What is the treatment for an Extended-Spectrum Beta-Lactamase (ESBL) Urinary Tract Infection (UTI)?

Treatment of ESBL UTI

Carbapenems are the first-line treatment for ESBL UTI, with ertapenem being the preferred option for non-critically ill patients due to its effectiveness against ESBL-producing organisms and its ability to spare broader-spectrum carbapenems. 1, 2

First-line Treatment Options

For non-critically ill patients:

• Ertapenem 1g IV daily - Recommended as first-line therapy for ESBL UTI 1, 2
  • FDA-approved for complicated UTIs including pyelonephritis due to E. coli and Klebsiella pneumoniae 2
  • Has activity against ESBL-producing pathogens without coverage for Pseudomonas or Enterococcus 1

For critically ill patients or nosocomial infections:

• Group 2 carbapenems: imipenem-cilastatin, meropenem, or doripenem 1
  • These provide broader coverage including against Pseudomonas aeruginosa 1

Alternative Options (Carbapenem-sparing)

When susceptibility is confirmed, the following alternatives can be considered:

1. Intravenous fosfomycin - High-certainty evidence for treatment of complicated UTI with or without bacteremia 1

   • Monitor for heart failure risk (8.6% in clinical trials) 1

2. Aminoglycosides (e.g., amikacin, gentamicin) - Moderate-certainty evidence for UTI treatment 1

   • Limit to shorter courses (<7 days) to reduce nephrotoxicity risk 1
   • Consider for urinary source infections 1

3. Beta-lactam/beta-lactamase inhibitors (BLBLI) - Moderate-certainty evidence for pyelonephritis 1

   • Piperacillin-tazobactam may be effective in stable patients 1
   • Use with caution as effectiveness against ESBL producers remains controversial 1

4. Oral options for uncomplicated or step-down therapy (when susceptible):

   • Nitrofurantoin 3, 4
   • Fosfomycin trometamol (3g single dose) 3, 4
   • Pivmecillinam 3, 4

Treatment Duration

• Uncomplicated cystitis: 5-7 days 5
• Complicated UTI: 7-14 days 5
• Pyelonephritis: 10-14 days 5

Important Considerations

1. Obtain cultures before starting antibiotics to guide targeted therapy 5

2. Reassess when culture results are available - De-escalate therapy when possible to reduce selective pressure 1

3. Avoid fluoroquinolones as empiric therapy due to high resistance rates and selective pressure for ESBL producers 1, 3

4. Avoid extended use of cephalosporins due to their selective pressure resulting in emergence of resistance 1

5. Monitor for clinical response within 48-72 hours - If inadequate, consider switching to a different agent 5

Pitfalls to Avoid

1. Not considering local resistance patterns when selecting empiric therapy, which may lead to treatment failure 5

2. Unnecessary prolonged carbapenem use when de-escalation is possible, which contributes to antimicrobial resistance 5

3. Not adjusting antibiotic doses based on renal function and patient-specific factors 5

4. Using fluoroquinolones empirically in areas with high resistance rates 1, 3

5. Failing to obtain cultures before initiating antibiotics, which may lead to inappropriate therapy 5

By following this approach, you can effectively treat ESBL UTI while practicing good antimicrobial stewardship to minimize the development of further resistance.