Optimization of therapeutic drug monitoring of vancomycin in patients with chronic hemodialysis

Purpose To validate a simplified vancomycin monitoring algorithm in patients on chronic hemodialysis who required intravenous vancomycin for at least 3 weeks. Materials and methods In this prospective study, all hemodialysis patients who were admitted between April 1, 2013, and March 31, 2015, in our unit for suspected or confirmed methicillin-resistant Staphylococcus aureus infection that required vancomycin were enrolled. All patients were categorized into two groups. In group 1 (standard vancomycin dosing algorithm), the maintenance doses of vancomycin were adjusted according to the pre-hemodialysis vancomycin concentrations determined before each hemodialysis session. In group 2 (simplified vancomycin dosing algorithm), pre-dialysis vancomycin trough levels were taken before the 2nd and the 6th session of hemodialysis. Maintenance doses were adjusted according to the residual concentrations of vancomycin. Results A total of 101 blood samples were collected, the average plasma concentration of vancomycin was 13.1 ± 3.8 µg/mL. 64 (63.4%) levels fell out of the therapeutic range. Seven (6.9%) of these exceeded the therapeutic range and 30 (29.7%) were lower. After the loading dose, the average plasma concentration was 11.2 ± 3.4 µg/mL. There were no statistically significant differences between the two groups with respect to the average plasma concentration of vancomycin and the proportion of vancomycin trough levels in the target range. Conclusion The vancomycin dosing algorithm using limited concentration monitoring for hemodialysis patients achieved drug concentrations comparable to those found with more frequent monitoring and resulted in significant cost savings. .