Abstract

Terfenadine (Triludan - Merrell) and astemizole (Hismanal - Janssen) are two chemically unrelated oral H₁-receptor antihistamines marketed recently for the relief of allergic rhinitis, conjunctivitis and other manifestations of histamine release, such as urticaria. Both are claimed to be free of the usual anticholinergic and CNS effects, especially sedation, which limit the use of other H₁ antihistamines. If this major claim justified?