“Both classical analgesics (…, paroxetine, escitalopram, phenytoin or … antioxidant processes in the mammalian tissues and these properties of drugs such as indomethacin, meloxicam, tenoxicam, valdecoxib or some metabolites of analgesic … efficacy and drug-related toxic effects, including gastrointestinal ulcers, hepatic failure, agranulocytosis, aplastic anemia, neutropenia, opiate-induced hyperalgesia and tolerance.”