NSAIDs-Induced Acute Renal Failure

Author: V. Dimov, M.D., Department of General Internal Medicine, Cleveland Clinic

46 yo CM with chronic back pain takes large doses of over-the-counter pain medications. He works 12-hour night shifts and has to take 15-20 pills (Motrin, Aleve) during the shift and about the same amount during the day.

He went to the ER today because of his back pain. CBC and BMP are ordered.

PMH:
Back pain

Medications:
Motrin, Aleve, Advil, Ultram, Tylenol

Physical examination:
Limited ROM of lower back, otherwise unremarkable

Lab work
BMP showed creatinine of 3.3, BUN 25. CBC is normal.

Patient had a normal CBC and BMP one month ago.

What is the likely diagnosis?
NSAIDs-induced renal failure

What tests would your order?
UA
Urine Na+ and creatinine
Urinary eosinophils
Renal ultrasound

What happened?
Patient was admitted to the hospital and IVF were started.

UA is normal. Microscopy is negative for eosinophils. Renal ultrasound is WNL.

His creatinine improved to 2.2 over the course of 2 days. He was making 2 L of urine per day and had no complaints. Back pain was controlled with Percocet.

The patient was discharged home with a follow up BMP in one week.

Final diagnosis:
NSAIDs-Induced Acute Renal Failure (ARF)

What did we learn from this case?
NSAIDs-induced ARF is a well-known complication of NSAIDs abuse. It is described in injured athletes who have an important game and take "mega" doses of OTC pain killers to play "through the pain".

NSAIDs can induce two different forms of ARF:
- hemodynamically-mediated due to local vasoconstriction
- acute interstitial nephritis (often accompanied by nephrotic syndrome)

Patients with acute interstitial nephritis present with hematuria, pyuria, white cell casts, proteinuria (not present in our patient).

A third type of ARF is due to an allergic reaction, in this case eosinophilia and eosinophiluria are noted in the urine.

References:
NSAIDs: Acute renal failure and nephrotic syndrome - UpToDate (subscription required)

Updated: 11/01/2006