Biopsy-proven vancomycin-associated interstitial nephritis and acute tubular necrosis.

Fewer than ten biopsy-proven case reports exist on vancomycin-associated interstitial nephritis (VAIN) and vancomycin-associated acute tubular necrosis (VAATN). Among these, several are confounded by the use of other potentially offending drugs. We report a case of isolated VAIN/VAATN in a patient on no other potentially nephrotoxic agents other than vancomycin. The patient received intravenous vancomycin for coagulase-negative staphylococcus bacteremia. Her baseline serum creatinine of 0.9 mg/dL increased to 9.6 mg/dL after 1 week of therapy during which vancomycin levels peaked at 141 μg/mL. Renal biopsy revealed acute interstitial nephritis with lymphocytic and eosinophilic infiltrate and acute tubular necrosis. Upon discontinuation of vancomycin and administration of prednisone complete renal recovery ensued over a period of 4 weeks.