European Journal of Biomedical and Pharmaceutical Sciences

COMPARISON OF FOUR METHODS IN COMPUTING AREA UNDER THE CONCENTRATION-TIME CURVE (AUC24) OF VANCOMYCIN VERSUS INTEGRATION APPROACH (STANDARD) IN HEMODYNAMICALLY STABLE PATIENTS- A SINGLE-CENTERED RETROSPECTIVE STUDY

Yen Ping Ng*, Yassini Maniam, Sam A. Thamby, Jing Ng, Boon Seng Tan, Jin Yi Choo, Cheng Hoon Yap

ABSTRACT

The updated guidelines recommend two approaches to estimate the AUC24 for patients receiving vancomycin; Bayesian-derived AUC24 monitoring or the first-order pharmacokinetic analytic equations. Bayesian approach is complex and unfamiliar to most pharmacists or clinicians. Several methods were developed to estimate AUC24 for vancomycin. However, which approach can produce a more accurate AUC24 remained unanswered. The main objectives of this study were to identify the method that able to provide a more accurate values of AUC24 and to explore the agreement of AUC24 estimated by the investigated methods to the integration model (standard). We conducted a retrospective analysis using the Electronic Hospital Information System from a tertiary hospital in Malaysia. Data pertaining to patients who received vancomycin treatment from 1st January 2021 to 31th of December 2022 were retrieved for analysis. The mean AUC24 of Simpson’s Rule integrated method (standard) versus 2-Point trapezoidal, 3-Point trapezoidal, Pharmacokinetic Method 1(PK1) and Pharmacokinetic Method 2 (PK2) showed a statistically significant difference by 91.05 ± 40.88 mg·h/L, 116.95 ± 33.71 mg·h/L, 119.60 ± 40.91 mg·h/L and 38.73 ± 59.56 mg·h/L respectively, p < 0.05. None of the methods agree with the Simpson’s Rule integrated method. The 2-Points, 3-Points, PK1 and PK2 methods also appeared to have some imprecision versus the Simpson’s Rule Integration method, as 40%, 67.5%, 65 % and 12.5% of AUC24 estimates were outside the upper and lower agreement level of ±100 mg*h/L, respectively. The present study failed to demonstrate agreement of calculated AUC24 by the four methods to the Simpson integration approach (standard). All the approaches underestimated the AUC24. Among the four methods, there is a modest variance of 38.73 mg*h/L in the PK2 values, which aligns most closely with the accuracy of Simpson's rule integration.

Keywords: AUC24, vancomycin, Simpson rule integrated approach, trapezoidal approach, log-linear approach.