Frequency of Nephrotoxicity with Vancomycin and Aminoglycoside Antibiotic Therapy

Three hundred and thirty four patients receiving aminoglycosides and/or vancomycin therapy for at least 72 hours were retrospectively reviewed for the development of nephrotoxicity. The patients' vancomycin and aminoglycoside serum concentrations were monitored by our clinical pharmacokinetics service. The average age, weight, and serum creatinine of the patients were 67.8 years, 71.3 kg, and 1.03 mg/dL, respectively. Nephrotoxicity occurred in 30 patients, but only 8 of these cases of renal toxicity (2.4%) were attributed to the use of vancomycin and/or aminoglycosides. The remaining 22 patients had other factors known to contribute to renal failure. Nephrotoxicity with aminoglycosides was more frequent than with vancomycin (2.8% versus 1.1%, respectively). Alarmingly, the frequency of renal toxicity increased by about four-fold when vancomycin was administered concomitantly with an aminoglycoside. Although further analysis is needed, preexisting renal impairment seems to be the major contributing factor for nephrotoxicity in our study.