What Is Oxymorphone ?/Oxymorphone is a semisynthetic narcotic analgesic related to hydromorphone and other opiates, Oxymorphone, hydroxy-dihydromorphinone, affects the central nervous system and smooth muscles by activation of specific opiate receptors. Similar to morphine, but more potent and without cough suppressant activity, it is used in the treatment of moderate to severe pain, including obstetrical pain, or as an adjunct to anesthesia.
Hydromorphone and oxymorphone are semisynthetic derivatives of morphine and potent opiate agonists which are used predominantly to treat moderate-to-severe pain. Neither hydromorphone nor oxymorphone has been linked to serum enzyme elevations during therapy or to clinically apparent liver injury.
Mechanism of Action of Oxymorphone
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.
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Oxymorphone is an opioid agonist whose principal therapeutic action is analgesia. In addition to analgesia, other pharmacological effects of opioid agonists include anxiolysis, euphoria, feelings of relaxation, respiratory depression, constipation, miosis, and cough suppression. Like all pure opioid agonist analgesics, with increasing doses, there is increasing analgesia, unlike with mixed agonist antagonists or non-opioid analgesics, where there is a limit to the analgesic effect with increasing doses. With pure opioid agonist analgesics, there is no defined maximum dose; the ceiling to analgesic effectiveness is imposed only by side effects, the more serious of which may include somnolence and respiratory depression.
Indications of Oxymorphone
Adjuvants, Anesthesia; Analgesics, Opioid; Narcotics
- For the treatment of moderate-to-severe pain.
- Hydromorphone and oxymorphone are semisynthetic derivatives of morphine and potent opiate agonists which are used predominantly to treat moderate-to-severe pain. Neither hydromorphone nor oxymorphone has been linked to serum enzyme elevations during therapy or to clinically apparent liver injury.
- Anxiety
- Severe Pain
- Moderate Pain
- Perioperative analgesia
- Obstetrical analgesia therapy
- Oxymorphone injection is indicated for the relief of moderate to severe pain. It is also indicated for preoperative medication, for support of anesthesia, for obstetrical analgesia, and for relief of anxiety in patients with dyspnea associated with pulmonary edema secondary to acute left ventricular dysfunction.
- Oxymorphone injection is not approved for use in detoxification or maintenance treatment of opioid addiction. However, the history of an addictive disorder does not necessarily preclude the use of this medication for the treatment of chronic pain. These patients will require intensive monitoring for signs of misuse, abuse, or addiction.
Contraindications of Oxymorphone
- are allergic to hydromorphone or any ingredients of the medication
- are allergic to another opioid (narcotic) pain medications (e.g., morphine, codeine, oxycodone)
- are experiencing acute alcoholism or delirium tremens
- are taking or have taken a monoamine oxidase inhibitor (MAOI; tranylcypromine, rasagiline, selegiline, moclobemide) in the last 14 days
- have acute asthma or other obstructive airway diseases
- have acute respiratory depression (slowed breathing)
- have a head injury or increased intracranial pressure (increased pressure inside the head)
- have severe central nervous system (CNS) depression (e.g., slowed nervous system)
- have suspected abdominal conditions which may require surgery (i.e., appendicitis, pancreatitis)
- have a blockage of the gastrointestinal tract, particularly paralytic ileus
- have pain that is mild or intermittent and can be treated with other pain medications
- are breast-feeding, pregnant, or in labor
Dosage of Oxymorphone
Strengths: 5 mg; 10 mg; 20 mg; 40 mg; 7.5 mg; 15 mg; 30 mg; 1 mg/mL; 1.5 mg/mL
Pain
The following dosing recommendations can only be considered suggested approaches to what is actually a series of clinical decisions over time; each patient should be managed individually.
ORAL Use as first Opioid Analgesic
- Initial dose: 10 to 20 mg orally every 4 to 6 hours as needed for pain
- Maximum initial dose: 20 mg
Chronic Pain
The following dosing recommendations can only be considered suggested approaches to what is actually a series of clinical decisions over time; each patient should be managed individually.
- Use as the First Opioid Analgesic or for those who are NOT Opioid Tolerant:
- Initial dose: Extended-release tablets: 5 mg orally every 12 hours.
CONVERSION DOSES
- Immediate-Release Oxymorphone to Extended-Release Oxymorphone Tablets: Administer same total daily dose
- Initial dose: One-half total daily immediate-release requirement as an extended-release tablet orally every 12 hours
From Other Oral Opioids to Oxymorphone Extended-Release Tablets
- Discontinue all other around-the-clock opioid drugs when oxymorphone extended-release therapy is initiated.
- Published potency tables can be used to estimate a patient’s 24-hour oral oxymorphone requirement; however, due to substantial inter-patient variability, the conversion should then underestimate a patient’s 24-hour requirement and provide rescue medication as the dose is titrated.
TITRATION AND MAINTENANCE
- Maintenance Dose: Individually titrate to a dose that provides adequate analgesia and minimizes adverse reactions; dose adjustments may be made in 5 to 10 mg increments every 12 hours, every 3 to 7 days.
Side Effects of Oxymorphone
More common
- Difficulty having a bowel movement
- the feeling of constant movement of self or surroundings
- relaxed and calm
- sensation of spinning
- sleepiness
- confusion
- constipation
- the decreased ability or interest in sexual activity
- decreased coordination
- dizziness, lightheadedness, or feeling faint
- drowsiness
- dry mouth
- headache
- nausea
- nightmares or unusual dreams
- trouble sleeping
- vomiting
- weakness
Common
- blurred or double vision or other changes in vision
- fast, slow, or pounding heartbeat
- increased sweating
- itching
- shortness of breath, wheezing, or troubled breathing
- symptoms of a bowel blockage (e.g., abdominal pain, severe constipation, nausea)
- withdrawal symptoms (e.g., nausea, vomiting, diarrhea, anxiety, shivering, cold and clammy skin, body aches, loss of appetite, sweating)
- seizures
- signs of a severe allergic reaction (hives; difficulty breathing; swelling of the face, throat, or tongue)
- symptoms of overdose (e.g., hallucinations, confusion, inability to walk normally, slow or weak breathing, “pinpoint” pupils of the eyes, extreme sleepiness, dizziness, floppy muscles, cold and clammy skin)
- symptoms of serotonin syndrome (e.g., agitation or restlessness, loss of muscle control, muscle twitching, tremor, diarrhea)
- slow or troubled breathing
Rare
- Belching
- decreased weight
- discouragement
- excess air or gas in the stomach or bowels
- feeling of warmth
- feeling sad or empty
- full or bloated feeling
- heartburn
- indigestion
- lack of appetite
- loss of interest or pleasure
- passing gas
- pressure in the stomach
- redness of the face, neck, arms, and occasionally, upper chest
- stomach discomfort or upset
- swelling of the abdominal or stomach area
- tiredness
- trouble concentrating
Drug Interactions of Oxymorphone
Oxymorphone may interact with following drugs, supplements, & may change the efficacy of drugs
- alcohol
- amphetamines (e.g., dextroamphetamine, lisdexamfetamine)
- antihistamines that cause drowsiness (e.g., cetirizine, doxylamine, chlorpheniramine, diphenhydramine, hydroxyzine, loratadine)
- antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
- barbiturates (e.g., phenobarbital, butalbital, thiopental)
- belladonna
- benzodiazepines (e.g., lorazepam, diazepam, clonazepam)
- beta-blockers (e.g., atenolol, metoprolol)
- brimonidine
- bromocriptine
- buprenorphine
- clonidine
- diuretics (water pills; e.g., furosemide, hydrochlorothiazide, triamterene)
- domperidone
- ergot alkaloids (e.g., ergotamine, dihydroergotamine)
- general anesthetics (medications used to put people to sleep before surgery)
- ipratropium
- ketotifen
- mirtazapine
- metoclopramide
- mirtazapine
- monoamine oxidase inhibitors (MAOIs; e.g., phenelzine, tranylcypromine, rasagiline, selegiline) taken within the past 14 days
- muscle relaxants (e.g., baclofen, cyclobenzaprine, methocarbamol, orphenadrine)
- other opioid medications (e.g., morphine, codeine, oxycodone, butorphanol)
- St. John’s wort
- seizure medications (e.g., carbamazepine, clobazam, levetiracetam, phenobarbital, phenytoin, primidone, topiramate, valproic acid, zonisamide)
- selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline)
- serotonin/norepinephrine reuptake inhibitors (SNRIs; e.g., desvenlafaxine, duloxetine, venlafaxine)
- tiotropium
- tolterodine
- tricyclic antidepressants (e.g., amitriptyline, desipramine)
- triptan migraine medications (e.g., eletriptan, sumatriptan)
- tryptophan
- umeclidinium
- warfarin
Pregnancy Category of Oxymorphone
Pregnancy
This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately. Infants born to mothers who have been taking hydromorphone for long periods of time or who are physically dependent on hydromorphone will also be physically dependent on the medication and may experience breathing difficulties as well as withdrawal symptoms.
Lactation
No data are available on the use of oxymorphone during breastfeeding. Maternal use of oral narcotics during breastfeeding can cause infant drowsiness, central nervous system depression, and even death. Newborn infants seem to be particularly sensitive to the effects of even small dosages of narcotic analgesics. Once the mother’s milk comes in, it is best to provide pain control with a nonnarcotic analgesic and limit maternal intake of oral oxymorphone to a few days at low dosages, with close infant monitoring. If the baby shows signs of increased sleepiness (more than usual), difficulty breastfeeding, breathing difficulties, or limpness, a physician should be contacted immediately. Other agents are preferred over oxymorphone during breastfeeding.
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