What is "acetoxyketobemidone"

n. (context pharmaceutical drug English) A particular narcotic painkiller.

Acetoxyketobemidone (O-Acetylketobemidone) is an opioid analgesic that is an acetylated derivative of ketobemidone. It was developed in the 1950s during research into analogues of pethidine and was assessed by the United Nations Office on Drugs and Crime but was not included on the list of drugs under international control, probably because it was not used in medicine or widely available.

Presumably acetoxyketobemidone produces similar effects to ketobemidone and other opioids, such as analgesia and sedation, along with side effects such as nausea, itching, vomiting and respiratory depression which may be harmful or fatal.