Ethotoin

Ethotoin (previously marketed as Peganone) is an anticonvulsant drug used in the treatment of epilepsy. It is a hydantoin, similar to phenytoin. It is not available in the United States.

Mechanism of action

The mechanism of action of ethotoin is similar to that of phenytoin.

Approval history

1957 Peganone was granted Food and Drug Administration (FDA) approval to Abbott Laboratories for treatment of grand mal (tonic clonic) and partial complex (psychomotor) seizures.
2003 Peganone was acquired from Abbott Laboratories by Ovation Pharmaceuticals (specialty pharmaceutical company who acquire underpromoted branded pharmaceutical products).
2018 It was announced by Recordati Rare Diseases Inc. that due to a combination of low product demand and complex manufacturing difficulties, product manufacturing, distribution and sale was being discontinued.

Indications and usage

Ethotoin is indicated for tonic-clonic and partial complex seizures.

Dosing

Ethotoin is available in 250 mg tablets. It is taken orally in 4 to 6 divided doses per day, preferably after food.

Side effects

Side effects include ataxia, visual disturbances, rash, and gastrointestinal problems.

Chemistry

Ethotoin is synthesized by the reaction of benzaldehyde oxynitrile (2) with urea or ammonium bicarbonate, which forms an intermediate urea derivative (3) which on acidic conditions cyclizes to 5-phenylhydantoin (4). Alkylation of this product using ethyl iodide leads to the formation of ethotoin (5).