Should I de-escalate or change the current IV cefepime (Cefepime) treatment for a patient with catheter-associated urinary tract infection (CAUTI) with E. coli and Providencia stuartii, given the patient's clinical improvement and intermediate sensitivity to cefepime?

Treatment of Catheter-Associated UTI with E. coli and Providencia stuartii

You should change the current IV cefepime treatment to an aminoglycoside (such as gentamicin) that has demonstrated sensitivity against the Providencia stuartii isolate, despite the patient's clinical improvement on cefepime. 1

Rationale for Treatment Change

• Cefepime has only intermediate sensitivity to the Providencia stuartii isolate, which increases the risk of treatment failure and development of resistance despite initial clinical improvement 1
• Providencia stuartii is a common cause of polymicrobial catheter-associated UTIs and is known for its ability to develop antimicrobial resistance when exposed to suboptimal antibiotic therapy 2, 3
• Guidelines specifically recommend aminoglycosides for complicated UTIs caused by resistant gram-negative organisms when active in vitro 1
• The European Society of Clinical Microbiology and Infectious Diseases (ESCMID) suggests avoiding cefepime for infections caused by resistant Enterobacterales due to concerns about efficacy 1

Considerations for Aminoglycoside Therapy

• Aminoglycosides demonstrate concentration-dependent activity, making once-daily dosing highly effective and potentially less nephrotoxic 1
• For complicated UTIs, guidelines specifically recommend aminoglycosides when active in vitro for short durations of therapy 1
• Therapeutic drug monitoring (TDM) should be considered when using aminoglycosides to optimize efficacy and minimize toxicity 1
• For patients with non-severe infections due to resistant organisms, using an in vitro active older antibiotic (like aminoglycosides) is considered good clinical practice 1

Why Not Continue Cefepime Despite Clinical Improvement?

• Intermediate sensitivity to cefepime raises concerns about inadequate bacterial eradication and potential for relapse 1
• Suboptimal antibiotic therapy against Providencia stuartii can lead to selection of resistant bacterial populations 3, 4
• The risk of urolithiasis and bacteremia is increased during Providencia stuartii infections, particularly in catheterized patients, making complete eradication important 5
• Antibiotic stewardship principles support de-escalation to targeted therapy based on susceptibility patterns rather than continuing broad-spectrum agents 1

Implementation Approach

1. Obtain blood cultures to confirm clearance of E. coli bacteremia before changing therapy 1
2. Switch to an aminoglycoside with demonstrated sensitivity against the Providencia stuartii isolate 1
3. Consider once-daily dosing of the aminoglycoside to maximize efficacy and minimize toxicity 1
4. Monitor renal function and drug levels as appropriate during aminoglycoside therapy 1
5. Consider catheter removal if feasible, as this is an important component of CAUTI management 1

Special Considerations

• If the patient has renal impairment, careful dose adjustment of aminoglycosides will be necessary 1
• If aminoglycoside therapy is contraindicated, consider consulting infectious disease specialists for alternative treatment options 1
• For patients with severe infections, maintaining adequate plasma concentrations of antibiotics is crucial - aminoglycosides achieve high urinary concentrations which is advantageous for UTIs 1

By changing to an aminoglycoside with demonstrated sensitivity against Providencia stuartii, you can ensure optimal treatment of both pathogens while adhering to antibiotic stewardship principles.