Cefepime Bridging Dose on Sunday
Yes, an additional dose of cefepime should be administered on Sunday to bridge the 72-hour interval before Monday's dialysis session. The FDA-approved dosing for hemodialysis patients explicitly accounts for the longer interdialytic interval, and maintaining therapeutic drug levels throughout this period is critical for preventing treatment failure and bacterial resistance.
Dosing Strategy for the 72-Hour Interval
The Sunday dose should be higher than the dose given before 48-hour intervals. According to the FDA label, cefepime is removed approximately 68% during a 3-hour hemodialysis session, necessitating post-dialysis replacement dosing 1. Research demonstrates that doses before 72-hour intervals must be significantly higher than those before 48-hour intervals to maintain adequate drug concentrations 2.
Specific Dosing Recommendations
- For highly susceptible pathogens (MIC ≤4 mg/L): Administer 1.5 g cefepime post-dialysis on Saturday before the 72-hour interval to Sunday-Monday 2
- For less susceptible organisms like Pseudomonas aeruginosa (MIC up to 8 mg/L): Administer 2 g cefepime post-dialysis on Saturday, with potential need for an additional bridging dose on Sunday 2, 3
- The dose before 48-hour intervals (Wednesday-Friday, Friday-Saturday) should be approximately 1 g for susceptible pathogens or 1.5 g for resistant organisms 2
Pharmacokinetic Rationale
The need for Sunday bridging relates to cefepime's elimination kinetics in anuric ESRD patients:
- Pre-dialysis trough concentrations at 72 hours average 11.3 ± 5.6 mg/L, which may fall below therapeutic targets for organisms with MIC >4 mg/L during the final 24 hours of the interval 2
- Hemodialysis removes 55-68% of circulating cefepime, reducing concentrations from approximately 64 mg/L to 20 mg/L during a single session 1, 4
- The elimination half-life in anuric patients is 33.6 hours between dialysis sessions, meaning drug levels decline substantially over 72 hours 4
Clinical Decision Algorithm
Step 1: Identify the pathogen and MIC
- If MIC ≤4 mg/L: Standard post-dialysis dosing (1.5 g Saturday) without Sunday bridge may suffice 2
- If MIC 4-8 mg/L or unknown pathogen: Sunday bridging dose is recommended 2, 3
- If MIC >8 mg/L or Pseudomonas aeruginosa: Sunday bridging dose is mandatory 2, 3
Step 2: Assess residual renal function
- Anuric patients (as specified in your case): Require higher doses due to complete dependence on dialytic clearance 2
- Patients with preserved diuresis achieve 40% lower trough levels and may need even more aggressive dosing 2
Step 3: Determine Sunday bridging dose
- For anuric patients with susceptible organisms: 500-750 mg on Sunday maintains therapeutic levels 3
- For resistant organisms or critically ill patients: 1 g on Sunday ensures >90% probability of target attainment 3
Critical Pitfalls to Avoid
Never skip the Sunday dose for infections with unknown susceptibility or resistant organisms. Subtherapeutic levels during the 72-hour interval risk treatment failure, particularly for Pseudomonas aeruginosa where maintaining drug concentrations >70% of the time above MIC is essential for bacterial eradication 2, 3.
Do not use the same dose before 48-hour and 72-hour intervals. Research clearly demonstrates that the Saturday dose before the 72-hour interval must be 45% higher (1125 mg vs 775 mg) than doses before 48-hour intervals to maintain equivalent trough concentrations 2.
Avoid administering cefepime before dialysis sessions. The FDA label and clinical guidelines emphasize post-dialysis administration to prevent premature drug removal and facilitate directly observed therapy 1, 5.