In an anuric end‑stage renal disease patient on thrice‑weekly hemodialysis, how should cefepime be dosed after each dialysis session to maintain therapeutic levels, especially given the 72‑hour interval between Saturday and Tuesday?

Cefepime Dosing in Anuric ESRD Patients on Thrice-Weekly Hemodialysis

For an anuric end-stage renal disease patient on thrice-weekly hemodialysis, administer cefepime 1 gram intravenously after each dialysis session (Monday, Wednesday, Friday), including after the Saturday session with a 72-hour interval until Tuesday. 1, 2

Core Dosing Principles for Hemodialysis Patients

Always maintain the full individual dose while extending the dosing interval—never reduce the milligram amount per dose. 3 This principle is critical because:

• Reducing individual doses creates subtherapeutic peak concentrations and leads to treatment failure, particularly for concentration-dependent antibiotics like cephalosporins 3
• Cefepime exhibits concentration-dependent killing, requiring adequate peak levels to achieve bacterial eradication 1
• The FDA label specifies that hemodialysis removes approximately 68% of cefepime during a 3-hour dialysis session, making post-dialysis dosing essential 1

Specific Dosing Regimen

Post-dialysis administration timing:

• Give cefepime immediately after each hemodialysis session to prevent premature drug removal and ensure adequate therapeutic levels 3, 1
• Administer at the same time each day on dialysis days to facilitate directly observed therapy 1

Dose selection:

• The FDA label recommends 1 gram on Day 1, followed by 500 mg every 24 hours for most infections in hemodialysis patients 1
• However, recent evidence supports 1 gram after each dialysis session (thrice-weekly) for adequate coverage, particularly for serious infections 2
• For febrile neutropenia specifically, the FDA label recommends 1 gram every 24 hours 1

Managing the 72-Hour Weekend Interval

The Saturday-to-Tuesday gap requires the same 1-gram dose without adjustment. 2 Here's why this approach is safe and effective:

• Cefepime's interdialytic half-life in anuric patients is sufficiently long to maintain therapeutic concentrations over 72 hours 4, 5
• Studies of similar cephalosporins (ceftazidime) demonstrate that 1-2 gram post-dialysis doses maintain concentrations above MIC thresholds for susceptible pathogens throughout both 48-hour and 72-hour interdialytic intervals 4
• The non-dialysis clearance of cephalosporins in anuric patients is minimal (half-life 26-33 hours), while dialysis clearance is high, supporting the post-dialysis dosing strategy 6, 5

Pharmacokinetic Rationale

Cefepime pharmacokinetics in hemodialysis:

• Approximately 68% of cefepime is removed during a 3-hour hemodialysis session 1
• The intradialytic half-life is dramatically shortened (approximately 2-3 hours) compared to the interdialytic half-life (9-33 hours for cephalosporins in anuric patients) 5, 7
• Peak concentrations after 1-2 gram doses remain well above MIC breakpoints (≤8 mg/L) for susceptible organisms throughout the interdialytic period 4

Common Pitfalls to Avoid

Critical errors in hemodialysis dosing:

• Never administer cefepime before dialysis—this wastes the dose through premature removal during the dialysis session 3, 8
• Never use daily dosing in hemodialysis patients—this leads to dangerous drug accumulation 3
• Never reduce the individual dose to 500 mg thinking it's "safer"—this creates subtherapeutic levels and treatment failure 3
• Do not add supplemental doses on non-dialysis days—the extended half-life in anuric patients maintains adequate levels 1, 2

Monitoring Recommendations

Therapeutic drug monitoring considerations:

• While not routinely required for cefepime, serum concentration monitoring can verify adequate exposure in patients with uncertain residual renal function or serious infections 3
• Target trough concentrations should remain above the MIC of the causative organism (typically ≥8 mg/L for susceptible pathogens) 4
• Monitor for neurological adverse effects (confusion, seizures), which can occur with cephalosporin accumulation even with appropriate dosing 1

Alternative Dosing Strategy

If using the FDA label's conservative approach:

• Day 1: 1 gram IV after dialysis
• Subsequent dialysis sessions: 500 mg IV after each dialysis 1

However, the 1-gram thrice-weekly regimen is better supported by recent literature for serious infections and provides more reliable pharmacodynamic target attainment across the 72-hour interval. 2