Objective: Our goal was to determine whether beta2-agonists improve the symptoms of acute bronchitis or acute cough in patients who do not have underlying pulmonary disease.
Study design: We performed a systematic review including meta-analysis.
Data sources: We included randomized controlled trials comparing beta2-agonists with placebo or alternative therapies identified from the Cochrane Library, MEDLINE, EMBASE, conference proceedings, Science Citation Index, the System for Information on Grey Literature in Europe, and letters to manufacturers of beta2-agonists.
Outcomes measured: We measured duration, persistence, severity or frequency of cough, productive cough, and night cough; duration of activity limitations; and adverse effects.
Results: Two trials in children with cough and no obvious airway obstruction did not find any benefits from beta2-agonists. Five trials in adults with cough and with or without airway obstruction had mixed results, but summary statistics did not reveal any significant benefits from beta2-agonists. Studies that enrolled more wheezing patients were more likely to show benefits from beta2-agonists, and in one study only patients with evidence of airflow limitation were more likely to benefit. Patients given beta2-agonists were more likely to report tremor, shakiness, or nervousness than those in the control groups.
Conclusions: There is no evidence to support using beta2-agonists in children with acute cough and no evidence of airflow obstruction. There is 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.