ABSTRACT
BACKGROUND: Acute cough and bronchitis are common primary care diagnoses often treated withβ2-agonists (eg, albuterol). This systematic review sought to assess whether β2-agonists constitute effective treatment for these conditions.
POPULATION STUDIED: A total of 492 patients older than 2 years was gathered from randomized controlled trials measuring the efficacy of β2-agonists versus placebo or erythromycin for treatment of “acute cough,” “acute bronchitis,” or “acute transient cough” without clear etiology (pneumonia, pertussis, or sinusitis). The maximum mean duration of cough acceptable for inclusion was 30 days. Although no information was provided about specific diagnostic criteria, numbers of adult smokers and wheezers, or specifics of clinical presentation (fever, tachypnea), the population studied seems similar to that of a typical family practice.
STUDY DESIGN AND VALIDITY: The authors searched multiple databases, including MEDLINE and EMBASE, The Cochrane Library, reference lists of retrieved articles, review articles, textbooks, and information from manufacturers. Two investigators examined the search results, forwarding those that met inclusion criteria to the remaining 3 investigators, who graded the studies using the Jadad methodology scale, on the basis of randomization, blinding, and withdrawals. Disagreement regarding study quality was common (κ= 0.27) and was resolved by discussion. Included studies were then divided into 3 groups for analysis: 2 pediatric trials comparing β2-agonists with placebo; 4 adult trials comparing β2-agonists with placebo; and 1 adult trial comparing β2-agonists with erythromycin. Summary statistics were generated using Review Manager 4.1.
OUTCOMES MEASURED: Outcomes measured included cough severity, duration, and productivity; lost work days; night cough; and adverse effects. Only one trial measured compliance. Cost and patient satisfaction were not addressed.
RESULTS: The overall quality of the included studies was fair. The pediatric studies revealed no benefit from albuterol. In the adult placebo trials, 1 demonstrated no benefit and 3 demonstrated slight improvement in cough severity. In the erythromycin study, those in the albuterol group had less cough or productive cough after 7 days, but the groups did not differ in night cough, time to improvement, or missed work days. When all the adult studies were combined, there was no difference in cough after 7 days, in productive cough, or in night cough. Studies that had enrolled more wheezing patients were more likely to show benefits than those that had not.
This systematic review demonstrates that oral β2-agonists provide little benefit for patients with uncomplicated bronchitis and may have adverse effects. Clinicians should keep in mind that the total number of trials in this review is limited and that their quality is fair. Further research is needed to evaluate β2-agonist utility in patients who are also wheezing or smoking, to compare oral vs inhaled β2-agonists with properly used spacers, and to assess the potential contributions of other symptomatic therapies.