Methadone

Methadone
Skeletal formula
The more active R enantiomer of methadone (levomethadone)
Ball-and-stick model based on the crystal structure[1][2]
Clinical data
Trade namesDolophine, Methadose, Methatab,[3] others
AHFS/Drugs.comMonograph
MedlinePlusa682134
License data
Pregnancy
category
  • AU: C
Addiction
liability		High[4]
Routes of
administration		By mouth, intravenous, insufflation, sublingual, rectal
Drug classOpioid
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability15–20% subcutaneous[6]

100% intravenous[6]

41–99% (by mouth)[6]
Protein binding85–90%[6]
MetabolismLiver (CYP3A4, CYP2B6 and CYP2D6-mediated)[6][8]
Onset of actionRapid[7]
Elimination half-life15 to 55 hours[8]
Duration of actionSingle dose: 4–8 h
Prolonged use:
• Withdrawal prevention: 1–2 days[7]
• Pain relief: 8–12 hours[7][9]
ExcretionUrine, faeces[8]
Identifiers
  • (RS)-6-(dimethylamino)-4,4-diphenylheptan-3-one
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.000.907 Edit this at Wikidata
Chemical and physical data
FormulaC21H27NO
Molar mass309.453 g·mol−1
3D model (JSmol)
ChiralityRacemic mixture
  • CCC(C(C1=CC=CC=C1)(C2=CC=CC=C2)CC(N(C)C)C)=O
  • InChI=1S/C21H27NO/c1-5-20(23)21(16-17(2)22(3)4,18-12-8-6-9-13-18)19-14-10-7-11-15-19/h6-15,17H,5,16H2,1-4H3 checkY
  • Key:USSIQXCVUWKGNF-UHFFFAOYSA-N checkY
 ☒NcheckY (what is this?)  (verify)

Methadone, sold under the brand names Dolophine and Methadose among others, is a synthetic opioid used medically to treat chronic pain and opioid use disorder.[7] Prescribed for daily use, the medicine relieves cravings and opioid withdrawal symptoms.[10] Withdrawal management using methadone can be accomplished in less than a month,[11] or it may be done gradually over a longer period of time, or simply maintained for the rest of the patient's life.[7] While a single dose has a rapid effect, maximum effect can take up to five days of use.[7][12] After long-term use, in people with normal liver function, effects last 8 to 36 hours.[7][9] Methadone is usually taken by mouth and rarely by injection into a muscle or vein.[7]

Side effects are similar to those of other opioids.[7] These frequently include dizziness, sleepiness, nausea, vomiting, and sweating.[7][13] Serious risks include opioid abuse and respiratory depression.[7] Abnormal heart rhythms may also occur due to a prolonged QT interval.[7] The number of deaths in the United States involving methadone poisoning declined from 4,418 in 2011[14] to 3,300 in 2015.[15] Risks are greater with higher doses.[16] Methadone is made by chemical synthesis and acts on opioid receptors.[7]

Methadone was developed in Germany in the late 1930s by Gustav Ehrhart and Max Bockmühl.[17][18] It was approved for use as an analgesic in the United States in 1947, and has been used in the treatment of addiction since the 1960s.[7][19] It is on the World Health Organization's List of Essential Medicines.[20]

  1. ^ "CSD Entry METHAD01: (6R)-Dimethylamino-4,4-diphenyl-3-heptanone, L-Methadone". Cambridge Structural Database: Access Structures. Cambridge Crystallographic Data Centre. Retrieved 22 November 2020.
  2. ^ Bye E (1974). "Crystal Structures of Synthetic Analgetics. II. l-Methadone". Acta Chem. Scand. 28b: 5–12. doi:10.3891/acta.chem.scand.28b-0005.
  3. ^ https://www.medsafe.govt.nz/consumers/cmi/m/Methatabs.pdf [bare URL PDF]
  4. ^ Bonewit-West K, Hunt SA, Applegate E (2012). Today's Medical Assistant: Clinical and Administrative Procedures. Elsevier Health Sciences. p. 571. ISBN 9781455701506.
  5. ^ "FDA-sourced list of all drugs with black box warnings (Use Download Full Results and View Query links.)". nctr-crs.fda.gov. FDA. Retrieved 22 October 2023.
  6. ^ a b c d e Fredheim OM, Moksnes K, Borchgrevink PC, Kaasa S, Dale O (August 2008). "Clinical pharmacology of methadone for pain". Acta Anaesthesiologica Scandinavica. 52 (7): 879–889. doi:10.1111/j.1399-6576.2008.01597.x. PMID 18331375. S2CID 25626479.
  7. ^ a b c d e f g h i j k l m n "Methadone Hydrochloride". The American Society of Health-System Pharmacists. Archived from the original on 23 December 2015. Retrieved 22 December 2015.
  8. ^ a b c Brown R, Kraus C, Fleming M, Reddy S (November 2004). "Methadone: applied pharmacology and use as adjunctive treatment in chronic pain" (PDF). Postgraduate Medical Journal. 80 (949): 654–659. doi:10.1136/pgmj.2004.022988. PMC 1743125. PMID 15537850. Archived (PDF) from the original on 2 May 2014.
  9. ^ a b Toombs JD, Kral LA (April 2005). "Methadone treatment for pain states". American Family Physician. 71 (7): 1353–1358. PMID 15832538. Archived from the original on 5 September 2017.
  10. ^ Cite error: The named reference JosephStancliffLangrod was invoked but never defined (see the help page).
  11. ^ World Health Organization (2009). Clinical Guidelines for Withdrawal Management and Treatment of Drug Dependence in Closed Settings. Geneva: World Health Organization.
  12. ^ Grissinger M (August 2011). "Keeping patients safe from methadone overdoses". P & T. 36 (8): 462–466. PMC 3171821. PMID 21935293.
  13. ^ "Methadone". The Substance Abuse and Mental Health Services Administration. 16 June 2015. Retrieved 14 October 2020.
  14. ^ "Data table for Figure 1. Age-adjusted drug-poisoning and opioid-analgesic poisoning death rates: United States, 1999–2011" (PDF). CDC. Archived (PDF) from the original on 23 November 2015. Retrieved 22 December 2015.
  15. ^ Rudd RA, Seth P, David F, Scholl L (December 2016). "Increases in Drug and Opioid-Involved Overdose Deaths - United States, 2010-2015". MMWR. Morbidity and Mortality Weekly Report. 65 (50–51): 1445–1452. doi:10.15585/mmwr.mm655051e1. PMID 28033313.
  16. ^ Chou R, Turner JA, Devine EB, Hansen RN, Sullivan SD, Blazina I, et al. (February 2015). "The effectiveness and risks of long-term opioid therapy for chronic pain: a systematic review for a National Institutes of Health Pathways to Prevention Workshop". Annals of Internal Medicine. 162 (4): 276–286. doi:10.7326/M14-2559. PMID 25581257. S2CID 207538295.
  17. ^ Methadone Matters: Evolving Community Methadone Treatment of Opiate Addiction. CRC Press. 2003. p. 13. ISBN 9780203633090. Archived from the original on 23 December 2015.
  18. ^ Kleiman MA, Hawdon JE (2011). "Diphenypropylamine Derivatives". Encyclopedia of Drug Policy. SAGE Publications. ISBN 9781506338248. Archived from the original on 23 December 2015.
  19. ^ Kuehn, B. M. (2005). Methadone Treatment Marks 40 Years. JAMA: The Journal of the American Medical Association, 294(8), 887–889. doi:10.1001/jama.294.8.887
  20. ^ World Health Organization (2021). World Health Organization model list of essential medicines: 22nd list (2021). Geneva: World Health Organization. hdl:10665/345533. WHO/MHP/HPS/EML/2021.02.