Material and Method: The present study was conducted on eight end-stage renal disease patients receiving HEHD. The patients received an initial dose of vancomycin 1 g followed by 500 mg immediately after HEHD session for a supplementation. Blood samplings were obtained to investigate vancomycin pharmacokinetic parameters. A Monte Carlo simulation was performed to determine the percentage of probability of target attainment (PTA) achieving AUC24/MIC ratio greater than or equal to 400 as the target of achievement of antimicrobial activity.

Results: A loading dose (LD) of vancomycin of 20 mg per kilogram of dry weight (DW) with or without a supplementation had the optimum effectiveness for pathogens with MICs not greater than 0.5 mg/L. For pathogens with an MIC of 1.0 mg/L, the LD of 25 mg/kgDW followed by 20 or 25 mg/kgDW supplementation was achieved the target in some cases. Therefore, the LD of 30 mg/kgDW followed by 25 mg/kgDW or the LD of 35 mg/kgDW with 10, 20 or 25 mg/kgDW supplementation was required to achieve the target of antimicrobial activity.

Conclusion: From the present study, the lowest vancomycin dosing regimen that had the optimum effectiveness was a 35 mg/kgDW LD followed by 10 mg/kgDW supplementation. This regimen is recommended to treat pathogens with MICs not greater than 1.0 mg/L.

Keywords: Vancomycin, Dosing regimen, Monte Carlo simulation, High-efficiency hemodialysis (HEHD)