Mephenytoin

Mephenytoin

File:Mephenytoin.png
Clinical data
Pregnancy category	US: C (Risk not ruled out)
Routes of administration	Oral
ATC code	N03AB04 (WHO)
Pharmacokinetic data
Elimination half-life	7 hours
Identifiers
IUPAC name 5-ethyl-3-methyl-5-phenyl-imidazolidine-2,4-dione
CAS Number	50-12-4
PubChem CID	4060
DrugBank	APRD00512
E number	{{#property:P628}}
ECHA InfoCard	{{#property:P2566}}
Chemical and physical data
Formula	C12H14N2O2
Molar mass	218.256

Mephenytoin (marketed as Mesantoin® by Novartis) is a hydantoin, used as an anticonvulsant. It was introduced approximately 10 years after phenytoin, in the late 1940s. The significant metabolite of mephenytoin is nirvanol (5-ethyl-5-phenylhydantoin), which was the first hydantoin (briefly used as a hypnotic). 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 1% of patients.

Mephenytoin is no longer available in the US or the UK. It is still studied largely because of its interesting hydroxylation polymorphism.

References

• The Treatment of Epilepsy edited by S. D. Shorvon, David R. Fish, Emilio Perucca, W. Edwin Dodson. Blackwell Publishing. 2004. ISBN 0-632-06046-8
• The Medical Treatment of Epilepsy by Stanley R Resor. Published by Marcel Dekker (1991). ISBN 0-8247-8549-5.
• The Comparative Toxicogenomics Database: Mephenytoin