ACUTE INTERSTITIAL NEPHRITIS

AIN is a hypersensitivity reaction, most often drug-induced, which results in acute renal impairment secondary to renal interstitial edema and an interstitial infiltrate consisting mostly of lymphocytes and monocytes. Many medications are known to cause this disorder and are listed below.

Clinically, patients develop fever, rash, eosinophilia, hematuria, proteinuria, and eosinophiluria after 3 to 10 days of receiving the inciting medication. Urinary eosinophils may be detected by collecting a urine sample for Wrights or Hansels staining but are not always present. Once the diagnosis is established, the offending medication or medications should be discontinued. Recovery from renal failure is variable and may occur over a few days or may take months. Steroids (prednisone at 60 mg/day and rapidly tapered in accordance with renal response) have been shown to be beneficial (the use of steroids is still controversial in this setting); however, relapse may occur upon discontinuation of treatment.

MEDICATIONS ASSOCIATED WITH ACUTE INTERSTITIAL NEPHRITIS