Fenofibrate-Induced Osmotic Nephropathy: A Novel Mechanism of Acute Kidney Injury

Fibrates are a commonly used medication in the management of dyslipidemia and cardiovascular risk. These agents have a well-documented association with reversible elevations in serum creatinine and in some instances acute kidney injury. The mechanism underlying the renal effects of fibrates are currently not well understood. We describe a case of acute kidney injury in a patient who was administered an unadjusted dose of fenofibrate in the setting of severe renal impairment. Kidney biopsy demonstrated extensive isometric vacuolization within tubular epithelial cells consistent with osmotic-type injury. Fenofibrate in this case was the likely causative agent based on the temporal relationship of drug administration and acute kidney injury. The acute kidney injury also recovered over a timeframe consistent with the known half-life of the drug metabolite. There were no other drugs, extreme instances of hyperglycemia, or intravenous (IV) agents administered to account for the biopsy findings. This case demonstrates a potential novel mechanism of fenofibrate-associated acute kidney injury with osmotic nephropathy. We review the current understanding of the effects of fenofibrate on the kidney and possible pathogenesis of osmotic nephropathy.