Oxymorphone

Oxymorphone is a semi-synthetic opioid analgesic derived from morphine. It acts as a potent agonist at the mu-opioid receptor, producing analgesia as well as euphoria and sedation. Compared with morphine, oxymorphone is typically more potent on a per-milligram basis, with potency influenced by the route of administration and the drug’s limited oral bioavailability.

Medical use and forms: Oxymorphone is used for the relief of moderate to severe acute pain and for certain cases of chronic cancer or severe refractory pain when other analgesics are inadequate. It is available in oral and injectable forms. An extended-release oral formulation was marketed under the name Opana ER but was withdrawn from the U.S. market in 2017 due to concerns about abuse and public health impact. Immediate-release oxymorphone remains available in some markets under generic or brand names.

Pharmacology and safety: After oral administration, oxymorphone has limited bioavailability because of first-pass metabolism; parenteral administration yields more predictable analgesia. It is predominantly metabolized in the liver, mainly by glucuronidation, and its metabolites are excreted in the urine. Common adverse effects resemble those of other opioids and include nausea, vomiting, constipation, sedation, dizziness, pruritus, and respiratory depression. The drug carries a notable risk of misuse, dependence, and fatal overdose, especially when combined with alcohol, benzodiazepines, or other central nervous system depressants.

Regulation: In the United States, oxymorphone is a Schedule II controlled substance with restrictions on prescribing and dispensing. It is similarly regulated in many other countries. As with all opioids, careful patient selection, dosing, and monitoring are essential to minimize risks.