Hydromorphinol

Hydromorphinol (RAM-320, 14-Hydroxydihydromorphine) is an opiate analogue that is a derivative of morphine, where the 14-position has been hydroxylated and the 7,8- double bond saturated. It has similar effects to morphine such as sedation, analgesia and respiratory depression, but is more potent and has a steeper dose-response curve and longer half-life. It is used in medicine as the bitartrate salt (free base conversion ratio 0.643, molecular weight 471.5) and hydrochloride (free base conversion ratio 0.770, molecular weight 393.9)

Hydromorphinol was developed in Austria in 1932. It is available, and commonly used, as a medicine in Sweden. In the United States, it was never available and is classified as a Schedule I drug with a DEA ACSCN of 9301. The salts in use are the bitartrate (free base conversion ratio 0.643) and hydrochloride (0.770). The 2014 national aggregate manufacturing quota was 2 grammes, unchanged from prior years.

Hydromorphinol is metabolised mainly in the liver in the same fashion as many other opioids and is itself a minor active metabolite of 14-Hydroxydihydrocodeine, an uncommonly used opiate (but is therefore also an active metabolite of a first-order active metabolite of oxycodone).

It is distributed under the trade name Numorphan in some countries. It is controlled under the Single Convention On Narcotic Drugs.