Augmented renal clearance and its association with vancomycin serum level

Abstract

Background: Patients with serious infections require special attention to achieve successful treatment. One of significant factors influencing drugs effect is augmented renal clearance (ARC) – a new phenomenon in medicine, which is important for drugs eliminated via kidneys (1, 2). Vancomycin could serve as a model drug for which the presence of ARC might be clinically important as renal clearance pathway is completely dominating (2, 3). Objective of our study was (i) to determine ARC proportion among patients with estimated creatinine clearance (eCrCl) > 90 ml/min and tested for vancomycin serum concentration (VSC); (ii) to evaluate its impact on vancomycin dosage and serum concentration. Methods: In the retrospective study, all measurements of trough vancomycin serum concentration at steady state during a two years period were analysed. ARC and Control groups were formed (VSC in patients with eCrCl >130 ml/min and eCrCl 90-130 ml/min respectively). Appropriateness of measured VSCs to therapeutic level was evaluated. Results: ARC was identified in 50 % of patients included in analysis, and 38 VSCs for ARC and 39 VSCs for Control group were identified. ARC impact on VSC is presented in Fig. 1. Fig. 1. Appropriateness of measured trough vancomycin serum concentration to recommended level between the ARC (n = 38) and the Control (n = 39) groups, % (n). * p < 0.05; ARC – augmented renal clearance The relative risk for VSC subtherapeutic trough is higher in case of ARC (RR, 1.84; 95% CI, 1.23-2.74; P = 0.011). While reviewing prescribtion of vancomycin, the therapeutic dosage between 15 mg/kg/day and 30 mg/kg/day was detected for most patients in both groups, although dosage up to 15 mg/kg/day is noticeable for 40.4 % of patients in the Control group and dosage over 30 mg/kg/day for 13.2 % of patients in the ARC group. The dose distribution between dosage groups is comparable (Fig. 2) except group above 30 mg/kg/day, where vancomycin dose reached 44 mg/kg/da