Methohexital

Last updated

Methohexital
Methohexital.svg
Methohexital-from-xtal-3D-bs-17.png
Clinical data
Trade names Brevital Sodium
Other namesMethohexitone
AHFS/Drugs.com Consumer Drug Information
License data
Routes of
administration 		Intravenous, rectal
Drug class Barbiturate
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability I.V. ~100%
Rectal ~17%
Metabolism Liver
Elimination half-life 5.6 ± 2.7 minutes
Excretion excreted in feces
Identifiers
  • 5-Hex-3-yn-2-yl-1-methyl-5-prop-2-enyl-1,3-diazinane-2,4,6-trione
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard 100.005.272 OOjs UI icon edit-ltr-progressive.svg
Chemical and physical data
Formula C14H18N2O3
Molar mass 262.309 g·mol−1
3D model (JSmol)
  • O=C1N(C(=O)NC(=O)C1(C\C=C)C(C#CCC)C)C
  • InChI=1S/C14H18N2O3/c1-5-7-8-10(3)14(9-6-2)11(17)15-13(19)16(4)12(14)18/h6,10H,2,5,9H2,1,3-4H3,(H,15,17,19) Yes check.svgY
  • Key:NZXKDOXHBHYTKP-UHFFFAOYSA-N Yes check.svgY
   (verify)

Methohexital or methohexitone (marketed under the brand names Brevital and Brietal) is a drug which is a barbiturate derivative. It is classified as short-acting, and has a rapid onset of action. [2] It is similar in its effects to sodium thiopental, a drug with which it competed in the market for anesthetics.

Contents

Pharmacology

Methohexital binds to a distinct site which is associated with Cl− ionophores at GABAA receptors. [3] This increases the length of time which the Cl− ionopores are open, thus causing an inhibitory effect.

Metabolism of methohexital is primarily hepatic via demethylation and oxidation. [1] Side-chain oxidation is the primary means of metabolism involved in the termination of the drug's biological activity.

Indications

Methohexital is primarily used to induce anesthesia, and is generally provided as a sodium salt (i.e. methohexital sodium). It is only used in hospital or similar settings, under strict supervision. [1] It has been commonly used to induce deep sedation or general anesthesia for surgery and dental procedures. Unlike many other barbiturates, methohexital actually lowers the seizure threshold, a property that makes it particularly useful when anesthesia is provided for an electroconvulsive therapy (ECT). [4] Its rapid recovery rate with consciousness being gained within three to seven minutes after induction and full recovery within 30 minutes is a major advantage over other ECT barbiturates. [4]

Synthesis

Methohexital can be synthesized in the classic manner of making barbituric acid derivatives, in particular by the reaction of malonic ester derivatives with derivatives of urea. [5] The resulting allyl-(1-methyl-2-pentynyl) malonic ester is synthesized by subsequent alkylation of the malonic ester itself, beginning with 2-bromo-3-hexyne, which gives (1-methyl-2-pentynyl)malonic ester, and then by allylbromide. In the final step, reaction of the disubstituted malonic ester with N-methylurea gives methohexital.

Methohexital synthesis Methohexital synthesis.png
Methohexital synthesis

References

  1. 1 2 3 "Brevital Sodium". DailyMed. July 24, 2019. Retrieved November 20, 2019.
  2. ↑ "Methohexital". MeSH.
  3. ↑ Katzung BG. Basic and Clinical Pharmacology (10th ed.). pp. 406–407.
  4. 1 2 Schulgasser H, Borowitz AH (August 1963). "Methohexital anaesthesia in electroconvulsive therapy". South African Medical Journal. 37: 870–1. PMID   14045806.
  5. ↑ US 2872448,Doran WJ,"1,5,5-Trisubstituted barbituric acids",issued February 3, 1959, assigned to Eli Lily and Company ( U.S. patent 2,872,448 )
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.