Hydromorphone, also known as dihydromorphinone, and sold under the brand name Dilaudid among others, is an opioid used to treat moderate to severe pain. Typically, long-term use is only recommended for pain due to cancer. It may be used by mouth or by injection into a vein, muscle, or under the skin. Effects generally begin within half an hour and last for up to five hours.Common side effects include dizziness, sleepiness, nausea, itchiness, and constipation. Serious side effects may include abuse, low blood pressure, seizures, respiratory depression, and serotonin syndrome. Rapidly decreasing the dose may result in opioid withdrawal. Generally, use during pregnancy or breastfeeding is not recommended. Hydromorphone is believed to work by activating opioid receptors, mainly in the brain and spinal cord. Hydromorphone 2 mg IV is equivalent to approximately 10 mg morphine IV.Hydromorphone was patented in 1923. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2017, it was the 205th most commonly prescribed medication in the United States, with more than two million prescriptions. Hydromorphone is made from morphine. Medical use
Hydromorphone is used to treat moderate to severe pain. It may be used by mouth or by injection into a vein, muscle, or under the skin. Effects generally begin within half an hour and last for up to five hours. Typically, long-term use is only recommended for pain due to cancer. A 2016 Cochrane review found little difference in benefit between hydromorphone and other opioids for cancer pain.
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.