title: Use of daptomycin to treat infections with methicillin-resistant Staphylococcus aureus isolates having vancomycin minimum inhibitory concentrations of 1.5 to 2 μg/mL.
abstract: OBJECTIVE
  To evaluate daptomycin use for the treatment of infections with methicillin-resistant Staphylococcus aureus (MRSA) isolates having vancomycin minimum inhibitory concentrations (MICs) of 1.5 to 2 µg/mL.
  
  
  METHODS
  The literature was retrieved through PubMed and EMBASE (January 2006 to August 2013).
  
  
  METHODS
  English articles were reviewed. Studies that included separate daptomycin data (clinical outcome or in vitro surveillance) for MRSA isolates with vancomycin MICs of 1.5 to 2 µg/mL by any testing methodology were included.
  
  
  RESULTS
  Clinical and microbiological outcomes associated with daptomycin used as first-line or subsequent therapy for MRSA infections with vancomycin MICs of 1.5 to 2 µg/mL were reported in 7 retrospective clinical studies; susceptibility information involving such isolates was reported from 12 surveillancestudies. Although not all studies demonstrated outcome differences between daptomycin and comparator treatments (usually vancomycin), when differences were reported, they were in favor of daptomycin. Individual studies found lower 60-day (8% vs 20%, P = .046) and 30-day mortality (3.5% vs 12.9%, P = .047) and increased treatment success with daptomycin (68.6% vs 43.1%, P = .008; 76.9% vs 53.8%, P = .048) in bacteremic patients. The median doses used for treatment of bacteremia were greater than that approved by the FDA for this indication (6 mg/kg/d).
  
  
  CONCLUSIONS
  Current published evidence indicates daptomycin may be an acceptable alternative to vancomycin for MRSA infections, especially bacteremia, involving isolates with vancomycin MIC values of 1.5 to 2 µg/mL. Additional evidence is needed to fully elucidate daptomycin utility in this area.
authors.affiliation: Massachusetts College of Pharmacy and Health Sciences, Worcester/Manchester Lexington, MA, USA.
authors.forename: Patrick M
authors.initials: PM
authors.lastname: McDaneld
authors.forename: Linda M
authors.initials: LM
authors.lastname: Spooner
authors.forename: John F
authors.initials: JF
authors.lastname: Mohr
authors.forename: Paul P
authors.initials: PP
authors.lastname: Belliveau
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D017576:Daptomycin / Q000627:therapeutic use*; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D013203:Staphylococcal Infections / Q000188:drug therapy*; D014640:Vancomycin / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin; D017576:Daptomycin
keywords: MRSA; daptomycin; elevated MIC; methicillin-resistant Staphylococcus aureus; tolerance; vancomycin