Etorphine

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Etorphine
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Clinical data
AHFS/Drugs.com International Drug Names
ATCvet code
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Legal status
Identifiers
  • (5α,6β,14β,18R)-18-[(2R)-2-Hydroxy-2-pentanyl]-6-methoxy-17-methyl-7,8-didehydro-18,19-dihydro-4,5-epoxy-6,14-ethenomorphinan-3-ol
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PubChem CID
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ECHA InfoCard 100.035.017 OOjs UI icon edit-ltr-progressive.svg
Chemical and physical data
Formula C25H33NO4
Molar mass 411.542 g·mol−1
3D model (JSmol)
  • C[C@](CCC)(O)[C@H]1C[C@]23C=C[C@]1(OC)[C@@H]4Oc5c(O)ccc6C[C@H]2N(C)CC[C@]43c65
  • InChI=1S/C25H33NO4/c1-5-8-22(2,28)17-14-23-9-10-25(17,29-4)21-24(23)11-12-26(3)18(23)13-15-6-7-16(27)20(30-21)19(15)24/h6-7,9-10,17-18,21,27-28H,5,8,11-14H2,1-4H3/t17-,18-,21-,22-,23-,24+,25-/m1/s1 Yes check.svgY
  • Key:CAHCBJPUTCKATP-FAWZKKEFSA-N Yes check.svgY
 X mark.svgNYes check.svgY  (what is this?)    (verify)

Etorphine (M99) is a semi-synthetic opioid possessing an analgesic potency approximately 1,000–3,000 times that of morphine. [1] It was first prepared in 1960 from oripavine, which does not generally occur in opium poppy extract but rather the related plants Papaver orientale and Papaver bracteatum . [2] It was reproduced in 1963 by a research group at MacFarlan Smith in Gorgie, Edinburgh, led by Kenneth Bentley. [3] It can be produced from thebaine. [4]

Contents

Veterinary use

Etorphine is available legally only for veterinary use and is strictly governed by law. It is often used to immobilize elephants and other large mammals. Diprenorphine (Revivon) is an opioid receptor antagonist that can be administered in proportion to the amount of etorphine used (1.3 times) to reverse its effects. Veterinary-strength etorphine is fatal to humans. For this reason the package as supplied to vets always includes the human antidote along with the etorphine.

The human antidote is generally naloxone, not diprenorphine, and is always prepared before the preparation of etorphine to be immediately administered following accidental human exposure to etorphine. The LD50 in humans is 3 μg which led to the requirement that the medicine include an equal dose of an antidote, diprenorphine or naloxone.

One of its main advantages is its speed of operation, and more importantly, the speed that diprenorphine reverses its effects. The high incidence of side effects, including severe cardiopulmonary depression, has caused etorphine to fall into disfavor in general veterinary practice. However, its high potency, combined with the rapid action of both etorphine and its antagonist, diprenorphine, means that it has found a place for use in the capture of large mammals, such as rhinoceroses and elephants, where rapid onset and rapid recovery are both very important. The high potency of etorphine means that sufficient etorphine can be administered to large wild mammals by projectile syringe (dart).

Large Animal Immobilon is a combination of etorphine plus acepromazine maleate. An etorphine antidote Large Animal Revivon contains mainly diprenorphine for animals and a human-specific naloxone-based antidote, which should be prepared prior to the etorphine. A 5–15 mg dose is enough to immobilize an African elephant and a 2–4 mg dose is enough to immobilize a black rhinoceros. [5]

Pharmacology

Etorphine is a potent, non-selective full agonist of the μ-, δ-, and κ-opioid receptors. [6] [7] It has a weak affinity for the nociceptin receptor. [8] Etorphine has an LD50 of 3 μg in humans. [9]

In Hong Kong, etorphine is regulated under Schedule 1 of Hong Kong's Chapter 134 Dangerous Drugs Ordinance. It can be used legally only by health professionals and for university research purposes. The substance can be given by pharmacists under a prescription. Anyone who supplies the substance without prescription can be fined $10,000 (HKD). The penalty for trafficking or manufacturing the substance is a $5,000,000 (HKD) fine and life imprisonment. Possession of the substance for consumption without license from the Department of Health is illegal with a $1,000,000 (HKD) fine and/or 7 years of jail time. [10]

In the Netherlands, etorphine is a Schedule I drug of the Opium Law. It is used only for veterinary purposes in zoos to immobilize large animals. [11]

In the US, etorphine is listed as a Schedule I drug with an ACSCN of 9056, although its hydrochloride salt is classified as Schedule II with an ACSCN of 9059. [12]

In the UK, under the Misuse of Drugs Act 1971, etorphine is controlled as a Class A substance. [13]

In Italy Etorphine is illegal, as are the parent compounds Dihydroetorphine and Acetorphine. (Datas from 2022) [14]

See also

Related Research Articles

<span class="mw-page-title-main">Thebaine</span> Opiate alkaloid constituent of opium

Thebaine (paramorphine), also known as codeine methyl enol ether, is an opiate alkaloid, its name coming from the Greek Θῆβαι, Thēbai (Thebes), an ancient city in Upper Egypt. A minor constituent of opium, thebaine is chemically similar to both morphine and codeine, but has stimulatory rather than depressant effects. At high doses, it causes convulsions similar to strychnine poisoning. The synthetic enantiomer (+)-thebaine does show analgesic effects apparently mediated through opioid receptors, unlike the inactive natural enantiomer (−)-thebaine. While thebaine is not used therapeutically, it is the main alkaloid extracted from Papaver bracteatum and can be converted industrially into a variety of compounds, including hydrocodone, hydromorphone, oxycodone, oxymorphone, nalbuphine, naloxone, naltrexone, buprenorphine, butorphanol and etorphine.

<span class="mw-page-title-main">Opioid</span> Psychoactive chemical

Opioids are a class of drugs that derive from, or mimic, natural substances found in the opium poppy plant. Opioids work in the brain to produce a variety of effects, including pain relief. As a class of substances, they act on opioid receptors to produce morphine-like effects.

<span class="mw-page-title-main">Buprenorphine</span> Opioid used to treat pain & opioid use disorder

Buprenorphine, sold under the brand name Subutex among others, is an opioid used to treat opioid use disorder, acute pain, and chronic pain. It can be used under the tongue (sublingual), in the cheek (buccal), by injection, as a skin patch (transdermal), or as an implant. For opioid use disorder, the patient must have moderate opioid withdrawal symptoms before buprenorphine can be administered under direct observation of a health-care provider.

<span class="mw-page-title-main">Oxymorphone</span> Opioid analgesic drug

Oxymorphone is a highly potent opioid analgesic 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. The elimination half-life of oxymorphone is much faster intravenously, and as such, the drug is most commonly used orally. Like oxycodone, which metabolizes to oxymorphone, oxymorphone has a high potential to be abused.

<span class="mw-page-title-main">Carfentanil</span> Synthetic opioid analgesic

Carfentanil or carfentanyl, sold under the brand name Wildnil, is an extremely potent opioid analgesic used in veterinary medicine to anesthetize large animals such as elephants and rhinoceroses. It is an analogue of fentanyl, which it is structurally a derivative of. It is typically administered in this context by tranquilizer dart. Carfentanil has also been used in humans to image opioid receptors. It has additionally been used as a recreational drug, typically by injection, insufflation, or inhalation. Deaths have been reported in association with carfentanil.

<span class="mw-page-title-main">Nalbuphine</span> Opioid analgesic

Nalbuphine, sold under the brand names Nubain among others, is an opioid analgesic which is used in the treatment of pain. It is given by injection into a vein, muscle, or fat.

<span class="mw-page-title-main">Dihydromorphine</span> Semi-synthetic opioid analgesic drug

Dihydromorphine is a semi-synthetic opioid structurally related to and derived from morphine. The 7,8-double bond in morphine is reduced to a single bond to get dihydromorphine. Dihydromorphine is a moderately strong analgesic and is used clinically in the treatment of pain and also is an active metabolite of the analgesic opioid drug dihydrocodeine. Dihydromorphine occurs in trace quantities in assays of opium on occasion, as does dihydrocodeine, dihydrothebaine, tetrahydrothebaine, etc. The process for manufacturing dihydromorphine from morphine for pharmaceutical use was developed in Germany in the late 19th century, with the synthesis being published in 1900 and the drug introduced clinically as Paramorfan shortly thereafter. A high-yield synthesis from tetrahydrothebaine was later developed.

<span class="mw-page-title-main">Opioid antagonist</span> Receptor antagonist that acts on one or more of the opioid receptors

An opioid antagonist, or opioid receptor antagonist, is a receptor antagonist that acts on one or more of the opioid receptors.

<span class="mw-page-title-main">Morphinan</span> Chemical compound

Morphinan is the prototype chemical structure of a large chemical class of psychoactive drugs, consisting of opiate analgesics, cough suppressants, and dissociative hallucinogens, among others. Typical examples include compounds such as morphine, codeine, and dextromethorphan (DXM). Despite related molecular structures, the pharmacological profiles and mechanisms of action between the various types of morphinan substances can vary substantially. They tend to function either as μ-opioid receptor agonists (analgesics), or NMDA receptor antagonists (dissociatives).

<span class="mw-page-title-main">Codeine</span> Opiate and prodrug of morphine used to treat pain

Codeine is an opiate and prodrug of morphine mainly used to treat pain, coughing, and diarrhea. It is also commonly used as a recreational drug. It is found naturally in the sap of the opium poppy, Papaver somniferum. It is typically used to treat mild to moderate degrees of pain. Greater benefit may occur when combined with paracetamol (acetaminophen) or a nonsteroidal anti-inflammatory drug (NSAID) such as aspirin or ibuprofen. Evidence does not support its use for acute cough suppression in children. In Europe, it is not recommended as a cough medicine for those under 12 years of age. It is generally taken by mouth. It typically starts working after half an hour, with maximum effect at two hours. Its effects last for about four to six hours. Codeine exhibits abuse potential similar to other opioid medications, including a risk of addiction and overdose.

<span class="mw-page-title-main">Diprenorphine</span> Chemical compound

Diprenorphine, also known as diprenorfin, is a non-selective, high-affinity, weak partial agonist of the μ- (MOR), κ- (KOR), and δ-opioid receptor (DOR) which is used in veterinary medicine as an opioid antagonist. It is used to reverse the effects of super-potent opioid analgesics such as etorphine and carfentanil that are used for tranquilizing large animals. The drug is not approved for use in humans.

<span class="mw-page-title-main">Dihydroetorphine</span> Opioid analgesic drug

Dihydroetorphine was developed by K. W. Bentley at McFarlan-Smith in the 1960s and is a potent opioid analgesic used mainly in China. It is a derivative of the better-known opioid etorphine, a very potent veterinary painkiller and anesthetic medication used primarily for the sedation of large animals such as elephants, giraffes, and rhinos.

<span class="mw-page-title-main">Oripavine</span> Chemical compound

Oripavine is an opioid and the major metabolite of thebaine. It is the precursor to the semi-synthetic compounds etorphine and buprenorphine. Although this chemical compound has analgesic potency comparable to morphine, it is not used clinically due to severe adverse effects and a low therapeutic index. Being a precursor to a series of extremely strong opioids, oripavine is a controlled substance in some jurisdictions.

<span class="mw-page-title-main">Tilidine</span> Synthetic opioid painkiller

Tilidine, sold under the brand name Valoron among others, is a synthetic opioid analgesic, used mainly in Belgium, Bulgaria, Germany, Albania, Luxembourg, South Africa, and Switzerland for the treatment of moderate to severe pain, both acute and chronic. Its onset of pain relief after oral administration is about 10–15 minutes and peak relief from pain occurs about 25–50 minutes after administration.

<span class="mw-page-title-main">Acetorphine</span> Opioid analgesic and anesthetic veterinary drug

Acetorphine is a potent opioid analgesic, up to 8700 times stronger than morphine by weight. It is a derivative of the more well-known opioid etorphine, which is used as a very potent veterinary painkiller and anesthetic medication, primarily for the sedation of large animals such as elephants, giraffes and rhinos.

<span class="mw-page-title-main">Cyprenorphine</span> Chemical compound

Cyprenorphine (M285), N-cyclo-propylmethyl-6,14-endoetheno-7α-(1-hydroxy-1-methylethyl)-6,7,8,14-tetrahydronororipavine, is an opioid drug. It is related to more well-known opioids such as buprenorphine, which is used as an analgesic and for the treatment of opioid addiction, and diprenorphine, which is used as an antidote to reverse the effects of other opioids. It is roughly 35 times as strong as nalorphine.

<span class="mw-page-title-main">Propiram</span> Opioid analgesic drug

Propiram is a partial μ-opioid receptor agonist and weak μ antagonist analgesic from the ampromide family of drugs related to other drugs such as phenampromide and diampromide. It was invented in 1963 in the United Kingdom by Bayer but was not widely marketed, although it saw some limited clinical use, especially in dentistry. Propiram reached Phase III clinical trials in the United States and Canada.

<span class="mw-page-title-main">7-PET</span> Opioid analgesic drug

7-PET is an opioid analgesic drug that has 300 times the potency of morphine by weight. It was discovered by K.W. Bentley and is related to the more well known oripavine derivative etorphine, which is used as a veterinary painkiller and anesthetic medication for the sedation of large animals such as elephants, giraffes, and rhinos. 7-PET itself has a 3-O-methyl ether which reduces potency, but the 3-OH derivative is around 2200 times more potent than morphine, almost the same potency as etorphine as a μ agonist, and unexpectedly the 3-hydrogen compound is also around the same potency of 2000 times morphine.

<span class="mw-page-title-main">Opiate</span> Substance derived from opium

An opiate is an alkaloid substance derived from opium. It differs from the similar term opioid in that the latter is used to designate all substances, both natural and synthetic, that bind to opioid receptors in the brain. Opiates are alkaloid compounds naturally found in the opium poppy plant Papaver somniferum. The psychoactive compounds found in the opium plant include morphine, codeine, and thebaine. Opiates have long been used for a variety of medical conditions, with evidence of opiate trade and use for pain relief as early as the eighth century AD. Most opiates are considered drugs with moderate to high abuse potential and are listed on various "Substance-Control Schedules" under the Uniform Controlled Substances Act of the United States of America.

<span class="mw-page-title-main">Thienorphine</span> Chemical compound

Thienorphine is a very potent, extremely long-acting, orally-active opioid analgesic with mixed agonist–antagonist properties which was developed by the Beijing Institute of Pharmacology and Toxicology as a potential treatment for opioid dependence. It is a high-affinity, balanced ligand of the μ-, δ-, and κ-opioid receptors, behaving as a partial agonist of the μ- and κ-opioid receptors and as an antagonist of the δ-opioid receptor. It also possesses relatively low affinity for the nociceptin receptor, where it acts as an antagonist.

References

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  2. Aggrawal A (1995). "Chapter 3 Opium: the king of narcotics". Narcotic Drugs. New Delhi: National Book Trust. pp. xvi+161. ISBN   81-237-1383-5.
  3. Bentley KW, Hardy DG (1963). "New potent analgesics in the morphine series". Proceedings of the Chemical Society. 220: 189–228. doi:10.1039/PS9630000189.
  4. Huang XR, Srimurugan S, Lee GH, Chen C (February 2011). "A Facile Synthesis and Structural Verification of Etorphine and Dihydroetorphine from Codeine". Journal of the Chinese Chemical Society. 58 (1): 101–107. doi: 10.1002/jccs.201190048 . ISSN   0009-4536.
  5. "Etorphine HCl". Veterinary medicine for wildlife: immobilisation medicine for animals zoo animals. Zoo Pharm. Archived from the original on 2016-09-08. Retrieved 2013-10-11.
  6. Pasternak G (17 April 2013). The Opiate Receptors. Springer Science & Business Media. pp. 444–. ISBN   978-1-60761-990-1.
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  8. Hawkinson JE, Acosta-Burruel M, Espitia SA (February 2000). "Opioid activity profiles indicate similarities between the nociceptin/orphanin FQ and opioid receptors". European Journal of Pharmacology. 389 (2–3): 107–114. doi:10.1016/S0014-2999(99)00904-8. PMID   10688973.
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  13. "List of most commonly encountered drugs currently controlled under the misuse of drugs legislation". GOV.UK. Retrieved 2022-03-30.
  14. "Tabelle delle sostanze stupefacenti e psicotrope". Ministero della Salute (in Italian). Retrieved 2022-04-09.