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Substance Name: Mephenytoin [USAN:USP:INN:BAN]
RN: 50-12-4
UNII: R420KW629U
InChIKey: GMHKMTDVRCWUDX-UHFFFAOYSA-N

Note

  • An anticonvulsant effective in tonic-clonic epilepsy (EPILEPSY, TONIC-CLONIC). It may cause blood dyscrasias.

Molecular Formula

  • C12-H14-N2-O2

Molecular Weight

  • 218.2546
 

Classification Codes

  • Anticonvulsant
  • Anticonvulsants
  • Central Nervous System Agents
  • Drug / Therapeutic Agent
  • Human Data
  • Mutation Data
  • Reproductive Effect

Names and Synonyms

Name of Substance

  • Mephenytoin
  • Mephenytoin [USAN:USP:INN:BAN]

MeSH Heading

  • Mephenytoin

Synonyms

  • (+-)-5-Ethyl-3-methyl-5-phenylhydantoin
  • 2,4-Imidazolidinedione, 5-ethyl-3-methyl-5-phenyl-
  • 2,4-Imidazolidinedione, 5-ethyl-3-methyl-5-phenyl-, (+-)-
  • 3-Ethylnirvanol
  • 3-Methyl-5,5-phenylethylhydantoin
  • 3-Methyl-5-ethyl-5-phenylhydantoin
  • 5-24-08-00093 (Beilstein Handbook Reference)
  • 5-Ethyl-3-methyl-5-phenyl-2,4(3H,5H)-imidazoledione
  • 5-Ethyl-3-methyl-5-phenyl-2,4-imidazolidinedione
  • 5-Ethyl-3-methyl-5-phenylhydantoin
  • 5-Ethyl-3-methyl-5-phenylimidazolidin-2,4-dione
  • 5-Ethyl-5-fenyl-3-methylhydantoin
  • 5-Ethyl-5-fenyl-3-methylhydantoin [Czech]
  • BRN 0017282
  • EINECS 200-012-8
  • Epiazin
  • Epilan
  • Fenantoin
  • HSDB 3581
  • Insulton
  • Mefenitoina
  • Mefenitoina [INN-Spanish]
  • Mephenetoinum
  • Mephenytoin
  • Mephenytoine
  • Mephenytoine [INN-French]
  • Mephenytoinum
  • Mephenytoinum [INN-Latin]
  • Mesantoin
  • Methoin
  • Methyl hydantoin
  • Methylphenetoin
  • Metydan
  • NSC 34652
  • NSC-34652
  • Phenantoin
  • Phenylethylmethylhydantoin
  • Sacerno
  • Sedantoin
  • Sedantoinal
  • Triantoin
  • UNII-R420KW629U

Systematic Names

  • 2,4-Imidazolidinedione, 5-ethyl-3-methyl-5-phenyl-
  • Hydantoin, 5-ethyl-3-methyl-5-phenyl-
  • Mephenytoin

Mixture Name

  • Hydantal

Registry Numbers

CAS Registry Number

  • 50-12-4

FDA UNII

  • R420KW629U

System Generated Number

  • 0000050124

Structure Descriptors

InChI

1S/C12H14N2O2/c1-3-12(9-7-5-4-6-8-9)10(15)14(2)11(16)13-12/h4-8H,3H2,1-2H3,(H,13,16)

InChIKey

GMHKMTDVRCWUDX-UHFFFAOYSA-N

Smiles

CCC1(NC(=O)N(C)C1=O)c2ccccc2

Toxicity

Organism Test Type Route Reported Dose (Normalized Dose) Effect Source
cat LD50 oral 190mg/kg (190mg/kg)   "Psychotropic Drugs and Related Compounds," 2nd ed., Usdin, E., and D.H. Efron, Washington, DC, 1972Vol. -, Pg. 263, 1972.
guinea pig LD50 oral 380mg/kg (380mg/kg)   "Psychotropic Drugs and Related Compounds," 2nd ed., Usdin, E., and D.H. Efron, Washington, DC, 1972Vol. -, Pg. 263, 1972.
mouse LD50 intraperitoneal 300mg/kg (300mg/kg)   Pharmaceutical Chemistry Journal Vol. 25, Pg. 181, 1991.
mouse LD50 oral 440mg/kg (440mg/kg)   Cesko-Slovenska Farmacie. Vol. 4, Pg. 333, 1955.
rabbit LD50 oral 430mg/kg (430mg/kg)   "Drug Dosages in Laboratory Animals - A Handbook," Rev. ed., Barnes, C.D., and L.G. Eltherington, Berkeley, Univ. of California Press, 1973Vol. -, Pg. 151, 1973.
rat LD50 oral 850mg/kg (850mg/kg)   "Psychotropic Drugs and Related Compounds," 2nd ed., Usdin, E., and D.H. Efron, Washington, DC, 1972Vol. -, Pg. 263, 1972.
rat LDLo intraperitoneal 270mg/kg (270mg/kg)   "Merck Index; an Encyclopedia of Chemicals, Drugs, and Biologicals", 11th ed., Rahway, NJ 07065, Merck & Co., Inc. 1989Vol. 11, Pg. 919, 1989.
women TDLo oral 1100mg/kg (1100mg/kg) BLOOD: HEMORRHAGE

BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY)

MUSCULOSKELETAL: CHANGES IN TEETH AND SUPPORTING STRUCTURES
JAMA, Journal of the American Medical Association. Vol. 138, Pg. 498, 1949.

Physical Properties

Physical Property Value Units Temp (deg C) Source
Melting Point 135 deg C   EXP
pKa Dissociation Constant 8.51 (none)   EXP
log P (octanol-water) 1.69 (none)   EXP
Water Solubility 1270 mg/L 25 EST
Vapor Pressure 3.80E-08 mm Hg 25 EST
Henry's Law Constant 4.90E-10 atm-m3/mole 25 EST
Atmospheric OH Rate Constant 1.07E-11 cm3/molecule-sec 25 EST

Physical property data is provided to ChemIDplus by SRC, Inc.