A comparative assessment of vancomycin-associated nephrotoxicity in the young versus the elderly hospitalized patient

The incidence of vancomycin-associated nephrotoxicity was determined in a younger (age < 60 y) versus elderly (age ≥ 60 y) hospitalized adult population to identify associated drug- and nondrug-related risk factors. Nephrotoxicity was defined as an acute increase in serum creatinine of ≥ 44{dot operator}2 μimol/L if baseline serum creatinine was ≤ 221 μimol/L or an increase in serum creatinine of ≥ 88{dot operator}4 μimol/L if baseline serum creatinine > 221 μimol/L. A total of 289 patients, 141 younger (mean age,±S.D. 37{dot operator}9 ± 12{dot operator}4 y) and 148 elderly (73{dot operator}6 ± 8{dot operator}5 years), was retrospectively reviewed. Nephrotoxicity occurred in 7{dot operator}8% younger vs 18{dot operator}9% elderly patients (P = 0{dot operator}003). Using multivariate logistic regression models for the pooled patient population, concurrent loop diuretic use was significantly associated with vancomycin-associated nephrotoxicity (relative risk (R.R.) = 5{dot operator}06); for the younger population, only concurrent amphotericin B use was significantly associated with vancomycin-associated nephrotoxicity (R.R. = 665); and for the elderly population, only concurrent loop diuretic use was significantly associated with vancomycin-associated nephrotoxicity (R.R. = 9{dot operator}70). These data suggest that elderly patients are at significantly greater risk of vancomycin-associated nephrotoxicity than are younger patients. However, because age was not a significant risk factor for nephrotoxicity in comparing the pooled vancomycin-associated nephrotoxicity group compared to the non-nephrotoxicity group, the differences observed between age groups probably reflect differences in risk factor prevalence.