Severe low back pain secondary to acute interstitial nephritis following administration of ranitidine

Acute interstitial nephritis is a disease characterized by renal inflammation and is thought to be secondary to a hypersensitivity reaction. Although the causes of acute interstitial nephritis are numerous, adverse reactions to many common drugs, particularly antibiotics and nonsteroidal anti-inflammatory agents, are important etiological factors. Acute interstitial nephritis has many clinical manifestations, most notably fever and rash. Flank pain is an uncommon presentation. A case of acute, severe, low-back pain and rash in a healthy woman found to be secondary to acute interstitial nephritis is reported. The etiology of acute interstitial nephritis in this patient's case is suspected to be ranitidine (Zantac; Glaxo Pharmaceuticals, Research Triangle Park, NC), which has not been previously associated with this syndrome.