Inhibitory effect of KWD 2131, terbutaline, and DSCG on the immediate and late allergen-induced bronchoconstriction.

β-adrenoceptor stimulants exhibit both bronchodilating and anti-allergic activities. KWD 2131 is a new β-agonist with preferably anti allergic property. In an earlier study, nebulized KWD 2131 in a non-bronchodilating dose (0.25 - 0.50 mg) did not give significant protection against immediate reaction. The present study evaluated whether an increased nebulized dose of the new compound (5 mg) could protect against either immediate and/or late responses. The response was compared with a nebulized dose of terbutaline (5 mg) and with twice the recommended dose DSCG (40 mg). The study included 10 patients with known allergic asthma. It was designed as a single-blind cross-over trial with randomized allocation of the drugs. Lung functions were measured spirometrically and by body-plethysmograph; flow volume curves were drawn. KWD 2131 gave no significant protection against immediate reaction. Both terbutaline and DSCG did so, terbutaline being more efficient. Contrary to the β-agonists, DSCG also gave protection against late response.