Vancomycin Dosing in SLED
For patients on SLED, administer a loading dose of 2400 mg followed by maintenance doses of 1600 mg daily, with mandatory therapeutic drug monitoring to guide subsequent dosing due to highly variable clearance. 1
Loading Dose Strategy
- Administer 2400 mg as a loading dose to rapidly achieve therapeutic concentrations in critically ill patients receiving SLED 1
- Alternatively, a weight-based loading dose of 25-30 mg/kg can be used in critically ill patients, infused over 2 hours with antihistamine premedication to minimize red man syndrome risk 2
- Loading doses are essential because SLED significantly removes vancomycin from the circulation 1, 3, 4
Maintenance Dosing
- Give 1600 mg daily as the empiric maintenance dose based on pharmacokinetic modeling that achieves target AUC/MIC ≥400 while maintaining AUC24 <700 to minimize nephrotoxicity risk 1
- SLED removes approximately 35-42% of vancomycin during an 8-hour session, with the greatest removal occurring in the first 4 hours 3, 4, 5
- Vancomycin clearance during SLED is highly variable, averaging 5.97 L/h on SLED versus 2.40 L/h off SLED 1
Post-SLED Supplementation
- Redose with at least 500-1000 mg after each SLED session if pre-dialysis levels are 20-30 mcg/mL, as serum concentrations drop below therapeutic range (<15 mcg/mL) in nearly half of patients by the end of an 8-hour session 3, 4
- Vancomycin rebound after SLED is minimal (approximately 9.8%), so additional dosing is required immediately post-SLED rather than waiting for redistribution 4
Therapeutic Drug Monitoring Requirements
- Obtain trough levels before the fourth dose to confirm steady-state, then monitor before each SLED session and after dose adjustments 6, 7
- Target trough concentrations of 15-20 mg/L for serious infections to achieve AUC/MIC ≥400 for organisms with MIC ≤1 mg/L 6, 7, 2
- Monitor serum creatinine at least twice weekly throughout therapy, as sustained trough concentrations >20 μg/mL increase nephrotoxicity risk 6, 2
Management of Elevated Levels
- Immediately hold the next dose when trough exceeds 20 mg/L and recheck levels before administering subsequent doses 6, 7, 2
- Once trough decreases to 15-20 mg/L, resume vancomycin at reduced dose or extend dosing interval by approximately 15-20% 6
Critical Considerations
- SLED clearance of vancomycin is 3-fold higher than continuous renal replacement therapy, requiring more aggressive dosing strategies 5
- The vancomycin half-life during SLED is approximately 13.6 hours with minimal rebound after dialysis completion 4
- Switch to alternative antibiotics when vancomycin MIC ≥2 mg/L, as target AUC/MIC ratios are not achievable with conventional dosing 6, 7, 2
Common Pitfalls to Avoid
- Never use fixed-dose maintenance regimens without therapeutic drug monitoring, as they fail to reach target levels in the majority of SLED patients 3, 8
- Do not rely on dosing recommendations from intermittent hemodialysis or continuous renal replacement therapy, as SLED pharmacokinetics differ significantly 4, 5
- Avoid monitoring only peak levels, as trough monitoring is the most accurate and practical method for guiding vancomycin dosing 6, 7