[Effect of azelastine on bronchial hyperresponsiveness].

We have investigated the effect of azelastine on bronchial responsiveness in 25 asthmatics, using methacholine inhalation challenge, (Astograph). Three parameters, initial respiratory resistance (RrsC), bronchial sensitivity (Dmin), and bronchial reactivity (SGrs/GrsC) were studied. After 8 weeks' treatment with 2 mg azelastine b.i.d., Dmin was increased significantly and after 4 weeks an insignificant increase was observed. RrsC and SGrs/GrsC did not change significantly during the 8 week treatment. Recent advances have revealed that various chemical mediators, especially leukotrienes, are closely related to bronchial hyperresponsiveness. Accordingly, the improvement of Dmin observed during azelastine treatment might be ascribed to its inhibitory action on the synthesis and release of leukotrienes.