Action And Clinical Pharmacology: Oxymorphone is a potent narcotic analgesic. When administered parenterally, 1 mg is approximately equivalent in analgesic activity to 10 mg of morphine sulfate. The onset of action of parenterally injected oxymorphone is rapid and the initial effects are usually perceived within 5 to 10 minutes, with analgesia persisting for approximately 3 to 6 hours. Oxymorphone is conjugated with glucuronic acid in the liver and excreted in the urine.
Oxymorphone produces mild sedation and causes little depression of the cough reflex. These properties make it particularly useful in postoperative patients.
Indications And Clinical Uses: For the relief of moderate to severe pain. Parenterally for preoperative medication, for support of anesthesia, for obstetrical analgesia, and for relief of anxiety in patients with dyspnea associated with acute left-ventricular failure and pulmonary edema.
Oxymorphone suppositories are useful in situations requiring a potent, rapid acting analgesic, i.e., in older or debilitated patients unable to tolerate injectable analgesics; for the control of pain in neoplastic disorders (terminal cancer including bone metastases); as an analgesic postoperatively for relief of moderate to severe pain.
Contra-Indications: Children: Safe use in children under 12 years of age has not been established.
Do not use in patients known to be hypersensitive to morphine analogs or with pre-existing respiratory depression or convulsive states.
Manufacturers’ Warnings In Clinical States: May be habit forming. As with other narcotic drugs, tolerance and addiction may develop. The addicting potential of the drug appears to be about the same as for morphine.
Drug Interactions: Interaction With Other CNS Depressants: Patients receiving other narcotic analgesics, general anesthetics, phenothiazines, other tranquilizers sedatives, hypnotics or other CNS depressants (including alcohol) concomitantly with oxymorphone may exhibit an additive CNS depression. When such combined therapy is contemplated, the dose of one or both agents should be reduced.
Pregnancy and Lactation: Safe use in pregnancy has not been established (relative to possible adverse effects on fetal development). As with other analgesics, the use of oxymorphone in pregnancy, in nursing mothers, or in women of childbearing potential requires that the possible benefits of the drug be weighed against the possible hazards to the mother and child.
Precautions: The same care and caution should be taken when administering oxymorphone as when other potent analgesics are used. It should be borne in mind that some respiratory depression may occur as with all potent narcotics, especially when other analgesic and/or anesthetic drugs with depressant action have been given shortly before administration of oxymorphone.
The respiratory depressant effects of narcotics and their capacity to elevate CSF pressure may be markedly exaggerated in the presence of head injury, other intracranial lesions or a pre-existing increase in intracranial pressure. Furthermore, narcotics produce adverse reactions which may obscure the clinical course of patients with head injuries.
Caution must also be exercised in elderly and debilitated patients and in patients who are known to be sensitive to CNS depressants, such as those with cardiovascular, pulmonary, or hepatic disease, in hypothyroidism (myxedema), acute alcoholism, delirium tremens, convulsive disorders, bronchial asthma and kyphoscoliosis. Debilitated and elderly patients and those with severe liver diseases should receive smaller doses.
Adverse Reactions: Include respiratory depression, drowsiness, nausea, vomiting, miosis, itching, dysphoria, lightheadedness, and headache.
Symptoms And Treatment Of Overdose: Symptoms: Respiratory depression (a decrease in respiratory rate and/or tidal volume, Cheyne-Stokes respiration, cyanosis), extreme somnolence progressing to stupor or coma, skeletal muscle flaccidity, cold and clammy skin, and sometimes bradycardia and hypotension. In severe overdosage, apnea, circulatory collapse, cardiac arrest and death may occur.
Treatment: 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.
Naloxone is a specific antidote against respiratory depression which may result from overdosage or unusual sensitivity to narcotics, including oxymorphone. Administer appropriate dose, [usual initial adult dose: 400 g (0.4 mg)] preferably i.v. 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. Administer repeated doses as needed to maintain adequate respiration. Oxygen, i.v. fluids, vasopressors and other supportive measures should be employed as indicated.
Dosage And Administration: Injection: Usual adult dose: s.c. or i.m. administration: 1 to 1.5 mg initially and every 4 to 6 hours thereafter, as needed. I.V.: 0.5 mg initially. In nondebilitated patients, the dose can be cautiously increased until satisfactory pain relief is obtained. For analgesia during labor: 0.5 to 1 mg i.m.
Suppositories: Adults: One suppository (5 mg), every 4 to 6 hours. In nondebilitated patients the dose can be cautiously increased until satisfactory pain relief is obtained.
Availability And Storage: Injection: Each mL of solution contains: 1.5 mg of oxymorphone HCl. Nonmedicinal ingredients: methylparaben, propylparaben, sodium chloride, sodium dithionite, sodium hydroxide solution and water for injection. Ampuls of 1 mL, boxes of 10. Store at 15 to 30°C. Protect from light.
Suppositories: Each suppository contains: oxymorphone HCl 5 mg in a base of polyethylene glycol 1 000 and 3 350. Gluten-, lactose-, sodium-, sulfite- and tartrazine-free. Boxes of 6. Store in refrigerator (2 to 8°C). Protect from light.
NUMORPHAN® DuPont Pharma Oxymorphone HCl Analgesic