title: Beta lactam antibiotic monotherapy versus beta lactam-aminoglycoside antibiotic combination therapy for sepsis.
abstract: BACKGROUND
  Optimal antibiotic treatment for sepsis is imperative. Combining a beta lactam antibiotic with an aminoglycoside antibiotic may provide certain advantages over beta lactam monotherapy.
  
  
  OBJECTIVE
  Our objectives were to compare beta lactam monotherapy versus beta lactam-aminoglycoside combination therapy in patients with sepsis and to estimate the rate of adverse effects with each treatment regimen, including the development of bacterial resistance to antibiotics.
  
  
  METHODS
  In this updated review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 11); MEDLINE (1966 to 4 November 2013); EMBASE (1980 to November 2013); LILACS (1982 to November 2013); and conference proceedings of the Interscience Conference of Antimicrobial Agents and Chemotherapy (1995 to 2013). We scanned citations of all identified studies and contacted all corresponding authors. In our previous review, we searched the databases to July 2004.
  
  
  METHODS
  We included randomized and quasi-randomized trials comparing any beta lactam monotherapy versus any combination of a beta lactam with an aminoglycoside for sepsis.
  
  
  METHODS
  The primary outcome was all-cause mortality. Secondary outcomes included treatment failure, superinfections and adverse events. Two review authors independently collected data. We pooled risk ratios (RRs) with 95% confidence intervals (CIs) using the fixed-effect model. We extracted outcomes by intention-to-treat analysis whenever possible.
  
  
  RESULTS
  We included 69 trials that randomly assigned 7863 participants. Twenty-two trials compared the same beta lactam in both study arms, while the remaining trials compared different beta lactams using a broader-spectrum beta lactam in the monotherapy arm. In trials comparing the same beta lactam, we observed no difference between study groups with regard to all-cause mortality (RR 0.97, 95% CI 0.73 to 1.30) and clinical failure (RR 1.11, 95% CI 0.95 to 1.29). In studies comparing different beta lactams, we observed a trend for benefit with monotherapy for all-cause mortality (RR 0.85, 95% CI 0.71 to 1.01) and a significant advantage for clinical failure (RR 0.75, 95% CI 0.67 to 0.84). No significant disparities emerged from subgroup and sensitivity analyses, including assessment of participants with Gram-negative infection. The subgroup of Pseudomonas aeruginosa infections was underpowered to examine effects. Results for mortality were classified as low quality of evidence mainly as the result of imprecision. Results for failure were classified as very low quality of evidence because of indirectness of the outcome and possible detection bias in non-blinded trials. We detected no differences in the rate of development of resistance. Nephrotoxicity was significantly less frequent with monotherapy (RR 0.30, 95% CI 0.23 to 0.39). We found no heterogeneity for all these comparisons.We included a small subset of studies addressing participants with Gram-positive infection, mainly endocarditis. We identified no difference between monotherapy and combination therapy in these studies.
  
  
  CONCLUSIONS
  The addition of an aminoglycoside to beta lactams for sepsis should be discouraged. All-cause mortality rates are unchanged. Combination treatment carries a significant risk of nephrotoxicity.
authors.affiliation: Division of Infectious Diseases, Rambam Health Care Campus and the Technion-Israel Institute of Technology, 6 Ha'Aliya Street, Haifa, Israel, 31096.
authors.forename: Mical
authors.initials: M
authors.lastname: Paul
authors.forename: Adi
authors.initials: A
authors.lastname: Lador
authors.forename: Simona
authors.initials: S
authors.lastname: Grozinsky-Glasberg
authors.forename: Leonard
authors.initials: L
authors.lastname: Leibovici
mesh_terms: D000617:Aminoglycosides / Q000009:adverse effects / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000188:drug therapy*; D002423:Cause of Death; D004359:Drug Therapy, Combination / Q000379:methods; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D047090:beta-Lactams / Q000627:therapeutic use*
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D047090:beta-Lactams