Comparison of the Effects on Airway Conductance of a New Selective Beta-adrenergic Blocking Drug, Atenolol, and Propranolol in Asthmatic Subjects

Five patients with mild to moderate asthma were studied after an intravenous saline control followed by atenolol (i.v. 7-9mg) and propranolol (i.v. 0.2-1.0 mg) in a body plethysmograph. Following propranolol, heart rate did not change but specific airway conductance dropped with 65% and airway resistance increased with 130%. Following atenolol, there was a dose-related decrease in heart rate (25% after 9 mg i.v.) and a slight but not significant tendency to a decrease in airway conductance on the highest doses. None of the patients experienced any change in symptoms after administration of atenolol but after propranolol two patients had worsened symptoms. It is concluded that, in contrast to propranolol, atenolol blocks the beta-receptors in the heart preferentially to those in the lungs, and thus could be given to patients with obstructive lung disease.