What cefepime dose should be given to a hemodialysis patient with a catheter exit‑site infection caused by Pseudomonas aeruginosa?

Cefepime Dosing for Hemodialysis Patients with Pseudomonas Catheter Exit-Site Infection

For a hemodialysis patient with a Pseudomonas aeruginosa catheter exit-site infection, administer cefepime 1 g IV after each dialysis session (three times weekly). 1

Rationale for Standard Dosing

The IDSA guidelines specifically recommend ceftazidime 1 g IV after each dialysis session for empirical gram-negative coverage in hemodialysis catheter-related infections 1. While cefepime is not explicitly listed in these guidelines, it shares similar pharmacokinetic properties with ceftazidime and provides equivalent or superior coverage against Pseudomonas aeruginosa 2, 3.

Evidence-Based Dosing Adjustments

For Highly Susceptible Pseudomonas (MIC ≤1 mg/L):

• 1 g before each 48-hour interval (e.g., Monday-Wednesday-Friday schedule) 2
• 1.5 g before each 72-hour interval (e.g., weekend dose) 2

For Less Susceptible Pseudomonas (MIC >1 mg/L or approaching 8 mg/L):

• 1.5 g before each 48-hour interval 2
• 2 g before each 72-hour interval 2
• These higher doses are particularly critical if the patient has residual renal function, as this increases drug clearance between dialysis sessions 2

Critical Pharmacokinetic Considerations

Cefepime is highly dialyzable, with approximately 68-72% removed during a 3-hour high-flux hemodialysis session 4, 2, 5. The interdialytic half-life is approximately 22 hours in anuric patients 5, allowing for sustained therapeutic levels between sessions.

Timing of Administration:

• Always administer immediately after dialysis completion 1, 4, 2
• Pre-dialysis trough levels should exceed 8 mg/L for Pseudomonas coverage (the EUCAST breakpoint) 2
• Anuric patients achieve higher trough levels (15.6 mg/L) compared to those with residual diuresis (9.25 mg/L) 2

Monitoring Strategy

For exit-site infections with confirmed Pseudomonas aeruginosa:

• Start with 1 g post-dialysis if the organism's MIC is ≤1 mg/L 2
• If MIC data is unavailable or the infection is severe, start with 1.5 g post-dialysis 2
• Consider measuring pre-dialysis trough levels before the second or third dose to ensure levels exceed the pathogen's MIC 2
• Target trough concentrations >8 mg/L for Pseudomonas (ideally 10-15 mg/L) 2

Duration and Adjunctive Therapy

Treatment duration: 10-14 days for catheter exit-site infections without bloodstream involvement 6. If the catheter is removed, 10 days is sufficient; if preserved with antibiotic lock therapy, extend to 14 days 6.

Consider antibiotic lock therapy with ceftazidime 0.5 mg/mL in heparin if attempting catheter salvage 1. However, for Pseudomonas infections, catheter removal is often necessary for cure 1, 6.

Common Pitfalls to Avoid

• Do not use standard renal dosing tables (e.g., 500 mg every 24 hours for CrCl <11 mL/min) 4, as these underestimate the drug removal by modern high-flux dialysis and result in subtherapeutic levels 2, 5
• Do not administer before dialysis, as this wastes 70-80% of the dose 2, 5
• Do not assume all Pseudomonas strains are equally susceptible—MIC values range widely, and empiric dosing should err toward higher doses (1.5-2 g) until susceptibility data confirm lower MICs 2, 7
• Avoid underdosing in patients with residual urine output, as they clear cefepime faster between sessions 2