Amfenac (AHR 5850) is a non-steroidal anti-inflammatory compound possessing antipyretic and analgesic properties. It is an inhibitor of cyclooxygenases. Amfenac sodium has been on the Japanese market since 1986 (as FENAZOX®, Meiji) in an oral dosage form (50 mg, four-times-daily) indicated for the treatment of pain and inflammation associated with rheumatoid and osteoarthritis and low back pain, as well as the treatment of pain and inflammation following surgery, injury or tooth extraction. Amfenac is an active moiety of nepafenac (amfenac amide), the prodrug has very weak cyclooxygenase inhibitory activity whereas amfenac exhibits more potent cyclooxygenase activity. Nepafenac at a concentration of 0.1% (NEVANAC) was approved for marketing in the US in 2005. Nepafenac is also approved for marketing in the European Union(EU) and Japan as well as over 60 other countries for the treatment of postoperative pain and inflammation associated with cataract surgery.