Retrospective multicentre matched cohort study comparing safety and efficacy outcomes of intermittent-infusion versus continuous-infusion vancomycin

Background Patients with good renal function receiving intermittent-infusion vancomycin (IIV) may require total daily doses ≥4 g to achieve trough concentrations of 15–20 mg/L, increasing the risk of vancomycin-associated nephrotoxicity. Continuous-infusion vancomycin (CIV) may be associated with a lower risk of vancomycin-associated nephrotoxicity compared with IIV, but studies comparing safety of both dosing strategies are lacking. Objectives To compare the risk of nephrotoxicity with CIV versus IIV when target concentration ranges were the same with both dosing modalities. Methods A retrospective multicentre matched cohort study of admitted patients between 1 January 2010 and 31 December 2016 was completed. Adult patients who received ≥48 h of vancomycin with at least one steady-state vancomycin concentration were eligible. The primary outcome was to compare the rates of nephrotoxic risk and renal injury, defined by the RIFLE criteria, between CIV and IIV. Results Of 2136 patients who received vancomycin during the study period, 146 CIV patients were eligible and matched to 146 IIV patients. After adjustment of potential confounders, CIV was found to have a lower odds of developing nephrotoxic risk (OR 0.42, 95% CI 0.21–0.98, P = 0.025) and renal injury (OR 0.19, 95% CI 0.05–0.59, P = 0.004). Conclusions CIV is associated with a lower odds of nephrotoxicity compared with IIV when targeting the same concentration range and should be an alternative dosing strategy for patients who will receive prolonged therapy or require >4 g/day to achieve therapeutic levels.