Metamizole

Source: Wikipedia, the free encyclopedia.
Not to be confused with Naproxen.
Not to be confused with methimazole or methazolamide.
Metamizole
Clinical data
Trade namesNovalgin, Algocalmin,[1] Analgin, others[2]
Other namesDipyrone (BAN UK, USAN US, Sulpyrine (JAN JP)
AHFS/Drugs.comInternational Drug Names
Pregnancy
category
  • None assigned; no evidence of teratogenicity in animal studies, but use in the third trimester may cause adverse effects in the newborn or ductus arteriosus (a heart defect) due to its weak NSAID activity.[3][4]
Routes of
administration		Oral, IM, IV, rectal
ATC code
Legal status
Legal status
  • AU: Withdrawn
  • BR: OTC (Over the counter)
  • CA: Veterinary only[5]
  • DE: § 48 AMG/§ 1 MPAV (Prescription only)[10]
  • NZ: Prescription only[6][7]
  • UK: Withdrawn
  • US: Veterinary only (horses)[8]
  • EU: Legally available[9]
Pharmacokinetic data
Bioavailability100% (active metabolites)[11]
Protein binding48–58% (active metabolites)[11]
MetabolismLiver[11]
Elimination half-life14 minutes (parent compound; parenteral);[4] metabolites: 2–4 h[11]
Duration of action4–6 h[12]
ExcretionUrine (96%, IV; 85%, oral), faeces (4%, IV).[4]
Identifiers
  • [(2,3-Dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)methylamino] methanesulfonic acid
JSmol)
  • c1ccccc1N2N(C)C(C)=C(C2=O)N(C)CS(=O)(=O)O
  • InChI=1S/C13H17N3O4S/c1-10-12(14(2)9-21(18,19)20)13(17)16(15(10)3)11-7-5-4-6-8-11/h4-8H,9H2,1-3H3,(H,18,19,20) ☒N
  • Key:LVWZTYCIRDMTEY-UHFFFAOYSA-N ☒N
 ☒NcheckY (what is this?)  (verify)

Metamizole or dipyrone is a painkiller, spasm reliever, and fever reliever drug. It is most commonly given by mouth or by intravenous infusion.[13][11][14] It belongs to the ampyrone sulfonate family of medicines and was patented in 1922. Metamizole is marketed under various trade names.[2][3] It was first used medically in Germany under the brandname "Novalgin".[15]

Metamizole is available over-the-counter in many countries, but from in the 1970s it was banned in some countries due to studies linking it to severe adverse effects, including agranulocytosis.[16] Other studies find that it is a safer drug than other painkillers.[17][18] Metamizole is popular in many countries where it is available.[19]

Medical uses

Metamizole, with its potent

muscle spasms.[20]

It is primarily used for perioperative pain, acute injury, colic, cancer pain, other acute/chronic forms of pain and high fever unresponsive to other agents.[4] Metamizole also effectively manages biliary and intestinal colic-like pain, and reduces the spasm of the smooth muscle of the sphincter of Oddi.[21]

Special populations

Its use in pregnancy is advised against, although animal studies are reassuring in that they show minimal risk of birth defects. Its use in the elderly and those with liver or kidney impairment is advised against, but if these groups of people must be treated, a lower dose and caution is usually advised. Its use during lactation is advised against, as it is excreted in breast milk.[4]

Adverse effects

While metamizole is a relatively safe medication,[22] it is not entirely devoid of adverse effects.[22]

Metamizole has a potential of blood-related toxicity (blood

non-steroidal anti-inflammatory drugs (NSAIDs).[11] Like NSAIDs, it can trigger bronchospasm or anaphylaxis, especially in those with asthma.[14]

Serious side effects include

aplastic anaemia, hypersensitivity reactions (like anaphylaxis and bronchospasm), toxic epidermal necrolysis and it may provoke acute attacks of porphyria, as it is chemically related to the sulfonamides.[3][11][14] The relative risk for agranulocytosis appears to greatly vary according to the country of estimates on said rate and opinion on the risk is strongly divided.[3][23][24] Genetics may play a significant role in metamizole sensitivity.[25] It is suggested that some populations are more prone to suffer from metamizole induced agranulocytosis than others. As an example, metamizole-related agranulocytosis seems to be an adverse effect more frequent in British population as opposed to Spaniards.[26] An assessment report by the European Medicines Agency remarked that "the potential to induce agranulocytosis may be associated with genetic characteristics of the population studied".[27]

A 2015 meta-analysis concluded that on the evidence available "for short-term use in the hospital setting, metamizole seems to be a safe choice when compared to other widely used analgesics", but that the "results were limited by the mediocre overall quality of the reports" analysed.[28]

A systematic review from 2016 found that metamizole significantly increased the relative risk of upper gastrointestinal bleeding, by a factor of 1.4–2.7 times.[29] A study by one of the manufacturers of the drug found the risk of agranulocytosis within the first week of treatment to be a 1.1 in a million, versus 5.9 in a million for diclofenac.[medical citation needed] Therapeutic effect of metamizole on intestinal colic is attributed to its analgesic properties, with no evidence of interference in small bowel or colon motility.[21]

Metamizole has potential for hepatotoxicity.[30]

Contraindications

Previous hypersensitivity (such as

excipients (e.g. lactose) in the preparation used, acute porphyria, impaired haematopoiesis (such as due to treatment with chemotherapy agents), third trimester of pregnancy (potential for adverse effects in the newborn), lactation, children with a body weight below 16 kg, history of aspirin-induced asthma and other hypersensitivity reactions to analgesics.[4]

In 2018, the

renal impairment or ductus arteriosus to the fetus or infant.[9]

Interactions

A clinically severe interaction has been identified between aspirin and metamizole for patients who regularly take aspirin to manage vascular disease: this interaction occurs due to steric hindrance at the active aspirin binding site of COX-1 by metamizole; to manage this interaction, it is recommended to make a delay between the intake of each of these drugs, with aspirin being taken at least 30 minutes before metamizole.[31]

Known interactions
Drug(s) Interaction/reason for theoretical potential for interaction
Aspirin Platelet aggregation inhibition (PAI) by aspirin; metamizole prevents aspirin from inhibiting COX-1.[31]
Ciclosporin Decreased serum levels of ciclosporin.[4]
Chlorpromazine Additive hypothermia (low body temperature) may result.[4]
Hydroxyethyl starch Acute renal insufficiency. Low evidence, but discouraged simultaneous administration.[32]
Methotrexate Additive risk for haematologic (blood) toxicity.[4] More specifically, bone marrow aplasia.[32]

Oral

antihypertensives may also interact with metamizole, as other pyrazolones
are known to interact adversely with these substances.

Overdose

It is considered fairly safe on overdose, but in these cases supportive measures are usually advised as well as measures to limit absorption (such as

haemodialysis).[4]

Physicochemistry

Metamizole is a sulfonic acid and comes in

monohydrate form is a white/almost crystalline powder that is unstable in the presence of light, highly soluble in water and ethanol but practically insoluble in dichloromethane.[33]

Pharmacology

Its precise mechanism of action of metamizole is unknown, although it is believed that metamizole generally exerts its action by inhibiting the COX-3 enzyme which is responsible for the biosynthesis of prostaglandins in the central nervous system (CNS)—in the brain and spinal cord. Prostaglandins are lipid compounds that play a role in inflammation, pain, and fever. By inhibiting the COX-3 enzyme in the CNS, metamizole reduces the production of prostaglandins, thereby alleviating pain, reducing fever, and potentially lessening inflammation.[14][34] Metamizole is classified as an atypical nonsteroidal anti-inflammatory drug (NSAID). Unlike typical NSAIDs, metamizole exhibits weak or no anti-inflammatory properties (at least in therapeutic doses),[20][34] but possesses potent analgesic effects via its action in the CNS: this central action distinguishes it from other NSAIDs, which generally exert their effects peripherally.[34] The inhibition by metamizole of COX-1 and COX-2 is less potent than the inhibition of these enzymes by traditional NSAIDs.[12]

Metamizole is metabolized in the liver, where it is converted into active metabolites through the process of N-demethylation.[35] The mechanism of action of metamizole is believed to be exerted via its active metabolites, specifically, arachidonoyl-4-methylaminoantipyrine (ARA-4-MAA) and arachidonoyl-4-aminoantipyrine (ARA-4-AA).[36][17][22] This mechanism of action has been compared to paracetamol and its active arachidonic acid metabolite AM404. The CB1 receptor inverse agonist AM-251 was able to reduce the cataleptic response and thermal analgesia of dipyrone.[37] Another study found its antihyperalgesic effect reversed by the CB2 inverse agonist AM-630[38] Although it seems to inhibit fevers caused by prostaglandins, especially prostaglandin E2,[39] metamizole appears to produce its therapeutic effects by means of its metabolites, especially N-methyl-4-aminoantipyrine (MAA) and 4-aminoantipyrine (AA) which form through the FAAH enzyme to create arachidonoyl-4-methylaminoantipyrine (ARA-4-MAA) and arachidonoyl-4-aminoantipyrine (ARA-4-AA).[4]

Metamizole likely induces the CYP2B6 and CYP3A4 enzymes.[20]


Pharmacokinetics of metamizole's major metabolites[4]
Metabolite Acronym Biologically active? Pharmacokinetic properties

N-methyl-4-aminoantipyrine
 MAA Yes Bioavailability≈90%. Plasma protein binding: 58%. Excreted in the urine as 3±1% of the initial (oral) dose

4-aminoantipyrine
 AA Yes Bioavailability≈22.5%. Plasma protein binding: 48%. Excreted in the urine as 6±3% of the initial (oral) dose

N-formyl-4-aminoantipyrine
 FAA No Plasma protein binding: 18%. Excretion in the urine as 23±4% of the initial oral dose

N-acetyl-4-aminoantipyrine
 AAA No Plasma protein binding: 14%. Excretion in the urine as 26±8% of the initial oral dose

History

pyramidon which was three times more active than antipyrine.[1]

In 1893, a derivative of antipyrine,

aminopyrine, was made by Friedrich Stolz at Hoechst.[41]: 26–27  Yet later, chemists at Hoechst made a derivative, melubrine (sodium antipyrine aminomethanesulfonate), which was introduced in 1913;[42] finally in 1920, metamizole was synthesized.[18] Metamizole is a methyl derivative of melubrine and is also a more soluble prodrug of pyramidon.[1][41]: 26–27  Metamizole was first marketed in Germany as "Novalgin" in 1922.[1][18]

Society and culture

Legal status

World map of availability of Metamizole
World map of availability of Metamizole (Dipyrone)
   Over-the-counter with limited restrictions.
   Available, but no data on the requirement of prescriptions.
   Prescription-only, with fairly limited restrictions on its use.
   Prescription-only, with extensive restrictions on its use.
   Banned for human use. It may still be used by veterinary cases in some countries.
   No data.

Metamizole is banned in several countries, available by prescription in others (sometimes with strong warnings, sometimes without), and available

over the counter in yet others.[16][43][44] For example, approval was withdrawn in Sweden (1974), the US (1977),[45] and India (2013, ban lifted in 2014).[46][47][48]

Although metamizole is banned in the US because of its risk of agranulocytosis,[49] it was reported by small surveys that 28% of Hispanics in Miami have possession of it,[50] and 38% of Hispanics in San Diego reported some usage.[51]

There were unauthorized sales and use of dipyrone in horses in the US. After reviewing trial data on its safety, the FDA approved it for treating fever in equines.[8]

Amid the opioid crisis, a study pointed out that the legal status of metamizole has a relation to the consumption of oxycodone, showing the use of those drugs were inversely correlated. Its use could be beneficial when adjusted for the addictive risk of opioids, especially on limited and controlled use of metamizole.[52] A 2019 Israeli conference also justified the approved status as a preventive to opioid dependence, and metamizole being safer than most analgesics for renal impaired patients.[53]

Metamizole is the most sold medication in São Paulo, Brazil, accounting for 488 tons in 2016.[54] Given this contrasting consumption compared to other countries, the Brazilian Health Regulatory Agency (ANVISA) convened an international panel for evaluating its safety in 2001, and the conclusion was that the benefits substantially outweighed the risks, and imposing restrictions would lead to significant negative consequences to the population.[55][24] It is also highly popular in Latin America overall. In 2022 in Brazil alone over 215 million doses were administered.[56]

The Bulgarian pharmaceutical Sopharma produces it under the brand Analgin, which as of 2014, has been the top-selling analgesic in Bulgaria for over a decade.[57]

In Germany, the drug is the most commonly prescribed painreliever.[52]

In 2012, headache accounts for 70% of its use in Indonesia.[58]

In 2018, investigators in Spain looked into Nolotil (as metamizole is known in Spain) after the death of several British people in Spain. A possible factor in these deaths might have been a side effect of metamizole that can cause agranulocytosis (a lowering of white blood cell count).[59]

Brand names

Metamizole is the international nonproprietary name, and in countries where it is marketed, it is available under many brand names.[2]

In Romania metamizole is available as the original marketed pharmaceutical product by Zentiva as Algocalmin, as 500 mg immediate release tablets. It's also available as an injection with 1 g of metamizole sodium dissolved in 2 ml of solvent.

In Israel it is sold under the brand name "Optalgin" (Hebrew: אופטלגין), manufactured by Teva.

It is known as Sulpyrin and Sulpyrine in South Korea (설피린) and Japan. (スルピリン)[60][61]

Analgin

Analgin (Russian: Анальгин) is a

pharmacopeia,[62] continuing in use in Slavic nations. A firm in Russia tried unsuccessfully in 2011 to claim the name as their trademark.[63][64] In Bulgaria, Sopharma succeeded in registering Analgin as a trademark in 2004.[65]

Analgin is also the common term used in the Indian pharmacopeia.[66]

References

  1. ^
    doi:10.1016/S1366-0071(97)80033-2
    .
  2. ^ a b c "Metamizole Annex I - List of nationally authorised medicinal products" (PDF). European Medicines Agency. 2018-06-01. Archived (PDF) from the original on 2022-02-05. Retrieved 2023-08-14.
  3. ^
    ISBN 978-0-85369-840-1
    .
  4. ^ a b c d e f g h i j k l "Fachinformation (Zusammenfassung der Merkmale des Arzneimittels) Novaminsulfon injekt 1000 mg Lichtenstein Novaminsulfon injekt 2500 mg Lichtenstein" (PDF). Winthrop Arzneimittel GmbH (in German). Zinteva Pharm GmbH. February 2013. Archived (PDF) from the original on 16 October 2018. Retrieved 19 April 2014.
  5. ^ "Notice of Amendment: Addition of Metamizole (Dipyrone) to the Prescription Drug List (PDL)". Government of Canada. 2022-07-18. Archived from the original on 2022-08-30. Retrieved 2023-08-04.
  6. ^ "Recent NZ Gazette Notices Relating to Classification". medsafe.govt.nz. 2020-03-06. Archived from the original on 2023-04-29. Retrieved 2023-08-04.
  7. ^ "Minutes of the 63rd meeting of the Medicines Classification Committee - 10 Oct 2019". medsafe.govt.nz. 2019-12-04. Archived from the original on 2023-06-10. Retrieved 2023-08-04.
  8. ^ a b FDA's Center for Veterinary Medicine (November 26, 2019). "Zimeta (dipyrone injection) - Veterinarians". FDA. Archived from the original on 2022-01-17. Retrieved 2023-08-04.
  9. ^ a b European Medicines Agency (2018-09-17). "Metamizole containing medicinal products - EMA recommends aligning doses of metamizole medicines and their use during pregnancy and breastfeeding". European Medicines Agency. Archived from the original on 2023-02-01. Retrieved 2023-08-04.
  10. ^ "Risikoinformationen - Metamizol (Novalgin, Berlosin, Novaminsulfon, etc.): BfArM weist auf richtige Indikationsstellung und Beachtung von Vorsichtsmaßnahmen und Warnhinweisen hin" [Risk information - Metamizol (Novalgin, Berlosin, Novaminsulfon, etc.): BfArM points out the correct indication and compliance with precautionary measures and warnings]. Bundesinstitut für Arzneimittel und Medizinprodukte (Federal Institute for Pharmaceuticals and Medical Products). 2009-05-28. Archived from the original on 2023-05-18. Retrieved 2023-08-04.
  11. ^
    S2CID 32814418
    .
  12. ^
    doi:10.52778/efsm.22.0153
    .
  13. ^ "Fachinformation (Zusammenfassung der Merkmale des Arzneimittels) Novaminsulfon injekt 1000 mg Lichtenstein Novaminsulfon injekt 2500 mg Lichtenstein" (PDF). Winthrop Arzneimittel GmbH (in German). Zinteva Pharm GmbH. February 2013. Archived (PDF) from the original on 16 October 2018. Retrieved 19 April 2014.
  14. ^
    S2CID 8829564
    .
  15. ISBN 978-3-527-60749-5
    .
  16. ^ a b United Nations Department of Economic and Social Affairs (2005). Consolidated List of Products Whose Consumption and/or Sale Have Been Banned, Withdrawn, Severely Restricted of Not Approved by Governments (PDF) (12th ed.). New York: United Nations. pp. 171–5. Archived (PDF) from the original on 21 April 2021. Retrieved 3 April 2013.
  17. ^
    S2CID 201118022
    .
  18. ^
    S2CID 56205439
    .
  19. PMID 35584441
    .
  20. ^
    PMID 25199942
    .
  21. ^
    PMID 30652827
    .
  22. ^
    PMID 24724493
    .
  23. S2CID 31337982
    .
  24. ^
    S2CID 252870061. Archived
    from the original on 2023-07-19. Retrieved 2023-07-19.
  25. PMID 26111152
    .
  26. PMID 19457324
    .
  27. ^ Assessment report: metamizole-containing medicinal products (PDF) (Report). European Medicines Agency, Committee for Medicinal Products for Human Use (CHMP). 13 December 2018. EMA/143912/2019. Archived (PDF) from the original on 5 February 2022. Retrieved 4 August 2023.
  28. PMID 25875821
    .
  29. S2CID 24538147
    .
  30. PMID 31433499
    .
  31. ^
    PMID 37109738. This article incorporates text from this source, which is available under the CC BY 4.0
    license.
  32. ^
    OCLC 927102885
    .
  33. ISBN 978-92-871-7527-4
    .
  34. ^
    PMID 31519356
    . Metamizole (dipyrone) is considered an atypical NSAID with weak antiinflammatory properties, but potent analgesic effects that are thought to be related mainly via central inhibition of COX-3 enzyme
  35. PMID 29746911
    .
  36. PMID 36364259
    .
  37. S2CID 13598808
    .
  38. S2CID 211112059
    .
  39. PMID 24712707
    .
  40. ^ "Emil Fischer – Biographical". Nobel Committee. Archived from the original on 2017-06-06. Retrieved 2017-06-14.
  41. ^
    ISBN 978-3-527-32669-3
    .
  42. ^ "New and Nonofficial Remedies: Melubrine". JAMA. 61 (11): 869. 1913.
  43. ^ Department of Economic and Social Affairs of the United Nations Secretariat Consolidated List of Products Whose Consumption and/or Sale Have Been Banned, Withdrawn, Severely Restricted or not Approved by Governments Fourteenth Issue (New data only) (January 2005 – October 2008): Pharmaceuticals Archived 2017-03-09 at the Wayback Machine United Nations – New York, 2009
  44. PMID 22172309
    .
  45. ISSN 0097-6326. Archived
    from the original on 2020-09-29. Retrieved 2023-08-04. This notice withdraws approval of the new drug applications (NDA's) for drug products containing dipyrone. The drug products have been used to reduce fever, but they are not shown to be safe for use. On the basis of new evidence, not contained in the applications or not available until after the applications were approved, evaluated together with the evidence available when the applications were approved, the Commissioner of Food and Drugs finds that such drugs have not been shown to be safe for use upon the basis of which the applications were approved. (...) approval of the NDA's providing for the drug products named above, and all amendments and supplements applying thereto, is withdrawn effective June 27,1977. Shipment in interstate commerce of the above-listed products or of any identical, related, or similar product, not the subject of an approved NDA, will then be unlawful.
  46. S2CID 45107003
    .
  47. ^ "Govt lifts ban on painkiller Analgin". Business Standard India. 19 March 2014. Archived from the original on 7 January 2018. Retrieved 7 January 2018.
  48. ^ Panda AK (2014-02-13). Drugs Rules - G.S.R. 86(E) 13.02.2014 Revoke GSR378(E) Reg. Suspension of Analgin (PDF) (Report). New Delhi: The Gazette of India. Archived (PDF) from the original on 2023-08-11. Retrieved 2023-08-11.
  49. PMID 12042592. Archived
    from the original on 2024-03-15. Retrieved 2024-03-15.
  50. S2CID 41638378
    .
  51. PMID 11527837
    .
  52. ^
    S2CID 52192130
    .
  53. PMID 31721040
    . ACMT/IST 2019 American-Israeli Medical Toxicology Conference
  54. S2CID 227168554
    .
  55. ^ Brazilian Health Regulatory Agency (ANVISA) (24 July 2001). Painel Internacional de Avaliação da Segurança da Dipirona [International Panel for the Evaluation of Dipyrone Safety] (PDF) (Report) (in Portuguese). Brasília. Archived from the original (PDF) on 2009-01-21.
  56. ^ Biernath A (2023-08-17). "Dipirona: por que é vendida no Brasil, mas proibida nos EUA e em parte da Europa?". BBC News Brasil (in Brazilian Portuguese). Archived from the original on 2023-10-14. Retrieved 2023-09-21.
  57. PMID 26019521
    .
  58. ^ Kurniawati M, Ikawati Z, Raharjo B (2012). "The evaluation of metamizole use in some places of pharmacy service in Cilacap county". Jurnal Manajemen Dan Pelayanan Farmasi (Journal of Management and Pharmacy Practice) (in Indonesian). 2 (1): 50–55. Archived from the original on 7 April 2023. Retrieved 15 March 2022.
  59. ^ "Exclusive: southern spain hospitals in british expat hotspot issue warning for 'lethal' painkiller nolotil". 23 April 2018. Archived from the original on 28 April 2018. Retrieved 27 April 2018.
  60. ^ Kim CH (2004-08-26). "해열진통제 '설피린' 국내사용 논란" [Controversy over domestic use of antipyretic analgesic Sulpyrin]. 경기신문 [kgnews] (in Korean). Archived from the original on 2023-08-14. Retrieved 2023-08-14.
  61. ISBN 978-4-8408-1589-5. Archived
    (PDF) from the original on 2023-01-20. Retrieved 2023-08-14.
  62. ^ Ministry of Health of the USSR (1968). Государственная Фармакопея Союза Советских Социалистических Республик [State Pharmacopoeia of the Union of Soviet Socialist Republics] (in Russian) (10th ed.). Moscow: Медицина [Medicine]. p. 94.
  63. ^ Ovchinnikov R (2011-12-22). "Анальгин хотят отпустить в одни руки" [Analgin want to let go in one hand]. Известия (in Russian). Archived from the original on 2023-08-12.
  64. ^ "Pavel Sadovsky comments on trademarks registering for RIA Novosti - Insights". EPAM Law. 2012-02-22. Archived from the original on 2021-02-25. Retrieved 2023-08-14.
  65. ^ "Sopharma wins TM battle over analgesic drug Analgin". FFBH. 2004-08-05. Archived from the original on 2023-08-14. Retrieved 2023-08-14.
  66. ^ Ministry of Health and Family Welfare (2007). Indian Pharmacopeia (PDF). Vol. 2. Ghaziabad, India: Indian Pharmacopoeia Commission. p. 117. Archived (PDF) from the original on 2023-07-28. Retrieved 2023-08-13.
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