Evaluation of body weight-based vancomycin therapy and the incidence of nephrotoxicity: a retrospective study in the northwest of China

•Associations between vancomycin treatment and nephrotoxicity were evaluated retrospectively in 90 patients in the northwest of China.•Fourteen (15.6%) patients developed nephrotoxicity, with serum creatinine elevated significantly from mean (standard deviation) 90.0 (18.8) μmol/l to 133.8 (63.2) μmol/l (p = 0.015).•Drug dosing >38mg/kg/day and a serum trough level >20mg/l were identified as risk factors of nephrotoxicity.•The renal function of critically ill patients receiving vancomycin should be monitored closely.