What is the recommended treatment for a complicated urinary tract infection (UTI) in a female adult with Extended-Spectrum Beta-Lactamase (ESBL) producing Escherichia coli (E. coli) and a nephrostomy?

Treatment of Complicated UTI in Female Adult with ESBL E. coli and Nephrostomy

For a female adult with complicated UTI caused by ESBL-producing E. coli who has a nephrostomy, ceftazidime-avibactam is the recommended first-line treatment due to its proven efficacy against ESBL-producing organisms and specific FDA approval for complicated UTIs. 1

Understanding the Condition

• This case represents a complicated UTI due to both the presence of ESBL-producing E. coli and the nephrostomy tube, which is considered a foreign body and structural abnormality of the urinary tract 2
• Complicated UTIs are defined as infections occurring in patients with underlying structural or medical problems, including foreign bodies, urinary tract obstruction, and indwelling catheters 2
• The presence of ESBL-producing organisms is specifically listed as a factor associated with complicated UTIs in current guidelines 2

Initial Assessment and Management

• Obtain urine culture and susceptibility testing before initiating antimicrobial therapy to guide targeted treatment 2
• Assess severity of illness and hemodynamic stability to determine if inpatient or outpatient management is appropriate 2
• Management of the underlying urological abnormality (in this case, ensuring proper nephrostomy function) is mandatory alongside antimicrobial therapy 2

Antimicrobial Treatment Options

First-line Treatment:

• Ceftazidime-avibactam (AVYCAZ): FDA-approved for complicated UTIs including those caused by ESBL-producing E. coli 1
  • Adult dosage: 2.5 grams (ceftazidime 2 grams and avibactam 0.5 grams) administered every 8 hours by intravenous infusion over 2 hours 1
  • Adjust dosage based on renal function if creatinine clearance is below 50 mL/min 1

Alternative Options (based on susceptibility testing):

• Carbapenems: Considered highly effective against ESBL-producing organisms 2, 3

  • Meropenem: 1g three times daily 2
  • Ertapenem: Can be administered intravenously or subcutaneously, suitable for outpatient parenteral antibiotic therapy 4

• Ceftolozane-tazobactam: Effective against many ESBL-producing organisms 5

• For oral step-down therapy (if organism is susceptible):

  • Fosfomycin: Highly effective against ESBL-producing E. coli (98% sensitivity) 6
  • Nitrofurantoin: Effective against ESBL-producing E. coli (93% sensitivity), but not recommended for pyelonephritis or complicated UTIs with systemic involvement 6
  • Pivmecillinam: Effective against ESBL-producing Enterobacteriaceae (>95% sensitivity) 6

Duration of Treatment

• Treatment for 7-14 days is generally recommended for complicated UTIs 2
• A shorter duration (7 days) may be considered when the patient has been hemodynamically stable and afebrile for at least 48 hours 2, 7
• Longer treatment (14 days) may be necessary in more severe cases or when the infection involves the upper urinary tract 2

Special Considerations

• Avoid fluoroquinolones for empiric treatment due to increasing resistance rates, especially in ESBL-producing organisms 2, 5
• Consider removal or exchange of the nephrostomy tube if clinically indicated, as foreign bodies can serve as a nidus for persistent infection 2
• Monitor for clinical improvement within 48-72 hours of initiating appropriate antimicrobial therapy 2

Follow-up

• Confirm clinical cure with resolution of symptoms 3
• Follow-up urine culture is not necessary if symptoms resolve completely 2
• Avoid surveillance urine testing in asymptomatic patients to prevent unnecessary treatment of asymptomatic bacteriuria 2

This approach prioritizes effective treatment against the ESBL-producing organism while addressing the complicated nature of the UTI due to the presence of a nephrostomy tube, with the goal of reducing morbidity and mortality associated with complicated UTIs.