Enflurane

Source: Wikipedia, the free encyclopedia.
Enflurane
Clinical data
AHFS/Drugs.comMicromedex Detailed Consumer Information
ATC code
Legal status
Legal status
Pharmacokinetic data
Protein binding97%
Identifiers
  • (RS)-2-chloro-1-(difluoromethoxy)-1,1,2-trifluoroethane
JSmol)
  • FC(Cl)C(F)(F)OC(F)F
  • InChI=1S/C3H2ClF5O/c4-1(5)3(8,9)10-2(6)7/h1-2H checkY
  • Key:JPGQOUSTVILISH-UHFFFAOYSA-N checkY
  (verify)

Enflurane (2-chloro-1,1,2-trifluoroethyl difluoromethyl ether) is a halogenated ether. Developed by Ross Terrell in 1963, it was first used clinically in 1966. It was increasingly used for inhalational anesthesia during the 1970s and 1980s[2] but is no longer in common use.[3]

Enflurane is a structural isomer of isoflurane. It vaporizes readily, but is a liquid at room temperature.

Physical properties

Property Value
atm
 56.5 °C
MAC 1.68
Vapor pressure at 20 °C 22.9 kPa (172 mm Hg)
Blood:gas partition coefficient
 1.9
Oil:gas partition coefficient 98

Pharmacology

The exact mechanism of the action of general anaesthetics

negative allosteric modulator of the AMPA, kainate, and NMDA receptors,[10][11][12] as well as of nicotinic acetylcholine receptors.[9]

Side effects

Clinically, enflurane produces a dose-related depression of

myocardial contractility with an associated decrease in myocardial oxygen consumption. Between 2% and 5% of the inhaled dose is oxidised in the liver, producing fluoride ions and difluoromethoxy-difluoroacetic acid. This is significantly higher than the metabolism of its structural isomer isoflurane
.

Enflurane also lowers the threshold for

seizures, and should especially not be used on people with epilepsy.[13] Like all potent inhalation anaesthetic agents it is a known trigger of malignant hyperthermia
.

Like the other potent inhalation agents it relaxes the uterus in pregnant women which is associated with more blood loss at delivery or other procedures on the gravid uterus.

The obsolete (as an anaesthetic) agent methoxyflurane had a nephrotoxic effect and caused acute kidney injury, usually attributed to the liberation of fluoride ions from its metabolism. Enflurane is similarly metabolised but the liberation of fluoride results in a lower plasma level and enflurane related kidney failure seemed unusual if seen at all.[14]

Occupational safety

The U.S.

respiratory depression.[15]

References

  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. ISBN 978-0-7817-5126-1
    .
  3. ISBN 9781437716795
    .
  4. ^ Perkins B (7 February 2005). "How does anesthesia work?". Scientific American.
  5. PMID 1667416
    .
  6. PMID 1326046
    .
  7. PMID 10683198
    .
  8. PMID 1331405
    .
  9. ^
    ISBN 978-1-58811-124-1
    .
  10. ^
    ISBN 978-1-4377-2792-0
    .
  11. ISBN 978-1-4698-3027-8
    .
  12. S2CID 1050582
    .
  13. doi:10.15363/thinklab.d224. Archived from the original
    on October 18, 2016. Retrieved October 17, 2016.
  14. ^ Morgan GE, Mikhail MS, Murray MJ, Larson CP (September 2006). Clinical Anesthesiology (3rd ed.). New York: Lange Medical Books/McGraw-Hill. p. 142.
  15. ^ "CDC - NIOSH Pocket Guide to Chemical Hazards - Enflurane". www.cdc.gov. Retrieved 2015-10-01.