an·​ti·​his·​ta·​mine ˌan-tē-ˈhi-stə-ˌmēn How to pronounce antihistamine (audio)
: any of various compounds that counteract histamine in the body and that are used for treating allergic reactions (such as hay fever) and cold symptoms
antihistamine adjective
antihistaminic adjective or noun

Example Sentences

Recent Examples on the Web Some antihistamines, such as Benadryl, can cause drowsiness. Jim Cobb, Field & Stream, 10 May 2023 The most common active ingredients include antihistamines, vasoconstrictors, and lubricating agents. Lindsay Modglin, Health, 1 May 2023 But many prescription medicines can cause constipation: iron supplements, the blood pressure medicine verapamil, antihistamines, antidepressants, and many others. Dr. Keith Roach, oregonlive, 26 Jan. 2023 Hydroxyzine is an antihistamine prescribed for allergies and anxiety. Stephanie Pagones, Fox News, 28 Dec. 2022 Another 14, including antihistamines, antidepressants and an antibiotic, were traced on all continents except Antarctica. Andrea Thompson, Scientific American, 1 June 2022 Contact dermatitis is also treated with antihistamines or anti-itch creams. Erica Sweeney, Good Housekeeping, 4 May 2023 The factory is owned and operated by PCI Synthesis/Seqens, a multinational company based in France that is involved in the production of generic drugs typically found in medicine cabinets, such as over-the-counter painkillers and antihistamines, according to the company’s website. John R. Ellement,, 4 May 2023 In the hopes of creating a safer environment for everyone, Fogarty landed on her project idea: a simple, color-changing sensor that can tell someone whether an antihistamine has been slipped into their drink. Teresa Nowakowski, Smithsonian Magazine, 24 Apr. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'antihistamine.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1946, in the meaning defined above

Time Traveler
The first known use of antihistamine was in 1946

Dictionary Entries Near antihistamine

Cite this Entry

“Antihistamine.” Dictionary, Merriam-Webster, Accessed 7 Jun. 2023.

Kids Definition


an·​ti·​his·​ta·​mine ˌant-i-ˈhis-tə-ˌmēn How to pronounce antihistamine (audio)
: any of various drugs used for treating allergic reactions and cold symptoms

Medical Definition


1 of 2 adjective
an·​ti·​his·​ta·​mine ˌant-i-ˈhis-tə-ˌmēn, ˌan-ˌtī-, -mən How to pronounce antihistamine (audio)
: tending to block or counteract the physiological action of histamine
human blood lacks antihistamine activity


2 of 2 noun
: any of various compounds that oppose the actions of histamine and are used especially for treating allergic reactions (as hay fever), cold symptoms, and motion sickness
Last Updated: - Updated example sentences
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