These include analgesia, drowsiness, mental clouding, changes in mood, euphoria or dysphoria, respiratory depression, cough suppression, decreased gastrointestinal motility, nausea, vomiting, increased cerebrospinal fluid pressure, increased biliary pressure, and increased pinpoint constriction of the pupils. Formulations
Hydromorphone is available in parenteral, rectal, subcutaneous, and oral formulations, and also can be administered via epidural or intrathecal injection. Hydromorphone also has been administered via nebulization to treat shortness of breath, but it is not used as a route for pain control due to low bioavailability. Transdermal delivery systems are also under consideration to induce local skin analgesia.Concentrated aqueous solutions of hydromorphone hydrochloride have a visibly different refractive index from pure water, isotonic 9‰ (0·9 per cent) saline and the like, especially when stored in clear ampoules and phials may acquire a slight clear amber discolouration upon exposure to light; this reportedly has no effect on the potency of the solution, but 14-dihydromorphinones such as hydromorphone, oxymorphone, and relatives come with instructions to protect from light. Ampoules of solution which have developed a precipitate should be discarded.Battery-powered intrathecal drug delivery systems are implanted for chronic pain when other options are ruled out, such as surgery and traditional pharmacotherapy, provided that the patient is considered a suitable fit in terms of any contraindications, both physiological and psychological.An extended-release (once-daily) version of hydromorphone is available in the United States. Previously, an extended-release version of hydromorphone, Palladone, was available before being voluntarily withdrawn from the market after a July 2005 FDA advisory warned of a high overdose potential when taken with alcohol.
Chemistry
With a formula of C17H19NO3 and a molecular weight of 285.343, both identical to morphine, hydromorphone can be considered a structural isomer of morphine and is a hydrogenated ketone thereof.Hydromorphone is made from morphine either by direct re-arrangement (made by reflux heating of alcoholic or acidic aqueous solution of morphine in the presence of platinum or palladium catalyst) or reduction to dihydromorphine (usually via catalytic hydrogenation), followed by oxidation with benzophenone in presence of potassium tert butoxide or aluminium tert butoxide (Oppenauer oxidation). The 6 ketone group may be replaced with a methylene group via the Wittig reaction to produce 6-Methylenedihydrodesoxymorphine, which is 80× stronger than morphine.Changing morphine into hydromorphone increases its activity and, therefore, makes hydromorphone approximately eight times stronger than morphine on a weight basis, all other things being equal. Changed also is lipid solubility, contributing to hydromorphones having a more rapid onset of action and alterations to the overall absorption, distribution, metabolism, and elimination profile as well as the side effect profile (in general, less nausea and itching) versus that of morphine. The semi-synthetic opiates, of which hydromorphone and its codeine analogue hydrocodone are among the best-known and oldest, include a huge number of drugs of varying strengths and with differences among themselves both subtle and stark, allowing for many different options for treatment. Hydromorphone is more soluble in water than morphine; therefore, hydromorphone solutions may be produced to deliver the drug in a smaller volume of water.