Effect of renal clearance on vancomycin area under the concentration-time curve deviations in critically ill patients

Augmented renal clearance (ARC) increases vancomycin (VCM) clearance. Therefore, higher VCM doses are recommended in patients with ARC; however, impacts of ARC on the area under the concentration-time curve (AUC) discrepancies between initial dosing design and therapeutic drug monitoring (TDM) period remains unclear.

We retrospectively collected data from critically ill patients treated with VCM. The primary endpoint was the association between ARC and AUC_24-48h deviations. ARC and AUC deviation were defined as a serum creatinine clearance (CCr) ≥130 mL/min/1.73 m² and an AUC at TDM 30% or more higher than the AUC at the initial dosing design, respectively. The pharmacokinetic profiles of VCM were analyzed with the trough levels or peak/trough levels using the Bayesian estimation software Practical AUC-guided TDM (PAT).

Among 141 patients (median [IQR]; 66 [58-74] years old; 30% women), 35 (25%) had ARC. AUC deviations were significantly more frequent in the ARC group than in the non-ARC group (20/35 [57.1%] and 17/106 [16.0%] patients, respectively, p < 0.001). Age- and sex-adjusted multivariate analyses revealed that the number of VCM doses before TDM ≥5 (odds ratio, 2.56; 95% confidence interval [CI]: 1.01-6.44, p = 0.047) and CCr ≥130 mL/min/1.73 m² were significantly associated with AUC deviations (odds ratio, 7.86; 95%CI: 2.91-21.19, p < 0.001).

Our study clarifies that the AUC of VCM in patients with ARC is higher at the time of TDM than at the time of dosage design.