Mephenytoin (marketed as Mesantoin by Novartis) is a

hydantoin Hydantoin, or glycolylurea, is a heterocyclic organic compound with the formula CH2C(O)NHC(O)NH. It is a colorless solid that arises from the reaction of glycolic acid and urea. It is an oxidized derivative of imidazolidine. In a more general sen ...

, used as an

anticonvulsant Anticonvulsants (also known as antiepileptic drugs, antiseizure drugs, or anti-seizure medications (ASM)) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also used in the treatme ...

. It was introduced approximately 10 years after

phenytoin Phenytoin (PHT), sold under the brand name Dilantin among others, is an anticonvulsant, anti-seizure medication. It is useful for the prevention of tonic-clonic seizures (also known as grand mal seizures) and focal seizures, but not absence se ...

, in the late 1940s. The significant

metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...

of mephenytoin is

nirvanol Nirvanol, also known as ethylphenylhydantoin, is a derivative of hydantoin with anticonvulsant properties. Its 5-ethyl-5-phenyl substitution pattern is similar to that of phenobarbital Phenobarbital, also known as phenobarbitone or phenob ...

(5-ethyl-5-phenylhydantoin), which was the first hydantoin (briefly used as a

hypnotic A hypnotic (from Ancient Greek, Greek ''Hypnos'', sleep), also known as a somnifacient or soporific, and commonly known as sleeping pills, are a class of psychoactive drugs whose primary function is to sleep induction, induce sleep and to trea ...

). However, nirvanol is quite toxic and mephenytoin was only considered after other less toxic anticonvulsants had failed. It can cause potentially fatal blood

dyscrasia In medicine, both ancient and modern, a dyscrasia is any of various disorders. The word has ancient Greek roots meaning "bad mixture". The concept of dyscrasia was developed by the Greek physician Galen (129–216 AD), who elaborated a model of ...

in 1% of patients. Mephenytoin is no longer available in the US or the UK. It is still studied largely because of its interesting

hydroxylation In chemistry, hydroxylation refers to the installation of a hydroxyl group () into an organic compound. Hydroxylations generate alcohols and phenols, which are very common functional groups. Hydroxylation confers some degree of water-solubility ...

polymorphism.

References

* * * Anticonvulsants Hydantoins {{anticonvulsant-stub