The original pseudopeptide drug ingamine (4-[N-[2-(imidazol-4-yl)ethyl]-carbamoyl] butyric acid) was studied on the traditional model of antigen-induced bronchospasm in actively sensitized guinea pigs. The drug was introduced using various methods (by inhalation, via intragastric tube, and by intraperitoneal injections) in a range of doses (20, 50, 150, or 500 mg/kg). The new drug exhibited a pronounced dose-dependent protector action for all ways of introduction, but the most significant effect was observed upon inhalation, whereby the degree of bronchospasm inhibition exceeded 80%. In comparison to the reference drug sodium cromoglycate, ingamine (in equimolar doses) showed a higher activity with respect to the antigen-dependent bronchospasmic reactions. It can be expected that ingamine will provide for the effective treatment of bronchial obstruction under clinical conditions.