Is vancomycin used to treat Extended-Spectrum Beta-Lactamase (ESBL) infections?

Vancomycin is NOT Appropriate for ESBL Infections

Vancomycin should NOT be used to treat Extended-Spectrum Beta-Lactamase (ESBL) producing bacterial infections as it lacks activity against gram-negative bacteria including ESBL-producing Enterobacteriaceae. 1, 2

Understanding ESBL Infections and Treatment Options

What are ESBL-producing organisms?

• ESBLs are enzymes produced by gram-negative bacteria (primarily Enterobacteriaceae like E. coli and Klebsiella)
• These enzymes hydrolyze and inactivate most beta-lactam antibiotics including penicillins, cephalosporins, and aztreonam
• ESBL-producing organisms are often multidrug-resistant, limiting treatment options 3

Why vancomycin is inappropriate for ESBL infections:

• Vancomycin is only active against gram-positive bacteria (staphylococci, streptococci, enterococci) 4
• ESBL-producing organisms are gram-negative bacteria and intrinsically resistant to vancomycin
• Using vancomycin for ESBL infections would result in treatment failure and potentially increased morbidity and mortality

Recommended Treatment Options for ESBL Infections

First-line therapy:

• Carbapenems (ertapenem, meropenem, imipenem, doripenem) are the gold standard for serious ESBL infections 2, 5
  • Most reliable option for severe infections
  • High efficacy against ESBL-producing organisms

Alternative options when carbapenems cannot be used:

1. Newer cephalosporin/β-lactamase inhibitor combinations:

   • Ceftazidime/avibactam
   • Ceftolozane/tazobactam 1, 2

2. Piperacillin-tazobactam:

   • May be effective for certain ESBL infections but should be used with caution 1, 2

3. For less severe infections (particularly urinary tract infections):

   • Fosfomycin (oral option)
   • Nitrofurantoin (for lower UTIs only)
   • Pivmecillinam (where available) 6

Special considerations:

• For neutropenic patients: Consider broader coverage with carbapenems or piperacillin-tazobactam plus an aminoglycoside 1, 2
• For intra-abdominal infections: Carbapenems or ceftolozane/tazobactam with metronidazole 1, 2

Antimicrobial Stewardship Considerations

Carbapenem-sparing strategies:

• Reserve carbapenems for serious infections to prevent emergence of carbapenem resistance 1
• Consider β-lactam/β-lactamase inhibitor combinations for less severe infections 1, 2
• Obtain cultures before initiating therapy to guide targeted treatment 2

Common pitfalls to avoid:

1. Using vancomycin for gram-negative infections including ESBL
2. Relying on third-generation cephalosporins alone for ESBL infections
3. Using fluoroquinolones empirically without susceptibility testing due to high rates of co-resistance 2

Treatment Algorithm for Suspected or Confirmed ESBL Infections

1. Severe infection or sepsis:

   • Start with a carbapenem (meropenem, imipenem, or doripenem)
   • Add vancomycin ONLY if MRSA is also suspected

2. Moderate infection without sepsis:

   • Consider carbapenem-sparing options: piperacillin-tazobactam, ceftolozane/tazobactam, or ceftazidime/avibactam

3. Mild infection (e.g., uncomplicated UTI):

   • Use oral options if susceptible: fosfomycin, nitrofurantoin, or pivmecillinam

4. De-escalate therapy once susceptibility results are available to the narrowest effective agent

Remember that vancomycin has no role in treating ESBL infections unless there is a concurrent gram-positive infection requiring coverage.