<unk>  (brand names: Acupan, Silentan, Nefadol and Ajan) is a centrally-acting but non-opioid analgesic drug of the benzoxazocine chemical class which was developed by Riker Laboratories in the 1960s. It is widely used, mainly in European countries, for the relief of moderate to severe pain as an alternative to opioid analgesic drugs.  Animal studies have shown that<unk>  has a potentiating (analgesic-sparing) effect on morphine and other opioids by broadening the antinociceptive action of the opioid and possibly other mechanisms, generally lowering the dose requirements of both when they are used concomitantly.
Nefopam
Propafenone
Lofexidine
Ivabradine
Fenoldopam
Verapamil
Alvimopan
Glymidine