Furethidine, a pethidine analog was studied as an analgesic agent. This compound is not currently used in medicine and is listed in schedules of the single convention on narcotic drugs of 1961 as amended by the 1972 protocol.

Furethidine:
https://drugs.ncats.io/drug/6U9XA4JOD4

Related to the clinically used opioid pethidine (meperidine) but with around 25x higher potency. This compound belongs to the class of organic compounds known as phenylpiperidines. These are compounds containing a phenylpiperidine skeleton, which consists of a piperidine bound to a phenyl group.