Response of asthmatics to isoprenaline and salbutamol aerosols administered by intermittent positive-pressure ventilation.
The bronchodilator and cardiac effects produced by aerosols of 0.5% isoprenaline and of 0.25, 0.5, and 1% salbutamol administered in 40% oxygen by intermittent positive-pressure ventilation were compared in 24 asthmatic patients. Isoprenaline and salbutamol in concentrations of 0.5% were equipotent in peak bronchodilator effect; salbutamol was superior in total bronchodilator effect and duration of average effect, but the peak bronchodilator effect occurred earlier after isoprenaline. Significantly greater tachycardia was produced by 0.5% isoprenaline than by the same concentration of salbutamol. The 0.25, 0.5, and 1% concentrations of salbutamol had about the same peak bronchodilator effect, but there was a stepwise increase in total effect and duration of average effect in relation to the concentration used. A similar stepwise increase in heart rate was also noted, but with all concentrations this was significantly less than with 0.5% isoprenaline. It was concluded that a 0.5% solution of salbutamol, which provided maximal bronchodilatation without important tachycardia, was therapeutically superior to the other three treatments.
D000293:Adolescent; D000328:Adult; D000336:Aerosols; D000368:Aged; D001249:Asthma / Q000188:drug therapy*; D001993:Bronchodilator Agents / Q000008:administration & dosage* / Q000009:adverse effects; D002986:Clinical Trials as Topic; D004562:Electrocardiography; D000431:Ethanol / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007545:Isoproterenol / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy; D011175:Positive-Pressure Respiration; D013147:Spirometry; D013610:Tachycardia / Q000139:chemically induced
D000336:Aerosols; D001993:Bronchodilator Agents; D000431:Ethanol; D007545:Isoproterenol