An evaluation of repeated injections of epinephrine for the initial treatment of acute asthma.

We evaluated 4 treatment regimens using single and multiple injections of epinephrine for the initial treatment of acute asthma in children. Twenty-five patients received 2 injections of epinephrine followed by Sus-Phrine (Group EES) given 20 min apart, 25 received Sus-Phrine only (Group S), 24 received Sus-Phrine followed by 2 placebo injections 20 min apart (Group SPP), and 14 received epinephrine only (Group E). Clinical score and pulmonary function were assessed over a 2-h period. The failure rate was similar in Groups EES, S, and SPP (combined failure rate, 17.8%). The failure rate (46%) in Group E was significantly greater (p less than 0.05). The clinical score and pulmonary function was significantly better 5 min after the first injection in Group EES than in Groups S and SPP, but no significant differences were noted thereafter. At 25 min the pulmonary function was similar whether 1 or 2 epinephrine injections were administered. The number of patients exhibiting side effects was significantly greater in the groups receiving epinephrine than in the groups receiving Sus-Phrine only (p less than 0.05). The relapse rates during the 24-h period after the emergency room treatment were similar in Groups EES, S, and SPP (combined relapse rate, 14.3%). We conclude that repeated injections of epinephrine are necessary to sustain bronchodilation but that they do not have a cumulative effect. Furthermore, there is little therapeutic advantage of these repeated injections over a single injection of Sus-Phrine for the initial treatment of acute asthma.