 Molecular structure of oxymorphone | |
 3D representation of an oxymorphone molecule | |
| Clinical data | |
|---|---|
| Trade names | Numorphan, Numorphone, Opana, others |
| Other names | 14-Hydroxydihydromorphinone |
| AHFS/Drugs.com | Monograph |
| MedlinePlus | a610022 |
| License data | |
| Dependence liability | High |
| Addiction liability | High |
| Routes of administration | By mouth,buccal,sublingual,intranasal,intravenous,epidural,subcutaneous,intramuscular |
| Drug class | Opioid |
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| Pharmacokinetic data | |
| Bioavailability | by mouth: 10% Buccal: 28% Sublingual: 37.5% Intranasal: 43%[3] IV, IM & IT: 100%[4] |
| Protein binding | 10%[4] |
| Metabolism | Liver (CYP3A4,glucuronidation)[4] |
| Metabolites | •Noroxymorphone • glucuronide |
| Eliminationhalf-life | 10–12 hours[5] |
| Duration of action | Duration of action: 6–8 hours orally,4–6 hrs parenteral |
| Excretion | Urine, feces[4] |
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| CompTox Dashboard(EPA) | |
| ECHA InfoCard | 100.000.873 |
| Chemical and physical data | |
| Formula | C17H19NO4 |
| Molar mass | 301.342 g·mol−1 |
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Oxymorphone (sold under the brand namesNumorphan andOpana among others) is a highly potentopioidanalgesic indicated for treatment of severe pain. Pain relief after injection begins after about 5–10 minutes; after oral administration it begins after about 30 minutes and lasts about 3–4 hours for immediate-release tablets and 12 hours for extended-release tablets.[6] The elimination half-life of oxymorphone is much faster intravenously, and as such, the drug is most commonly used orally.[7] Likeoxycodone, which metabolizes to oxymorphone, oxymorphone has a high abuse potential.[8]
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Oxymorphone was developed in Germany in 1914. It was patented in 1955 and approved for medical use in 1959.[9] In June 2017 theFDA askedEndo Pharmaceuticals to remove its product from the US market.[10] This was in part due to theopioid epidemic in the US, and the fact that a 2012 reformulation failed to stop illicit injection of the drug. Endo responded by voluntarily removing Opana ER from the market a month later.[11] Generic versions of extended-release oxymorphone, such as those manufactured byAmneal Pharmaceuticals, are still available in the US.[12]
Oxymorphone Immediate Release is indicated for the relief of moderate to severe pain, such as treatment of acute post-surgical pain.[13] For any chronic treatment of pain, clinicians should only consider long term use if there is significant clinical benefit to the patient's therapy that outweigh any potential risk. The first line treatment choices for chronic pain are non-pharmacological and non-opioid agents.[14]
Oxymorphone extended-release tablets are indicated for the management of chronic pain and only for people already on a regular schedule of strong opioids for a prolonged period. Immediate-release oxymorphone tablets are recommended for breakthrough pain for people on the extended-release version. Compared to other opioids, oxymorphone has similar pain relieving efficacy.[15]
In the United States it is a Schedule II controlled substance with anACSCN of 9652.[16]
Oxymorphone ER Tablets should be taken on an empty stomach.[17]
Oxymorphone was marketed by Endo Pharmaceuticals, under the brand name(s) Opana and Opana ER. Opana ER was withdrawn by the manufacturer in 2017 due to anFDA request, making it unavailable in the US.[18] However, both IR (immediate release) and ER (extended release) formulations are still available under the generic names Oxymorphone and Oxymorphone ER and available from a multitude of manufacturers.
Oxymorphone is also available as an injectable for inpatient use, available for IV (intravenous), IM (intramuscular), and SC (subcutaneous) injection.
An extended release (ER)modified-release dosage form is commonly used, which modifies thepharmacokinetics of the drug.
Oxymorphone comes in a variety of doses.
| IR Tablet[19] | ER 12 Hour Tablet[19] |
|---|---|
| 5 mg | 5 mg |
| 10 mg | 7.5 mg |
| 10 mg | |
| 15 mg | |
| 20 mg | |
| 30 mg | |
| 40 mg |
Patients already suffering from debilitation are at a much higher risk of respiratory depression. Nonopioid analgesics should be considered in this population.
Elderly patients are much more sensitive to adverse effects such as falls, cognitive impairment and constipation, and should be monitored for such. Decreased renal function associated with aging leads to decreased clearance of the drug, resulting in narrow therapeutic windows and increasing the danger of overdose. If oxymorphone is absolutely indicated, smaller initial doses should be started for this population.
There is a risk of neonatal withdrawal symptom in the newborn if pregnant women take oxymorphone for a prolonged period. Oxymorphone crosses the placenta and holds risk of birth defects, poor fetal growth, stillbirth, and preterm delivery. The children of mothers who are physically dependent on oxymorphone have a higher risk of similar dependence. Due to these severe risks, oxymorphone is highly discouraged among this population. The amount of transfer of oxymorphone into the breast milk is not known and women are cautioned to weigh the risks and benefits before breastfeeding while on this medication.[20]
The principal adverse effects of oxymorphone are similar to other opioids with constipation, nausea, vomiting, dizziness, dry mouth and drowsiness being the most common adverse effects. This drug is highly addictive as with other opioids and can lead to chemical dependence and withdrawal.[21]
In common with other opioids, oxymorphone overdosage is characterized by respiratory depression, sleepiness progressing to stupor or coma, skeletal muscleweakness, cold and clammy skin, and sometimesslow heart rate andlow blood pressure. In a severe case of overdose,apnea,circulatory collapse, cardiac arrest and death can occur.[21]
Oxymorphone elicits its effects by binding to and activating theμ-opioid receptor (MOR) and, to a much lesser extent, theδ-opioid receptor (DOR) andκ-opioid receptor (KOR).[4] Its activity at the DOR may augment its action at the MOR.[4] Oxymorphone is 10 times more potent than morphine.[22] Calculation of relative potency indicates that 1 mg of oxymorphone hydrochloride is equivalent to 9.85 mg of morphine sulfate, or equivalently, 1.02 mg of oxymorphone hydrochloride is equivalent to 10 mg of morphine sulfate.[23]
| Affinities (KiTooltip Inhibitor constant) | Ratio | ||
|---|---|---|---|
| MORTooltip μ-Opioid receptor | DORTooltip δ-Opioid receptor | KORTooltip κ-Opioid receptor | MOR:DOR:KOR |
| 0.78 nM | 50 nM | 137 nM | 1:64:176 |
| Compound | Route | Dose |
|---|---|---|
| Codeine | PO | 200 mg |
| Hydrocodone | PO | 20–30 mg |
| Hydromorphone | PO | 7.5 mg |
| Hydromorphone | IV | 1.5 mg |
| Morphine | PO | 30 mg |
| Oxycodone | IV | 20 mg |
| Morphine | IV | 10 mg |
| Oxycodone | PO | 20 mg |
| Oxymorphone | PO | 7–10 mg |
| Oxymorphone | IV | 1 mg |
Oxymorphone is commercially produced fromthebaine, which is a minor constituent of theopium poppy (Papaver somniferum) but thebaine is found in greater abundance (3%) in the roots of theoriental poppy (Papaver orientale).[4][28]German patents from the mid-1930s indicate that oxymorphone as well ashydromorphone,hydrocodone,oxycodone, andacetylmorphone can be prepared—without the need for hydrogen gas—from solutions ofcodeine,morphine, anddionine by refluxing an acidic aqueous solution, or the precursor drug dissolved inethanol, in the presence of certain metals, namelypalladium andplatinum in fine powder or colloidal form or platinum black.
Oxymorphone hydrochloride occurs as odourless white crystals or white to off-white powder. It darkens in colour with prolonged exposure to light. One gram of oxymorphone hydrochloride is soluble in 4 ml of water and it is sparingly soluble in alcohol and ether. It degrades upon contact with light.[21]
Oxymorphone can be acetylated like morphine, hydromorphone, and some other opioids. Mono-, di-, tri-, and tetra- esters of oxymorphone were developed in the 1930s but are not used in medicine at this time. Presumably other esters such as nicotinyl, benzoyl, formyl, cinnimoyl &c.can be produced.[citation needed]
The 2013 USDEA annual manufacturing quotas were 18 375 kilogrammes for conversion (a number of drugs can be made from oxymorphone, both painkillers andopioid antagonists likenaloxone) and 6875 kg for direct manufacture of end-products.[29] Oxymorphone is also a minor metabolite ofoxycodone, which is formed byCYP2D6-mediated O-demethylation.[4]
Oxymorphone was first developed in Germany in 1914,[30] and patented in the US byEndo Pharmaceuticals in 1955.[31] It was introduced in the United States in January 1959 and other countries around the same time.[4]
The brand name Numorphan is derived by analogy to the Nucodan name for anoxycodone product (or vice versa) as well as Paramorphan/Paramorfan fordihydromorphine and Paracodin (dihydrocodeine). The only commercially available salt of oxymorphone in most of the world at this time is thehydrochloride, which has a free base conversion ratio of 0.891, and oxymorphone hydrochloride monohydrate has a factor of 0.85.[21]
Generic pill markings are ATV10/APO; HK10 (10 mgs) oblong white and ATV20/APO; HK20 (20 mgs) oblong white.[citation needed]
In 1924, the United States banned the sale and importation of opium for the manufacture of heroin, an opioid pain medication which was being abused. SeeAnti-Heroin Act of 1924.[relevant?]
Beginning in the 1990s,prescription opioid drug abuse has been a prevalent public health issue of concern.[33] Since 2013, with greatly increasingmorbidity and deaths from overdoses ofsynthetic opioids, such asoxycodone,tramadol, andfentanyl, this issue has developed into a full-fledged epidemic.[34] This has led to several other public health issues, including the spread of diseases likehepatitis C and human immunodeficiency virus (HIV).[35][verification needed]
In the United States, as of 2013 more than 12 million people abused opioid drugs at least once a year.[36] In 2010, 16,652 deaths were related to opiate overdose, in 2015 this number increased to 33,091.[37][38] In September 2013, new FDA labeling guidelines for long-acting and extended-release opioids required manufacturers to remove moderate pain as use indication, reserving the drug for "pain severe enough to require daily, around-the-clock, long-term opioid treatment"[39] however it did not restrict physicians from prescribing opioids for moderate, "as needed" usage.[36]
In January 2013, the Centers for Disease Control and Prevention (CDC) reported an illness associated with intravenous (IV) abuse of oral Opana ER (oxymorphone) in Tennessee. The syndrome resembled that ofthrombotic thrombocytopenic purpura (TTP).[40] Initial therapy included therapeuticplasma exchange, as for TTP. Unlike TTP, no deficientADAMTS13 activity nor anti-ADAMTS13 antibody was found indicating athrombotic microangiopathy of different underlying cause. If IV Opana abuse is acknowledged, supportive care, instead of therapeutic plasma exchange could be considered.[41]
In January 2015, the first HIV outbreak linked to abuse of prescription opioid drugs was identified by the Indiana State Department of Health (ISDH), in the small, rural community of Scott County in southeastern Indiana.[42] ISDH launched an investigation into this HIV outbreak when 11 individuals were confirmed positive for HIV with ties tracing back to the same community. Three months into this investigation, ISDH diagnosed a total of 135 people with HIV, with the numbers still increasing. The cause of this outbreak has been linked to the sharing of needles between opioid abusers, which in some cases, involves sharing needles with up to nine different partners.[35]
In late March 2015, reports indicatedAustin, Indiana, was the center of an outbreak of HIV caused by oxymorphone use as an injectable recreational drug. The outbreak required emergency action by state officials.[43][44][45] The NPR podcast "embedded" episode of 31 March 2016 was an in-depth account of a visit to oxymorphone abusers in Austin, Indiana. In 2016, the street price of oxymorphone was reported to be $140.[46]
The common opioid of abuse in this outbreak has been identified as Opana ER, a time-released oxymorphone pain killer formulated to be resistant to crushing, manufactured by Endo Pharmaceuticals. This harder to crush formulation was put into production in 2012 in an effort to reduce the risk of abuse from snorting the crushed up pill. However, opioid abusers circumvented this issue by finding a way to dissolve and inject the drug.[42]
The extent of this outbreak has garnered the attention of both the CDC and FDA. The CDC opened a larger investigation into all disease outbreaks involving Opana ER, focusing on the incidence of thrombotic thrombocytopenic purpura (TTP)-like illness in the 2012 Tennessee outbreak, as well as the 2015 HIV outbreak in Indiana. The FDA launched a post-marketing safety study regarding the reformulation of Opana ER in 2012[47] and the Indiana state government helped fund another study exploring the link between HIV infection and injection use of oxymorphone in Indiana from 2014 to 2015.[48]
The results of these studies found that the reformulation of Opana to a hard to crush tablet unintentionally increased the risk of transmission of acquired blood borne infections because opioid abusers switched from using the drug through the nasal route to injection. This epidemic caused the risk of acquiring a blood borne infection with the use of injectable opioids to increase in comparison to the risk of acquiring an infection when using injectable heroin or cocaine.[47][48][verification needed]
In June 2017, faced with the public health crisis, the opioid epidemic, the FDA askedEndo Pharmaceuticals to "remove its opioid pain medication, reformulated Opana ER (oxymorphone hydrochloride), from the market". In their 8 June 2017 press release they also noted that, this was the first time the FDA had taken steps to "remove a currently marketed opioid pain medication from sale due to public health consequences of abuse."[32] By 6 July 2017, Endo International voluntarily complied with the FDA removal request.[49]
Oxymorphone provides 5–6 hours of analgesia when adminstered intravenously to cats and dogs. Oxymorphone is ineffective when give via oral-transmucosal. Little data exists regarding oxymorphone in large animals and equines due to oxymorphone's higher cost.[50]
Today, the U.S. Food and Drug Administration requested that Endo Pharmaceuticals remove its opioid pain medication, reformulated Opana ER (oxymorphone hydrochloride), from the market... This is the first time the agency has taken steps to remove a currently marketed opioid pain medication from sale due to the public health consequences of abuse...[FDA Commissioner Scott Gottlieb, M.D.]: "We are facing an opioid epidemic – a public health crisis, and we must take all necessary steps to reduce the scope of opioid misuse and abuse.
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