Hydromorphone, a more common synonym for dihydromorphinone and dimorphone, commonly a hydrochloride (trade names Palladone, Palladone SR, Dilaudid and numerous others) is a potent centrally-acting analgesic drug of the opioid class. It is a derivative of morphine, specifically a hydrogenated ketone thereof and therefore a semi-synthetic drug. It is both medically an opiate analgesic and legally a narcotic. It should not be confused with hydromorphinol, also known as 14-hydroxydihydromorphine and RAM-320 nor dihydromorphine (Paramorfan). While all of these are strong opioids, they are indeed different drugs. Additional confusion arises from the fact that in a handful of countries hydromorphinol is distributed under the trade name Numorphan, which is the trade name for oxymorphone in the rest of the world according to the current version of The A-Z Encyclopaedia of Alcohol & Drug Abuse and other references. Hydromorphone is known in various countries around the world by the trade names Hydal, Sophidone, Hydrostat Hydromorfan, Hydromorphan, Laudicon, Hymorphan, Opidol, Palladone and others (warning: the brand names are inconsistent from country to country).