“… nonsteroidal anti-inflammatory drugs , opioid drugs) and many … between pro-oxidant and antioxidant processes in the mammalian tissues and these properties of drugs such as indomethacin, meloxicam, tenoxicam, valdecoxib or some metabolites …-related toxic effects, including gastrointestinal ulcers, hepatic failure, agranulocytosis, aplastic anemia, neutropenia, opiate-induced hyperalgesia and tolerance.”