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 > or = 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 > or = 44.2 mumol/L if baseline serum creatinine was < or = 221 mumol/L or an increase in serum creatinine of > or = 88.4 mumol/L if baseline serum creatinine > 221 mumol/L. A total of 289 patients, 141 younger (mean age, +/- S.D. 37.9 +/- 12.4 y) and 148 elderly (73.6 +/- 8.5 years), was retrospectively reviewed. Nephrotoxicity occurred in 7.8% younger vs 18.9% elderly patients (P = 0.003). 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.) = 5.06); for the younger population, only concurrent amphotericin B use was significantly associated with vancomycin-associated nephrotoxicity (R.R. = 6.65); and for the elderly population, only concurrent loop diuretic use was significantly associated with vancomycin-associated nephrotoxicity (R.R. = 9.70). 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.