What is the best IV antibiotic option for a patient with a single kidney and impaired renal function (eGFR of 35) suffering from urinary tract infection (UTI) sepsis?

Best IV Antibiotic Option for UTI Sepsis in a Patient with Single Kidney and eGFR of 35

For a patient with UTI sepsis, single kidney, and eGFR of 35, meropenem-vaborbactam 4g IV q8h is recommended as the best IV antibiotic option if carbapenem-resistant Enterobacterales (CRE) is suspected, while a carbapenem (imipenem or meropenem) with appropriate renal dose adjustment is recommended for non-CRE infections. 1

Initial Assessment and Antibiotic Selection

For Suspected CRE Infections:

• Meropenem-vaborbactam 4g IV q8h with renal dose adjustment is recommended for complicated UTIs caused by CRE (weak recommendation, low quality of evidence) 1
• Ceftazidime-avibactam 2.5g IV q8h with renal dose adjustment is an alternative option for CRE UTIs (weak recommendation, very low quality of evidence) 1
• Imipenem-cilastatin-relebactam 1.25g IV q6h with renal dose adjustment is another option for CRE UTIs (weak recommendation, low quality of evidence) 1

For Non-CRE Infections:

• A carbapenem (imipenem or meropenem) is strongly recommended for patients with bloodstream infections and severe infections due to third-generation cephalosporin-resistant Enterobacterales (3GCephRE) 1
• For patients with impaired renal function (eGFR 35), dose adjustment is necessary 1, 2

Renal Considerations for Antibiotic Selection

Dose Adjustments for Renal Impairment:

• With eGFR of 35 ml/min/1.73m², dose adjustments are required for most antibiotics 1
• For meropenem, consider reducing frequency to every 12 hours (1g IV q12h) in patients with creatinine clearance below 50 ml/min 2, 3
• Aminoglycosides require significant dose reduction when GFR < 60 ml/min/1.73m² and should be used with caution due to nephrotoxicity risk in patients with already impaired renal function 1

Special Considerations for Single Kidney Patients:

• Patients with a single kidney are at higher risk for further renal deterioration if nephrotoxic agents are used 4, 5
• Avoid potentially nephrotoxic antibiotics when possible, including aminoglycosides and polymyxins, especially for prolonged therapy 1, 4

Antibiotic Options Based on Infection Severity

For Sepsis/Severe Infection:

• Carbapenems remain the first-line treatment for severe UTI/sepsis in patients with impaired renal function 1
• Meropenem-vaborbactam has shown efficacy in the TANGO-II trial for CRE infections including bacteremia and UTI/acute pyelonephritis 1, 6
• For patients with septic shock, avoid aminoglycosides as monotherapy due to variable tissue penetration 1

For Non-Severe Infection:

• Single-dose aminoglycosides may be considered for simple cystitis due to CRE (weak recommendation, very low quality of evidence) 1
• Plazomicin 15 mg/kg IV q12h (with renal adjustment) is recommended for complicated UTI due to CRE (weak recommendation, very low quality of evidence) 1

Monitoring Recommendations

• Monitor renal function closely during antibiotic therapy, especially in patients with baseline renal impairment 1, 4
• For patients receiving potentially nephrotoxic agents, check renal function every 48-72 hours 1
• Consider therapeutic drug monitoring for antibiotics with narrow therapeutic windows 1

Common Pitfalls and Caveats

• Avoid fluoroquinolones in elderly patients with renal impairment due to increased risk of tendon disorders and QT prolongation 7
• Do not use oral phosphate-containing bowel preparations in people with eGFR < 60 ml/min/1.73m² 1
• Avoid NSAIDs in patients with eGFR < 60 ml/min/1.73m² as they can worsen renal function 1
• Remember that patients with diabetes mellitus, older age, and lower baseline eGFR are at higher risk for developing acute kidney injury during UTI treatment 4