The effect of single and multiple dose therapy with azelastine on the immediate asthmatic response to allergen provocation testing.

The effect of 2.2 or 4.4 mg of azelastine administered orally on immediate allergen-induced airflow obstruction was studied in 20 young patients with asthma. Provocation testing was performed after a single oral dose of azelastine or placebo and repeated after 3 weeks of twice daily therapy with azelastine or placebo. After multiple dose therapy with 4.4 mg of azelastine for 21 days, significantly more allergen was required to produce a 35% fall in specific airways conductance than after placebo therapy (p less than 0.008). Apart from a "bitter, metallic" taste in the mouth reported by 41.2% of the patients while they were receiving azelastine, no other unwanted effects were encountered.