JAC Advance Access originally published online on March 10, 2008
Journal of Antimicrobial Chemotherapy 2008 62(1):168-171; doi:10.1093/jac/dkn080
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Original research |
Risk factors for nephrotoxicity associated with continuous vancomycin infusion in outpatient parenteral antibiotic therapy
1 Department of Medicine, National University Hospital, Singapore 2 Yong Loo Lin School of Medicine, National University of Singapore, Singapore 3 Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore 4 University of Houston College of Pharmacy, 1441 Moursund Street, Houston, TX 77030, USA
Received 20 December 2007; returned 22 January 2008; revised 5 February 2008; accepted 6 February 2008
* Corresponding author. Tel: +1-713-795-8316; Fax: +1-713-795-8383; E-mail: vtam{at}uh.edu
Objectives: Continuous vancomycin infusion is increasingly used for outpatient management of infections, but the relationship between vancomycin and nephrotoxicity is controversial. We investigated the risk factors associated with nephrotoxicity in this setting.
Methods: A retrospective cohort study of patients receiving continuous vancomycin infusion as outpatient parenteral antibiotic therapy (OPAT) was performed. The likelihood of developing nephrotoxicity (
50% increase in serum creatinine from baseline) was evaluated in relation to demographic variables, underlying co-morbidities, infectious disease diagnoses, concomitant drug exposures and vancomycin concentration. Logistic regression was used to determine the association of various variables. Classification and regression tree analysis was used to determine the most significant breakpoint for continuous variables.
Results: We examined 102 adult patients between January 2004 and June 2007. The mean ± SD age, baseline serum creatinine and steady-state vancomycin concentration were 48.2 ± 17.6 years, 78.0 ± 32.5 µmol/L and 15.5 ± 10.8 mg/L, respectively. The majority of the patients (66.7%) were treated for bone and joint infection. The cumulative incidence of nephrotoxicity was 15.7%. Nephrotoxicity was found to be associated with hypertension [odds ratio (OR) 5.302 (95% confidence interval (CI) 1.159–24.246), P = 0.031], exposure to aminoglycosides [OR 6.594 (95% CI 1.026–42.385), P = 0.047], loop diuretics [OR 8.123 (95% CI 1.449–45.528), P = 0.017], and steady-state vancomycin concentration 28 mg/L [OR 21.236 (95% CI 2.687–167.857), P = 0.004].
Conclusions: We have identified independent risk factors for nephrotoxicity in patients receiving continuous infusion vancomycin in OPAT. A serum steady-state vancomycin concentration 28 mg/L markedly increases the risk.
Keywords: renal dysfunction , vancomycin monitoring , continuous infusion , OPAT