Empiric Antibiotics: MRSA (HINT: not just Vanc!)


  • Uncomplicated Bacteremia
    • Must meet all of following: No IE (by TEE); No prostheses; Negative f/u blood cultures at 2-4 days; Defervescence within 72 h of effective therapy; No metastatic infection
    • Vancomycin or Daptomycin for minimum 2 weeks
  • Complicated Bacteremia or Endocarditis
    • 4-6 weeks at minimum
    • No benefit to adding gentamicin or rifampin for native valve IE
  • Treatment Failure
    • Generally defined as persistent bacteremia around day 7 of therapy (median time to clearance of MRSA bacteremia is 7-9 days)
    • May also define failure as patient getting worse on current tx
    • Remember SOURCE CONTROL!!!

Antibiotic Choices

  • MRSA Abx
  • PO options acceptable for SSTI or completion of osteo Rx; IV preferred for invasive disease
  • Vancomycin is the empiric drug of choice in most serious infections (duh!)
    • Vanc MIC ≥ 2 associated with higher rates of Rx failure so consider alternative agents
  • If vancomycin intolerance or failure:
    • PNA: Linezolid, Ceftaroline
    • Bacteremia/Endocarditis: Daptomycin, Ceftaroline
    • CNS: Linezolid
    • Osteo: Dapto, Ceftaroline