Hydromorphone is a more common synonym for dihydromorphinone, commonly a hydrochloride (brand names Palladone, Dilaudid, and numerous others). Not to be confused with dihydromorphine, which is a different derivative of the morphine family. It is a very potent centrally acting analgesic drug of the opioid class. It is a derivative of morphine; to be specific, it is a hydrogenated ketone thereof. Comparatively, hydromorphone is to morphine as hydrocodone is to codeine—that is, a semi-synthetic drug. In medical terms, it is an opioid analgesic and, in legal terms, a narcotic. Hydromorphone is commonly used in the hospital setting, mostly intravenously (IV) because its bioavailability is very low orally, rectally, and intranasally. Sublingual administration (under the tongue) is usually superior to swallowing for bioavailability and effects; however, hydromorphone is bitter and hydrophilic like most opiates, not lipophilic, so it is absorbed poorly and slowly through mouth membranes.

Hydromorphone is a more common synonym for dihydromorphinone, commonly a hydrochloride (brand names Palladone, Dilaudid, and numerous others). Not to be confused with dihydromorphine, which is a different derivative of the morphine family. It is a very potent centrally acting analgesic drug of the opioid class. It is a derivative of morphine; to be specific, it is a hydrogenated ketone thereof. Comparatively, hydromorphone is to morphine as hydrocodone is to codeine—that is, a semi-synthetic drug. In medical terms, it is an opioid analgesic and, in legal terms, a narcotic. Hydromorphone is commonly used in the hospital setting, mostly intravenously (IV) because its bioavailability is very low orally, rectally, and intranasally. Sublingual administration (under the tongue) is usually superior to swallowing for bioavailability and effects; however, hydromorphone is bitter and hydrophilic like most opiates, not lipophilic, so it is absorbed poorly and slowly through mouth membranes.