Oxymorphone (Injection)

Oxymorphone is an analgesic drug used to treat moderate to severe pain, including the pain caused by childbirth.


Oxymorphone is a semi-synthetic opioid which is derived from a part of the poppy plant. It works in a similar way to morphine, which is to act on the opioid receptors in the body in a way that reduces the pain signals your body sends to the brain. People are normally only prescribed this medication if they have been unresponsive to other medications, or if the pain is particularly severe.

This medication is a central nervous system depressant and can cause drowsiness or fatigue. It should not be combined with other central nervous system depressants such as benzodiazepines or alcohol.

If oxymorphone is used over a long period of time, patients may develop a physical or psychological dependence on the drug. However, clinical research has shown that when patients use the medication only for the purpose of treating their pain, they are unlikely to develop an addition.

In some cases this medication can cause breathing problems. Consult your doctor immediately if you have any trouble breathing while you are taking this medication, including shallow breaths and wheezing. This is most likely to occur when you first start taking the drug, or if your dosage is increased.

You may experience withdrawal symptoms when you stop taking this medication. For this reason, your doctor will usually reduce your dose of the medication gradually over a period of time. Even if you do taper off your usage, you may still experience some withdrawal effects, but these are usually manageable.

You can only obtain this medication with a prescription from your doctor.

Oxymorphone injections are more commonly known under the brand name Numorphan.

Conditions Treated

* Moderate to severe pain
* Labor pain

Type Of Medicine

* Narcotic analgesic (painkiller)
* Opioid analgesic

Side Effects

Oxymorphone can cause breathing problems in some people who take it. In some cases this can be fatal. Tell your doctor immediately if you experience any problems with your breathing, including:

* Difficulty breathing
* Heaviness or tightness in the chest
* Noisy breathing
* Shortness of breath
* Wheezing

Although it is rare, oxymorphone can also cause serious or life-threatening side effects in some people. Contact the doctor or nurse on duty immediately if you experience any of the following side effects:

* A bad headache
* Breathing problems (see above)
* Changes to your heart rate, such as quickened pulse, slower pulse, or an irregular heartbeat
* Changes to your mood
* Changes to your vision
* Chest pain or feelings of pressure in the chest
* Chills
* Difficulty passing urine, or changes in the amount of urine
* Dizziness, confusion or disorientation
* Extreme tiredness, sleepiness or fatigue
* Fever
* Hallucinations (seeing or hearing things that are not real)
* Hard stools or constipation
* Nausea or vomiting
* Seizures, convulsions, or muscle spasms
* Stomach pain

Oxymorphone may cause other side effects that are less serious but are still unpleasant. Talk to the doctor or nurse if you experience any of these side effects:

* Constipation
* Dry mouth or increased thirst
* Increased gas or trapped gas
* Increased sweating
* Itching
* Mild dizziness or sleepiness
* Upset stomach
* Tiredness or weakness

This is not a complete list of the side effects that this medication might cause. Medications can affect people in unpredictable ways so it is not possible to produce an exhaustive list of side effects. When you are given the medication, pay attention to your body and inform the doctor or nurse if you experience anything that is out of the ordinary, or that is concerning to you.

In many cases, side effects will just pass on their own. In other cases, you may be given another medication to help relieve them. Talk to your doctor if you have any concerns about the side effects that this medication can cause.


An overdose of this medication can have very serious health consequences and in some circumstances can be fatal. Contact the doctor or nurse on duty immediately if you notice any of the symptoms of overdose, which include the following:

* Cold or clammy skin
* Small or constricted pupils (the black area of the eye)
* Low blood pressure or slow pulse
* Lowered awareness or responsiveness
* Muscle weakness
* Severe fatigue, sleepiness, or drowsiness
* Very slow rate of breathing

Allergic reaction

Allergic reactions to oxymorphone are rare, but they have been documented. Tell your doctor if you have an allergy to morphine or any drug that is similar to morphine. You should seek emergency medical assistance immediately if you experience any of the common symptoms of an allergic reaction after being given oxymorphone, which include the following:

* Breathing problems

* Hives, redness, itching, or a rash on the skin

* Swelling especially when occurring in the throat, face or tongue

* Extreme fatigue, dizziness, or drowsiness


Dosages of oxymorphone can vary greatly depending factors such as:

* The type and severity of the pain you are experiencing
* Whether you have been prescribed oxymorphone or other opioids in the past
* Whether you have developed a tolerance to oxymorphone or other opioids
* How it is administered to you

However, a typical dose of oxymorphone:

* Intravenous injection (into a vein): 0.5 mg
* Subcutaneous injection (under the skin): between 1 mg and 1.5 mg
* Intramuscular injection (into a muscle): between 0.5 mg and 1.5 mg

This dose will be repeated every 4 to 6 hours, depending on your response to the medication and how effectively it has been in relieving your pain.

You will be given oxymorphone in a hospital or other facility by medical professionals who are experienced in administering the drug, and where there are facilities for dealing with any potential side effects that may arise. You will not be given injectable oxymorphone to take home with you and dose yourself.

If you are given oxymorphone over a long period of time, for example if you spend a longer time-period in hospital, or if you are given oral tablets of the medication after the injection, you may experience withdrawal when you stop taking the medication. For this reason, you will usually reduce your dosage gradually over a period of weeks. This reduces the severity of the withdrawal symptoms that you may experience.


Some other medications can cause complications if they are taken at the same time as oxymorphone. They may increase the likelihood that you will experience side effects, and in some cases can be fatal. It is important that you tell your doctor about any other medications you are taking, as well as any vitamins or herbal supplements. The interactions below are of particular concern:

* Central nervous system depressants: This includes alcohol and benzodiazepines. As oxymorphone is a central nervous system itself, the combined effect of the drugs can cause coma, an inability to breathe, or in some cases can be fatal.
* Drugs given for depression or low mood: This includes but is not limited to drugs such as tranylcypromine, isocarboxazid or phenelzine. These can cause the blood pressure to rise to dangerous levels when taken at the same time as oxymorphone. You should leave a period of at least 14 days between the last day you took these drugs and the day you are due to take oxymorphone.
* Medication that is given for Parkinson's disease: This includes drugs like rasagiline and selegiline. These drugs can cause dangerously high blood pressure when taken with oxymorphone. You should not have taken any of these drugs for at least 14 days before you are given oxymorphone.
* Other opioids: It can be very dangerous to combine two different opioid drugs because this can stop the central nervous system from functioning correctly, potentially leading to coma or even death. In some cases doctors may prescribe more than one opioid drug, but this will be in special circumstances, and the doses of each drug will be adjusted to safer levels.
* Alcohol: You should not consume alcohol during a course of treatment with oxymorphone. Alcohol can slow the elimination of this drug from the body, which can lead to dangerously high levels of oxymorphone in the blood, or even overdose. You should also avoid any other medications or over-the-counter medicines that contain alcohol.


Because this medication can cause breathing problems in some individuals, you should inform your doctor if you have previously suffered from any breathing problems, including:

* Asthma
* Difficulty breathing
* High carbon dioxide levels in the blood
* Sleep apnea

This drug is known to cause drowsiness and weakness in many people who take it. Do not drive or operate machinery after taking this medication.

Regular, long-term use of oxymorphone can cause a tolerance to the drug. This means that your body has adapted to the medication, and you will require a larger dose in the future to produce the same effect. Higher doses increase the risk of side effects, but in some cases it may be necessary for you to do so. If you find that the medication is not working as well as it normally does, contact your doctor for advice.

Long-term use of this medication can lead to lower levels of sex hormones. This can cause a reduction in sex drive and performance, and in women can lead to alteration or cessation of the menstrual period, and fertility problems. Talk to your doctor if you are concerned about this.

Oxymorphone can make the symptoms of certain medical conditions worse. It also may be less safe to use by people with certain conditions. Tell your doctor about any other medical conditions you have so that they can determine whether this medication is appropriate for you. The conditions listed below are of particular concern:

* Adrenal gland problems (such as Addison's disease)
* Alcohol abuse
* Any breathing problems
* Asthma
* Brain tumor
* Curvature of the spine (Kyphoscoliosis)
* Difficulty passing urine
* Drug abuse disorders, especially with narcotics/opioids
* Gallbladder problems including gallstones
* Kidney problems
* Head injuries
* Heart problems including chronic obstructive pulmonary disease (COPD), cor pulmonale, heart disease
* Hypovolemia (low blood volume)
* Inflammation of the pancreas (pancreatitis)
* Liver problems including liver disease
* Low blood pressure (hypotension)
* Obesity
* Paralytic ileus (blocked or non-functioning intestine)
* Prostate problems including prostate enlargement
* Respiratory depression (slow rates of breathing)
* Seizures
* Sleep apnea (breathing problems while sleeping)
* Underactive thyroid (hypothyroidism)

You should also tell your doctor if you have a history of any of the above conditions, even if you do not suffer from them presently.

In some cases, your doctor may not prescribe oxymorphone to you and will discuss other options with you. In other cases, you may still be prescribed oxymorphone, but you may be given a different dose than you normally would, or you may be held for observation for longer than usual to ensure that the drug is not affecting you adversely.


This medication can be harmful to the unborn baby if taken by pregnant women. Therefore it is normally not recommended that pregnant women take this medication unless the potential benefits outweigh the risks. Always employ two effective forms of birth control while you are using this medication. If you do become pregnant during a course of treatment with oxymorphone, contact your doctor immediately.


Oxymorphone can pass into the breast milk and therefore transfer to the infant via breastfeeding. This medication can be dangerous to infants, as it can cause breathing difficulties that can potentially be serious. You should not breastfeed while you are taking this medication.


This medication is not recommended for use by children due to the depressant effect it can have on the respiratory system -- meaning that the medication can make breathing difficult or more shallow.

Older individuals

Older people are more likely to experience side effects when taking oxymorphone. If you are over the age of 65, your doctor may adjust your dose slightly to compensate for this.


Because of the risk of side effects and the potential for dependence, the injectable form of this medication will only be administered to you in a hospital by trained medical professionals. You will not be given any of the medication to take home and store yourself.

In hospitals, medical staff observe strict guidelines when storing medications to ensure the potency and safety of the drugs. In the case of oxymorphone solution for injection, the following guidelines apply:

* Store at room temperature: Oxymorphone should be stored at room temperature. Keep the medication away from sources of heat, and do not refrigerate or freeze it.

* Dry location: Store the medication in a dry location away from sources of moisture.

* Avoid light: Keep the medication in its original container, and do not store it near any sources of light such as near windows.

* Child safety: Keep the medication out of the sight and reach of children, and keep it in child-safe containers.

* Shelf life: Store the medication only up until the expiry date on the packaging. Do not administer the medication after this date because the potency may be affected, or it may be harmful. Dispose of the medication safely and do not throw it away in the trash or flush it down the toilet.


Oxymorphone is a powerful opioid painkiller that is similar to morphine. It is used in people who are experiencing moderate to severe pain, for labor pain, and for people who have been unresponsive to other medications.

This medication is known to produce a range of side effects. In some people, oxymorphone can cause breathing problems, such as difficulty breathing or shallow breathing. Other side effects can occur that are less severe but unpleasant such as headaches, itching, drowsiness, and constipation.

This drug will only be administered in a hospital or other facility by trained personnel. You will not be given the injectable form of this medication to take home.

Like all opioid drugs, oxymorphone can be habit-forming, meaning that patients who use it may develop an urge to keep taking the drug. This rarely occurs when the drug is only used to manage pain; however, patients who use it for a longer period of time may experience withdrawal symptoms when they stop taking the medication. Because of this, dosages are usually tapered off gradually over a period of time.