Risk factors for acute kidney injury in adult patients receiving vancomycin

Questions have been raised regarding nephrotoxicity from vancomycin. A few small studies have shown that higher trough concentrations of vancomycin result in more nephrotoxicity. The purpose of this study was to evaluate risk factors that may predispose patients to nephrotoxicity in those concomitantly receiving vancomycin.

This was a single-center retrospective chart review conducted on adult subjects 18 years and older who received at least three doses of vancomycin. Exclusion criteria included sepsis, septic shock, or acute renal failure or stage 5 chronic kidney disease. Subjects were divided into two groups: those who developed nephrotoxicity and those who did not. Data collected included co-morbidities (diabetes mellitus, hypertension, congestive heart failure), creatinine clearance (CLCR), concomitant treatment with potentially nephrotoxic drugs, vancomycin trough concentrations, total daily dose, and duration of therapy.

Seventy-seven subjects were included in the nephrotoxic group and 149 were in the control group. The proportion of men in the nephrotoxic group was higher (68 vs. 50 %, p = 0.0135). Hypertension (74 vs. 51 %, p = 0.0009), diabetes (49 vs. 30 %, p = 0.0046), and furosemide use (65 vs. 39 %, p = 0.0009) were more common in the nephrotoxic group. The proportion of subjects with baseline CLCR ≤63.5 mL/min was higher in the nephrotoxic group. Furosemide use (odds ratio [OR] 2.91, 95 % CI 1.64-5.15), hypertension (OR 2.74, 95 % CI 1.5-5.0), and vancomycin trough concentration ≥16.2 μg/mL (OR 2.33, 95 % CI 1.25-4.44) were each associated with nephrotoxicity during vancomycin therapy.

In summary, the patient profile exhibiting the greatest risk (OR 4.99) of developing kidney injury is one who has hypertension, is receiving furosemide therapy, and has vancomycin trough concentrations ≥16.2 μg/mL.