antihistamine (ănˌtĭhĭsˈtəmēn) [key], any one of a group of compounds having various chemical structures and characterized by the ability to antagonize the effects of histamine. Their principal use in medicine is in the control of allergies such as hay fever and hives. Some antihistamines are also useful as sedatives and for the prevention of motion sickness; others, such as fexofenadine (Allegra) and loratadine (Claritin) are nonsedating.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
More on antihistamine from Fact Monster:
See more Encyclopedia articles on: Biochemistry