What is the recommended IV vancomycin (vancomycin) dose for patients with Continuous Ambulatory Peritoneal Dialysis (CAPD) and impaired renal function?

IV Vancomycin Dosing in CAPD Patients

For CAPD patients requiring IV vancomycin, administer a full loading dose of 15-20 mg/kg (or 25-30 mg/kg for serious infections) based on actual body weight, followed by maintenance dosing of 1 gram every 5-7 days, with mandatory trough monitoring before each subsequent dose to target levels of 15-20 mg/L for serious infections. 1

Loading Dose Strategy

• The loading dose is NOT affected by renal function and must be given at full weight-based dosing to rapidly achieve therapeutic concentrations, even in patients with end-stage renal disease on CAPD. 1
• For serious infections (bacteremia, endocarditis, osteomyelitis, meningitis, pneumonia), administer a loading dose of 25-30 mg/kg based on actual body weight. 1
• For less severe infections, a loading dose of 15-20 mg/kg is appropriate. 1
• Infuse the loading dose over 2 hours to minimize the risk of red man syndrome, particularly with doses exceeding 1 gram. 1, 2

Maintenance Dosing in CAPD Patients

• After the loading dose, maintenance dosing should be 1 gram every 5-7 days based on pharmacokinetic studies in end-stage renal failure patients. 3, 4
• Research demonstrates that vancomycin elimination half-life in end-stage renal failure is approximately 121-131 hours, supporting extended dosing intervals. 3, 4
• Studies show that 500 mg every 7 days may be adequate for some patients, but 1 gram every 7 days provides more consistent therapeutic levels. 4

Therapeutic Monitoring Requirements

• Obtain trough levels immediately before each subsequent dose (every 5-7 days) to guide dosing adjustments. 1
• Target trough concentrations of 15-20 mg/L for serious infections such as CAPD-associated peritonitis, bacteremia, or other invasive infections. 1, 2
• For less severe infections, target trough levels of 10-15 mg/L. 1
• Research shows that 16-42% of patients may have subtherapeutic levels with standard dosing, making monitoring essential. 5, 4

Special Considerations for CAPD-Associated Peritonitis

• If treating CAPD-associated peritonitis specifically, intraperitoneal vancomycin administration is preferred over IV dosing, as IV vancomycin does not consistently achieve therapeutic intraperitoneal concentrations. 6
• Studies demonstrate poor correlation (R² = 0.18) between serum and peritoneal dialysate vancomycin concentrations, with 23% of patients having subtherapeutic peritoneal levels despite adequate serum levels. 6
• If IV vancomycin must be used for peritonitis, more frequent dosing may be necessary to maintain therapeutic peritoneal concentrations. 6

Dosing Adjustment Algorithm

• If trough level is <10 mg/L: Shorten the dosing interval to every 5 days or increase the dose. 1
• If trough level is 10-15 mg/L for non-severe infections: Maintain current regimen. 1
• If trough level is 15-20 mg/L for serious infections: Maintain current regimen. 1
• If trough level is >20 mg/L: Hold the next dose and recheck trough; resume at extended interval once level decreases to target range. 7

Critical Pitfalls to Avoid

• Never reduce or omit the loading dose based on renal function—this is the most common error and leads to delayed achievement of therapeutic levels. 1
• Do not use fixed 1-gram loading doses without weight-based calculation, as this results in subtherapeutic levels in most patients. 1
• Avoid using vancomycin dosing schedules designed for hemodialysis patients, as CAPD provides continuous but minimal drug clearance (vancomycin clearance averages only 0.086 mL/min/kg in dialysis patients). 8
• Do not assume adequate serum levels guarantee therapeutic peritoneal concentrations when treating peritonitis. 6
• Monitor for nephrotoxicity even in anuric patients, as vancomycin can cause additional renal injury that may affect residual renal function. 1

Alternative Considerations

• If vancomycin MIC is ≥2 μg/mL, consider alternative agents such as daptomycin, linezolid, or ceftaroline, as target AUC/MIC ratios may not be achievable. 1
• For CAPD-associated peritonitis, intraperitoneal vancomycin dosing (loading dose of 30 mg/kg in one exchange, followed by 15-25 mg/L in each subsequent exchange) is the preferred route. 6