Prediction of Area Under the Curve from Urinary Vancomycin Concentrations Measured Using a Simple Method

Area of Science:

• Pharmacology
• Analytical Chemistry
• Clinical Pharmacy

Background:

• Therapeutic drug monitoring (TDM) of vancomycin (VCM) is crucial for optimizing patient outcomes.
• Current methods for VCM TDM, particularly calculating the area under the curve (AUC), involve frequent blood sampling, increasing costs and patient burden.
• There is a need for simpler, less invasive methods for VCM TDM.

Purpose of the Study:

• To develop and validate a rapid method for measuring urinary VCM levels.
• To assess the feasibility of using urinary VCM concentrations to predict VCM AUC.
• To reduce the burden associated with traditional VCM TDM.

Main Methods:

• Development of a method using solid-phase extraction and fluorescence spectrometry for urinary VCM quantification.
• Validation of the method for accuracy, precision, and quantification range.
• Analysis of urinary VCM concentration trends to correlate with AUC in patients receiving VCM.

Main Results:

• The developed method demonstrated a quantification range of 100-2,000 µg/mL with high accuracy (100.0%-108.5%).
• Intra- and inter-day relative standard deviations were below 3.39% and 4.48%, respectively, indicating good precision.
• A negative correlation (r=0.65) was observed between the slope of urinary VCM concentrations and AUC, suggesting predictive potential.

Conclusions:

• A simple and rapid method for measuring urinary VCM levels has been successfully developed.
• Urinary VCM concentration trends show potential for predicting VCM AUC, facilitating AUC-guided TDM.
• This approach using urine samples can lead to more appropriate vancomycin therapy and reduced healthcare workload.