Norpipanone
Norpipanone is an opioid analgesic related to methadone which was developed in Germany and distributed in Hungary, Argentina, and other countries. It had originally not been under international control but upon observation of case reports of addiction it was reviewed and shortly thereafter became a controlled substance. In the United States, it is a Schedule I controlled substance. The salts in use are the hydrobromide and hydrochloride.