title: Implementation of an antimicrobial stewardship pathway with daptomycin for optimal treatment of methicillin-resistant Staphylococcus aureus bacteremia.
abstract: OBJECTIVE
  To evaluate a clinical pathway using daptomycin in patients with bacteremia caused by methicillin-resistant Staphylococcus aureus (MRSA) isolates exhibiting vancomycin minimum inhibitory concentrations (MICs) greater than 1 mg/L.
  
  
  METHODS
  Two-phase quasi-experimental study.
  
  
  METHODS
  Level I trauma center in Detroit, Michigan.
  
  
  METHODS
  The study population consisted of a total of 170 patients with MRSA bacteremia susceptible to vancomycin: 70 patients who had initial blood MRSA isolates exhibiting a vancomycin MIC > 1 mg/L and were treated with vancomycin were included in phase I (retrospective baseline period [2005-2007]) and 100 patients who were switched to daptomycin after initial vancomycin therapy according to the institutional MRSA bacteremia treatment pathway were included in phase II (the period after implementation of the treatment pathway [2008-2010]).
  
  
  METHODS
  The MRSA bacteremia treatment pathway was as follows: vancomycin therapy was initiated, optimizing target trough concentrations to 15-20 mg/L; for isolates demonstrating vancomycin MICs greater than 1 mg/L, therapy was switched to daptomycin, initiated at dosages of 6 mg/kg/day or higher.
  
  
  RESULTS
  Infection characteristics, patient outcomes, and costs were evaluated. Patient characteristics were similar between the phase I and phase II groups. Phase II patients were more likely to achieve clinical success than were phase I patients (75.0% vs 41.4%, p<0.001). Phase II patients demonstrated a shorter total hospital length of stay and shorter durations of inpatient therapy, fever, and bacteremia. Treatment during phase I was independently associated with failure. Nine patients during phase I experienced nephrotoxicity, and two patients during phase II experienced increases in creatine kinase level. Costs were similar between phases I and II ($18,385 vs $19,755, p>0.05), although the hospital readmission rate was higher in phase I (33% vs 21%, p=0.08).
  
  
  CONCLUSIONS
  Among the patients with bacteremia who had MRSA isolates that exhibited elevated vancomycin MICs, the switch to daptomycin improved clinical success without increasing treatment cost.
authors: Anti-Infective Research Laboratory, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan 48201, USA.
authors: Ravina
authors: R
authors: Kullar
authors: Susan L
authors: SL
authors: Davis
authors: Keith S
authors: KS
authors: Kaye
authors: Donald P
authors: DP
authors: Levine
authors: Jason M
authors: JM
authors: Pogue
authors: Michael J
authors: MJ
authors: Rybak
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D016470:Bacteremia / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D017576:Daptomycin / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D008875:Middle Aged; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D017576:Daptomycin