Phenotype description: Glomerular, tubular dysfunction,
AKI and nephrolithiasis/crystalluria
Tubular dysfunction refers to RTA, Fanconis,
SIADH, DI, phosphate wasting
AKI refers to ATN, AIN or osmotic nephrosis.
While not discussed in article- pre renal insult from pharmacologic agents
might be under this category as well
The mechanism then is divided in two types A and
B. Type A reaction are dose dependent
toxicities and that are predictable based on drug exposure and pharmacology of
agent for example aminoglycoside. Type B
reaction is unpredictable such as AIN from PPI or any agent for the
matter. A Type B reaction in glomerular
category would be hydralazine or PTU induced lupus nephritis.
Same drug can cause Type A or B reaction.
Acute ( 1-7 days), sub acute
(8-90 days) and chronic(>90 days).
Setting: Hospitalized vs outpatient
setting. Outpatient setting drug injury
is the most missed type as not easy to recognize as compared to inpatient
setting as more reliable and easily visible data by consultants.
The authors propose that drug induced kidney
injury meet the following criteria:
The drug exposure must be 24 hours before renal
Reasonable evidence for biological plausibility
for the casual drug
Complete data( full medication list, biomarker
Strength of the relationship between attributable
drug and phenotype should be based on drug exposure and duration, extent of
primary and secondary criteria met and the time course of injury.
Transient factors that affect change is important
to know- BP trends, infections, and medications that can alter hemodynamics
Kidney biopsy should be used to define ATN vs
AIN or Gn to better get the phenotype.
In patients with CKD, reference baseline crt
might be used to use as value to which crt might return back to. In cases of AIN, the crt may take much longer
to return to baseline—making it a sub acute injury.
Tools such as the Naranjo scale can be used to
help guide but sometimes with multi drug exposure and other events, this might
be not that helpful.
This is an interesting start to a common problem
we face. Sometimes biopsies are not that easy in the sick patient and guidance
tools as this paper might be useful.