Brands, Medical Use, Clinical Data
- Opiate Agonists
Brands / Synonyms
Dihydrohydroxymorphinone; Dihydroxymorphinone; Numorphan; Opana; Opana ER; Oximorphonum; Oxymorphine
For the treatment of moderate-to-severe pain
Oxymorphone is a semi-synthetic opioid substitute for morphine. It is a potent analgesic. Opioid analgesics exert their principal pharmacologic effects on the CNS and the gastrointestinal tract. The principal actions of therapeutic value are analgesia and sedation. Opioids produce respiratory depression by direct action on brain stem respiratory centers. The mechanism of respiratory depression involves a reduction in the responsiveness of the brain stem respiratory centers to increases in carbon dioxide tension and to electrical stimulation.
Mechanism of Action
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.
Biotrnasformation / Drug Metabolism
NUMORPHAN should not be administered to patients who are hypersensitive to oxymorphone hydrochloride or to any of
the other ingredients in NUMORPHAN, or hypersensitive to morphine analogs.
NUMORPHAN should not be administered to individuals during an acute asthmatic attack or to patients with severe
respiratory depression, upper airway obstruction, or any patient who has or is suspected of having a paralytic ileus.
NUMORPHAN should not be used in the treatment of pulmonary edema secondary to a chemical respiratory irritant. Opioid
analgesics cause pooling of blood in the extremities by decreasing peripheral vascular resistance. This effect
results in decreases in venous return, cardiac work, and pulmonary venous pressure, and blood is shifted from the
central to peripheral circulation which would not be beneficial in the treatment of pulmonary edema secondary to a
chemical respiratory irritant.
The concomitant use of other CNS depressants including sedatives, hypnotics, tranquilizers, general anesthetics,
phenothiazines, other opioids, tricyclic antidepressants, monoamine oxidase (MAO) inhibitors, and alcohol may produce
additive CNS depressant effects. When such combined therapy is contemplated, the dose of one or both agents should be
Anticholinergics or other medications with anticholinergic activity when used concurrently with opioid analgesics
may result in increased risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
It has been reported that the incidence of bradycardia was increased when oxymorphone was combined with propofol
for induction of anesthesia.
In addition, CNS toxicity has been reported (confusion, disorientation, respiratory depression, apnea, seizures)
following coadministration of cimetidine with opioid analgesics; no clear-cut cause and effect relationship was