High Quality Content by WIKIPEDIA articles! Ketobemidone (Cliradon, Ketogan, Ketodur, Cymidon, Ketorax, c.) is a powerful opioid analgesic. Its effectiveness against pain is in the same range as morphine, and it also has some NMDA-antagonist properties imparted by it`s metabolite norketobemidone. This makes it useful for some types of pain that don`t respond well to other opioids. The most commonly cited equalisation ratio for analgesic doses is 25 mg of ketobemidone hydrobromide to 60 mg of morphine hydrochloride or sulfate and circa 8 mg of ketobemidone by injection.