As with all potent opioid analgesics, possible side effects when using NUMORPHAN (oxymorphone) include:

Central Nervous System

Drowsiness, sedation, lightheadedness, unusual tiredness or weakness, headache, dysphoria, euphoria, miosis, diplopia, blurred vision, nervousness, restlessness, confusion, mental clouding, trouble sleeping, paradoxical CNS stimulation, hallucinations, mental depression.

Gastrointestinal System

Nausea, vomiting, dry mouth, constipation, biliary tract spasm, cramps or pain, loss of appetite, paralytic ileus or toxic megacolon in patients with inflammatory bowel disease.

Cardiovascular System

Hypotension, orthostatic hypotension particularly in ambulatory patients, tachycardia, bradycardia, palpitations, flushing.

Respiratory System

Respiratory depression, atelectasis, allergic bronchospastic reaction, allergic laryngeal edema, allergic laryngospasm.

Genitourinary System

Ureteral spasm, urinary hesitancy or retention, antidiuretic effect.

Dermatologic

Itching, sweating, injection site reaction, allergic reaction (such as skin rash, hives, and/or itching, swelling of the face).

Drug Abuse And Dependence

NUMORPHAN (oxymorphone) is a Schedule II opioid and is subject to the Federal Controlled Substances Act.

NUMORPHAN (oxymorphone) , as with other opioid drugs, can produce tolerance, psychological dependence, and physical dependence and has the potential for being abused. The addiction potential of the drug appears to be about the same as for morphine.

Withdrawal symptoms may occur when opioids are abruptly discontinued after prolonged use. Withdrawal symptoms may be characterized by some or all of the following: restlessness, lacrimation, rhinorrhea, yawning, perspiration, gooseflesh, restless sleep, and mydriasis during the first 24 hours. These symptoms often increase in severity and over the next 72 hours may be accompanied by increasing irritability, anxiety, weakness, twitching, and spasms of muscles; kicking movements; severe backaches; abdominal and leg pains; abdominal and muscle cramps; hot and cold flashes; insomnia; nausea, anorexia, vomiting, intestinal spasm, diarrhea, coryza, and repetitive sneezing; increase in body temperature, blood pressure, respiratory rate and heart rate. Because of excessive loss of fluids through sweating, vomiting and diarrhea, there is usually marked weight loss, dehydration, ketosis, and disturbances in acid-base balance. Cardiovascular collapse can occur. Without treatment most observable symptoms disappear in 5-14 days; however, there appears to be a phase of secondary or chronic abstinence which may last for 2-6 months characterized by decreasing insomnia, irritability, and muscular aches. In addition, the patient may have miosis and a slight lowering of blood pressure, pulse rate, and body temperature;respiratory centers exhibit a decreased response to the stimulatory effects of carbon dioxide.

The dose of NUMORPHAN (oxymorphone) should be gradually reduced before discontinuation in those patients who require treatment for physical dependence.

Infants born to mothers physically dependent on opioids will also be physically dependent and may exhibit respiratory difficulties and withdrawal symptoms (see PRECAUTIONS; Usage in Pregnancy).

Read the Numorphan (oxymorphone) Side Effects Center for a complete guide to possible side effects »

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 reduced (see WARNINGS).

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 established.

Last reviewed on RxList: 6/24/2008
This monograph has been modified to include the generic and brand name in many instances.