A comparison of the effect on airway resistance of a new beta blocking drug, ICI.50,172 and propranolol.

A new beta-adrenergic receptor blocking agent, ICI.50,172, has been compared with propranolol with respect to the effects on airway resistance (AWR), forced expiratory volume (FEVi) and pulse rate. AWR was measured by body plethysmography. The drugs were given intravenously to ten asthmatic patients on different occasions. ICI.50,172 caused no subjective alteration of their respiratory condition, and only a slight increase in AWR. Propranolol caused dyspnoea and wheeze in all but one of the subjects together with a marked increase in AWR. It is concluded that ICI.50,172 can safely be administered to asthmatic patients and that its introduction could represent an important advance in beta blocking therapy.