ISOETHARINE VERSUS ALBUTEROL FOR ACUTE ASTHMA - GREATER IMMEDIATE EFFECT, BUT MORE SIDE-EFFECTS

PURPOSE: TO compare the magnitudes of the immediate effects of the neb ulized beta-agonists isoetharine and albuterol in the treatment of acu te severe asthma. PATIENTS AND METHODS: Fifty-one adults presenting wi th severe asthma exacerbations (forced expiratory volumes in the first second of exhalation [FEV(1)] < 40% of predicted) to the emergency de partment were randomized (double-blind) to receive hourly inhaled nebu lization treatment with either isoetharine (5 mg) or albuterol (2.5 mg ). The FEV(1) was measured immediately before and after each nebulized treatment. Any side effects were recorded. RESULTS: Immediately after the first nebulized treatment, the isoetharine group improved its mea n FEV(1) (+/- SEM) by a significantly greater amount than did the albu terol group: 60% +/- 11% versus 39% +/- 5%, respectively (P < 0.05). O ne hour later the mean FEV(1) were equivalent. This pattern repeated i tself after the second hourly treatment. The two groups did not differ in any outcome parameters (FEV(1) at discharge, number of nebulized t reatments required, the number of inpatient admissions, number of clin ical relapses after discharge). More patients treated with isoetharine had side effects (36% versus 4% for albuterol, P < 0.01), 1 of whom r equired discontinuation from the study. CONCLUSIONS: Both medications were equally effective in alleviating bronchospasm. The immediate effe ct of isoetharine was significantly greater, but equalized that of alb uterol within an hour after treatment. There were more side effects wi th isoetharine.