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Metydan: Full Drug Profile

Medically reviewed by Min Clinic Staff | Updated: January 2026

Metydan - General Information

An anticonvulsant effective in tonic-clonic epilepsy (epilepsy, tonic-clonic). It may cause blood dyscrasias. [PubChem]

 

Pharmacology of Metydan

Metydan is an antiepileptic drug which can be useful in the treatment of epilepsy. The primary site of action appears to be the motor cortex where spread of seizure activity is inhibited. Possibly by promoting sodium efflux from neurons, mephenytoin tends to stabilize the threshold against hyperexcitability caused by excessive stimulation or environmental changes capable of reducing membrane sodium gradient. This includes the reduction of posttetanic potentiation at synapses. Loss of posttetanic potentiation prevents cortical seizure foci from detonating adjacent cortical areas. Metydan reduces the maximal activity of brain stem centers responsible for the tonic phase of tonic-clonic (grand mal) seizures.

 

Metydan for patients

Discuss with your doctor about the risks of taking Mephenytoin. Mephenytoin may pass into the breast milk. If you are breast feeding or have any other medical condition, make sure you let the doctor know. Alcohol and some other medications may affect the effect of Mephenytoin. Do not change dose and dosing schedule without consulting your doctor.

 

Metydan Interactions

Some anticonvulsants may interact with Mephenytoin. They can either increase or decrease the effect of Mephenytoin. Those anticonvulsants include divalproex sodium, valproic acid, and phenobarbital.

Mephenytoin may also affect the effects of other drugs, which include some steroid medications, warfarin, certain heart medicines, birth control pills, anti-infective medicines, furosemide and theophylline

Please note that Mephenytoin may interact with other drugs that are not listed here.

 

Metydan Contraindications

 

Additional information about Metydan

Metydan Indication: For the treatment of refractory partial epilepsy. Mechanism Of Action: The mechanism of action of mephenytoin is not definitely known, but extensive research strongly suggests that its main mechanism is to block frequency-, use- and voltage-dependent neuronal sodium channels, and therefore limit repetitive firing of action potentials. Drug Interactions: Not Available Food Interactions: Not Available Generic Name: Mephenytoin Synonyms: Mephentoin; Methyl Hydantoin; Methylphenetoin Drug Category: Anticonvulsants Drug Type: Small Molecule; Approved Other Brand Names containing Mephenytoin: Epiazin; Gerot-Epilan; Insulton; Mesdontoin; Mesontoin; Methoin; Metydan; Phenantoin; Sacerno; Sedantional; Sedantoin; Sedantoinal; Triantoin; Absorption: Not Available Toxicity (Overdose): Not Available Protein Binding: Not Available Biotransformation: Not Available Half Life: Approximately 7 hours Dosage Forms of Metydan: Not Available Chemical IUPAC Name: 5-ethyl-3-methyl-5-phenylimidazolidine-2,4-dione Chemical Formula: C12H14N2O2 Mephenytoin on Wikipedia: https://en.wikipedia.org/wiki/Mephenytoin Organisms Affected: Humans and other mammals