Isoetharine versus albuterol for acute asthma: greater immediate effect, but more side effects.
OBJECTIVE
To compare the magnitudes of the immediate effects of the nebulized beta-agonists isoetharine and albuterol in the treatment of acute severe asthma.


METHODS
Fifty-one adults presenting with severe asthma exacerbations (forced expiratory volumes in the first second of exhalation [FEV1] <40% of predicted) to the emergency department were randomized (double-blind) to receive hourly inhaled nebulization treatment with either isoetharine (5 mg) or albuterol (2.5 mg). The FEV1 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 mean FEV1 (+/-SEM) by a significantly greater amount than did the albuterol group: 60% +/- 11% versus 39% +/- 5%, respectively (P <0.05). One hour later the mean FEV1 were equivalent. This pattern repeated itself after the second hourly treatment. The two groups did not differ in any outcome parameters (FEV1 at discharge, number of nebulized treatments required, the number of inpatient admissions, number of clinical relapses after discharge). More patients treated with isoetharine had side effects (36% versus 4% for albuterol, P <0.01), 1 of whom required discontinuation from the study.


CONCLUSIONS
Both medications were equally effective in alleviating bronchospasm. The immediate effect of isoetharine was significantly greater, but equalized that of albuterol within an hour after treatment. There were more side effects with isoetharine.
Shrestha
M
M
Division of Emergency Medicine, Department of Surgery, University of Texas Southwestern Medical School, Dallas, USA.
Gourlay
S
S
Robertson
S
S
Bidadi
K
K
Wainscott
M
M
Hayes
J
J
D000208:Acute Disease; D000280:Administration, Inhalation; D000328:Adult; D000420:Albuterol / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects*; D006801:Humans; D007528:Isoetharine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D016896:Treatment Outcome
D001993:Bronchodilator Agents; D000420:Albuterol; D007528:Isoetharine