Etazocine (NIH-7856) is an opioid analgesic of the benzomorphan family which was never marketed.

[1][2] It acts as a partial agonist of the opioid receptors, with mixed agonist and antagonist effects.

[1] In animal studies, it was shown to induce analgesia, dependency, and respiratory depression, with overall effects similar to those of morphine, but with substantially reduced potency in comparison.

[1][2][3]