Meta-analysis: effect of long-acting beta-agonists on severe asthma exacerbations and asthma-related deaths.
BACKGROUND
Long-acting beta-agonists may increase the risk for fatal and nonfatal asthma exacerbations.


OBJECTIVE
To assess the risk for severe, life-threatening, or fatal asthma exacerbations associated with long-acting beta-agonists.


METHODS
English- and non-English-language searches of MEDLINE, EMBASE, and Cochrane databases; the U.S. Food and Drug Administration Web site; and references of selected reviews through December 2005.


METHODS
Randomized, placebo-controlled trials that lasted at least 3 months and evaluated long-acting beta-agonist use in patients with asthma. All trials allowed the use of as-needed short-acting beta-agonists.


METHODS
Outcomes measured were Peto odds ratio (OR) and risk difference of severe exacerbations requiring hospitalization, life-threatening exacerbations requiring intubation and ventilation, and asthma-related deaths. The OR for asthma-related deaths was obtained from the Salmeterol Multi-center Asthma Research Trial (SMART).


RESULTS
Pooled results from 19 trials with 33 826 participants found that long-acting beta-agonists increased exacerbations requiring hospitalization (OR, 2.6 [95% CI, 1.6 to 4.3]) and life-threatening exacerbations (OR, 1.8 [CI, 1.1 to 2.9]) compared with placebo. Hospitalizations were statistically significantly increased with salmeterol (OR, 1.7 [CI, 1.1 to 2.7]) and formoterol (OR, 3.2 [CI, 1.7 to 6.0]) and in children (OR, 3.9 [CI, 1.7 to 8.8]) and adults (OR, 2.0 [CI, 1.1 to 3.9]). The absolute increase in hospitalization was 0.7% (CI, 0.1% to 1.3%) over 6 months. The risk for asthma-related deaths was increased (OR, 3.5 [CI, 1.3 to 9.3]), with a pooled risk difference of 0.07% (CI, 0.01% to 0.1%).


CONCLUSIONS
The small number of deaths limited the reliability in assessing this risk, and 28 studies did not report information on the outcomes of interest.


CONCLUSIONS
Long-acting beta-agonists have been shown to increase severe and life-threatening asthma exacerbations, as well as asthma-related deaths.
Salpeter
Shelley R
SR
Santa Clara Valley Medical Center, San Jose, California 95128, USA. Salpeter@stanford.edu
Buckley
Nicholas S
NS
Ormiston
Thomas M
TM
Salpeter
Edwin E
EE
D000318:Adrenergic beta-Agonists / Q000008:administration & dosage / Q000009:adverse effects*; D000328:Adult; D000420:Albuterol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage / Q000009:adverse effects*; D001249:Asthma / Q000188:drug therapy* / Q000401:mortality*; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000009:adverse effects; D002648:Child; D004334:Drug Administration Schedule; D004983:Ethanolamines / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D000068759:Formoterol Fumarate; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D016032:Randomized Controlled Trials as Topic; D012008:Recurrence; D012307:Risk Factors; D000068299:Salmeterol Xinafoate; D016896:Treatment Outcome
D000318:Adrenergic beta-Agonists; D018927:Anti-Asthmatic Agents; D001993:Bronchodilator Agents; D004983:Ethanolamines; D000068299:Salmeterol Xinafoate; D000420:Albuterol; D000068759:Formoterol Fumarate