What is the antibiotic of choice for a patient with Chronic Kidney Disease (CKD) stage 5 and panresistant Catheter-Associated Urinary Tract Infection (CAUTI) due to Escherichia coli (E. coli)?

Antibiotic Management for Panresistant E. coli CAUTI in CKD Stage 5

Direct Recommendation

For a CKD stage 5 patient with panresistant E. coli CAUTI, use a single-dose aminoglycoside (amikacin or gentamicin) if the infection is limited to simple cystitis, or ceftazidime-avibactam 2.5 g IV every 8 hours for complicated UTI, with mandatory infectious disease consultation and catheter removal when feasible. 1, 2, 3

Critical First Steps

Source Control is Paramount

• Remove or replace the urinary catheter immediately if clinically feasible - this is the single most important intervention to prevent complications and treatment failure 4, 5
• Duration of catheterization is the predominant risk factor for CAUTI, and the catheter itself harbors biofilm that protects organisms from both antimicrobials and host immune response 6, 5

Obtain Infectious Disease Consultation

• Infectious disease consultation is highly recommended (strong recommendation) for all multidrug-resistant organism infections 1
• This is particularly critical in CKD stage 5 patients where drug dosing, nephrotoxicity risks, and dialysis timing must be carefully coordinated 1

Antibiotic Selection Algorithm

For Simple Cystitis (Lower UTI Without Systemic Signs)

• Single-dose aminoglycoside (amikacin or gentamicin) is the recommended first-line therapy 1, 2
• Aminoglycosides achieve urinary concentrations 25- to 100-fold higher than plasma levels, making them ideal for UTI treatment despite systemic resistance 2
• Meta-analysis of 13,804 patients demonstrated microbiologic cure rates of 87-100% with single-dose aminoglycoside for lower UTI 2

Critical Caveat for CKD Stage 5:

• Aminoglycosides require careful dosing adjustment based on residual renal function and dialysis schedule 1
• Single-dose strategy minimizes nephrotoxicity risk while maintaining efficacy in the urinary tract 2
• Coordinate timing with dialysis sessions through nephrology consultation 1

For Complicated UTI (Pyelonephritis, Systemic Signs, or Sepsis)

Preferred First-Line Agents (in order of preference):

1. Ceftazidime-avibactam 2.5 g IV every 8 hours infused over 3 hours 1, 2, 3

   • This is the most strongly recommended agent for carbapenem-resistant Enterobacterales (CRE) complicated UTI 1, 2
   • Effective against most carbapenemase-producing organisms 1

2. Meropenem-vaborbactam 4 g IV every 8 hours 1, 2, 3

   • Alternative newer β-lactam/β-lactamase inhibitor combination 2

3. Imipenem-cilastatin-relebactam 1.25 g IV every 6 hours 1, 2, 3

   • Another alternative newer agent 2

4. Plazomicin 15 mg/kg IV every 12 hours 1, 2

   • Aminoglycoside option for complicated UTI 2
   • Requires careful renal dosing adjustment in CKD stage 5 2

Alternative Options When Above Agents Unavailable

• IV fosfomycin for non-severe complicated UTI without septic shock 2, 3
• Polymyxins (colistin) in combination therapy - but avoid as monotherapy 1, 2
• Tigecycline - but never use as monotherapy for bloodstream infections 1, 2

Critical Dosing Considerations for CKD Stage 5

Agents to AVOID Completely

• Nitrofurantoin is absolutely contraindicated - it should be avoided in patients with GFR <30 mL/min due to inefficacy and risk of peripheral neuritis from toxic metabolite accumulation 3, 1
• Aminoglycoside antibiotics (except single-dose for cystitis) and tetracyclines should be avoided due to nephrotoxicity 1

Dosing Adjustments Required

• Many drugs are excreted by the kidney; diminished renal function changes volume of distribution, metabolism, elimination rate, and bioavailability 1
• Even liver-metabolized drugs can lead to increased toxicity risk in renal failure 1
• Lengthen the interval between doses according to the degree of elimination impairment 1
• Coordinate all dosing with the patient's nephrologist before initiating therapy 1

Treatment Duration and Monitoring

Duration

• 10-14 days is the standard duration for complicated UTI 6
• Patients who respond promptly may be treated with a shorter 7-day course if the catheter must remain in place, to reduce antimicrobial pressure 6
• Adjust treatment duration based on clinical response and source control 2

Therapeutic Drug Monitoring

• Consider prolonged infusion of β-lactams for pathogens with high minimum inhibitory concentration (MIC) - this is a strong recommendation 1, 2
• For ceftazidime-avibactam, infuse over 3 hours rather than standard infusion time 1

Susceptibility Testing

• Always obtain susceptibility testing or genotypic characterization of resistance before finalizing therapy 1, 2
• This serves as the definitive guide for antimicrobial selection 1
• Initial empiric therapy may be necessary, but adjust based on culture results 1, 2

Common Pitfalls to Avoid

Do NOT Treat Asymptomatic Bacteriuria

• Asymptomatic catheter-acquired UTI should never be treated with antimicrobials 6, 5
• Antimicrobial treatment does not decrease symptomatic episodes but will lead to emergence of more resistant organisms 6
• This accounts for excess antimicrobial use in hospitals and should be avoided 5

Avoid Empiric Broad-Spectrum Therapy Without Plan

• Reserve newer β-lactam/β-lactamase inhibitor combinations for extensively resistant bacteria 2
• Empiric use without culture data drives further resistance 6

Do Not Ignore Biofilm

• Bacteria in catheter biofilm are protected from both antimicrobials and host immune response 6
• Catheter replacement or removal is essential - antimicrobials alone will not eradicate biofilm-associated infection 6, 5

Prevention of Future Episodes

• Avoid catheter use entirely or limit duration to as short a time as possible - this is the most effective prevention strategy 6, 5
• Maintaining a closed drainage system and adhering to appropriate catheter care techniques will limit infection 6
• Consider alternatives: condom catheter, intermittent catheterization, or suprapubic catheterization when appropriate 4
• Catheter flushing or daily perineal care do not prevent infection and may increase infection risk 6