Impact of physical build on serum vancomycin concentrations of patients undergoing hemodialysis: A retrospective cohort study at an acute care hospital

Introduction: Estimating the serum vancomycin (VCM) concentrations of lean and patients with obesity is challenging. Additionally, VCM dosing for Japanese patients undergoing hemodialysis remains particularly unclear. This study aimed to determine the impact of the physical build on serum VCM concentrations of Japanese patients undergoing hemodialysis. Methods: This retrospective cohort study included hospitalized patients undergoing hemodialysis, who received treatment with VCM between May 1, 2019, and December 31, 2021, at Kansai Rosai Hospital, which is a 642-bed acute care hospital in Japan. Patients were divided into the following three groups based on their body mass index (BMI): lean group (<= 18.5 kg/m(2)), normal group (18.5-25 kg/m(2)), , and obese group (>= 25 kg/m(2)). The VCM dose and predialysis serum VCM concentration (PVC) were compared. Results: This study included 191 patients. There were 50 patients in the lean group, 85 in the normal group, and 56 in the obese group. The median loading doses per body weight were 24.0, 22.1, and 21.2 mg/kg for the lean, normal, and obese groups, respectively. The VCM dose per body weight decreased significantly with increasing BMI. The median PVCs of the lean and normal groups were approximately 15 mg/L (not significantly different). However, the median PVC of the obese group was 18.3 mg/L, which was significantly higher (P < 0.001). Conclusions: The VCM dose per body weight for Japanese patients undergoing hemodialysis should be adjusted based on the BMI.