ContaminantDB: Methohexital

Identification Taxonomy Biological Properties Physical Properties Toxicity Profile Spectra Concentrations Links References Targets (1)XML

Record Information

Version

1.0

Creation Date

2009-07-21 20:26:59 UTC

Update Date

2026-05-14 16:39:54 UTC

Accession Number

CHEM002205

Identification

Common Name

Methohexital

Class

Small Molecule

Description

Methohexital is only found in individuals that have used or taken this drug. It is an intravenous anesthetic with a short duration of action that may be used for induction of anesthesia. Methohexital binds at a distinct binding site associated with a Cl^- ionopore at the GABA_A receptor, increasing the duration of time for which the Cl^- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged.

Contaminant Sources

HMDB Contaminants - Urine
STOFF IDENT Compounds
T3DB toxins

Contaminant Type

Amide
Amine
Anesthetic
Anesthetic, Intravenous
Barbiturate
Drug
Human Neurotoxin
Metabolite
Organic Compound
Synthetic Compound

Chemical Structure

MOL SDF PDB SMILES InChI

Synonyms

Value	Source
(+-)-5-Allyl-1-methyl-5-(1-methyl-2-pentynyl)barbituric acid	ChEBI
5-Allyl-1-methyl-5-(1-methyl-2-pentynyl)-2,4,6(1H,3H,5H)-pyrimidinetrione	ChEBI
5-Allyl-1-methyl-5-(1-methyl-pent-2-ynyl)-pyrimidine-2,4,6-trione	ChEBI
5-Allyl-5-(3-hexyn-2-yl)-1-methylbarbituric acid	ChEBI
alpha-DL-1-Methyl-5-allyl-5-(1'-methylpentyn-2-yl)barbituric acid	ChEBI
Methohexitalum	ChEBI
Methohexitone	ChEBI
Metohexital	ChEBI
(+-)-5-Allyl-1-methyl-5-(1-methyl-2-pentynyl)barbitate	Generator
(+-)-5-Allyl-1-methyl-5-(1-methyl-2-pentynyl)barbitic acid	Generator
5-Allyl-5-(3-hexyn-2-yl)-1-methylbarbitate	Generator
5-Allyl-5-(3-hexyn-2-yl)-1-methylbarbitic acid	Generator
a-DL-1-Methyl-5-allyl-5-(1'-methylpentyn-2-yl)barbitate	Generator
a-DL-1-Methyl-5-allyl-5-(1'-methylpentyn-2-yl)barbitic acid	Generator
alpha-DL-1-Methyl-5-allyl-5-(1'-methylpentyn-2-yl)barbitate	Generator
alpha-DL-1-Methyl-5-allyl-5-(1'-methylpentyn-2-yl)barbitic acid	Generator
Α-DL-1-methyl-5-allyl-5-(1'-methylpentyn-2-yl)barbitate	Generator
Α-DL-1-methyl-5-allyl-5-(1'-methylpentyn-2-yl)barbitic acid	Generator
Methodrexitone	HMDB
Brevital	MeSH, HMDB
Sodium, methohexital	MeSH, HMDB
Brietal	MeSH, HMDB
Lilly brand OF methohexital sodium	MeSH, HMDB
Methohexital sodium	MeSH, HMDB
Brietal-sodium	MeSH, HMDB
Brevimytal natrium	MeSH, HMDB
Jones brand OF methohexital sodium	MeSH, HMDB
Methohexital, monosodium salt	MeSH, HMDB
Monosodium salt methohexital	MeSH, HMDB
Natrium, brevimytal	MeSH, HMDB
Brietal sodium	MeSH, HMDB

Chemical Formula

C₁₄H₁₈N₂O₃

Average Molecular Mass

262.304 g/mol

Monoisotopic Mass

262.132 g/mol

CAS Registry Number

151-83-7

IUPAC Name

5-(hex-3-yn-2-yl)-1-methyl-5-(prop-2-en-1-yl)-1,3-diazinane-2,4,6-trione

Traditional Name

methohexital

SMILES

CCC#CC(C)C1(CC=C)C(=O)NC(=O)N(C)C1=O

InChI Identifier

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)

InChI Key

NZXKDOXHBHYTKP-UHFFFAOYSA-N

Chemical Taxonomy

Description

belongs to the class of organic compounds known as barbituric acid derivatives. Barbituric acid derivatives are compounds containing a perhydropyrimidine ring substituted at C-2, -4 and -6 by oxo groups.

Kingdom

Organic compounds

Super Class

Organoheterocyclic compounds

Class

Diazines

Sub Class

Pyrimidines and pyrimidine derivatives

Direct Parent

Barbituric acid derivatives

Alternative Parents

Substituents

Barbiturate
N-acyl urea
Ureide
1,3-diazinane
Dicarboximide
Urea
Carbonic acid derivative
Carboxylic acid derivative
Azacycle
Organic nitrogen compound
Organonitrogen compound
Organooxygen compound
Hydrocarbon derivative
Organic oxide
Organopnictogen compound
Organic oxygen compound
Carbonyl group
Aliphatic heteromonocyclic compound

Molecular Framework

Aliphatic heteromonocyclic compounds

External Descriptors

barbiturates (CHEBI:102216 )
acetylenic compound (CHEBI:102216 )

Biological Properties

Status

Detected and Not Quantified

Origin

Exogenous

Cellular Locations

Membrane

Biofluid Locations

Not Available

Tissue Locations

Not Available

Pathways

Not Available

Applications

intravenous anaesthetic

Biological Roles

Not Available

Chemical Roles

Not Available

Physical Properties

State

Solid

Appearance

White powder.

Experimental Properties

Property	Value
Melting Point	Not Available
Boiling Point	Not Available
Solubility	5.24e-02 g/L

Predicted Properties

Property	Value	Source
Water Solubility	0.052 g/L	ALOGPS
logP	2.43	ALOGPS
logP	2.29	ChemAxon
logS	-3.7	ALOGPS
pKa (Strongest Acidic)	8.73	ChemAxon
Physiological Charge	0	ChemAxon
Hydrogen Acceptor Count	3	ChemAxon
Hydrogen Donor Count	1	ChemAxon
Polar Surface Area	66.48 Å²	ChemAxon
Rotatable Bond Count	5	ChemAxon
Refractivity	71.51 m³·mol⁻¹	ChemAxon
Polarizability	27.4 Å³	ChemAxon
Number of Rings	1	ChemAxon
Bioavailability	1	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	Yes	ChemAxon
Veber's Rule	No	ChemAxon
MDDR-like Rule	No	ChemAxon

Spectra

Spectrum Type	Description	Splash Key	View
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	splash10-001j-4390000000-8c577a429e1b4575b629	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 35V, Positive	splash10-00ya-3900000000-577a972e968dc27cf6a6	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-03di-2090000000-43730b3bde391b731ebe	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-00dl-3970000000-fc9a91490da8afc576f0	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-0f9x-9000000000-93587b41eae6b9864e81	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Negative	splash10-001i-2920000000-ad50a444d0a4a9a5af2c	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Negative	splash10-0a4l-4910000000-c5dc261173ac7024e26f	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Negative	splash10-0006-9200000000-7cedeac5d5e1a5954aa4	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Negative	splash10-03di-0090000000-c3de47045d3b9ea5dd1f	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Negative	splash10-03dl-4890000000-e57232418c552e436a95	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Negative	splash10-015c-3910000000-34338787c291ec35bb4c	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-03di-0190000000-859e807fb540e8aaf091	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-053r-0910000000-70fde9c253e18d448791	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-0udi-9300000000-67ceed0497570d0689e3	Spectrum
MS	Mass Spectrum (Electron Ionization)	splash10-0fbc-9520000000-5141cdceea7f6d5013b0	Spectrum

Toxicity Profile

Route of Exposure

Parenteral (intramuscular, intravenous). The absolute bioavailability following rectal administration of methohexital is 17%.

Mechanism of Toxicity

Methohexital binds at a distinct binding site associated with a Cl^- ionopore at the GABA_A receptor, increasing the duration of time for which the Cl^- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged.

Metabolism

Metabolism occurs in the liver through demethylation and oxidation. Side-chain oxidation is the most important biotransformation involved in termination of biologic activity. Route of Elimination: Excretion occurs via the kidneys through glomerular filtration. Half Life: 5.6 ± 2.7 minutes

Toxicity Values

Not Available

Lethal Dose

Not Available

Carcinogenicity (IARC Classification)

No indication of carcinogenicity to humans (not listed by IARC).

Uses/Sources

Methohexital is indicated for use as an intravenous anaesthetic. It has also been commonly used to induce deep sedation. It is only used in hospital or similar settings, under strict supervision.

Minimum Risk Level

Not Available

Health Effects

They cause slurred speech, disorientation and "drunken" behavior. They are physically and psychologically addictive.

Symptoms

The onset of toxicity following an overdose of intravenously administered methohexital will be within seconds of the infusion. If methohexital is administered rectally or is ingested, the onset of toxicity may be delayed. The manifestations of an ultrashort-acting barbiturate in overdose include central nervous system depression, respiratory depression, hypotension, loss of peripheral vascular resistance, and muscular hyperactivity ranging from twitching to convulsive-like movements. Other findings may include convulsions and allergic reactions.

Treatment

Establish an airway and ensure oxygenation and ventilation. Resuscitative measures should be initiated promptly. For hypotension, intravenous fluids should be administered and the patient's legs raised. If desirable increase in blood pressure is not obtained, vasopressor and/or inotropic drugs may be used as dictated by the clinical situation. For convulsions, diazepam intravenously and phenytoin may be required. If the seizures are refractory to diazepam and phenytoin, general anesthesia and paralysis with a neuromuscular blocking agent may be necessary. Protect the patient's airway and support ventilation and perfusion. Meticulously monitor and maintain, within acceptable limits, the patient's vital signs, blood gases, serum electrolytes, etc. Absorption of drugs from the gastrointestinal tract may be decreased by giving activated charcoal, which, in many cases, is more effective than emesis or lavage; consider charcoal instead of or in addition to gastric emptying. Repeated doses of charcoal over time may hasten elimination of some drugs that have been absorbed. Safeguard the patient's airway when employing gastric emptying or charcoal. (3)

Concentrations

Not Available

External Links

DrugBank ID

DB00474

HMDB ID

HMDB0258127

FooDB ID

Not Available

Phenol Explorer ID

Not Available

KNApSAcK ID