EFFICACY AND SIDE-EFFECTS OF BETA(2)-AGONISTS BY INHALED ROUTE IN ACUTE ASTHMA IN CHILDREN - COMPARISON OF SALBUTAMOL, TERBUTALINE, AND FENOTEROL

Thirty-seven separate episodes of acute bronchial asthma were studied in 21 asthmatic children. The bronchodilator, cardiovascular, and trem origenic responses following administration of salbutamol (SAL), terbu taline (TER) and fenoterol (FEN) by closed-port intermittent nebulizat ion were compared for a period of 8 hr. SAL was used at the maximum do se recommended by the manufacturer and TER and FEN at the average dose s commonly used in children. Eleven acute attacks were treated with SA L, 12 with TER, and 14 with FEN. Pulmonary function was evaluated by c linical assessment and by the spirometric indices FEV(1) and FEF(25-75 ). Tremor was objectively measured, as well as heart rate (HR), respir atory rate, and blood pressure. The onset of bronchodilating effect oc curred at 5 min for all three drugs and there were no differences in i ntensity and duration of bronchodilation between drugs. ALl three drug s caused rapid onset of tremor (5 min) and this tended to be more inte nse with SAL. There was a slight decrease in HR in the TER group, wher eas SAL and FEN caused increase in HR, with mean values significantly greater than in the TER group from 5 to 30 min after drug administrati on. Our results indicate that the three short-acting beta(2)-agonists studied are equally effective in treatment of acute bronchospasm by th e inhaled route in children, in the doses used. Our findings imply tha t a dose of SAL twice as great as that commonly used by nebulization i n children is equipotent to those usually employed for TER and FEN, as far as therapeutic effect is concerned, but it could generate more in tense tremorigenic and tachycardic side effects.