Isoflurane

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Isoflurane
Clinical data
Trade namesForane, others
AHFS/Drugs.comFDA Professional Drug Information
License data
Pregnancy
category
Routes of
administration
Inhalation
ATC code
Legal status
Legal status
Identifiers
  • (RS)-2-Chloro-2-(difluoromethoxy)-1,1,1-trifluoro-ethane
    OR
    (RS)-1-chloro-2,2,2-trifluoroethyl difluoromethyl ether
JSmol)
  • FC(F)(F)C(Cl)OC(F)F
  • InChI=1S/C3H2ClF5O/c4-1(3(7,8)9)10-2(5)6/h1-2H checkY
  • Key:PIWKPBJCKXDKJR-UHFFFAOYSA-N checkY
 ☒NcheckY (what is this?)  (verify)

Isoflurane, sold under the brand name Forane among others, is a

general anesthetic.[4] It can be used to start or maintain anesthesia; however, other medications are often used to start anesthesia, due to airway irritation with isoflurane.[3][5] Isoflurane is given via inhalation.[4]

Side effects of isoflurane include a

cesarean section appears to be safe.[3][4] Isoflurane is a halogenated ether.[6]

Isoflurane was approved for medical use in the United States in 1979.[4][7] It is on the World Health Organization's List of Essential Medicines.[8][9]

Medical uses

Isoflurane is always administered in conjunction with

thiopentone or propofol.[11][12][13]

Mechanism of action

Similar to many general anesthetics, the exact mechanism of the action

plasma membrane calcium ATPases (PMCAs) which affects membrane fluidity by hindering the flow of Ca2+ (calcium ions) out across the membrane, this in turn affects neuron depolarization.[21][22] It binds to the D subunit of ATP synthase and NADH dehydrogenase
.

General anaesthesia with isoflurane reduces plasma endocannabinoid AEA concentrations, and this could be a consequence of stress reduction after loss of consciousness.[23]

Adverse effects

Isoflurane can cause a sudden decrease in blood pressure due to dose-dependent peripheral vasodilation. This may be specially marked in hypovolemic patients.[13]

Animal studies have raised safety concerns of certain general anesthetics, in particular

benzodiazepines such as midazolam.[24] Whether these concerns occur in humans is unclear.[24]

Elderly

Biophysical studies using

NMR spectroscopy has provided molecular details of how inhaled anesthetics interact with three amino acid residues (G29, A30 and I31) of amyloid beta peptide and induce aggregation.[25] This area is important as "some of the commonly used inhaled anesthetics may cause brain damage that accelerates the onset of Alzheimer's disease".[26]

Physical properties

Molecular weight
184.5g/mol[27]
atm
):
48.5 °C[27]
Density (at 25 °C): 1.496 g/mL[27]
MAC : 1.15 vol %
Vapor pressure: 238 mmHg 31.7 kPa (at 20 °C)
295 mmHg 39.3 kPa (at 25 °C)
367 mmHg 48.9 kPa (at 30 °C)
450 mmHg 60.0 kPa (at 35 °C)[27]
Water solubility 13.5 mM (at 25 °C)[28]
Blood:gas partition coefficient
:
1.4
Oil:gas partition coefficient: 98

It is administered as a racemic mixture of (R)- and (S)-optical isomers.[29] Isoflurane has a boiling point of 48.5 - 49 °C (119 - 120 °F).[27] It is non-combustible but can give off irritable and toxic fumes when exposed to flame.[27]

History

Together with enflurane and halothane, Isoflurane began to replace the flammable ethers used in the pioneer days of surgery; this shift began in the 1940s to the 1950s.[30] Its name comes from being a structural isomer of enflurane, hence they have the same empirical formula.[31]

Environment

The average lifetime of isoflurane in the atmosphere is 3.2 years, its global warming potential is 510 and the yearly emissions add up to 880 tons.[32]

Veterinary use

Isoflurane is frequently used for

veterinary anaesthesia.[33][34]

References

  1. ^ "Isoflurane Use During Pregnancy". Drugs.com. 2 September 2020. Retrieved 9 September 2020.
  2. ^ 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.
  3. ^ a b c d e "Isoflurane 100% Inhalation Vapour, Liquid - Summary of Product Characteristics (SmPC)". (emc). 29 October 2019. Retrieved 9 September 2020.
  4. ^ a b c d e f "Forane- isoflurane inhalant". DailyMed. Retrieved 11 February 2022.
  5. from the original on 2016-12-20.
  6. from the original on 2016-12-20.
  7. ^ "Forane: FDA-Approved Drugs". U.S. Food and Drug Administration (FDA). Retrieved 11 February 2022.
  8. . WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
  9. . WHO/MHP/HPS/EML/2021.02.
  10. from the original on 2016-05-09.
  11. .
  12. .
  13. ^ .
  14. ^ "How does anesthesia work?". Scientific American. February 7, 2005. Archived from the original on May 29, 2016.
  15. PMID 1326046
    .
  16. .
  17. .
  18. .
  19. .
  20. .
  21. .
  22. ^ "Protein kinases A and C phosphorylate..." www.diagnosticpathology.eu. Retrieved 2022-04-07.
  23. PMID 20525978
    .
  24. ^ from the original on 2009-03-09.
  25. .
  26. .
  27. ^ a b c d e f "Isoflurane". PubChem. U.S. National Library of Medicine. Retrieved 2022-04-07.
  28. PMID 1391078
    .
  29. .
  30. .
  31. .
  32. .
  33. .
  34. ^ "Isoflurane-Vet 100% w/w Inhalation vapour, liquid". www.noahcompendium.co.uk. Retrieved 2022-04-07.

External links