[Effect of loratadine--selective antagonist of histamine (H1) receptor--on allergen-induced bronchoconstriction in atopic asthmatics].

The aim of this study was to evaluate the effect of loratadine on allergen-induced bronchoconstriction. The study was performed in 7 asthmatic patients with sensitivity to Dermatophagoides pteronyssinus, 4 women and 3 men. aged from 19 to 37 years. The allergen inhalatory--challenge test was performed according to Chai et al. Early phase of Dermatophagoides pteronyssinus--induced bronchoconstriction appeared in all examined patients, but late phase of bronchial obstruction was observed only in 3 persons. 30 mg orally administered of loratadine have no protect effect on early phase of allergen--induced bronchoconstriction. After loratadine ingestion the late phase of this bronchial obstruction disappeared.