Oxymorphone: characteristics, side effects and precautions

Oxymorphone is an analgesic-type drug prescribed mostly for chronic pain. It is not considered one of the main routes of treatment for pain, and since it is an opioid, treatments with this drug are very controlled.

Next we will see in more detail the pharmacological properties of this drug, what it is used for, what are its side effects, precautions to take in case of being consumed and the effects of its overdose.

• Related article: "Types of drugs (according to their use and side effects)"

What is oxymorphone?

Oxymorphone, whose chemical formula is C17H19NO4, is an opioid pain reliever, marketed under the trademarks Numorphan, Numorphone, and Opana. It is used to relieve moderate and severe pain in people in whom other pain-reducing drugs have not worked. Oxymorphone is also indicated for the treatment of acute postoperative pain.

Normally, non-pharmacological agents and non-opioids are used as the first option for chronic pain, since opioids carry serious dangers. Long-term use should only be considered for any chronic pain treatment if there are significant clinical benefits outweighing the risks. The first-line treatment options for chronic pain are non-pharmacological agents and non-opioids, that is, oxymorphone would not be one of the first options since it is a opioid.

This drug was originally designed in Germany in 1914 and patented in 1955, being approved for medical use in 1959. It is a highly addictive drug, which has not been the subject of debate on a few occasions. The US Food and Drug Administration (FDA) in 2017 asked the manufacturer to withdraw the product from the market, especially concerned about the use of opioids in society North American.

Pharmacokinetics and pharmacodynamics

Its oral bioavailability is 10%, and the intranasal one is 43%. Its metabolism is hepatic, through glucuronidation and the cytochrome CYP3A. Its half-life in the body is 7 to 9 hours and is excreted in urine and feces. Its routes of administration are oral, intravenous, intramuscular, subcutaneous, rectal and intranasal.

The mechanism of action of oxymorphone consists of activating the μ-opioid receptor and, to a lesser extent, the δ-opioid and κ-opioid receptors. The activity of oxymorphone appears to be 10 times greater than that of morphine.

Administration

Its administration can be done in several ways. If it is done by injection, its effects on pain relief begin shortly thereafter., approximately between 5 and 10 minutes, and 15 to 30 minutes after rectal administration, lasting its effects approximately 3-4 hours for immediate-release tablets and 12 hours for release tablets slow.

Slow-release tablets, taken by mouth, are the most common. It is advisable to consume it with the oral stomach, at least one or two hours after meals. The pills are generally taken every 4 to 6 hours. It is very important to take this drug as prescribed by the doctor, without taking more or less than the prescribed amount or increasing the frequency prescribed by the doctor. The tablet should be swallowed, without being chewed or crushed.

It is common for the first doses to be low when starting oxymorphone treatment and gradually increase until pain control is achieved. In case the medicine is not working, It will be the doctor who is in charge of adjusting the dose and the patient should never be the one who takes the liberty of increasing or reducing it..

In case a dose is missed, that dose should be taken as quickly as you remember. However, if the missed dose is remembered just shortly after it is time to take the Next, it is recommended to skip the missed dose and continue with the regular program of dosage. The dose should not be doubled to make up for the missed dose..

• You may be interested in: "Morphine: characteristics and effects in the short and long term"

Side effects

Oxymorphone, like any other drug, can cause side effects, whether due to too high a dose of the medicine or to characteristics of the organism of the patient who consumes it that has caused such symptom. Between the most common side effects that we can find we have:

• Dry mouth
• Stomach pain or bloating
• Sickness
• Vomiting
• Gases
• Excessive sweating
• Blush
• Fast heartbeat
• Redness of the eyes
• Headache
• Anxiety or confusion
• Itch

Some of these side effects may not go away and may even increase their medical severity.. In case these symptoms appear, the doctor should be kept informed. However, the following symptoms are considered more serious and, if they appear, a medical consultation should be sought urgently.

• Agitation
• Hallucinations (seeing things or hearing voices that don't exist)
• Fever
• Sweating
• Confusion
• Fast heart rate
• Tremors
• Severe muscle stiffness or spasms
• Loss of coordination
• Nausea
• Vomiting
• Diarrhea
• Lack of appetite
• Weakness
• Dizziness
• Inability to achieve or maintain an erection
• Irregular menstruation
• Lower sex drive
• Changes in heart rate
• Seizures
• Rash
• Urticaria
• Itch
• Hoarseness
• Difficulty breathing or swallowing
• Chest pain
• Swelling of the hands, eyes, face, lips, mouth, tongue, or throat
• Extreme drowsiness
• Fainting

In addition to these effects, there is the possibility of developing drug dependence, fertility problems in both men and women, and constipation. In the latter case, some changes in the diet may have to be included to facilitate defecation, although the normal thing is that this symptom does not appear and it is not recommended to change your diet as soon as you start treatment unless your doctor has told you to. explicitly.

Overdose

Symptoms of oxymorphone overdose include:

• Difficulty breathing, slow or stopped breathing
• Blue-colored skin, lips, or nails
• Clammy skin
• Dilated or contracted pupils
• Muscle or limb weakness
• Extreme drowsiness
• Unusual snoring
• Slow heart rate
• Loss of consciousness

In case of overdose, it will be necessary to call the emergency services while a family member or acquaintance takes care of the patient, especially if the patient has collapsed to the ground, has a seizure, trouble breathing, or cannot wake up. Normally, to avoid these situations it is recommended to have on hand the antidote of oxymorphone, the naloxone, a drug that works by blocking the effects of opioids, reducing their dangerous effects.

Overdose symptoms may return within a few minutes after taking naloxone. If these symptoms return, the person will need to take another dose of naloxone. Additional doses may be given every 2 to 3 minutes if symptoms reappear before medical help arrives.

Abstinence syndrome

It's very important follow the doctor's guidelines and not take the liberty of stopping the drug without telling them, since, doing it abruptly, you run the risk of the effects of withdrawal syndrome occurring. Among the symptoms of this syndrome due to oxymorphone we have.

• Restlessness
• Crying eyes
• Runny nose
• Yawning
• Sweating
• Shaking chills
• Muscle, joint and / or back pain
• Dilated pupils
• Irritability
• Anxiety
• Weakness
• Stomach cramps
• Difficulty falling asleep or staying asleep
• Nausea, vomiting
• Diarrhea
• Loss of appetite
• Tachycardia
• Fast breathing

Precautions

There are several precautions to be taken into account if oxymorphone treatment is to be started., just like any other drug. Next we will see the main ones.

1. Allergies

In case it is known, it will be necessary to tell your doctor or pharmacist if you are allergic to oxymorphone and related drugs, including oxycodone, codeine, hydrocodone, dihydrocodeine, hydromorphone, or any other medication.

2. Interactions

Interactions with other drugs may occur, with which it will be necessary to inform the doctor that another medication is being taken if this is the case, in addition to indicating the dose and frequency. It is also important to inform them whether they are prescription or non-prescription, also including vitamins, nutritional supplements and herbal medicine.

The main drugs it can interact with are: antihistamines; buprenorphine, butorphanol, cimetidine, diuretics, ipratropium, medications for irritable colon disease, for motion sickness, for Parkinson's disease; or for urinary problems; nalbuphine and pentazocine.

3. Previous health problems

The following health concerns will need to be reported before starting oxymorphone treatment: obstruction in the stomach or intestines, paralytic ileus, seizures, urination difficulties, kidney disease, liver disease, thyroid disease, or gallbladder problems bile.

4. Respiratory problems

Oxymorphone can cause serious breathing problems, especially during the first 72 hours after starting treatment or at any time when the dose of the drug is increased. For this reason, special caution should be exercised in patients with respiratory problems, such as asthma, chronic obstructive pulmonary disease, and sleep apnea.

5. Special populations

Patients who have already suffered from some type of debilitating illness are more prone to respiratory depression. In this type of population, the prescription of non-opioid analgesics should be considered.

Older patients are more sensitive to adverse effects, such as falls, cognitive decline, and constipation. The decreased kidney function associated with aging can increase the damage of this drug, especially its overdose. In case it is the only drug that can be prescribed in this population, it is recommended to prescribe low doses when starting treatment.

There is a risk that the baby will be affected in case the pregnant woman has taken the drug for a long time. Oxymorphone crosses the placenta and it can involve damage at birth, as well as poor fetal growth and premature birth. Children of mothers who are physically dependent on the drug are more likely to develop the same dependence.

6. Machinery handling

Oxymorphone may cause drowsiness, dizziness, or lightheadedness, thereby operating heavy machinery after taking the drug is not recommended. Dizziness can appear just by getting up after lying down, so it is recommended to rest your feet on the ground for a few minutes before standing up.

Bibliographic references:

• Hussain MA, Aungst BJ (August 1997). Intranasal absorption of oxymorphone. Journal of Pharmaceutical Sciences 86 (8): 975-6. PMID 9269879. doi: 10.1021 / js960513x.
• Davis, MP; Glare, PA; Hardy, J (2009). Oxford University Press, ed. Opioids in Cancer Pain (2nd edition). Oxford, UK. ISBN 978-0-19-157532-7.