Carfentanil

Carfentanil

Systematic (IUPAC) name
4-((1-oxopropyl)-phenylamino)-1-(2-phenylethyl)-4-piperidinecarboxylic acid methyl ester
Clinical data
Legal status	AU: S8 (Controlled) DE: Anlage I (Controlled) UK: Class A US: Schedule II ℞ (Prescription only)
Routes of administration	Oral
Pharmacokinetic data
Biological half-life	7.7 hrs
Identifiers
CAS Number	59708-52-0 Y
ATC code	none
PubChem	CID: 62156
DrugBank	DB01535 Y
ChemSpider	55986 Y
UNII	LA9DTA2L8F Y
ChEBI	CHEBI:61084 Y
ChEMBL	CHEMBL290429 Y
Chemical data
Formula	C24H30N2O3
Molecular mass	394.514 g/mol
SMILES O=C(C1(CCN(CC1)CCC2=CC=CC=C2)N(C(CC)=O)C3=CC=CC=C3)OC
InChI InChI=1S/C24H30N2O3/c1-3-22(27)26(21-12-8-5-9-13-21)24(23(28)29-2)15-18-25(19-16-24)17-14-20-10-6-4-7-11-20/h4-13H,3,14-19H2,1-2H3 Y Key:YDSDEBIZUNNPOB-UHFFFAOYSA-N Y
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Carfentanil or carfentanyl (Wildnil) is an analogue of the popular synthetic opioid analgesic fentanyl, and is one of the most potent opioids known (also the most potent opioid used commercially). Carfentanil was first synthesized in 1974 by a team of chemists at Janssen Pharmaceutica which included Paul Janssen. It has a quantitative potency approximately 10,000 times that of morphine and 100 times that of fentanyl, with activity in humans starting at about 1 microgram. It is marketed under the trade name Wildnil as a general anaesthetic agent for large animals. Carfentanil is intended for large-animal use only as its extreme potency makes it inappropriate for use in humans. Currently sufentanil, approximately 10–20 times less potent (500 to 1000 times the efficacy of morphine per weight) than carfentanil, is the maximum strength fentanyl analog for use in humans.

Side effects of fentanyl analogs are similar to those of fentanyl itself, which include itching, nausea and potentially serious respiratory depression, which can be life-threatening. Fentanyl analogs have killed hundreds of people throughout Europe and the former Soviet republics since the most recent resurgence in use began in Estonia in the early 2000s, and novel derivatives continue to appear.

Carfentanil is a Schedule II Narcotic controlled substance in the United States with a DEA ACSCN of 9743 and a 2013 annual aggregate manufacturing quota of 6 grams, unchanged from the prior year.

Moscow theater hostage crisis

Main article: Moscow theater hostage crisis

Recently, a new study found evidence supporting the claim that during the 2002 Moscow theater hostage crisis, the Russian military made use of an aerosol form of carfentanil and another similar drug, remifentanil, to subdue Chechen hostage takers. Its short action, easy reversibility and therapeutic index (10,600 vs. 300 for fentanyl) would make it a potential agent for this purpose. Riches, et al., found evidence from liquid chromatography-tandem mass spectrometry analysis of extracts of clothing from two British survivors, and urine from a third survivor, that the aerosol comprised a mixture of the two anaesthetics, the exact proportions of which the study was unable to verify. Previously, Wax et al. had surmised from the available evidence that the Moscow emergency services had not been informed of the use of the agent, but were instructed to bring opioid antagonists. Because of the lack of information provided, the emergency workers did not bring adequate supplies of naloxone (opioid inverse agonist) or naltrexone (opioid antagonist) to prevent complications in many of the victims and there were subsequently over 125 confirmed deaths from both respiratory failure and aerosol inhalation during the incident. Assuming that carfentanil and remifentanil were the only active constituents (which has not been verified by the Russian military), the primary acute toxic effect to the theatre victims would have been opioid-induced apnea; in this case mechanical ventilation and/or treatment with opioid antagonists would have been life-saving for many or all victims.

See also

• 4-Phenylfentanyl
• N-Methylcarfentanil
• Sufentanil
• Opioid comparison
• R-30490
• 1-(4-Nitrophenylethyl)piperidylidene-2-(4-chlorophenyl)sulfonamide