Vancomycin audit in the paediatric population: Patterns of use and appropriateness of therapeutic drug monitoring

Abstract

Aims: This study aims to investigate prescribing and therapeutic drug monitoring (TDM) practices for vancomycin in paediatrics at the Jordan University Hospital and to determine the impact of inaccuracies in TDM data on dosing decisions.

Methods: Patterns of vancomycin prescriptions, appropriateness of vancomycin dosing, duration, TDM, and the accuracy of the recorded dosing/sampling times were determined prospectively based on prespecified criteria. Finally, Monte Carlo simulations were undertaken using the mrgsolve-package in R to assess the effect of inaccuracies in recording dosing/sampling times on subsequent dose adjustments.

Results: Four hundred forty-two vancomycin courses were analysed. Vancomycin prescriptions were mainly empirical (77.4%). Initial vancomycin doses were appropriate in 73.1% of vancomycin courses. Prolonged use (>5 days) was found in 45.7% of admissions with negative cultures; this was related to the diagnosis of suspected sepsis unadjusted-OR: 1.8 (1.1-2.9). TDM was appropriately ordered in 90.7% of concentrations. Discrepancies between the recorded and actual times were noted in 83.9% and 82.7% of audited times of dose administration and sample collection, respectively. Based on simulations, these discrepancies were predicted to result in inappropriate dose adjustment in 37.9% of patients.

Conclusions: Inappropriate empirical and prolonged vancomycin use and inaccuracies in recording dosing/sampling times are important areas of improvement in the current clinical practice.

Keywords: TDM; dose adjustment; empiric; paediatrics; simulation; vancomycin.