Efficacy of Epinastine Hydrochloride for Antigen-Provoked Nasal Symptoms in Subjects with Orchard Grass Pollinosis

ABSTRACTBackgroundAmong the gramineae species, orchard grass is a typical causative pollen that provokes seasonal rhinitis. The purpose of this study was to examine the protective efficacy of epinastine hydrochloride for signs and symptoms caused by repeated nasal provocation with discs containing orchard grass pollen.MethodsA single-dose, placebo-controlled, double-blind, crossover clinical study was conducted in subjects with orchard grass pollinosis. The pollen challenge was conducted with the use of provocation discs containing orchard grass pollen.ResultsEpinastine hydrochloride suppressed nasal symptoms caused by nasal provocation tests using orchard grass pollen discs. Among the nasal symptoms, the number of sneezing was significantly inhibited 30 minutes and 60 minutes after the administration of epinastine hydrochloride, as compared with placebo. There were no adverse reactions to the study drugs.ConclusionsOur results suggest that nasal provocation tests with discs containing orchard grass pollen is a useful method for evaluating the onset of action of antiallergic drugs. As compared with placebo, epinastine hydrochloride decreased early-phase sneezing and the total nasal symptom score after repeated nasal provocations with orchard grass pollen discs.