TY - JOUR
AR - JCMCR-2020-1-106
TI - Letrozole-Induced Acute Interstitial Nephritis
AU - M , Fadia
AU - Prianka , Puri
AU - Simon , Jiang
AU - Wajih , Z
JO - Journal of Clinical and Medical Case Reports
PY - 2020
DA - Mon 18, May 2020
SN - 2733-2268
DO - http://dx.doi.org/10.31487/j.JCMCR.2020.01.06
UR - https://www.sciencerepository.org/letrozole-induced-acute-interstitial-nephritis_JCMCR-2020-1-106 
KW - Acute interstitial nephritis, letrozole, aromatase inhibitor
AB - Background: Acute interstitial nephritis is often associated with drug therapy. It can be a common cause
of acute kidney injury, traditional chemotherapy agents have been associated with various forms of renal
damage, but this is not commonly seen with anti-hormone therapy. Here we report a case of aromatase
inhibitor associated acute interstitial nephritis with the use of letrozole.
Case Presentation: We present the case of an 84-year-old female commended on letrozole for the
management of estrogen sensitive breast cancer. The patient developed oliguric acute kidney injury 3-weeks
after initiation, with a creatinine rise to 1069µmol/L, from a previously normal baseline. She had no
response to hydration and underwent a renal biopsy which demonstrated acute interstitial nephritis. She was
commended on 4 weeks of oral prednisone starting at 20mg with a tapering dose. Renal function returned
to baseline on discharge and her aromatase inhibitor was ceased.
Conclusions: This is the first reported case of letrozole induced acute interstitial nephritis. It appears the
disease was steroid responsive however it is unclear if this is a class effect of aromatase inhibitors or
letrozole alone.