Inhaled ICI 204,219 Blocks Antigen-Induced Bronchoconstriction in Subjects With Bronchial Asthma

Three inhalation formulations of ICI 204,219 were compared for antagonism of antigen-induced bronchoconstriction in 16 subjects with asthma who demonstrated reproducible hypersensitivity to allergen during screening challenges. Each subject received a single 0.2-mg dose of each formulation and was challenged with ragweed 30 min after administration of ICI 204,219 until the forced expiratory volume in 1 s (FEV 1 ) decreased by 20 percent or the maximum allergen concentration (100 νg/ml) was reached. The majority of subjects tolerated 100 µg/ml of allergen without a 20 percent decrease in FEV 1 . Inhalation formulations of ICI 204,219 successfully inhibited bronchoconstriction in subjects with reproducible sensitivity to ragweed challenges.