Subcutaneous epinephrine versus nebulized terbutaline in the emergency treatment of asthma

The efficacy of aerosolized terbutaline compared with subcutaneous epinephrine in the treatment of acute asthma was studied. The study population consisted of 30 men and women, 17 to 35 years old who were diagnosed at a hospital emergency department as having acute asthmatic attacks. Heart rate, blood pressure, and peak expiratory flow rate (PEFR) were measured on admission and 5, 15, and 30 minutes after initial drug treatment. One group received an initial dose of epinephrine hydrochloride (1:1000) 0.3 ml subcutaneously and a second, identical dose 15 minutes later. The other group received terbutaline sulfate 1 mg (for patients weighing ≤ 40 kg) or 2 mg (for patients weighing > 40 kg) by nebulizer over a five-minute period. Treatment was considered successful in patients whose PEFR was both greater than 60 liters/min and more than 16% greater than the individual's baseline PEFR. Improvements in the PEFR and in the ratio of the measured PEFR to the expected PEFR were compared for the two test groups. Five minutes after the initial drug administration, the mean improvement in PEFR was significantly greater in the terbutaline group (40% improvement) than in the epinephrine group (17% improvement). At 15 and 30 minutes, there were no significant differences in mean improvement in PEFR, but a trend favoring epinephrine was observed. The numbers of patients showing ≥ 16% improvement in PEFR over baseline were not significantly different between the two groups. For patients in both drug groups with initial PEFR less than 60 liters/min, PEFR did not exceed 100 liters/min after treatment. No significant effect on heart rate was observed after administration of either drug. Aerosolized terbutaline is as effective as subcutaneous epinephrine in management of patients with acute bronchoconstricting episodes.