Metopon (5-methylhydromorphone hydrochloride) is an opiate analogue that is a methylated derivative of hydromorphone which was invented in 1948 as an analgesic. [1]
Metopon is sometimes used in medicine, but although longer acting than hydromorphone, metopon is less potent and its oral bioavailability, while higher than that of morphine, is still fairly low, so generally metopon has few advantages to distinguish it from other, more commonly used opioid analgesics,[2] although it does have a slightly lower tendency to produce nausea and respiratory depression compared to morphine.[3]
^ Eddy NB. Pharmacology of Metopon and other new analgesic opium derivatives. Annals of the New York Academy of Sciences. 1948; 51(1):51–58.
^ McLaughlin JP, Nowak D, Sebastian A, Schultz AG, Archer S, Bidlack JM. Metopon and two unique derivatives: affinity and selectivity for the multiple opioid receptors. European Journal of Pharmacology. 1995 Dec 27;294(1):201-6.