Chemicals and Drugs

Phenytoin

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.

National Library of MedicineMedical Subject Headings2026

Structured Summary

Abstract

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.

Chemical Identity

Chemical Information

Molecular Formula
C15H12N2O2
Molecular Weight
252.27 g/mol
CAS Registry No.
57-41-0
IUPAC Name
5,5-diphenylimidazolidine-2,4-dione
InChIKey
CXOFVDLJLONNDW-UHFFFAOYSA-N
SMILES
C1=CC=C(C=C1)C2(C(=O)NC(=O)N2)C3=CC=CC=C3
MeSH Unique ID
D010672
Source
PubChem CID 1775

MeSH Record

Classification

Broader headings

Related Concepts

Knowledge Graph

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Drug Class

Pharmacological Action

MeSH Record

Synonyms

15 entry terms
  • 5,5-Diphenylhydantoin
  • 5,5-diphenylimidazolidine-2,4-dione
  • Diphenylhydantoin
  • Fenitoin
  • Antisacer
  • Difenin
  • Dihydan
  • Dilantin
  • Epamin
  • Epanutin
  • Hydantol
  • Phenhydan
  • Phenytoin Sodium
  • Sodium Diphenylhydantoinate
  • Diphenylhydantoinate, Sodium

MeSH Record

Aspects Covered

25 allowable subheadings

Indexed with the subheadings administration & dosage, adverse effects, agonists, analogs & derivatives, analysis, antagonists & inhibitors, blood, cerebrospinal fluid, chemical synthesis, chemistry, classification, economics, history, immunology, isolation & purification, metabolism, pharmacokinetics, pharmacology, poisoning, radiation effects, standards, supply & distribution, therapeutic use, toxicity, urine.

MeSH Record

History Note

78; was DIPHENYLHYDANTOIN 1963-77

MeSH Hierarchy

Tree Number

  1. D03w.383.129w.308.432.555.730w

MeSH Record

NLM Classification

QV 85

AMA Style

References

  1. National Library of Medicine. Phenytoin. Medical Subject Headings (MeSH). 2026. Unique ID D010672. http://id.nlm.nih.gov/mesh/2026/D010672
  2. Phenytoin. In: Wikipedia. https://en.wikipedia.org/wiki/Phenytoin
  3. Phenytoin. In: Wikidata. https://www.wikidata.org/wiki/Q410400
  4. Phenytoin. In: PubChem Compound. CID 1775. https://pubchem.ncbi.nlm.nih.gov/compound/1775