3057 Oxymorphone An opioid analgesic with actions and uses similar to those of morphine, apart from an absence of cough suppressant activity. It is used in the treatment of moderate to severe pain, including pain in obstetrics. It may also be used as an adjunct to anesthesia. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1092) 76-41-5 5284604 C17H19NO4 301.131410 White powder. 248-249°C 2.4E+004 mg/L Enteral(rectal). Oxymorphone interacts predominantly with the opioid mu-receptor. These mu-binding sites are discretely distributed in the human brain, with high densities in the posterior amygdala, hypothalamus, thalamus, nucleus caudatus, putamen, and certain cortical areas. They are also found on the terminal axons of primary afferents within laminae I and II (substantia gelatinosa) of the spinal cord and in the spinal nucleus of the trigeminal nerve. Also, it has been shown that oxymorphone binds to and inhibits GABA inhibitory interneurons via mu-receptors. These interneurons normally inhibit the descending pain inhibition pathway. So, without the inhibitory signals, pain modulation can proceed downstream. Oxymorphone undergoes extensive hepatic metabolism in humans. After a 10 mg oral dose, 49% was excreted over a five-day period in the urine. Of this, 82% was excreted in the first 24 hours after administration. The recovered drug-related products contained the oxymorphone (1.9%), the conjugate of oxymorphone (44.1%), the 6(beta)-carbinol produced by 6-keto reduction of oxymorphone (0.3%), and the conjugates of 6(beta)-carbinol (2.6%) and 6(alpha)-carbinol (0.1%). Route of Elimination: Oxymorphone is highly metabolized, principally in the liver, and undergoes reduction or conjugation with glucuronic acid to form both active and inactive products. Because oxymorphone is extensively metabolized, <1% of the administered dose is excreted unchanged in the urine. Half Life: 1.3 (+/-0.7) hours Intravenous mouse LD₅₀ is 172 mg/kg. No indication of carcinogenicity to humans (not listed by IARC). For the treatment of moderate-to-severe pain. Medical problems can include congested lungs, liver disease, tetanus, infection of the heart valves, skin abscesses, anemia and pneumonia. Death can occur from overdose. Oxymorphone overdosage is characterized by respiratory depression, extreme somnolence progressing to stupor or coma, skeletal muscle flaccidity, cold and clammy skin, and sometimes bradycardia and hypotension. In a severe case of overdose, apnea, circulatory collapse, cardiac arrest, and death may occur. Primary attention should be given to the reestablishment of adequate respiratory exchange through provision of a patent airway and the institution of assisted or controlled ventilation. The opioid antagonist naloxone hydrochloride is a specific antidote against respiratory depression which may result from overdosage or unusual sensitivity to opioids including oxymorphone. Therefore, an appropriate dose of naloxone hydrochloride should be administered (usual initial adult dose 0.4 mg-2 mg) preferably by the intravenous route and simultaneously with efforts at respiratory resuscitation. Since the duration of action of oxymorphone may exceed that of the antagonist, the patient should be kept under continued surveillance and repeated doses of the antagonist should be administered as needed to maintain adequate respiration. Naloxone hydrochloride should not be administered in the absence of clinically significant respiratory or cardiovascular depression. In addition, it should be considered that the use of an opioid antagonist in patients physically dependent on opioids may precipitate an acute withdrawal syndrome that cannot be readily suppressed while the action of the antagonist persists. If respiratory depression is associated with muscular rigidity, administration of a neuromuscular blocking agent may be necessary to facilitate assisted or controlled ventilation. Muscular rigidity may also respond to opioid antagonist therapy. Oxygen, intravenous fluids, vasopressors and other supportive measures should be employed as indicated. (L1712) 2009-07-21T20:28:36Z 2014-12-24T20:25:55Z Oxymorphone C08019 194484 Oxymorphone DB01192 true [H][C@@]12OC3=C(O)C=CC4=C3[C@@]11CCN(C)[C@]([H])(C4)[C@]1(O)CCC2=O C17H19NO4 InChI=1S/C17H19NO4/c1-18-7-6-16-13-9-2-3-10(19)14(13)22-15(16)11(20)4-5-17(16,21)12(18)8-9/h2-3,12,15,19,21H,4-8H2,1H3/t12-,15+,16+,17-/m1/s1 InChIKey=UQCNKQCJZOAFTQ-ISWURRPUSA-N 301.3371 301.131408101 Exogenous Solid 0.83 HMDB15323 CHEMBL963 4447650 <p>Bao-Shan Huang, Yansong Lu, Ben-Yi Ji, Aris P Christodoulou, &#8220;Preparation of oxymorphone from morphine.&#8221; U.S. Patent US5922876, issued May, 1992.</p>