METHSUXIMIDE

Toxicity

Acute overdoses may produce nausea, vomiting, and CNS depression including coma with respiratory depression. Levels greater than 40 μg/mL have caused toxicity and coma has been seen at levels of 150 μg/mL.

Description

Methsuximide is a succinimide that is converted to N-desmethylmethosuximide, a channel blocker that targets low threshold calcium currents. Methsuximide is a substrate of cytochrome P450 (CYP) isoform 2C19 that, in turn, inhibits CYP2C19-mediated metabolism of biguanides. Methsuximide has been shown to have anticonvulsant properties in clinical trials.

Chemical properties

Light Yellow Oil

Originator

Celontin,Parke Davis,US,1957

The Uses of METHSUXIMIDE

A calcium channel succinimide antiepileptic drug. Anticonvulsant.

Background

Mesuximide (or methsuximide) is an anticonvulsant medication. It is sold by Pfizer under the name Petinutin.

Indications

For the control of absence (petit mal) seizures that are refractory to other drugs.

What are the applications of Application

Methsuximide is a succinimide with anti-epileptic and anti-convulsant properties

Definition

ChEBI: Methsuximide is an organic molecular entity.

Manufacturing Process

100 g of α-phenyl-α-methylsuccinic acid and 110 g of 40% aqueous methyl amine are heated together at 200 to 250°C until no more distillate is obtained. Upon vacuum distillation of the residue, the N-methyl-α-phenyl-αmethylsuccinimide, of BP 121° to 122°C at 0.1 mm is obtained. After recrystallization from aqueous ethanol, this compound melts at 52° to 53°C.

brand name

Celontin (Parke-Davis).

Therapeutic Function

Anticonvulsant

Pharmacokinetics

Used in the treatment of epilepsy. Methsuximide suppresses the paroxysmal three cycle per second spike and wave activity associated with lapses of consciousness which is common in absence (petit mal) seizures. The frequency of epileptiform attacks is reduced, apparently by depression of the motor cortex and elevation of the threshold of the central nervous system to convulsive stimuli.

Clinical Use

Although methsuximide is less commonly used, it may be indicated for the control of absence seizures refractory to other drugs. Although it does not precipitate tonic-clonic convulsions, it often is combined with phenytoin or phenobarbital when absence seizures coexist with tonic-clonic symptoms. Much of the efficacy of methsuximide is attributed to its desmethyl metabolite. The half-life of methsuximide is between 2.6 and 4.0 hours, but the half-life for N-desmethylsuximide is 25 hours, causing it to accumulate substantially. Concentrations of greater than 40 g/mL may be associated with toxicity. Methsuximide is considered to be more toxic than ethosuximide.

Metabolism

Not Available

References

[1] nicholls, p. j., and orton, t.c. the physiological disposition of 14c-methsuximide in the rat. br.j.pharmacol. 45(1), 48-59 (1972).
[2] chen g, weston j k, bratton a c. anticonvulsant activity and toxicity of phensuximide, methsuximide and ethosuximide[j]. epilepsia, 1963, 4(1‐4): 66-76.
[3] sigler m, strassburg h m, boenigk h e. effective and safe but forgotten: methsuximide in intractable epilepsies in childhood[j]. seizure, 2001, 10(2): 120-124.
[4] wright j d, helsby n a, ward s a. the role of s‐mephenytoin hydroxylase (cyp2c19) in the metabolism of the antimalarial biguanides[j]. british journal of clinical pharmacology, 1995, 39(4): 441-444.
[5] guengerich f p. human cytochrome p450 enzymes[m]//cytochrome p450. springer us, 1995: 473-535.