Acute bronchitis occurs in patients without underlying chronic pulmonary disease and is characterized by acute onset of productive cough and sputum and no evidence of pneumonia or sinusitis. Many patients with acute bronchitis receive antibiotic treatment, but it is unclear if it is effective. Bent and colleagues conducted this meta-analysis to determine if antibiotic treatment was beneficial in patients with acute bronchitis.

English-language, randomized, controlled trials were included if they used an antibiotic in the treatment group and a placebo in the control group. Patients were not included if they had a history of chronic pulmonary disease or currently had pneumonia. Treatment in the studies had to last for at least five days to be included in the analysis. Outcomes measured included number of days of sputum production and amount of coughing. Eight trials were included in the analysis, and three antibiotics were studied: erythromycin, doxycycline and trimethoprim-sulfamethoxazole.

Overall, there was a small but statistically significant benefit in the patients who received antibiotics. This quantified to approximately one half day less of sputum production and coughing. However, four of the studies showed no significant benefit from the use of antibiotics. Although the authors found a benefit from antibiotic use in adults with acute bronchitis, they recommend considering the possible adverse effects and increase in antibiotic resistance before prescribing antibiotics. The benefit, although statistically significant, is small enough that it does not outweigh the risks.