title: Effectiveness of beta lactam antibiotics compared with antibiotics active against atypical pathogens in non-severe community acquired pneumonia: meta-analysis.
abstract: OBJECTIVE
  To systematically compare beta lactam antibiotics with antibiotics active against atypical pathogens in the management of community acquired pneumonia.
  
  
  METHODS
  Medline, Embase, Cochrane register of controlled trials, international conference proceedings, drug registration authorities, and pharmaceutical companies. Review methods Double blind randomised controlled monotherapy trials comparing beta lactam antibiotics with antibiotics active against atypical pathogens in adults with community acquired pneumonia. Primary outcome was failure to achieve clinical cure or improvement.
  
  
  RESULTS
  18 trials totalling 6749 participants were identified, with most patients having mild to moderate community acquired pneumonia. The summary relative risk for treatment failure in all cause community acquired pneumonia showed no advantage of antibiotics active against atypical pathogens over beta lactam antibiotics (0.97, 95% confidence interval 0.87 to 1.07). Subgroup analysis was undertaken in those with a specific diagnosis involving atypical pathogens. We found a significantly lower failure rate in patients with Legionella species who were treated with antibiotics active against atypical pathogens (0.40, 0.19 to 0.85). Equivalence was seen for Mycoplasma pneumoniae (0.60, 0.31 to 1.17) and Chlamydia pneumoniae (2.32, 0.67 to 8.03).
  
  
  CONCLUSIONS
  Evidence is lacking that clinical outcomes are improved by using antibiotics active against atypical pathogens in all cause non-severe community acquired pneumonia. Although such antibiotics were superior in the management of patients later shown to have legionella related pneumonia, this pathogen was rarely responsible for pneumonia within the included trials. beta lactam agents should remain the antibiotics of initial choice in adults with non-severe community acquired pneumonia.
authors.affiliation: Respiratory and Infectious Diseases Department, Waikato Hospital, Private Bag 3200, Hamilton 2001, New Zealand. millsg@waikatodhb.govt.nz
authors.forename: Graham D
authors.initials: GD
authors.lastname: Mills
authors.forename: Michael R
authors.initials: MR
authors.lastname: Oehley
authors.forename: Bruce
authors.initials: B
authors.lastname: Arrol
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D017714:Community-Acquired Infections / Q000188:drug therapy; D004311:Double-Blind Method; D006801:Humans; D018410:Pneumonia, Bacterial / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome; D047090:beta-Lactams / Q000627:therapeutic use*
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams