Survey of nephrotoxicity caused by the initial loading dose of vancomycin in patients with decreased renal function

Abstract

The Therapeutic Drug Monitoring (TDM) guidelines recommend the administration of initial loading dose of vancomycin to patients with normal renal function (i.e., an estimated glomerular filtration rate (eGFR) > 80 mL/min/1.73 m²), because the optimum concentration of vancomycin in the blood is >10 mg/L. This TDM guideline determines the initial dosage of vancomycin. However, because the clinical safety of vancomycin is limited in patients with reduced renal function (i.e., eGFR < 80 mL/min/1.73 m²), initial loading dose of vancomycin is not recommended. However, the initial loading dose of vancomycin should be recommended to patients with decreased renal function because the attainment of steady state is delayed by pharmacokinetics. Therefore, we surveyed the nephrotoxicity and efficacy that resulted from the administration of initial loading dose vancomycin in patients with reduced renal function. We retrospectively examined the medical records of patients who were administered vancomycin at our hospital between January 2015 and December 2016. During the study period, the trough values and eGFR were calculated for 22 cases: load-administered group, 6 cases; standard treatment group, 16 cases. We compared the rate of therapeutic range and kidney injury between both groups. The rate of therapeutic range was 83.3% (load-administered group) and 50% (standard treatment group). It tends to be higher in the load-administered group than in the standard treatment group. Kidney impairment was observed to be 0% in the load-administered group and 12.5% in the standard treatment group.In patients with decreased renal function, safety of the initial dosage of vancomycin TDM is comparable with that of the standard treatment group.