Pentazocine

Pentazocine
Clinical data
AHFS/Drugs.comMonograph (hydrochloride)
Monograph (lactate)
Pregnancy
category
  • AU: C
Routes of
administration		Oral, IV, IM
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability~20% orally
MetabolismHepatic
Onset of action15 min[2]
Elimination half-life2 to 3 hours
ExcretionRenal
Identifiers
  • (2RS,6RS,11RS)-6,11-dimethyl-3-(3-methylbut-2-en-1-yl)-1,2,3,4,5,6-hexahydro-2,6-methano-3-benzazocin-8-ol
    or
    2-dimethylallyl-5,9-dimethyl-2'-hydroxybenzomorphan
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.006.032 Edit this at Wikidata
Chemical and physical data
FormulaC19H27NO
Molar mass285.431 g·mol−1
3D model (JSmol)
  • Oc1ccc3c(c1)[C@]2([C@H]([C@H](N(CC2)C\C=C(/C)C)C3)C)C
  • InChI=1S/C19H27NO/c1-13(2)7-9-20-10-8-19(4)14(3)18(20)11-15-5-6-16(21)12-17(15)19/h5-7,12,14,18,21H,8-11H2,1-4H3/t14-,18+,19+/m0/s1 checkY
  • Key:VOKSWYLNZZRQPF-GDIGMMSISA-N checkY
  (verify)

Pentazocine,[3] sold under the brand name Talwin among others, is a painkiller used to treat moderate to severe pain. It is believed to work by activating (agonizing) κ-opioid receptors (KOR) and μ-opioid receptors (MOR). As such it is called an opioid as it delivers its effects on pain by interacting with the opioid receptors. It shares many of the side effects of other opioids like constipation, nausea, itching, drowsiness and respiratory depression, but unlike most other opioids it fairly frequently causes hallucinations, nightmares and delusions. It is also, unlike most other opioids, subject to a ceiling effect, which is when at a certain dose (which differs from person to person) no more pain relief is obtained by increasing the dose any further.[4]

Chemically it is classed as a benzomorphan and it comes in two enantiomers, which are molecules that are exact (non-superimposable) mirror images of one another.

It was patented in 1960 and approved for medical use in 1964.[5] Usually, in its oral formulations, it is combined with naloxone so as to prevent people from crushing the tablets, dissolving them in a solvent (like water) and injecting them for a high (as orally administered naloxone produces no opioid-negating effects, whereas intravenous or intramuscular administration does).[4]

  1. ^ Anvisa (2023-03-31). "RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial" [Collegiate Board Resolution No. 784 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control] (in Brazilian Portuguese). Diário Oficial da União (published 2023-04-04). Archived from the original on 2023-08-03. Retrieved 2023-08-16.
  2. ^ Stitzel RE (2004). Modern pharmacology with clinical applications (6th ed.). Philadelphia: Lippincott Williams & Wilkins. p. 325. ISBN 9780781737623.
  3. ^ US Patent 4105659 Analgesia producing benzazocines
  4. ^ a b Cite error: The named reference mart was invoked but never defined (see the help page).
  5. ^ Fischer J, Ganellin CR (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 527. ISBN 9783527607495.