Opioid antagonists, such as naloxone, also may be administered concurrently with oxygen supplementation. Naloxone works by reversing the effects of hydromorphone, and only is administered in the presence of significant respiratory depression and circulatory depression.Sugar cravings associated with hydromorphone use are the result of a glucose crash after transient hyperglycemia following injection, or a less profound lowering of blood sugar over a period of hours, in common with morphine, heroin, codeine, and other opiates. Hormone imbalance
As with other opioids, hydromorphone (particularly during heavy chronic use) often causes temporary hypogonadism or hormone imbalance. Neurotoxicity
In the setting of prolonged use, high dosage, and/or kidney dysfunction, hydromorphone has been associated with neuroexcitatory symptoms such as tremor, myoclonus, agitation, and cognitive dysfunction. This toxicity is less than that associated with other classes of opioids such as the pethidine class of synthetics in particular. Withdrawal
Users of hydromorphone may experience painful symptoms if the drug is suspended. Some people cannot tolerate the symptoms, which results in continuous drug use. Symptoms of opioid withdrawal are not easy to decipher, as there are differences between drug-seeking behaviors and true withdrawal effects. Symptoms associated with hydromorphone withdrawal include:
Abdominal pain
Anxiety or panic attacks
Depression
Goose bump skin
Inability to enjoy daily activities
Muscle and joint pain
Nausea
Runny nose and excessive secretion of tears
Sweating
VomitingIn the clinical setting, excessive secretion of tears, yawning, and dilation of pupils are helpful presentations in diagnosing opioid withdrawal. Hydromorphone is a rapid acting pain killer; however, some formulations may last up to several hours.
As of March 2010, it is still available in the United Kingdom under the brand name Palladone SR, Nepal under the brand name Opidol, and in most other European countries. Pharmacokinetics
The chemical modification of the morphine molecule to hydromorphone results in higher lipid solubility and greater ability to cross the blood–brain barrier to produce more rapid and complete central nervous system penetration. On a per milligram basis, hydromorphone is considered to be five times as potent as morphine; although the conversion ratio may vary from 4–8 times, five times is in typical clinical usage. The development of tolerance also may vary among individuals. Patients with renal abnormalities must exercise caution when dosing hydromorphone. In those with renal impairment, the half-life of hydromorphone may increase to as much as 40 hours. The typical half-life of intravenous hydromorphone is 2.3 hours. Peak plasma levels usually occur between 30 and 60 minutes after oral dosing.The onset of action for hydromorphone administered intravenously is less than 5 minutes and within 30 minutes of oral administration (immediate release). Metabolism
While other opioids in its class, such as codeine or oxycodone, are metabolized via CYP450 enzymes, hydromorphone is not. Hydromorphone is extensively metabolized in the liver to hydromorphone-3-glucoronide, which has no analgesic effects. As similarly seen with the morphine metabolite, morphine-3-glucoronide, a build-up in levels of hydromorphone-3-glucoronide may produce excitatory neurotoxic effects such as restlessness, myoclonus and hyperalgesia. Patients with compromised kidney function and older patients are at higher risk for metabolite accumulation.