What antibiotic to give an 87-year-old patient with Extended-Spectrum Beta-Lactamase (ESBL) in the urine?

Treatment of ESBL in Urine for an 87-Year-Old Patient

Carbapenems are the first-line treatment for urinary tract infections caused by ESBL-producing organisms in elderly patients, with ertapenem being preferred due to its once-daily dosing and excellent efficacy against ESBL-producing bacteria. 1, 2

First-Line Treatment Options

• Ertapenem 1g IV daily is the recommended first-line treatment for ESBL urinary tract infections in elderly patients due to its once-daily dosing, excellent activity against ESBL-producing organisms, and minimal impact on Pseudomonas and Acinetobacter species (reducing risk of selecting for resistant strains) 1, 3
• Group 2 carbapenems (imipenem/cilastatin, meropenem, doripenem) are alternatives but should be reserved for more severe infections or when Pseudomonas coverage is needed 1, 2
• Clinical studies have shown favorable response rates of 78-96% when using ertapenem for ESBL-producing infections 3, 4

Alternative Options Based on Infection Severity

• For uncomplicated lower UTIs (no fever, minimal symptoms):

  • Fosfomycin shows high efficacy (>95% susceptibility) and can be used for uncomplicated lower UTIs 1, 5
  • Nitrofurantoin is effective against ESBL-producing E. coli (>90% susceptibility) but not for other Enterobacteriaceae or upper UTIs 5, 6
  • Aminoglycosides may be effective for short-duration therapy if susceptibility is confirmed 1, 5

• For complicated UTIs or pyelonephritis:

  • Carbapenems remain the treatment of choice 1, 7
  • Newer agents like ceftazidime-avibactam and ceftolozane-tazobactam can be considered as carbapenem-sparing options when susceptibility is confirmed 8, 5

Treatment Duration Considerations

• For uncomplicated lower UTIs: 5-7 days 5
• For complicated UTIs or pyelonephritis: 7-14 days 5
• For bacteremia: 10-14 days depending on source control and clinical response 5

Important Clinical Considerations

• Local antimicrobial resistance patterns should guide therapy decisions 5
• Avoid extended use of cephalosporins in settings with high ESBL prevalence, as this can select for resistance 8
• Fluoroquinolones should be discouraged due to high resistance rates and should generally be reserved for patients with beta-lactam allergies 8, 5
• Piperacillin/tazobactam may be considered for stable patients with mild infections, though this remains controversial 8, 5

Monitoring and Follow-up

• Reassess when microbiological testing results are available 8
• Consider antimicrobial de-escalation if susceptibility allows 8
• Monitor for clinical response within 48-72 hours of initiating therapy 5
• For patients on ertapenem, monitor for common adverse effects including diarrhea (5.5%), infused vein complications (3.7%), and nausea (3.1%) 9

Carbapenem-Sparing Strategy

• For mild to moderate infections, consider non-carbapenem options when susceptibility is confirmed to reduce carbapenem use and prevent emergence of resistance 5
• Newer beta-lactam/beta-lactamase inhibitor combinations should be reserved for extensively resistant infections 1