Antihistamines or histamine antagonists are of three types:
· H1-receptor antagonists (classical antihistamines) lessen histamine-mediated symptoms of allergic reaction.
· H2-receptor antagonists reduce gastric acidity.
· H3-receptor antagonists have no therapeutic indication, and hence will not be discussed at all.
Brompheniramine, chlorpheniramine, dexbrompheniramine, dexchlorpheniramine, dimethindene, pheniramine, pyrrobu-tamine, triprolidine, carbinoxamine, clemastine, dimenhy-drinate, diphenhydramine, diphenylpyraline, doxylamine, phenyltoloxamine, antazoline, methapyrilene, pyrilamine, thenyldiamine, tripelennamine, methdilazine, promethazine, trimeprazine, astemizole, azatadine, azelastine, cyproheptadine, desloratadine, diphenylpyraline, ebastine, emedastine, lorata-dine, mebhydrolin, olopatadine, phenindamine, terfenadine, buclizine, cetirizine, chlorcyclizine, cyclizine, hydroxyzine, meclizine, niaprazine.
Some of these have been discussed elsewhere (Consult Index).