Drotebanol is an opioid drug developed in Japan and used for the treatment of cough under the name Metebanyl, although it is now no longer used. Drotebanol possess CNS activity and is considered to be narcotic in many countries.

Drotebanol:
https://drugs.ncats.io/drug/7RS2Q8MCK8

Drotebanol:
A morphinan derivative that acts as an opioid agonist. It is synthesized from thebaine. It has powerful cough suppressant effects, and is around 10x more potent than codeine in producing this effect. It also has pain relieving effects several times stronger than codeine, but weaker than morphine. It was invented by Sankyo Company in Japan during the 1970s - no longer used in medicine.