Comparison of the effect of alprenolol and propranolol on specific airway conductance in asthmatic subjects.

Alprenolol did not cause a significant fall in the mean of the specific airway conductance in nine asthmatic subjects who did show a significant fall with propranolol. Thus alprenolol is not contraindicated in asthmatic subjects, though it should be used with caution intravenously, as one subject showed a substantial fall in airway conductance at three minutes which recovered within 30 minutes. Until further studies are completed these results should not be applied to bronchitics with increased airway resistance.