Sevoflurane

Sevoflurane

Clinical data
Trade names	Sojourn, Ultane, Sevorane, others
AHFS/Drugs.com	Consumer Drug Information
Pregnancy category	AU: B2
Routes of administration	Inhaled
ATC code	N01AB08 (WHO) QN01AB08 (WHO)
Legal status
Legal status	AU: S4 (Prescription only) UK: POM (Prescription only) EU: Rx-only
Pharmacokinetic data
Metabolism	Liver by CYP2E1
Metabolites	Hexafluoroisopropanol
Elimination half-life	15–23 hours
Excretion	Kidney
Identifiers
IUPAC name 1,1,1,3,3,3-Hexafluoro-2-(fluoromethoxy)propane
CAS Number	28523-86-6 Y
PubChem CID	5206
IUPHAR/BPS	7296
DrugBank	DB01236 Y
ChemSpider	5017 Y
UNII	38LVP0K73A
KEGG	D00547 Y
ChEBI	CHEBI:9130 Y
ChEMBL	ChEMBL1200694 N
CompTox Dashboard (EPA)	DTXSID8046614
ECHA InfoCard	100.171.146
Chemical and physical data
Formula	C4H3F7O
Molar mass	200.056 g·mol−1
3D model (JSmol)	Interactive image
Boiling point	58.5 °C (137.3 °F)
SMILES FC(F)(F)C(OCF)C(F)(F)F
InChI InChI=1S/C4H3F7O/c5-1-12-2(3(6,7)8)4(9,10)11/h2H,1H2 Y Key:DFEYYRMXOJXZRJ-UHFFFAOYSA-N Y
NY (what is this?)  (verify)

Sevoflurane, sold under the brand name Sevorane, among others, is a sweet-smelling, nonflammable, highly fluorinated methyl isopropyl ether used as an inhalational anaesthetic for induction and maintenance of general anesthesia. After desflurane, it is the volatile anesthetic with the fastest onset. While its offset may be faster than agents other than desflurane in a few circumstances, its offset is more often similar to that of the much older agent isoflurane. While sevoflurane is only half as soluble as isoflurane in blood, the tissue blood partition coefficients of isoflurane and sevoflurane are quite similar. For example, in the muscle group: isoflurane 2.62 vs. sevoflurane 2.57. In the fat group: isoflurane 52 vs. sevoflurane 50. As a result, the longer the case, the more similar will be the emergence times for sevoflurane and isoflurane.

Medical uses

It is one of the most commonly used volatile anesthetic agents, particularly for outpatient anesthesia, across all ages, as well as in veterinary medicine. Together with desflurane, sevoflurane is replacing isoflurane and halothane in modern anesthesia practice. It is often administered in a mixture of nitrous oxide and oxygen.

Physiologic effects

Sevoflurane is a potent vasodilator, as such it induces a dose dependent reduction in blood pressure and cardiac output. It is a bronchodilator, however, in patients with pre-existing lung pathology it may precipitate coughing and laryngospasm. It reduces the ventilatory response to hypoxia and hypercapnia and impedes hypoxic pulmonary vasoconstriction. Sevoflurane vasodilatory properties also cause it to increase intracranial pressure and cerebral blood flow. However, it reduces cerebral metabolic rate.

Adverse Effects

Sevoflurane has an excellent safety record, but is under review for potential hepatotoxicity, and may accelerate Alzheimer's. There were rare reports involving adults with symptoms similar to halothane hepatotoxicity. Sevoflurane is the preferred agent for mask induction due to its lesser irritation to mucous membranes.

Sevoflurane was discovered by Ross Terrell and independently by Bernard M Regan. A detailed report of its development and properties appeared in 1975 in a paper authored by Richard Wallin, Bernard Regan, Martha Napoli and Ivan Stern. It was introduced into clinical practice initially in Japan in 1990 by Maruishi Pharmaceutical Co., Ltd. Osaka, Japan. The rights for sevoflurane worldwide were held by AbbVie. It is now available as a generic drug.

Sevoflurane is an inhaled anaesthetic that is often used to induction and maintenance of anaesthesia in children for surgery. During the process of awakening from the medication, it has been associated with a high incidence (>30%) of agitation and delirium in preschool children undergoing minor noninvasive surgery. It is not clear if this can be prevented.

Adverse effects

Studies examining a current significant health concern, anesthetic-induced neurotoxicity (including with sevoflurane, and especially with children and infants) are "fraught with confounders, and many are underpowered statistically", and so are argued to need "further data... to either support or refute the potential connection".

Concern regarding the safety of anaesthesia is especially acute with regard to children and infants, where preclinical evidence from relevant animal models suggest that common clinically important agents, including sevoflurane, may be neurotoxic to the developing brain, and so cause neurobehavioural abnormalities in the long term; two large-scale clinical studies (PANDA and GAS) were ongoing as of 2010, in hope of supplying "significant [further] information" on neurodevelopmental effects of general anaesthesia in infants and young children, including where sevoflurane is used.

In 2021, researchers at Massachusetts General Hospital published in Communications Biology research that sevoflurane may accelerate existing Alzheimer's or existing tau protein to spread: "These data demonstrate anesthesia-associated tau spreading and its consequences. [...] This tau spreading could be prevented by inhibitors of tau phosphorylation or extracellular vesicle generation." According to Neuroscience News, "Their previous work showed that sevoflurane can cause a change (specifically, phosphorylation, or the addition of phosphate) to tau that leads to cognitive impairment in mice. Other researchers have also found that sevoflurane and certain other anesthetics may affect cognitive function."

Pharmacology

The exact mechanism of the action of general anaesthetics has not been delineated. Sevoflurane acts as a positive allosteric modulator of the GABA_A receptor in electrophysiology studies of neurons and recombinant receptors. However, it also acts as an NMDA receptor antagonist, potentiates glycine receptor currents, and inhibits nAChR and 5-HT₃ receptor currents.

Global-warming potential

Sevoflurane is a greenhouse gas. The twenty-year global-warming potential, GWP(20), for sevoflurane is 349.

Further reading

External links

• "Propofol and Sevoflurane Anesthesia".