Pharmacology General b95f78ee All of the following antihistaminics can be used topically except: A Ketotifen B Levocetrizine C Olapatadine D Astemizole High-Yield Explanation Azelastine, Astemizole, Ketotifen, Olapatadine are the antihistaminics that can be used topically in allergic rhinitis and conjuctivitis.