Antihistamines

Part of speech: noun

Definitions

1. Drugs designed to mitigate allergic responses by blocking the action of histamines in the body
2. Substances used to relieve allergy symptoms by preventing histamine from affecting the body
3. Medicinal compounds that stop or reduce allergic reactions by blocking histamine activity

Etymology: "Antihistamine" is built from "anti-", a Greek-derived prefix meaning "against," and "histamine," a compound name whose parts come from Greek "histos," meaning "tissue" or "web," and "amine," a chemical term. Histamine itself is a substance the body releases during allergic reactions, and the drugs named for opposing it block its effects, which is why the name is so literal: the word means something like "against histamine." The chain behind "histamine" is more roundabout than its parts suggest. The "-amine" ending traces back to "ammonia," which was named after the Egyptian god Amun, whose Greek form was "Ammon." Ancient Egyptian worshippers linked him with a salt-rich region, and the substance ammonia came to be called "sal ammoniacus" by Latin writers. Chemists later used "-amine" for compounds derived from ammonia, and "histamine" was coined by combining that ending with "hist-" from the Greek word for tissue, reflecting where the chemical was found in the body. Because the word is a chemist's coinage, it describes the drug by its target rather than by its effect on symptoms. Plural "antihistamines" simply refers to the whole class of such drugs.

Synonyms: medications, drugs