antihistamine

American  

[an-ti-his-tuh-meen, -min] / ˌæn tɪˈhɪs təˌmin, -mɪn /

noun

Physiology, Pharmacology.

1. any of certain compounds or medicines that neutralize or inhibit the effect of histamine in the body, used chiefly in the treatment of allergic disorders and colds.

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antihistamine British  

/ -mɪn, ˌæntɪˈhɪstəˌmiːn /

noun

1. any drug that neutralizes the effects of histamine, used esp in the treatment of allergies

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antihistamine Scientific  

/ ăn′tē-hĭs′tə-mēn′ /

1. Any of various drugs that relieve cold or allergy symptoms by blocking the action of histamine.

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Etymology

Origin of antihistamine

First recorded in 1930–35; anti- + histamine

Explanation

An antihistamine is a type of drug you might take if you suffer from allergies. If your friend's cat makes your throat itch and your eyes swell, you should probably take an antihistamine. Antihistamines work by suppressing the effects of histamine in your body — this is substance released by your cells when you're exposed to allergens, or things you're allergic to. It's histamine that makes you sneeze or get itchy hives, and it's antihistamine that soothes this reaction. This scientific word comes from anti-, "against," histidine, an amino acid, and amine, a certain kind of organic compound.

Example Sentences

The medical area didn’t have any regular antihistamine.

From The Wall Street Journal • Apr. 6, 2026

Wright gives the example of a "hyper-niche" program about pollen counts in a specific city, heard by a few dozen people that can attract antihistamine advertisers.

From Barron's • Oct. 13, 2025

Some studies have suggested long-term antihistamine use is associated with increased dementia risk, although the link is not definitive.

From Seattle Times • Feb. 8, 2024

We inquire about the medicine she's giving her daughter and find that it is a common antihistamine or anti-allergy drug.

From BBC • Dec. 17, 2023

Mom gave me some antihistamine pills after I got out of the bath.

From "100 Sideways Miles" by Andrew Smith