title: Daptomycin versus linezolid for treatment of vancomycin-resistant enterococcal bacteremia: systematic review and meta-analysis.
abstract: BACKGROUND
  Linezolid, which has bacteriostatic activity, is approved for the treatment of vancomycin-resistant enterococci (VRE) infections. Meanwhile, daptomycin exerts bactericidal activity against VRE, but is not approved for the treatment of VRE bacteremia. Only a few studies with small sample sizes have compared the effectiveness of these drugs for treatment of VRE bacteremia.
  
  
  METHODS
  PubMed, EMBASE, and the Cochrane Library were searched for studies of VRE bacteremia treatment published before January 1, 2014. All studies reporting daptomycin and linezolid treatment outcomes simultaneously were included. The endpoints were mortality and microbiological cure. The adjusted odds ratios (aORs) of mortality in daptomycin- and linezolid-treated patients were extracted if available. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for all outcomes using a random-effects model.
  
  
  RESULTS
  Thirteen studies (532 patients receiving daptomycin, 656 patients receiving linezolid) met the selection criteria. All studies had retrospective cohort designs and relatively small sample sizes. Eight studies compared the aORs of mortality in daptomycin- and linezolid-treated patients. Four studies were published as conference papers and there was significant heterogeneity among these studies (I2 = 63%, p = 0.04). Daptomycin use was not associated with better microbiological cure (daptomycin vs. linezolid, OR: 0.67, 95% CI: 0.42-1.06, p = 0.09). However, mortality was higher in patients receiving daptomycin (OR: 1.43, 95% CI: 1.09-1.86, p = 0.009). Subgroup analysis of studies that reported aORs indicated that daptomycin was associated with higher mortality (OR: 1.59, 95% CI: 1.02-2.50, p = 0.04). There was no evidence of publication bias, but all enrolled studies were retrospective, had small sample sizes, and had substantial limitations.
  
  
  CONCLUSIONS
  Although limited data is available, the current meta-analysis shows that linezolid treatment for VRE bacteremia was associated with a lower mortality than daptomycin treatment. However, the results should be interpreted cautiously because of limitations inherent to retrospective studies and the high heterogeneity among studies. A large randomized trial is needed to confirm the present results.
authors.forename: Yu-Chung
authors.initials: YC
authors.lastname: Chuang
authors.affiliation: Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, 7 Chung-Shan South Road, Taipei 100, Taiwan. 14bcr@yahoo.com.tw.
authors.forename: Jann-Tay
authors.initials: JT
authors.lastname: Wang
authors.forename: Hsin-Yi
authors.initials: HY
authors.lastname: Lin
authors.forename: Shan-Chwen
authors.initials: SC
authors.lastname: Chang
mesh_terms: D000081:Acetamides / Q000494:pharmacology / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy* / Q000382:microbiology; D017576:Daptomycin / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D000069349:Linezolid; D023303:Oxazolidinones / Q000494:pharmacology / Q000627:therapeutic use*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014640:Vancomycin / Q000494:pharmacology / Q000627:therapeutic use; D020713:Vancomycin Resistance; D065507:Vancomycin-Resistant Enterococci / Q000187:drug effects
chemical_list: D000081:Acetamides; D000900:Anti-Bacterial Agents; D023303:Oxazolidinones; D014640:Vancomycin; D000069349:Linezolid; D017576:Daptomycin