Effects of H1-receptor antagonists on nasal obstruction in atopic patients.

The aim of this study is to investigate whether H1-receptor antagonists, besides their effect on nasal itching and sneezing, also have a measurable effect on nasal obstruction caused by allergen challenge. The antihistamine used was astemizole (10 mg) versus placebo, in a double-blind, cross-over, randomized study of two groups. Between the two sessions there was a wash-out period of at least 4 weeks. Seven patients of both sexes, with proven allergy to grass pollen, underwent a specific long-term provocation with grass pollen in the Vienna challenge chamber. Using a physiological method of challenge and a sensitive method for evaluating nasal function, we were able to prove H1-receptor antagonist influence on nasal airway obstruction. The main parameters obtained are nasal flow and nasal resistance at 75, 150 and 300 Pa, evaluated by active anterior rhinomanometry. We also investigated subjective symptom scores (0-3) of nasal, eye, and lung symptoms. It can be shown that the nasal flow under astemizole treatment is statistically significantly higher than the nasal flow under placebo treatment (P = 0.034). This is in accordance with the findings in subjective nasal itching and sneezing.