What are the dosing recommendations for cefepime and vancomycin for a patient with impaired renal function on dialysis (hemodialysis) three times a week?

Dosing Orders for Cefepime and Vancomycin in Hemodialysis Patients

For a patient on hemodialysis three times weekly (Tuesday, Thursday, Saturday), administer vancomycin 15-20 mg/kg after each dialysis session and cefepime 2 g after each dialysis session.

Vancomycin Dosing Protocol

Loading Dose

• Administer a loading dose of 20-25 mg/kg (based on actual body weight) after the first dialysis session to rapidly achieve therapeutic concentrations 1, 2
• This loading dose is critical regardless of renal function, as it establishes adequate initial drug levels 1

Maintenance Dosing

• Give 15-20 mg/kg after each dialysis session (Tuesday, Thursday, Saturday) 1
• The dose should be administered immediately following completion of hemodialysis to avoid premature drug removal 3, 1
• Dosing frequency of three times weekly (not daily) is appropriate for patients on intermittent hemodialysis 3

Target Trough Levels

• Target pre-dialysis trough concentrations of 15-20 mg/L for serious infections 1, 4
• For less severe infections, target trough levels of 10-15 mg/L 1
• Draw trough levels immediately before the dialysis session (before the fourth or fifth dose) to assess steady-state concentrations 1, 4

Monitoring Requirements

• Measure trough vancomycin level before the fourth dose (which would be before the Tuesday dialysis session of the second week) 1, 4
• Monitor serum creatinine at least twice weekly throughout therapy 4
• Recheck trough levels with each dose adjustment 4

Cefepime Dosing Protocol

Standard Dosing for Hemodialysis

• Administer 2 g IV after each hemodialysis session (Tuesday, Thursday, Saturday) 5, 6, 7
• This dosing achieves drug levels well above the MIC90 for most target pathogens 6
• The FDA label specifies that for hemodialysis patients, cefepime should be given at 1 g on Day 1 followed by 500 mg every 24 hours for most infections, but recent evidence supports 2 g post-dialysis three times weekly as more effective 5, 6, 7

Administration Timing

• Administer cefepime immediately after completion of hemodialysis 5, 6
• Approximately 68-72% of cefepime is removed during a 3-hour dialysis period with high-flux membranes 5, 6
• Infuse over approximately 30 minutes 5

Pharmacokinetic Considerations

• The interdialytic half-life of cefepime is approximately 22 hours, supporting three-times-weekly dosing 6
• Trough levels with 2 g post-dialysis dosing remain above MIC for most pathogens throughout the interdialytic interval 6

Critical Implementation Points

Timing Coordination

• Both antibiotics should be administered after dialysis on the same days (Tuesday, Thursday, Saturday) to facilitate directly observed therapy and avoid premature drug removal 3, 1
• Schedule administration immediately following dialysis completion 3, 1

Common Pitfalls to Avoid

• Never reduce the per-dose amount of vancomycin; instead extend the interval between doses 1
• Reducing per-dose amounts decreases efficacy due to vancomycin's concentration-dependent bactericidal activity 1
• Do not use fixed 1 g vancomycin doses, as this results in subtherapeutic levels in most patients, particularly those weighing >70 kg 2, 8
• Avoid administering antibiotics before or during early dialysis, as this leads to significant drug removal and underexposure 3, 9

Infusion Precautions

• Infuse vancomycin over at least 1 hour to minimize red man syndrome risk 10
• Consider antihistamine premedication for large vancomycin doses 10
• Infuse cefepime over approximately 30 minutes 5

Alternative Therapy Considerations

• If vancomycin MIC ≥2 μg/mL, switch to alternative agents (daptomycin, linezolid, or ceftaroline) 1, 4
• Target AUC/MIC ratios may not be achievable with conventional vancomycin dosing when MIC is elevated 1

Sample Order Set

Vancomycin:

• Loading dose: [Calculate 20-25 mg/kg based on actual body weight] IV after first dialysis session
• Maintenance: [Calculate 15-20 mg/kg based on actual body weight] IV after each dialysis session (Tuesday, Thursday, Saturday)
• Infuse over 60-120 minutes
• Target trough: 15-20 mg/L (draw before Tuesday dialysis of week 2)

Cefepime:

• 2 g IV after each dialysis session (Tuesday, Thursday, Saturday)
• Infuse over 30 minutes
• Administer immediately following dialysis completion