihistamines (sedating)

Diphenhydramine — Benadryl, ZzzQuil, Unisom

Chlorpheniramine — Chlor-Trimeton

Brompheniramine — Dimetapp

Dimenhydrinate — Dramamine

Hydroxyzine — Atarax, Vistaril (prescription only)

Thank you to our allergists

A huge thank you to every allergist who stopped what they were doing at the AAAAI conference to talk to us. We could not make this episode without you.

Dr. Mansi Kotwal, Instagram

Dr. Lauren Davidson, Instagram

Dr. Joel Brooks, LinkedIn

Dr. Pratibha Vakharia, allergyv.com

Dr. Rathika Gupta

Dr. David Wertheim

Thanks to Opella for sponsoring today’s episode.

This podcast is for informational purposes only and does not substitute professional medical advice. Always consult with your healthcare provider for any medical concerns.

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By The Itch: Allergies, Asthma & Immunology

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