title: Prophylactic antibiotic therapy for chronic bronchitis.
abstract: BACKGROUND
  The use of prophylactic antibiotics to reduce the frequency and severity of acute exacerbations of chronic bronchitis is controversial.
  
  
  OBJECTIVE
  To determine if prophylactic antibiotics reduce the frequency of exacerbations and/or days of disability in subjects with chronic bronchitis.
  
  
  METHODS
  We searched the Cochrane Airways Group Register of Clinical Trials and the bibliographies of relevant articles.
  
  
  METHODS
  Randomised controlled trials of prophylactic antibiotics in patients with chronic bronchitis and/or COPD were selected.
  
  
  METHODS
  The eligibility of studies for inclusion was evaluated by three independent reviewers.
  
  
  RESULTS
  Nine trials involving 1055 subjects were included in the analysis. All were performed before 1970. Concealment of allocation was assessed as clearly adequate in only 3 studies. The likelihood of having a exacerbation at any time during the course of the study was decreased with treatment (Relative Risk 0.91, 95% Confidence Intervals (CI) 0.84, 0.99). There was a small reduction in the number of exacerbations per patient per year with prophylactic antibiotics but this was not statistically significant ( Weighted Mean Difference (WMD) -0.15, 95%CI -0.34, 0.04 ). There was a modest but significant reduction of 22% in the number of days of disability per patient per month treated ( WMD -0.95, 95%CI -1.89 to - 0.01 ). A parallel reduction in the days of disability for each exacerbation (WMD -2.08, 95% CI -4.08 to -0.07) was seen. There was a small increase in adverse effects with antibiotics.
  
  
  CONCLUSIONS
  Prophylactic antibiotics in chronic bronchitis / COPD have a small but statistically significant effect in reducing the days of illness due to exacerbations of chronic bronchitis. They do not have a place in routine treatment because of concerns about the development of antibiotic resistance and the possibility of adverse effects. The available data are over 30 years old, so the pattern of antibiotic sensitivity may have changed and there is a wider range of antibiotics in use.
authors.affiliation: Dept of Medicine, University of Auckland, New Zealand. pn.black@auckland.ac.nz
authors.forename: T
authors.initials: T
authors.lastname: Staykova
authors.forename: P N
authors.initials: PN
authors.lastname: Black
authors.forename: E E
authors.initials: EE
authors.lastname: Chacko
authors.forename: P
authors.initials: P
authors.lastname: Poole
mesh_terms: D019072:Antibiotic Prophylaxis / Q000379:methods*; D029481:Bronchitis, Chronic / Q000188:drug therapy*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D055502:Secondary Prevention