Vancomycin-associated nephrotoxicity in adult medicine patients: incidence, outcomes, and risk factors.

OBJECTIVE: The prevalence of vancomycin-associated nephrotoxicity (VAN) is reported to vary from 1.0-42.6%, with most data from critically ill patients. Evaluation of VAN among internal medicine patients is lacking. Our objectives were to determine the incidence, time-course, outcomes, and risk factors of VAN in adult internal medicine patients.

DESIGN: Retrospective cohort.

SETTING: Tertiary care academic medical center.

PATIENTS: A total of 125 adult internal medicine patients receiving vancomycin treatment with mean baseline creatinine clearance of 84.6 ± 27.6 ml/min.

INTERVENTION: Vancomycin treatment for a minimum of 72 hours.

MEASUREMENTS AND MAIN RESULTS: Nephrotoxicity, defined as an increase in serum creatinine of 0.5 mg/dl or 50% above baseline (whichever was larger), occurred in 17 (13.6%) of 125 patients. No patients with VAN progressed to Loss or End stage as defined by the RIFLE criteria. The incidence rate of VAN was 0.02 cases/day of vancomycin treatment. Nephrotoxicity developed at a median of 4.5 days (interquartile range [IQR] 2.2-4.9) peaked at 5.7 days (IQR: 3.8-9.6), and resolved in 70.6% of the cases within 16.5 days (IQR: 6.0-17.8) after onset. On multivariable logistic regression analysis, after controlling for hypotensive episodes, Charlson Comorbidity Index, and baseline creatinine clearance, concomitant use of piperacillin-tazobactam was associated with increased VAN (adjusted odds ratio 5.36, 95% confidence interval 1.41-20.5).

CONCLUSIONS: Vancomycin-associated nephrotoxicity is prevalent among internal medicine patients, with 5.36-fold higher odds if piperacillin-tazobactam is concomitantly administered.