Does pyrazolone-induced renal injury exist?

On the basis of animal experiments and clinical findings, pyrazolones are found to have adverse renal effects. However, the latter are minor, very rare, and of practically no clinical relevance. In animals, pyrazolones induce proteinuria, oliguria, retention of substances excreted via the urine, and probably, in rare cases, papillary necrosis. Oliguria is rare in humans. A contribution of pyrazolone drugs in a specific case of papillary necrosis and in rare cases of acute interstitial nephritis is not proven, yet possible. Pyrazolone drugs induce renal injury less frequently than do the other classical analgesics.