Clinical Health Updates

Second-line antibiotics more effective than first-line in AECB

Clinical Question:
Are second-line antibiotics more effective for the treatment of acute exacerbation of chronic bronchitis than first-line antibiotics?

Bottom Line:
Compared to first-line antibiotics, second-line antibiotics are more effective, but not less safe, when administered to patients with AECB. The available data did not allow for stratified analyses according to the presence of risk factors for poor outcome, such as increased age, impaired lung function, airway obstruction, and frequency of exacerbations; this fact should be taken into consideration when interpreting the findings of this metaanalysis.

Dimopoulos G, Siempos II, Korbila IP, Manta KG, Falagas ME. Comparison of first-line with second-line antibiotics for acute exacerbations of chronic bronchitis: a meta-analysis of randomized controlled trials. Chest 2007;132:447-55.

Study Design:
Meta-analysis (randomized controlled trials)

Although first-line antibiotics are still recommended by most guidelines as the treatment of choice for patients with AECB, increasing resistance to these antibiotics has prompted many clinicians to reconsider that choice. The authors identified 12 randomized controlled trials with 2261 adults that compared first-line antibiotics (amoxicillin, ampicillin, pivampicillin, trimethoprim sulfamethoxazole, and doxycycline) with broad-spectrum antibiotics (amoxicillin/clavulanic acid, cefaclor, macrolides, and quinolones). Nine studies were double-blinded and 3 were single-blinded; the study quality was judged as good for for all but 2 studies. However, only 2 studies reported data on the basis of intention to treat. Also, many studies included both inpatients and outpatients, which might cloud the analysis. The mean age of patients was approximately 60 years for most studies. The primary outcome was treatment success; only 5 studies reported mortality data, and there were too few deaths for useful analysis (7 – 10 in each group). First-line antibiotics were less likely to result in treatment success than broad-spectrum antibiotics (odds ratio = 0.51; 95% CI, 0.34 – 0.75). The authors performed subgroup analyses and found similar results when they included only double-blinded studies, only studies after 1991, and only studies rated as “good quality.” They did not find an advantage to second-line antibiotics when the analysis was limited to older studies.