Mefenitoína

Mefenitoína Uses, Dosage, Side Effects, Food Interaction and all others data.

Mefenitoína is used for the treatment of refractory partial epilepsy. Mefenitoína is a solid. This compound belongs to the phenylhydantoins. These are heterocyclic aromatic compounds containing an imiazolidinedione moiety substituted by a phenyl group. Mefenitoína is known to target sodium channel protein type 5 subunit alpha. Cytochrome P450 2C19, Cytochrome P450 2C8, Cytochrome P450 2C9, Cytochrome P450 2B6, Cytochrome P450 1A2, and Cytochrome P450 2D6 are known to metabolize mephenytoin. Mefenitoína is a hydantoin-derivative anticonvulsant used to control various partial seizures. Mefenitoína and oxazolidinedione derivatives are associated with higher incidences of blood dyscrasias compared to other anticonvulsants.

Mefenitoína 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. Mefenitoína reduces the maximal activity of brain stem centers responsible for the tonic phase of tonic-clonic (grand mal) seizures.

Trade Name Mefenitoína
Availability Discontinued
Generic Mephenytoin
Mephenytoin Other Names mefenitoína, Mephenytoin
Type
Formula C12H14N2O2
Weight Average: 218.2518
Monoisotopic: 218.105527702
Groups Approved, Investigational, Withdrawn
Therapeutic Class
Manufacturer
Available Country
Last Updated: September 19, 2023 at 7:00 am
Mefenitoína
Mefenitoína

Uses

Mefenitoína is a phenylhydantoin used to treat refractory partial epilepsy.

For the treatment of refractory partial epilepsy.

How Mefenitoína works

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.

Food Interaction

[Moderate] ADJUST DOSING INTERVAL: Phenytoin bioavailability may decrease to subtherapeutic levels when the suspension is given concomitantly with enteral feedings.

The mechanism may be related to phenytoin binding to substances in the enteral formula (e.g., calcium, protein) and

Data have been conflicting and some studies have reported no changes in phenytoin levels, while others have reported significant reductions.

MONITOR: Acute consumption of alcohol may increase plasma phenytoin levels.

Chronic consumption of alcohol may decrease plasma phenytoin levels.

The mechanism of this interaction is related to induction of phenytoin metabolism by ethanol during chronic administration.

Other hydantoin derivatives may be similarly affected by ethanol.

MANAGEMENT: Some experts have recommended interrupting the feeding for 2 hours before and after the phenytoin dose, giving the phenytoin suspension diluted in water, and flushing the tube with water after administration; however, this method may not entirely avoid the interaction and is not always clinically feasible.

Patients should be closely monitored for clinical and laboratory evidence of altered phenytoin efficacy and levels upon initiation and discontinuation of enteral feedings.

Dosage adjustments or intravenous administration may be required until therapeutic serum levels are obtained.

In addition, patients receiving phenytoin therapy should be warned about the interaction between phenytoin and ethanol and they should be advised to notify their physician if they experience worsening of seizure control or symptoms of toxicity, including drowsiness, visual disturbances, change in mental status, nausea, or ataxia.

Volume of Distribution

  • 1.4 L/kg

Half Life

Approximately 7 hours

Innovators Monograph

You find simplified version here Mefenitoína

*** Taking medicines without doctor's advice can cause long-term problems.
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