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Identification
NameMethylphenobarbital
Accession NumberDB00849  (APRD00047)
TypeSmall Molecule
GroupsApproved
Description

A barbiturate that is metabolized to phenobarbital. It has been used for similar purposes, especially in epilepsy, but there is no evidence mephobarbital offers any advantage over phenobarbital. [PubChem]

Structure
Thumb
Synonyms
1-Methylphenobarbital
5-Ethyl-1-methyl-5-phenyl-2,4,6(1H,3H,5H)-pyrimidinetrione
5-Ethyl-1-methyl-5-phenyl-pyrimidine-2,4,6-trione
5-Ethyl-1-methyl-5-phenylbarbituric acid
Enphenemal
Mebaral
Mephobarbital
Mephobarbitone
Méthylphénobarbital
Methylphenobarbital
Methylphenobarbitalum
Methylphenobarbitone
Metilfenobarbital
Metilfenobarbitale
N-Methylphenobarbital
External Identifiers Not Available
Approved Prescription ProductsNot Available
Approved Generic Prescription ProductsNot Available
Approved Over the Counter ProductsNot Available
Unapproved/Other Products Not Available
International Brands
NameCompany
MebaralLundbeck A/S
MephyltalettenNot Available
PhemitonNot Available
PhemitoneNot Available
PhenmitonNot Available
ProminalNot Available
Brand mixturesNot Available
SaltsNot Available
Categories
UNII5NC67NU76B
CAS number115-38-8
WeightAverage: 246.2619
Monoisotopic: 246.100442324
Chemical FormulaC13H14N2O3
InChI KeyInChIKey=ALARQZQTBTVLJV-UHFFFAOYSA-N
InChI
InChI=1S/C13H14N2O3/c1-3-13(9-7-5-4-6-8-9)10(16)14-12(18)15(2)11(13)17/h4-8H,3H2,1-2H3,(H,14,16,18)
IUPAC Name
5-ethyl-1-methyl-5-phenyl-1,3-diazinane-2,4,6-trione
SMILES
CCC1(C(=O)NC(=O)N(C)C1=O)C1=CC=CC=C1
Taxonomy
DescriptionThis compound belongs to the class of organic compounds known as barbituric acid derivatives. These are compounds containing a perhydropyrimidine ring substituted at C-2, -4 and -6 by oxo groups.
KingdomOrganic compounds
Super ClassOrganoheterocyclic compounds
ClassDiazines
Sub ClassPyrimidines and pyrimidine derivatives
Direct ParentBarbituric acid derivatives
Alternative Parents
Substituents
  • Barbiturate
  • Ureide
  • Benzenoid
  • 1,3-diazinane
  • Monocyclic benzene moiety
  • Urea
  • Tertiary amine
  • Carboxamide group
  • Azacycle
  • Carboxylic acid derivative
  • Hydrocarbon derivative
  • Organooxygen compound
  • Organonitrogen compound
  • Carbonyl group
  • Amine
  • Aromatic heteromonocyclic compound
Molecular FrameworkAromatic heteromonocyclic compounds
External DescriptorsNot Available
Pharmacology
IndicationFor the relief of anxiety, tension, and apprehension, also used as an anticonvulsant for the treatment of epilepsy.
PharmacodynamicsMethylphenobarbital, a barbiturate, is used in combination with acetaminophen or aspirin and caffeine for its sedative and relaxant effects in the treatment of tension headaches, migraines, and pain. Barbiturates act as nonselective depressants of the central nervous system (CNS), capable of producing all levels of CNS mood alteration from excitation to mild sedation, hypnosis, and deep coma. In sufficiently high therapeutic doses, barbiturates induce anesthesia.
Mechanism of actionMethylphenobarbital binds at a distinct binding site associated with a Cl- ionopore at the GABAA 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.
Related Articles
AbsorptionApproximately 50% of an oral dose of mephobarbital is absorbed from the gastrointestinal tract.
Volume of distributionNot Available
Protein binding70-76%
Metabolism

Hepatic, primarily by the hepatic microsomal enzyme system. About 75% of a single oral dose of mephobarbital is metabolized to phenobarbital in 24 hours.

SubstrateEnzymesProduct
Methylphenobarbital
Not Available
PhenobarbitalDetails
Route of eliminationNot Available
Half life34 (range 11-67) hours
ClearanceNot Available
ToxicityNot Available
Affected organisms
  • Humans and other mammals
PathwaysNot Available
SNP Mediated EffectsNot Available
SNP Mediated Adverse Drug ReactionsNot Available
ADMET
Predicted ADMET features
PropertyValueProbability
Human Intestinal Absorption+0.9952
Blood Brain Barrier+0.9859
Caco-2 permeable+0.5674
P-glycoprotein substrateNon-substrate0.6107
P-glycoprotein inhibitor INon-inhibitor0.5213
P-glycoprotein inhibitor IINon-inhibitor0.8987
Renal organic cation transporterNon-inhibitor0.8913
CYP450 2C9 substrateNon-substrate0.7897
CYP450 2D6 substrateNon-substrate0.9138
CYP450 3A4 substrateNon-substrate0.6613
CYP450 1A2 substrateNon-inhibitor0.857
CYP450 2C9 inhibitorNon-inhibitor0.6815
CYP450 2D6 inhibitorNon-inhibitor0.9404
CYP450 2C19 inhibitorNon-inhibitor0.7403
CYP450 3A4 inhibitorNon-inhibitor0.935
CYP450 inhibitory promiscuityLow CYP Inhibitory Promiscuity0.9254
Ames testNon AMES toxic0.727
CarcinogenicityNon-carcinogens0.754
BiodegradationNot ready biodegradable0.9668
Rat acute toxicity2.6756 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.9848
hERG inhibition (predictor II)Non-inhibitor0.8733
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397 )
Pharmacoeconomics
ManufacturersNot Available
Packagers
Dosage formsNot Available
Prices
Unit descriptionCostUnit
Mentax 1% cream4.0USD g
Mebaral 100 mg tablet1.73USD tablet
Mebaral 50 mg tablet1.28USD tablet
Mebaral 32 mg tablet0.87USD tablet
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
PatentsNot Available
Properties
StateSolid
Experimental Properties
PropertyValueSource
melting point176 °CPhysProp
water solubilitySlightly solubleNot Available
logP1.84HANSCH,C ET AL. (1995)
pKa7.8Not Available
Predicted Properties
PropertyValueSource
Water Solubility0.71 mg/mLALOGPS
logP1.95ALOGPS
logP1.63ChemAxon
logS-2.5ALOGPS
pKa (Strongest Acidic)8.4ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count1ChemAxon
Polar Surface Area66.48 Å2ChemAxon
Rotatable Bond Count2ChemAxon
Refractivity64.64 m3·mol-1ChemAxon
Polarizability24.62 Å3ChemAxon
Number of Rings2ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectra
Mass Spec (NIST)Download (8.57 KB)
Spectra
Spectrum TypeDescriptionSplash Key
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, NegativeNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, NegativeNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, NegativeNot Available
References
Synthesis ReferenceNot Available
General ReferencesNot Available
External Links
ATC CodesN03AA01
AHFS CodesNot Available
PDB EntriesNot Available
FDA labelNot Available
MSDSNot Available
Interactions
Drug Interactions
Drug
MefloquineThe therapeutic efficacy of Methylphenobarbital can be decreased when used in combination with Mefloquine.
OrlistatThe serum concentration of Methylphenobarbital can be decreased when it is combined with Orlistat.
Food InteractionsNot Available

Targets

Kind
Protein
Organism
Human
Pharmacological action
yes
Actions
potentiator
General Function:
Inhibitory extracellular ligand-gated ion channel activity
Specific Function:
Component of the heteropentameric receptor for GABA, the major inhibitory neurotransmitter in the vertebrate brain. Functions also as histamine receptor and mediates cellular responses to histamine. Functions as receptor for diazepines and various anesthetics, such as pentobarbital; these are bound at a separate allosteric effector binding site. Functions as ligand-gated chloride channel (By si...
Gene Name:
GABRA1
Uniprot ID:
P14867
Molecular Weight:
51801.395 Da
References
  1. Whiting PJ: The GABAA receptor gene family: new opportunities for drug development. Curr Opin Drug Discov Devel. 2003 Sep;6(5):648-57. [PubMed:14579514 ]
  2. Mehta AK, Ticku MK: An update on GABAA receptors. Brain Res Brain Res Rev. 1999 Apr;29(2-3):196-217. [PubMed:10209232 ]
  3. Yamakura T, Bertaccini E, Trudell JR, Harris RA: Anesthetics and ion channels: molecular models and sites of action. Annu Rev Pharmacol Toxicol. 2001;41:23-51. [PubMed:11264449 ]
  4. Krasowski MD, Harrison NL: General anaesthetic actions on ligand-gated ion channels. Cell Mol Life Sci. 1999 Aug 15;55(10):1278-303. [PubMed:10487207 ]
  5. Chen X, Ji ZL, Chen YZ: TTD: Therapeutic Target Database. Nucleic Acids Res. 2002 Jan 1;30(1):412-5. [PubMed:11752352 ]
  6. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. [PubMed:17139284 ]
  7. Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. [PubMed:17016423 ]
  8. Olsen RW, Li GD: GABA(A) receptors as molecular targets of general anesthetics: identification of binding sites provides clues to allosteric modulation. Can J Anaesth. 2011 Feb;58(2):206-15. doi: 10.1007/s12630-010-9429-7. Epub 2010 Dec 31. [PubMed:21194017 ]
  9. Roden WH, Peugh LD, Jansen LA: Altered GABA(A) receptor subunit expression and pharmacology in human Angelman syndrome cortex. Neurosci Lett. 2010 Oct 15;483(3):167-72. doi: 10.1016/j.neulet.2010.08.001. Epub 2010 Aug 6. [PubMed:20692323 ]
Kind
Protein
Organism
Human
Pharmacological action
yes
Actions
potentiator
General Function:
Inhibitory extracellular ligand-gated ion channel activity
Specific Function:
GABA, the major inhibitory neurotransmitter in the vertebrate brain, mediates neuronal inhibition by binding to the GABA/benzodiazepine receptor and opening an integral chloride channel.
Gene Name:
GABRA2
Uniprot ID:
P47869
Molecular Weight:
51325.85 Da
References
  1. Yamakura T, Bertaccini E, Trudell JR, Harris RA: Anesthetics and ion channels: molecular models and sites of action. Annu Rev Pharmacol Toxicol. 2001;41:23-51. [PubMed:11264449 ]
  2. Mehta AK, Ticku MK: An update on GABAA receptors. Brain Res Brain Res Rev. 1999 Apr;29(2-3):196-217. [PubMed:10209232 ]
  3. Olsen RW, Li GD: GABA(A) receptors as molecular targets of general anesthetics: identification of binding sites provides clues to allosteric modulation. Can J Anaesth. 2011 Feb;58(2):206-15. doi: 10.1007/s12630-010-9429-7. Epub 2010 Dec 31. [PubMed:21194017 ]
Kind
Protein
Organism
Human
Pharmacological action
yes
Actions
potentiator
General Function:
Inhibitory extracellular ligand-gated ion channel activity
Specific Function:
GABA, the major inhibitory neurotransmitter in the vertebrate brain, mediates neuronal inhibition by binding to the GABA/benzodiazepine receptor and opening an integral chloride channel.
Gene Name:
GABRA3
Uniprot ID:
P34903
Molecular Weight:
55164.055 Da
References
  1. Yamakura T, Bertaccini E, Trudell JR, Harris RA: Anesthetics and ion channels: molecular models and sites of action. Annu Rev Pharmacol Toxicol. 2001;41:23-51. [PubMed:11264449 ]
  2. Mehta AK, Ticku MK: An update on GABAA receptors. Brain Res Brain Res Rev. 1999 Apr;29(2-3):196-217. [PubMed:10209232 ]
  3. Olsen RW, Li GD: GABA(A) receptors as molecular targets of general anesthetics: identification of binding sites provides clues to allosteric modulation. Can J Anaesth. 2011 Feb;58(2):206-15. doi: 10.1007/s12630-010-9429-7. Epub 2010 Dec 31. [PubMed:21194017 ]
Kind
Protein
Organism
Human
Pharmacological action
yes
Actions
potentiator
General Function:
Inhibitory extracellular ligand-gated ion channel activity
Specific Function:
GABA, the major inhibitory neurotransmitter in the vertebrate brain, mediates neuronal inhibition by binding to the GABA/benzodiazepine receptor and opening an integral chloride channel.
Gene Name:
GABRA4
Uniprot ID:
P48169
Molecular Weight:
61622.645 Da
References
  1. Mehta AK, Ticku MK: An update on GABAA receptors. Brain Res Brain Res Rev. 1999 Apr;29(2-3):196-217. [PubMed:10209232 ]
  2. Olsen RW, Li GD: GABA(A) receptors as molecular targets of general anesthetics: identification of binding sites provides clues to allosteric modulation. Can J Anaesth. 2011 Feb;58(2):206-15. doi: 10.1007/s12630-010-9429-7. Epub 2010 Dec 31. [PubMed:21194017 ]
Kind
Protein
Organism
Human
Pharmacological action
yes
Actions
potentiator
General Function:
Transporter activity
Specific Function:
GABA, the major inhibitory neurotransmitter in the vertebrate brain, mediates neuronal inhibition by binding to the GABA/benzodiazepine receptor and opening an integral chloride channel.
Gene Name:
GABRA5
Uniprot ID:
P31644
Molecular Weight:
52145.645 Da
References
  1. Yamakura T, Bertaccini E, Trudell JR, Harris RA: Anesthetics and ion channels: molecular models and sites of action. Annu Rev Pharmacol Toxicol. 2001;41:23-51. [PubMed:11264449 ]
  2. Mehta AK, Ticku MK: An update on GABAA receptors. Brain Res Brain Res Rev. 1999 Apr;29(2-3):196-217. [PubMed:10209232 ]
  3. Olsen RW, Li GD: GABA(A) receptors as molecular targets of general anesthetics: identification of binding sites provides clues to allosteric modulation. Can J Anaesth. 2011 Feb;58(2):206-15. doi: 10.1007/s12630-010-9429-7. Epub 2010 Dec 31. [PubMed:21194017 ]
Kind
Protein
Organism
Human
Pharmacological action
yes
Actions
potentiator
General Function:
Inhibitory extracellular ligand-gated ion channel activity
Specific Function:
GABA, the major inhibitory neurotransmitter in the vertebrate brain, mediates neuronal inhibition by binding to the GABA/benzodiazepine receptor and opening an integral chloride channel.
Gene Name:
GABRA6
Uniprot ID:
Q16445
Molecular Weight:
51023.69 Da
References
  1. Mehta AK, Ticku MK: An update on GABAA receptors. Brain Res Brain Res Rev. 1999 Apr;29(2-3):196-217. [PubMed:10209232 ]
  2. Yamakura T, Bertaccini E, Trudell JR, Harris RA: Anesthetics and ion channels: molecular models and sites of action. Annu Rev Pharmacol Toxicol. 2001;41:23-51. [PubMed:11264449 ]
  3. Olsen RW, Li GD: GABA(A) receptors as molecular targets of general anesthetics: identification of binding sites provides clues to allosteric modulation. Can J Anaesth. 2011 Feb;58(2):206-15. doi: 10.1007/s12630-010-9429-7. Epub 2010 Dec 31. [PubMed:21194017 ]
Kind
Protein
Organism
Human
Pharmacological action
unknown
Actions
antagonist
General Function:
Ligand-gated ion channel activity
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane permeable to sodium ions.
Gene Name:
CHRNA4
Uniprot ID:
P43681
Molecular Weight:
69956.47 Da
References
  1. Yamakura T, Bertaccini E, Trudell JR, Harris RA: Anesthetics and ion channels: molecular models and sites of action. Annu Rev Pharmacol Toxicol. 2001;41:23-51. [PubMed:11264449 ]
  2. Arias HR, Bhumireddy P: Anesthetics as chemical tools to study the structure and function of nicotinic acetylcholine receptors. Curr Protein Pept Sci. 2005 Oct;6(5):451-72. [PubMed:16248797 ]
  3. Krasowski MD, Harrison NL: General anaesthetic actions on ligand-gated ion channels. Cell Mol Life Sci. 1999 Aug 15;55(10):1278-303. [PubMed:10487207 ]
Kind
Protein
Organism
Human
Pharmacological action
unknown
Actions
antagonist
General Function:
Toxic substance binding
Specific Function:
After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. The channel is blocked by alpha-bungarotoxin.
Gene Name:
CHRNA7
Uniprot ID:
P36544
Molecular Weight:
56448.925 Da
References
  1. Yamakura T, Bertaccini E, Trudell JR, Harris RA: Anesthetics and ion channels: molecular models and sites of action. Annu Rev Pharmacol Toxicol. 2001;41:23-51. [PubMed:11264449 ]
  2. Arias HR, Bhumireddy P: Anesthetics as chemical tools to study the structure and function of nicotinic acetylcholine receptors. Curr Protein Pept Sci. 2005 Oct;6(5):451-72. [PubMed:16248797 ]
  3. Krasowski MD, Harrison NL: General anaesthetic actions on ligand-gated ion channels. Cell Mol Life Sci. 1999 Aug 15;55(10):1278-303. [PubMed:10487207 ]
Kind
Protein
Organism
Human
Pharmacological action
unknown
Actions
antagonist
General Function:
Ionotropic glutamate receptor activity
Specific Function:
Receptor for glutamate that functions as ligand-gated ion channel in the central nervous system and plays an important role in excitatory synaptic transmission. L-glutamate acts as an excitatory neurotransmitter at many synapses in the central nervous system. Binding of the excitatory neurotransmitter L-glutamate induces a conformation change, leading to the opening of the cation channel, and t...
Gene Name:
GRIA2
Uniprot ID:
P42262
Molecular Weight:
98820.32 Da
References
  1. Yamakura T, Bertaccini E, Trudell JR, Harris RA: Anesthetics and ion channels: molecular models and sites of action. Annu Rev Pharmacol Toxicol. 2001;41:23-51. [PubMed:11264449 ]
  2. Krasowski MD, Harrison NL: General anaesthetic actions on ligand-gated ion channels. Cell Mol Life Sci. 1999 Aug 15;55(10):1278-303. [PubMed:10487207 ]
Kind
Protein
Organism
Human
Pharmacological action
unknown
Actions
antagonist
General Function:
Kainate selective glutamate receptor activity
Specific Function:
Ionotropic glutamate receptor. L-glutamate acts as an excitatory neurotransmitter at many synapses in the central nervous system. Binding of the excitatory neurotransmitter L-glutamate induces a conformation change, leading to the opening of the cation channel, and thereby converts the chemical signal to an electrical impulse. The receptor then desensitizes rapidly and enters a transient inacti...
Gene Name:
GRIK2
Uniprot ID:
Q13002
Molecular Weight:
102582.475 Da
References
  1. Yamakura T, Bertaccini E, Trudell JR, Harris RA: Anesthetics and ion channels: molecular models and sites of action. Annu Rev Pharmacol Toxicol. 2001;41:23-51. [PubMed:11264449 ]
  2. Krasowski MD, Harrison NL: General anaesthetic actions on ligand-gated ion channels. Cell Mol Life Sci. 1999 Aug 15;55(10):1278-303. [PubMed:10487207 ]

Enzymes

Kind
Protein
Organism
Human
Pharmacological action
unknown
Actions
substrateinhibitor
General Function:
Steroid hydroxylase activity
Specific Function:
Responsible for the metabolism of a number of therapeutic agents such as the anticonvulsant drug S-mephenytoin, omeprazole, proguanil, certain barbiturates, diazepam, propranolol, citalopram and imipramine.
Gene Name:
CYP2C19
Uniprot ID:
P33261
Molecular Weight:
55930.545 Da
References
  1. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256 ]
  2. Drug Interactions: Cytochrome P450 Drug Interaction Table [Link]
Kind
Protein
Organism
Human
Pharmacological action
unknown
Actions
substrate
General Function:
Steroid hydroxylase activity
Specific Function:
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally unrelated compounds, including steroids, fatty acids, and xenobiotics. Acts as a 1,4-cineole 2-exo-monooxygenase.
Gene Name:
CYP2B6
Uniprot ID:
P20813
Molecular Weight:
56277.81 Da
References
  1. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256 ]
Comments
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Drug created on June 13, 2005 07:24 / Updated on August 17, 2016 12:23