Background: Vancomycin is considered the drug of choice for methicillin-resistant Staphylococcus aureus infection; however, it has also been linked with nephrotoxicity in the past, sometimes leading to its substitution with linezolid. We hypothesized that patients treated with vancomycin for gram-positive (GP) infections would have an increased incidence of rise in creatinine and need for hemodialysis (HD) compared with patients receiving linezolid.
Methods: This was a retrospective cohort study of a prospectively maintained database of all surgical patients treated with either vancomycin or linezolid for GP infections in a single intensive care unit from 2001 to 2008 and managed under a cycling antibiotic protocol. Patients were followed up until hospital discharge. Categorical and continuous variables were evaluated. Multivariable logistic regression was performed.
Results: A total of 545 patients were treated for 1,046 GP infections (571 with vancomycin, 475 with linezolid) over 7 years. Patient demographics were similar between groups; however, the vancomycin group was associated with a longer treatment course (16.2 [0.5] days vs. 14.3 [0.5] days; p = 0.022). Unadjusted outcomes were similar between groups. Multivariable analysis revealed that Acute Physiology and Chronic Health Evaluation II score predicted an increase in creatinine levels greater than 1.0 following antibiotic therapy (relative risk [RR], 3.01; 95% confidence interval [CI], 1.22-7.42) and subsequent need for HD (RR, 3.07; 95% CI, 1.23-7.62). In addition, initial creatinine level predicted an increase in creatinine levels greater than 1.0 following antibiotic therapy (RR, 4.36; 95% CI, 1.46-12.99) and subsequent need for HD (RR, 10.83; 95% CI, 3.19-36.77). Linezolid was found to be protective regarding rise in creatinine levels greater than 1.0 following antibiotic therapy; however, this was only experienced when vancomycin trough levels greater than 20 were encountered (RR, 5.4;95% CI, 1.19-24.51).
Conclusion: These data suggest that vancomycin is minimally nephrotoxic and has a similar nephrotoxic profile as compared with linezolid when appropriate dosing is used, even among critically ill patients with complex infections.
Level of evidence: Therapeutic/care management, level II.