Beta2-agonists for acute bronchitis

Abstract

Background: The optimal treatment for acute bronchitis is not clear. Because many patients with acute bronchitis have airflow limitation as well as cough, beta2-agonists may be useful.

Objectives: To determine whether beta2-agonists improve the symptoms of acute bronchitis in patients who do not have underlying pulmonary disease.

Search strategy: Cochrane Library, MEDLINE, EMBASE, and Conference Proceedings using "bronchodilator (exp)", "adrenergic beta-agonist (exp)", or "sympathomimetics (exp)" and "bronchitis" or "cough"; Science Citation Index for referenced publications; and letters to manufacturers of beta2-agonists.

Selection criteria: Trials in which patients (adults or children age > 2 years) without known pulmonary disease who were diagnosed with acute bronchitis or acute cough without other cause were randomized to beta2-agonist vs. placebo, no treatment, or alternative treatment.

Data collection and analysis: Three reviewers independently first selected outcomes and evaluated trial quality while blinded to study results, and then extracted data. Trials in children and in adults were analyzed separately.

Main results: Two trials in children with acute cough and no evidence of airway obstruction did not find any benefits from beta2-agonists. Five trials in adults with acute cough or acute bronchitis had mixed results, but overall summary statistics did not reveal any significant benefits from beta2-agonists. Subgroups of patients with evidence of airflow limitation had lower symptom scores if given beta2-agonists in one trial; and the trials that did note quicker resolution of cough in patients given beta2-agonists were those that had a higher proportion of patients with wheezing at baseline. Patients given beta2-agonists (whether oral or inhaled) were more likely to report tremor, shakiness, or nervousness than patients in the control groups (NNH for children 9, 95% CI 5 to 100; NNH for adults 2.3, 95% CI 2 to 3).

Reviewer's conclusions: There is no evidence to support using beta2-agonists in children with acute cough who do not have evidence of airflow obstruction. There is also little evidence that the routine use of beta2-agonists for adults with acute cough is helpful. These agents may reduce symptoms, including cough, in patients with evidence of airflow obstruction; but this potential benefit is not well-supported by the available data and must be weighed against the adverse effects associated with beta2-agonists.