Pharmacology of non-sedating H1 antihistamines

A review of the preclinical pharmacology of non-sedating H1 antihistamines includes comparative data on potency, duration of action, side effect liability, especially CNS depressant and anticholinergic activity and new approaches that may further enhance the efficacy of these newer compounds. Data discussed mainly involve studies in which multiple comparative agents were used and usually include astemizole, cetirizine, loratadine and terfenadine. New research approaches include the combination of PAF inhibition with antihistamine activity and the inhibitory effects these compounds may have on cellular influx in allergic diseases.