Budesonide reduces sensitivity to antigen but does not alter baseline tone or responsiveness to carbachol, terbutaline, and enprofylline in IgE-sensitized guinea-pig tracheae.

In vitro incubation of IgE-sensitized guinea-pig tracheal rings with 10(-7) M budesonide for 24 h significantly shifted the concentration-response curve to antigen by 5-fold to the right. Smooth muscle characteristics such as baseline tone, muscarinic contraction or relaxation to beta 2-receptor agonists and xanthines were not or only marginally affected by this exposure of airway tissue to a glucocorticoid drug. It is concluded that budesonide reduced anaphylactic IgE-driven release of contractile mediators.