What is the recommended treatment for a patient with a urinary catheter and a urinary culture (UC) growing Pseudomonas and Enterococcus, both sensitive to Ciprofloxacin (ciprofloxacin), who also has atrial fibrillation (afib) with an intramural thrombus and is not on anticoagulation?

Treatment for Urinary Catheter-Associated Infection with Pseudomonas and Enterococcus

For a patient with a urinary catheter and a urinary culture growing Pseudomonas and Enterococcus (both sensitive to ciprofloxacin) who also has atrial fibrillation with an intramural thrombus, ciprofloxacin should be administered for 10-14 days with catheter removal if possible.

Management Algorithm

Step 1: Catheter Management

• Remove the urinary catheter if clinically feasible 1
• If catheter removal is not possible (e.g., patient requires ongoing catheterization):
  • Consider catheter exchange to a new catheter
  • Implement antibiotic lock therapy in addition to systemic antibiotics 1, 2

Step 2: Antimicrobial Therapy

• Ciprofloxacin is the optimal choice given:
  • Both organisms (Pseudomonas and Enterococcus) are reported sensitive
  • Ciprofloxacin has FDA approval for urinary tract infections caused by both Pseudomonas aeruginosa and Enterococcus faecalis 3, 4
  • Quinolones are preferred for gram-negative catheter-related infections due to excellent oral bioavailability and ability to eradicate gram-negative bacilli from foreign bodies 1

Dosing:

• Oral therapy: 500-750 mg twice daily 1, 4
• IV therapy (if oral not tolerated): 400 mg every 12 hours 3

Step 3: Duration of Therapy

• 10-14 days of antimicrobial therapy 1, 2
• The Infectious Diseases Society of America recommends 10-14 days for gram-negative bacteremia 2

Step 4: Special Considerations for This Patient

• Atrial fibrillation with intramural thrombus:
  • Monitor for potential drug interactions if anticoagulation is initiated during treatment
  • Ciprofloxacin has no significant interaction with common anticoagulants
  • The presence of intramural thrombus increases risk of endocarditis, which may warrant longer therapy if clinical deterioration occurs

Evidence Strength and Considerations

The recommendation for ciprofloxacin is strongly supported by guidelines and clinical evidence:

1. Guideline support: The Infectious Diseases Society of America guidelines specifically state that quinolones such as ciprofloxacin are preferred for catheter-related gram-negative infections 1

2. Antimicrobial coverage: Ciprofloxacin provides effective coverage against both organisms:

   • Demonstrated efficacy against Pseudomonas in urinary tract infections with 93% success rates 5
   • FDA-approved for Enterococcus faecalis urinary infections 3, 4

3. Catheter removal importance: Removal of the infected catheter significantly improves outcomes and reduces risk of persistent infection 1

Potential Pitfalls and Caveats

• Resistance development: Monitor for emergence of resistance, particularly with Pseudomonas aeruginosa, which can develop resistance during therapy 6

• Superinfection risk: Patients with underlying conditions (especially diabetes or neurological disease) have higher risk of superinfection during ciprofloxacin therapy 5

• Follow-up cultures: Obtain follow-up urine cultures after completion of therapy to confirm eradication, as reinfection rates can be significant in catheterized patients 5, 6

• Duration extension: Consider extending treatment to 4-6 weeks if the patient develops persistent bacteremia, especially with the underlying cardiac condition 1

• Fluoroquinolone adverse effects: Monitor for tendinopathy, CNS effects, and QT prolongation, particularly important in a patient with existing cardiac disease