Factors associated with development of nephrotoxicity in patients treated with vancomycin versus daptomycin for severe Gram-positive infections: A practice-based study.

OBJECTIVE: To evaluate nephrotoxicity development in patients treated with vancomycin (VAN) and daptomycin (DAP) for proven severe Gram-positive infections in daily practice. METHODS: A practice-based, observational, retrospective study (eight Spanish hospitals) was performed including patients ≥18 years with a baseline glomerular filtration rate (GFR)>30 mL/min and/or serum creatinine level<2 mg/dL treated with DAP or VAN for >48h. Nephrotoxicity was considered as a decrease in baseline GRF to <50 mL/min or decrease of >10 mL/min from a baseline GRF<50 mL/min. Multivariate analyses were performed to determine factors associated with 1) treatment selection, 2) nephrotoxicity development, and 3) nephrotoxicity development within each antibiotic group. RESULTS: A total of 133 patients (62 treated with DAP, 71 with VAN) were included. Twenty-one (15.8%) developed nephrotoxicity: 4/62 (6.3%) patients with DAP and 17/71 (23.3%) with VAN (p=0.006). No differences in concomitant administration of aminoglycosides or other potential nephrotoxic drugs were found between groups. Factors associated with DAP treatment were diabetes mellitus with organ lesion (OR=7.81, 95%CI:1.39-4.35) and basal creatinine ≥0.9 mg/dL (OR=2.53, 95%CI:1.15-4.35). Factors associated with VAN treatment were stroke (OR=7.22, 95%CI:1.50-34.67), acute myocardial infarction (OR=6.59, 95%CI:1.51-28.69) and primary bacteremia (OR=5.18, 95%CI:1.03-25.99). Factors associated with nephrotoxicity (R2=0.142; p=0.001) were creatinine clearance<80 mL/min (OR=9.22, 95%CI:1.98-30.93) and VAN treatment (OR=6.07, 95%CI:1.86-19.93). Factors associated with nephrotoxicity within patients treated with VAN (R2=0.232; p=0.018) were congestive heart failure (OR=4.35, 95%CI:1.23-15.37), endocarditis (OR=7.63, 95%CI:1.02-57.31) and basal creatinine clearance<80 mL/min (OR=7.73, 95%CI:1.20-49.71). CONCLUSIONS: Nephrotoxicity with VAN was significantly higher than with DAP despite poorer basal renal status in the DAP group.