Consult Rounds: Vancomycin induced renal toxicity

Why are we noticing more vancomycin induced renal injury these days? Is it because we are using more vancomycin as there are more resistant bugs or the trough levels have been raised to higher limits? Vancomycin-associated nephrotoxicity was reported in 0% to 5% of patients in the 1980s.  Initially, the first few reports many years ago of vancomycin induced renal damage was presumed to be from the impurities it carried that used to be called "Mississippi

Mud". As soon that was recognized, this was reduced.  

Treatment failures following vancomycin therapy in patients with methicillin-resistant Staphylococcus aureus infections have led to the utilization of higher doses of this antibiotic to achieve the trough concentrations of 10-20 μg/mL recommended by the Infectious Diseases Society of America clinical practice guideline. Vancomycin-induced renal toxicity was reported in 10-20 % and 30-40 % of patients following conventional and high doses of vancomycin therapy, respectively . Injury appears to be oxidative stress related.

Risk factors:

High level >20
Over 4g/day dose
Concomitant nephrotoxin on board
>7 days of treatment
ICU admission

Another study found rates of dialysis higher as well in those cases, but most reversible

What is the pathology in most of these cases?

ATN
Accelerated ATN ( as some authors called it)

AIN ( can be from any drug)