Drotebanol is a morphinan

Morphinan

Morphinan is the base chemical structure of a large chemical class of psychoactive drugs, consisting of opioid analgesics, cough suppressants, and dissociative hallucinogens, among others.- Chemical Derivatives :Immediate derivatives of morphinan include:...

 derivative that acts as an opioid

Opioid

An opioid is a psychoactive chemical that works by binding to opioid receptors, which are found principally in the central and peripheral nervous system and the gastrointestinal tract...

 agonist. It was invented by Sankyo Company

Daiichi Sankyo Co.

is a global pharmaceutical company and the second largest pharmaceutical company in Japan. It achieved JPY 970 billion in revenue in 2010 and is currently ranked number 17 in world sales. Its headquarter is based in Tokyo. The company also owns the American biotechnology company Plexxikon, the...

 in Japan during the 1970s. It is synthesised from thebaine

Thebaine

Thebaine , its name coming from the Greek Θῆβαι, Thēbai, an ancient city in Upper Egypt, is an opiate alkaloid. A minor constituent of opium, thebaine is chemically similar to both morphine and codeine, but has stimulatory rather than depressant effects, causing convulsions similar to strychnine...

.

Drotebanol has powerful antitussive (cough suppressant) effects, and is around 10x more potent than codeine in producing this effect. It also has analgesic effects several times stronger than codeine, but weaker than morphine. In animal studies it was found to be moderately addictive and produced limited physical dependence, but not as severe as that seen with morphine or pethidine. It was previously marketed for human use under the brand name Metebanyl, although it is now no longer used in medicine.