Short-term niflumic-acid-induced acute renal failure in children

Several reports emphasize the adverse effects of non-steroidal anti-inflammatory drugs (NSAIDs) on renal function. We have observed over the last 10 years seven cases of acute renal failure (ARF) due to immune interstitial nephritis in children. A recommended oral or rectal dose of niflumic acid was prescribed for ear-nose-throat disorders. Length of exposure was 1-5 days. Clinical symptoms (oedema, oliguria or anuria) appeared between 3 and 6 days. Three patients had previously received the drug. Hypersensitivity signs (fever, skin rash, eosinophilia, and/or increased IgE) were present in all cases, leukocyturia in five cases, and haematuria in six cases. Renal biopsy showed interstitial lesions with lymphocyte, eosinophil, and plasma cell infiltrates without tubular cell necrosis. Glomeruli were normal on light-microscopy, except in one patient. Electron-microscopy showed extensive podocyte fusion in two patients, who had clinical and laboratory evidence of nephrotic syndrome (NS). ARF rapidly disappeared after NSAID withdrawal, except in two patients whose renal failure was irreversible despite methylprednisolone bolus. ARF is very rare in children treated with niflumic acid. When ARF occurs, different pathophysiological mechanisms are involved but the most common is immunological.