Reversal of refractory sulfasalazine-related renal failure after treatment with corticosteroids

Abstract Background: Sulfasalazine is a combination of sulfapyridine and 5-aminosalicylic acid and is used as a first-line treatment in inflammatory bowel disease. Objective: We describe a case of acute interstitial nephritis that presented after 7 months of sulfasalazine therapy. Despite the discontinuation of the drug, the patient's renal function continued to deteriorate and recovered only when systemic corticosteroid treatment was initiated. Case summary: A 19-year-old white male (weight, 65 kg) presented in November 2006 with upper abdominal pain, fever ≥38°C, bloody diarrhea, anorexia, and weight loss. Ulcerative colitis involving the left colon was diagnosed based on results of a colonoscopy and intestinal biopsy, and treatment was initiated with cefprozil 1 g/d, mesalamine 3 g/d, methylprednisolone 32 mg/d, and ranitidine 300 mg/d. All drugs were administered orally. Cefprozil and ranitidine were discontinued after 10 days. Mesalamine was discontinued 1 month later because of gastrointestinal adverse effects (vomiting and diarrhea), and methylprednisolone was tapered over the next 3 months to zero. The patient then had a relapse, and sulfasalazine 2 g/d orally was administered. Seven months after the initiation of sulfasalazine, the patient developed fatigue, nausea, fever more prominent in the afternoon (increased from 38°C to 40°C), and nocturia, and he was admitted to the hospital. He had no history of renal impairment. Laboratory test results showed elevated serum urea and creatinine levels (170 and 7 mg/dL, respectively), while kidney ultrasound showed normal kidneys without obstruction. The patient had a Naranjo Adverse Drug Reaction Probability scale score of 6, indicating a probable adverse drug reaction with sulfasalazine. Based on these findings, sulfasalazine-related nephrotoxicity was suspected, and the drug was discontinued. During the next 4 days, serum urea and creatinine values increased to 212 and 8.3 mg/dL, respectively, and then remained stable for 3 days. A renal biopsy was performed, which revealed changes compatible with granulomatous interstitial nephritis. The patient received methylprednisolone 500 mg IV for 3 days, followed by oral administration of methylprednisolone 16 mg/d for 1 month. Renal function recovered completely a few days after initiation of corticosteroids, and the patient's condition continued to be stable 1 year later (eg, serum urea, 34 mg/dL; creatinine level, 0.9 mg/dL). Conclusions: Although this isolat