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Substance Name: Phenytoin [USAN:USP:INN:BAN:JAN]
RN: 57-41-0
UNII: 6158TKW0C5
InChIKey: CXOFVDLJLONNDW-UHFFFAOYSA-N

Note

  • An anticonvulsant that is used to treat a wide variety of seizures. It is also an anti-arrhythmic and a muscle relaxant. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. The mechanism of its muscle relaxant effect appears to involve a reduction in the sensitivity of muscle spindles to stretch. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs.

Molecular Formula

  • C15-H12-N2-O2

Molecular Weight

  • 252.2718
 

Classification Codes

Classification Codes

  • Anticonvulsant
  • Anticonvulsants
  • Cardiovascular Agents
  • Central Nervous System Agents
  • Cytochrome P-450 CYP1A2 Inducers
  • Drug / Therapeutic Agent
  • Human Data
  • Membrane Transport Modulators
  • Mutation Data
  • Reproductive Effect
  • Sodium Channel Blockers
  • Tumor Data
  • Voltage-Gated Sodium Channel Blockers

Superlist Classification Codes

  • Overall Carcinogenic Evaluation: Group 2B
  • Reasonably Anticipated to be a Carcinogen

Names and Synonyms

Name of Substance

  • Phenytoin
  • Phenytoin [USAN:USP:INN:BAN:JAN]

MeSH Heading

  • Phenytoin

Synonyms

  • 5,5-Diphenyl-2,4-imidazolidinedione
  • 5,5-Diphenylhydantoin
  • 5,5-Diphenylhydantoin (IUPAC)
  • 5,5-Diphenylimidazolidin-2,4-dione
  • 5,5-Dwufenylohydantoina
  • 5,5-Dwufenylohydantoina [Polish]
  • AI3-52498
  • Aleviatin
  • Auranile
  • Causoin
  • CCRIS 515
  • Comitoina
  • Convul
  • Danten
  • Dantinal
  • Dantoinal
  • Dantoinal klinos
  • Dantoine
  • Denyl
  • Di-Hydan
  • Di-Lan
  • Di-Lan (VAN)
  • Di-Phetine
  • Didan TDC 250
  • Difenilhidantoina
  • Difenilhidantoina [Spanish]
  • Difenin
  • Difetoin
  • Difhydan
  • Dihycon
  • Dihydantoin
  • Dilabid
  • Dilantin
  • Dilantin acid
  • Dilantin-125
  • Dilantin-30
  • Dilantine
  • Dillantin
  • Dintoin
  • Dintoina
  • Diphantoin
  • Diphedal
  • Diphedan
  • Diphenin
  • Diphenine
  • Diphentyn
  • Diphenylan
  • Diphenylhydantoin
  • Diphenylhydantoin (VAN)
  • Diphenylhydantoine
  • Diphenylhydantoine [French]
  • Diphenylhydatanoin
  • Ditoinate
  • DPH
  • DPH (VAN)
  • EINECS 200-328-6
  • Ekko
  • Ekko capsules
  • Elepsindon
  • Enkelfel
  • Epamin
  • Epasmir 5
  • Epdantoin Simple
  • Epdantoine simple
  • Epelin
  • Epifenyl
  • Epihydan
  • Epilan D
  • Epilan-D
  • Epilantin
  • Epinat
  • Epised
  • Eptal
  • Fenantoin Mn Pharma
  • Fenidantoin s
  • Fenitoina
  • Fenitoina [INN-Spanish]
  • Fentoin
  • Fenylepsin
  • Fenytoin Dak
  • Fenytoine
  • Gerot-epilan-D
  • Hidan
  • Hidantal
  • Hidantilo
  • Hidantina
  • Hidantina senosian
  • Hidantina vitoria
  • Hidantomin
  • HSDB 3160
  • Hydantal
  • Hydantoinal
  • Ictalis simple
  • Idantoil
  • Idantoin
  • Iphenylhydantoin
  • Kessodanten
  • Labopal
  • Lehydan
  • Lepitoin
  • Lepsin
  • Minetoin
  • NCI-C55765
  • Neos-hidantoina
  • Neosidantoina
  • Novantoina
  • Novophenytoin
  • NSC 8722
  • OM hidantoina simple
  • OM-Hydantoine
  • Oxylan
  • Phanantin
  • Phanatine
  • Phenatine
  • Phenatoine
  • Phenhydanin
  • Phentoin
  • Phentytoin
  • Phenytoin
  • Phenytoin AWD
  • Phenytoin-Gerot
  • Phenytoine
  • Phenytoine [INN-French]
  • Phenytoinum
  • Phenytoinum [INN-Latin]
  • Ritmenal
  • Saceril
  • Sanepil
  • Silantin
  • Sinergina
  • Sodanthon
  • Sodantoin
  • Sodanton
  • Solantin
  • Sylantoic
  • Thilophenyl
  • TOIN
  • Toin unicelles
  • UNII-6158TKW0C5
  • Zentronal
  • Zentropil

Systematic Names

  • 2,4-Imidazolidinedione, 5,5-diphenyl-
  • Hydantoin, 5,5-diphenyl-
  • Phenytoin

Superlist Names

  • 2,4-Imidazolidinedione, 5,5-diphenyl-
  • 5,5-Diphenylhydantoin
  • Diphenylhydantoin
  • Phenytoin

Mixture Name

  • Mebroin

Registry Numbers

CAS Registry Number

  • 57-41-0

FDA UNII

  • 6158TKW0C5

Other Registry Number

  • 125-59-7

System Generated Number

  • 0000057410

Structure Descriptors

InChI

1S/C15H12N2O2/c18-13-15(17-14(19)16-13,11-7-3-1-4-8-11)12-9-5-2-6-10-12/h1-10H,(H2,16,17,18,19)

InChIKey

CXOFVDLJLONNDW-UHFFFAOYSA-N

Smiles

c1ccc(cc1)C2(C(=O)NC(=O)N2)c3ccccc3

Toxicity

Organism Test Type Route Reported Dose (Normalized Dose) Effect Source
child LDLo oral 100mg/kg (100mg/kg)   Neurology. Vol. 11, Pg. 138, 1961.
child TDLo intravenous 15mg/kg (15mg/kg) BEHAVIORAL: CHANGES IN MOTOR ACTIVITY (SPECIFIC ASSAY) Clinical Pediatrics Vol. 24, Pg. 467, 1985.
child TDLo intravenous 15mg/kg (15mg/kg) BEHAVIORAL: EXCITEMENT

BEHAVIORAL: ALTERED SLEEP TIME (INCLUDING CHANGE IN RIGHTING REFLEX)

BEHAVIORAL: MUSCLE CONTRACTION OR SPASTICITY)
Pediatrics. Vol. 72, Pg. 831, 1983.
child TDLo oral 3mg/kg/3W (3mg/kg) SKIN AND APPENDAGES (SKIN): "DERMATITIS, OTHER: AFTER SYSTEMIC EXPOSURE" Clinical Pharmacology and Therapeutics Vol. 20, Pg. 48, 1976.
child TDLo oral 11mg/kg/D (11mg/kg) BEHAVIORAL: ATAXIA

BEHAVIORAL: CHANGES IN MOTOR ACTIVITY (SPECIFIC ASSAY)
American Journal of Diseases of Children. Vol. 130, Pg. 75, 1976.
child TDLo oral 140mg/kg/2W-I (140mg/kg) SKIN AND APPENDAGES (SKIN): "DERMATITIS, OTHER: AFTER SYSTEMIC EXPOSURE"

LIVER: "JAUNDICE, OTHER OR UNCLASSIFIED"

BLOOD: OTHER CHANGES
Pediatrics. Vol. 28, Pg. 943, 1961.
child TDLo unreported 18mg/kg/3D-I (18mg/kg) BEHAVIORAL: MUSCLE CONTRACTION OR SPASTICITY)

BEHAVIORAL: EXCITEMENT
Pediatrics. Vol. 72, Pg. 831, 1983.
dog LD50 intravenous 90mg/kg (90mg/kg)   "Psychotropic Drugs and Related Compounds," 2nd ed., Usdin, E., and D.H. Efron, Washington, DC, 1972Vol. -, Pg. 224, 1972.
mammal (species unspecified) LD50 oral 250mg/kg (250mg/kg) BEHAVIORAL: ANTICONVULSANT Journal of Medicinal Chemistry. Vol. 8, Pg. 836, 1965.
man TDLo oral 31mg/kg/4D-I (31mg/kg) BEHAVIORAL: "HALLUCINATIONS, DISTORTED PERCEPTIONS"

BRAIN AND COVERINGS: ENCEPHALITIS

BEHAVIORAL: IRRITABILITY
Journal of Clinical Gastroenterology. Vol. 9, Pg. 337, 1987.
man TDLo oral 1300mg/kg (1300mg/kg) BLOOD: OTHER CHANGES Annals of Internal Medicine. Vol. 69, Pg. 557, 1968.
mouse LD50 intraperitoneal 100mg/kg (100mg/kg)   Journal of Medicinal Chemistry. Vol. 24, Pg. 465, 1981.
mouse LD50 intravenous 92mg/kg (92mg/kg)   Arzneimittel-Forschung. Drug Research. Vol. 4, Pg. 723, 1954.
mouse LD50 oral 150mg/kg (150mg/kg) BEHAVIORAL: ANTICONVULSANT Journal of Medicinal Chemistry. Vol. 18, Pg. 383, 1975.
mouse LD50 subcutaneous 110mg/kg (110mg/kg)   Arzneimittel-Forschung. Drug Research. Vol. 4, Pg. 723, 1954.
mouse LD50 unreported 800mg/kg (800mg/kg)   Acta Pharmaceutica Suecica. Vol. 2, Pg. 155, 1965.
rabbit LD50 intravenous 56400ug/kg (56.4mg/kg) LUNGS, THORAX, OR RESPIRATION: RESPIRATORY STIMULATION

BEHAVIORAL: CONVULSIONS OR EFFECT ON SEIZURE THRESHOLD
Arzneimittel-Forschung. Drug Research. Vol. 33, Pg. 1168, 1983.
rabbit LD50 oral > 3gm/kg (3000mg/kg)   French Medicament Patent Document. Vol. #2292M,
rat LD50 intraperitoneal 352mg/kg (352mg/kg)   Archives Internationales de Pharmacodynamie et de Therapie. Vol. 193, Pg. 37, 1971.
rat LD50 intravenous 101mg/kg (101mg/kg) BEHAVIORAL: ALTERED SLEEP TIME (INCLUDING CHANGE IN RIGHTING REFLEX) Japanese Kokai Tokyo Koho Patents. Vol. #79-163823,
rat LD50 oral 1635mg/kg (1635mg/kg) BEHAVIORAL: MUSCLE WEAKNESS

BEHAVIORAL: ALTERED SLEEP TIME (INCLUDING CHANGE IN RIGHTING REFLEX)

BEHAVIORAL: SLEEP
Arzneimittel-Forschung. Drug Research. Vol. 33, Pg. 1168, 1983.
rat LD50 subcutaneous > 1500mg/kg (1500mg/kg)   Arzneimittel-Forschung. Drug Research. Vol. 30, Pg. 477, 1980.
women TDLo oral 106mg/kg/2W-I (106mg/kg) BEHAVIORAL: "HALLUCINATIONS, DISTORTED PERCEPTIONS"

BRAIN AND COVERINGS: ENCEPHALITIS

BEHAVIORAL: ATAXIA
Journal of Clinical Gastroenterology. Vol. 9, Pg. 337, 1987.
women TDLo oral 200mg/kg (200mg/kg) BEHAVIORAL: ATAXIA

BEHAVIORAL: "HALLUCINATIONS, DISTORTED PERCEPTIONS"

BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY)
Annals of Emergency Medicine. Vol. 16, Pg. 1387, 1987.
women TDLo oral 540mg/kg/90D- (540mg/kg) LUNGS, THORAX, OR RESPIRATION: OTHER CHANGES

BLOOD: EOSINOPHILIA

LUNGS, THORAX, OR RESPIRATION: STRUCTURAL OR FUNCTIONAL CHANGE IN TRACHEA OR BRONCHI
American Journal of Medicine. Vol. 87, Pg. 93, 1989.

Physical Properties

Physical Property Value Units Temp (deg C) Source
Melting Point 286 deg C   EXP
pKa Dissociation Constant 8.33 (none)   EXP
log P (octanol-water) 2.47 (none)   EXP
Water Solubility 32 mg/L 22 EXP
Vapor Pressure 1.20E-10 mm Hg 25 EST
Henry's Law Constant 1.02E-11 atm-m3/mole 25 EST
Atmospheric OH Rate Constant 1.06E-11 cm3/molecule-sec 25 EST

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