Selective histamine blockade in asthma: the effect of astemizole on resting bronchial tone and exercise induced broncho-constriction

The orally active histamine HI-blocker astemizole was investigated for its effect on resting bronchial tone and exercise-induced broncho-constriction in 20 asthmatic patients by a double-blind placebo-controlled study. Astemizole produced acute bronchodilation with an average 16% improvement in FEVl by 3 hours. After exercise challenge, astemizole partially inhibited exercise induced bronchoconstriction. These results suggest that asthmatic patients have augmented background resting histamine tone which is reversible by Hl blockade