title: Combination therapy with an aminoglycoside for Staphylococcus aureus endocarditis and/or persistent bacteremia is associated with a decreased rate of recurrent bacteremia: a cohort study.
abstract: OBJECTIVE
  Although limited data exist on the efficacy and potential risk of synergistic aminoglycoside therapy for persistent Staphylococcus aureus bacteremia and endocarditis, aminoglycosides are frequently used in clinical practice.
  
  
  METHODS
  As our study population, we included subjects fulfilling the modified Duke criteria for S. aureus endocarditis and/or having greater than 72 h of S. aureus bacteremia. Among these subjects, we compared patients who did and did not receive aminoglycoside therapy for their S. aureus bloodstream infection. These groups were compared for the primary outcome of recurrent bacteremia, as well as for the duration of bacteremia, mortality, complication rate, and incident renal failure.
  
  
  RESULTS
  Eighty-seven subjects fulfilled the inclusion criteria. Of these, 49 received aminoglycoside therapy, whereas 38 did not. There were no significant differences in the baseline characteristics when comparing groups who did or did not receive aminoglycoside therapy. Four (8.2%) subjects treated with aminoglycoside therapy experienced recurrent bacteremia versus nine (23.7%) who did not receive aminoglycoside therapy [relative risk and 95% confidence interval [RR (95%CI)] = 0.51 (0.22-1.17), p = 0.04]. In multivariable analyses, aminoglycoside use remained significantly associated with a decrease in recurrent bacteremia [adjusted odds ratio (OR) (95%CI) = 0.26 (0.07-0.98), p = 0.046]. No significant differences were seen between groups treated with and without an aminoglycoside in terms of the 6-month all-cause mortality (51.0 vs. 42.1%, p = 0.41), complication rate (71.4 vs. 73.7%, p = 0.82), or incident renal failure (54.5 vs. 46.9%, p = 0.54).
  
  
  CONCLUSIONS
  The use of combination therapy with an aminoglycoside in persistent S. aureus bacteremia and/or endocarditis may be associated with a lower rate of recurrent bacteremia without significant differences in the incident renal failure.
authors: Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, 11100 Euclid Ave., Cleveland, OH 44106, USA. tracy.lemonovich@UHhospitals.org
authors: T L
authors: TL
authors: Lemonovich
authors: K
authors: K
authors: Haynes
authors: E
authors: E
authors: Lautenbach
authors: V K
authors: VK
authors: Amorosa
mesh_terms: D000368:Aged; D000617:Aminoglycosides / Q000008:administration & dosage*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D016470:Bacteremia / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality; D015331:Cohort Studies; D004359:Drug Therapy, Combination / Q000379:methods; D004697:Endocarditis, Bacterial / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055502:Secondary Prevention; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents