Prophylactic effect of aminophylline and salbutamol on histamine-induced bronchoconstriction

The effect of salbutamol 200 micrograms aerosol, i.v. high-dose aminophylline 670 mg or placebo (aerosol and infusion) on bronchomotor tone were compared in normal volunteers before and after bronchial provocation with histamine aerosol 500 micrograms. The study was a double-blind cross-over design. Specific airways conductance of the lower airway (s. Glaw) was measured using a forced airflow oscillation technique. All subjects receiving aminophylline had tremor and irritability, whereas after salbutamol there were no noticeable systemic or psychological effects. Before the administration of histamine, salbutamol caused significant bronchodilatation compared with control: aminophylline did not induce a significant change in airway conductance. The effect of histamine administration on s. Glaw was only partially blocked by the high dose of aminophylline, but was completely blocked by salbutamol.