Changes in aeroallergen-induced pulmonary mechanics in actively sensitized guinea pig: inhibition by azelastine.

The influence of orally administered azelastine and selected H1-receptor antagonists on aeroallergen-induced acute lung anaphylactic responses in actively sensitized guinea pigs (experimental asthma model) was studied. Azelastine (1 mg/kg, PO, two hours) exerted significant inhibition of the aeroallergen-induced decline in dynamic lung compliance and an elevation in pulmonary airway resistance. Terfenadine, pyrilamine, and diphenhydramine given as oral doses of 1 mg/kg two hours before aeroallergen challenge exerted weak or no inhibition of acute lung anaphylactic responses. In conclusion, the data obtained in this study showed that azelastine administered orally is capable of exerting antiasthmatic effects in both the central and peripheral airways of guinea pigs. This effect may be attributed to its ability to inhibit the formation or secretion of pharmacologic mediators (ie, histamine, LTC4/D4, .O2-) from inflammatory cells.