Evaluation of Therapeutic Vancomycin Monitoring in Taiwan.

This study aimed to evaluate whether trough level-guided monitoring can be replaced by area under the concentration-time curve (AUC) and MIC ratio-guided monitoring (AUC/MIC ratio = 400) in patients infected with methicillin-resistant Staphylococcus aureus (MRSA) with a vancomycin MIC = 1 mg/L in Taiwan. In this retrospective study, patients treated with vancomycin for Methicillin-resistant Staphylococcus aureus (MRSA) infection were recruited from a teaching hospital in Taiwan from January 2016 to December 2017. Average trough concentrations were adjusted based on the average daily vancomycin dose, and the AUC/MIC ratio was calculated using the AUC/MIC conversion formula to analyze the correlation between trough or AUC/MIC ratio, nephrotoxicity, and clinical efficacy. As the primary outcome, the overall mean adjusted vancomycin average AUC/MIC ratio was 526.87 for a total of 102 patients. A total of 67% and 76% of the patients attained an AUC/MIC of ≥400 when the adjusted vancomycin trough concentrations were 10 to 15 mg/L and 15 to 20 mg/L, respectively. Additionally, 81.37% of the total study population had MRSA isolates with a vancomycin MIC of ≤1 mg/L. Moreover, in the subgroup, 92% of the patients attained an AUC/MIC of ≥400 on receiving vancomycin in the 10 to 15 mg/L trough range. An AUC/MIC of ≥400 was attained in patients infected with MRSA strains, who were treated by maintaining the vancomycin trough concentrations at 10 to 15 mg/L. Moreover, these patients demonstrated a lower incidence of nephrotoxicity. These findings support the use of the AUC/MIC ratio as a useful marker for the therapeutic monitoring of vancomycin owing to the clinical efficacy and safety of vancomycin in Taiwan.