Medical Definition of clemastine
: an antihistamine drug administered orally in the form of its fumarate C21H26ClNO·C4H4O4 to relieve the symptoms of hay fever and the common cold … oral antihistamines, such as chlorpheniramine and clemastine, reduce sneezing and, to a lesser extent, rhinorrhea, probably because of their anticholinergic effects, but they are often associated with excess sedation.—Frederick G. Hayden, Scientific American Medicine Bulletin, March 1997
Seen and Heard
What made you want to look up clemastine? Please tell us where you read or heard it (including the quote, if possible).