Comparative Incidence of Nephrotoxicity by Age Group among Adult Patients Receiving Vancomycin.

Introduction: Little is known regarding age-related risk of nephrotoxicity during vancomycin therapy after the publication of the 2009 vancomycin consensus guidelines for therapeutic drug monitoring. We sought to evaluate incidence and risk factors for acute kidney injury in three age groups.

Methods: Matched cohort study of patients receiving vancomycin, grouped by age: young adults (18-64 years), older adults (65-79 years) and very elderly (≥80 years), matched on previously published risk factors for nephrotoxicity. Outcomes included traditional vancomycin nephrotoxicity and Acute Kidney Injury Network-modified definition of nephrotoxicity.

Results: The incidence of acute kidney injury was 34.1% vs. 34.1% vs. 31.8% in the young, older adults and very elderly groups, respectively (p = 0.97). In the logistic regression model, after adjusting for baseline risk factors, age was not a significant predictor of acute kidney injury. Lower respiratory tract infection (adjusted odds ratio [aOR] 5.18; 95% confidence interval [CI] 2.15-12.41) and duration of treatment (aOR 1.12; 95% CI 1.03-1.22) were found to be independently associated with outcome.

Conclusion: No differences in risk of acute kidney injury were identified between young, older, and very elderly adults when adjusting for other risk factors. Further research is required to identify strategies to optimize the safety of vancomycin in the aging population.