Study ObjectiveTelavancin and vancomycin are both approved for treatment of hospital‐acquired and ventilator‐associated bacterial pneumonias caused by Staphylococcus aureus, and both agents can cause renal dysfunction. The objective of this study was to assess renal function changes by performing renal shift table analyses of telavancin‐ and vancomycin‐treated patients in phase III trials.DesignRetrospective, descriptive analysis of data from the safety population from the Assessment of Telavancin for Treatment of Hospital‐Acquired Pneumonia (ATTAIN) trials.PatientsA total of 1503 adults with hospital‐acquired or ventilator‐associated bacterial pneumonia primarily caused by gram‐positive pathogens and who received telavancin (n = 751) or vancomycin (n = 752).Measurements and Main ResultsDecline or improvement in creatinine clearance (CrCl) across seven defined categories (≤30, >30–40, >40–50, >50–60, >60–70, >70–80, and >80 ml/min) was classified as negative or positive shifts, respectively. The number of categories crossed (either positive or negative) determined the grade of shift (of a potential grades 1–6, with crossing from one category to the next adjacent category defined as a grade 1 shift) at specific time points compared with baseline: day 4, day 7, and end of therapy (EOT). Approximately 77%–91.6% of patients had either no change or improvement of CrCl across all time points for both treatments. Negative shifts were consistent for telavancin (day 4, 19.3%; day 7, 19.0%; EOT, 23.0%) but increased over time for vancomycin (day 4, 8.4%; day 7, 12.3%; EOT, 19.3%). A significantly lower proportion of patients receiving vancomycin showed renal function decline on day 4 and day 7. At EOT, negative shift rates were similar between treatments (treatment difference 3.6% [95% CI −0.7 to 7.9]). At day 7 and EOT, a higher percentage of vancomycin‐treated patients experienced high‐grade negative shifts relative to telavancin (day 7, vancomycin 2.8% vs telavancin 1.9%; EOT, vancomycin 4.7% vs telavancin 4.1%), though differences were not statistically significant.ConclusionUse of shift tables revealed differences in timing of renal function changes in patients receiving telavancin and vancomycin. Telavancin‐related declines in renal function were similar at day 4 and day 7, with a slight increase by EOT. This differed from vancomycin, which caused a steady increase in the percentage of patients with renal function decline over time. A significant difference in negative renal shifts between treatments occurred at day 4 and day 7 and favored vancomycin; however, the difference was minimal and not significant at EOT.