Internal guidelines, pharmacokinetic consultation improve vancomycin therapy

A study has shown that implementing internal guidelines and a pharmacokinetic (PK) consultation service leads to a significant improvement in use of vancomycin and, consequently, patient safety.

The investigators performed a prospective study from September 2014 to May 2017 to compare a control and a therapeutic drug monitoring (TDM) intervention group in a tertiary care centre. They implemented internal guidelines on correct vancomycin dosing, TDM timing, and targeted trough level range, as well as installed a PK consultation service to adapt vancomycin dosing to individually calculated PK parameters, as part of an antibiotic stewardship programme.

The following clinical outcomes were then analysed: the percentage of patients with sustained therapeutic vancomycin trough levels and treatment days with therapeutic vancomycin trough levels, which were defined as 10–15 mg/L (primary), as well as nephrotoxicity, readmission rate, and mortality (secondary). The investigators also assessed the median daily dose needed to achieve therapeutic trough levels.

Comparisons were made for clinical outcomes between 90 controls and 19 patients guided by a PK consultation service. Patients with sustained therapeutic vancomycin trough levels increased from 17.8 percent to 94.7 percent (p<0.001), while treatment days with therapeutic vancomycin trough levels improved from 18.4 percent (117/637) to 66.5 percent (155/233; p<0.001).

A decrease in readmission rate was noted, from 24.4 percent to 5.3 percent (p=0.07), but there were no between-group differences in nephrotoxicity or mortality rate.

Of note, a median daily dose of 72 mg/kg/d was required to achieve therapeutic trough levels.

“Vancomycin has been a first-line treatment for Gram-positive infections for decades,” the authors said, noting that strategies for TDM and dose-optimization in paediatrics remain controversial.