Isoflurane: Difference between revisions

Isoflurane
	File:Isoflurane2.png
	File:Isoflurane-3D-vdW.png
Clinical data
ATC code	N01AB06 (WHO) ;
Identifiers
	IUPAC name 2-chloro-2-(difluoromethoxy)-1,1,1-trifluoro-ethane;
CAS Number	26675-46-7;
PubChem CID	3763;
DrugBank	APRD00212;
E number	{{#property:P628}}
ECHA InfoCard	{{#property:P2566}}Lua error in Module:EditAtWikidata at line 36: attempt to index field 'wikibase' (a nil value).
Chemical and physical data
Formula	C3H2ClF5O
Molar mass	184.5 g/mol

VisualWikitext

Revision as of 03:02, 11 June 2014

Isoflurane (2-chloro-2-(difluoromethoxy)-1,1,1-trifluoro-ethane) is a halogenated ether used for inhalational anesthesia. Together with enflurane and halothane, it replaced the flammable ethers used in the pioneer days of surgery. Its use in human medicine is now starting to decline, being replaced with sevoflurane, desflurane and the intravenous anaesthetic propofol. Isoflurane is still frequently used for veterinary anaesthesia.

Isoflurane is always administered in conjunction with air and/or pure oxygen. Often nitrous oxide is also used. Although its physical properties means that anaesthesia can be induced more rapidly than with halothane, its pungency can irritate the respiratory system, negating this theoretical advantage conferred by its physical properties. It is usually used to maintain a state of general anesthesia that has been induced with another drug, such as thiopentone or propofol. It vaporizes readily, but is a liquid at room temperature. It is completely non-flammable.

A major advantage of isoflurane is that the patent covering its use has expired, therefore it is very economical to use.

Physical properties

Molecular weight	184.5g/mol
Boiling point (at 1 atm):	48.5 °C
Density (at 25 °C):	1.496 g/mL
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)
Water Solubility	Insoluble
Blood:Gas Partition coefficient:	1.4
Oil:Gas Partition coefficient:	98

Mechanism of action

Isoflurane reduces pain sensitivity (analgesia) and relaxes muscles. The mechanism by which general anesthetics produce the anesthetic state is not clearly understood but likely involves interactions with multiple receptor sites to interfere with synaptic transmission. Isoflurane binds to GABA receptors, glutamate receptors and glycine receptors, and also inhibits conduction in activated potassium channels. Glycine inhibition helps to inhibit motor function, while bonding to glutamate receptors mimics the efects of NDMA. It activates calcium ATPase through an increase in membrane fluidity, and binds to the D subunit of ATP synthase and NADH dehydrogenase. In addition, a number of general anesthetics attenuate gap junction commmunication, which could contribute to anesthetic action.

Possible link to cognitive decline

Isoflurane exposure has been shown to induce cognitive decline in mice.^[1] Exposure of cultured human cells to isoflurane has been reported to induce apoptosis and accumulation and aggregation of amyloid beta protein.^[2] Further research will be required to establish whether or not clinical exposure to isoflurane leads to dementia (Alzheimer's disease).^[3]^[4]

References

↑ S. L. Bianchi, T. Tran, C. Liu, S. Lin, Y. Li, J. M. Keller, R. G. Eckenhoff, M. F. Eckenhoff (2007). "Brain and behavior changes in 12-month-old Tg2576 and nontransgenic mice exposed to anesthetics". Neurobiology of Aging. 28 (in press): in press. doi:10.1016/j.neurobiolaging.2007.02.009.
↑ Z. Xie, Y. Dong, U. Maeda, R. D. Moir, W. Xia, D. J. Culley, G. Crosby, R. E. Tanzi (2007). "The Inhalation Anesthetic Isoflurane Induces a Vicious Cycle of Apoptosis and Amyloid β-Protein Accumulation". Journal of Neuroscience. 27 (6): 1247–1254. doi:10.1523/JNEUROSCI.5320-06.2007.
↑ M. C. Lewis, I. Nevoa, M. A. Paniaguaa, A. Ben-Aric, E. Prettoa, S. Eisdorfera, E. Davidsona, I. Matotc, C. Eisdorfer (2007). "Uncomplicated general anesthesia in the elderly results in cognitive decline: Does cognitive decline predict morbidity and mortality?". Medical Hypotheses. 68 (3): 484–492. doi:10.1016/j.mehy.2006.08.030.
↑ Reinberg, Steven (15 January 2007). "Anesthetic Linked to Alzheimer's Risk". HealthDay News. Retrieved 2007-08-08.

External links

Rx Med

Template:General anesthetics

de:Isofluran it:Isoflurano nl:Isofluraan Template:WikiDoc Sources

[1] S. L. Bianchi, T. Tran, C. Liu, S. Lin, Y. Li, J. M. Keller, R. G. Eckenhoff, M. F. Eckenhoff (2007). "Brain and behavior changes in 12-month-old Tg2576 and nontransgenic mice exposed to anesthetics". Neurobiology of Aging. 28 (in press): in press. doi:10.1016/j.neurobiolaging.2007.02.009.

[2] Z. Xie, Y. Dong, U. Maeda, R. D. Moir, W. Xia, D. J. Culley, G. Crosby, R. E. Tanzi (2007). "The Inhalation Anesthetic Isoflurane Induces a Vicious Cycle of Apoptosis and Amyloid β-Protein Accumulation". Journal of Neuroscience. 27 (6): 1247–1254. doi:10.1523/JNEUROSCI.5320-06.2007.

[3] M. C. Lewis, I. Nevoa, M. A. Paniaguaa, A. Ben-Aric, E. Prettoa, S. Eisdorfera, E. Davidsona, I. Matotc, C. Eisdorfer (2007). "Uncomplicated general anesthesia in the elderly results in cognitive decline: Does cognitive decline predict morbidity and mortality?". Medical Hypotheses. 68 (3): 484–492. doi:10.1016/j.mehy.2006.08.030.

[4] Reinberg, Steven (15 January 2007). "Anesthetic Linked to Alzheimer's Risk". HealthDay News. Retrieved 2007-08-08.

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