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. Assessment 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 vancomycin 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. Key words: guideline - therapeutic drug monitoring - vancomycin.