The scottish model of vancomycin dosing and therapeutic drug monitoring improves both efficacy and safety of vancomycin therapy

Abstract

Objective: Vancomycin therapeutic drug monitoring (TDM) is recommended for better treatment efficacy and safety. The Scottish Antimicrobial Prescribing Group model recommends weight-based loading dose, next 3–4 doses based on creatinine clearance and maintenance doses according to trough concentrations. Methods: Retrospective cohort study of all adult patients treated with vancomycin before and after introducing the guideline in a large Czech hospital in 2015 compares the success rate in achieving recommended trough concentrations (10–20 mg/l) during first measurement and efficiency of maintaining these concentrations subsequently. Assess-ment of vancomycin related nephrotoxicity is included. Results: In 2014, 74/163 (45.4 %) patients achieved recommended concentrations in the first measurement, compared to 101/160 (63.1 %) patients in 2016 (χ2; p = 0.001). Recommended trough concentrations in more than half of subsequent measurements were detected in 51/105 patients (48.6 %) in 2014 and in 80/117 patients (68.4 %) in 2016. Not a single level in subsequent measurements within the range was detected in 28 (26.7 %) cases in 2014 and in 10 (8.5 %) cases in 2016 (Mann-Whitney; p = 0.026). There was no difference in nephropathy occurrence (χ2; p = 0.286). Conclusion: The adopted Scottish model of vanco-mycin TDM resulted in very significantly higher achievement of recommended trough concentrations during first measurements and significantly more effective maintenance of subsequent concentrations, without increased nephrotoxicity.