Methylphenobarbital

Methylphenobarbital

Systematic (IUPAC) name
5-phenyl-5-ethyl- 3-methylbarbituric acid
Clinical data
AHFS/Drugs.com	International Drug Names
MedlinePlus	a605022
Pregnancy cat.	?
Legal status	Schedule IV (US)
Routes	?
Pharmacokinetic data
Bioavailability	?
Protein binding	70-76%
Metabolism	Hepatic
Half-life	34 hours
Excretion	?
Identifiers
CAS number	115-38-8 Y
ATC code	N03AA01
PubChem	CID 8271
DrugBank	APRD00047
ChemSpider	7972 Y
UNII	5NC67NU76B Y
KEGG	D00700 Y
ChEBI	CHEBI:6758 Y
ChEMBL	CHEMBL45029 Y
Chemical data
Formula	C13H14N2O3
Mol. mass	246.3 g/mol
SMILES	eMolecules & PubChem
InChI InChI=1S/C13H14N2O3/c1-3-13(9-7-5-4-6-8-9)10(16)14-12(18)15(2)11(13)17/h4-8H,3H2,1-2H3,(H,14,16,18) Y Key:ALARQZQTBTVLJV-UHFFFAOYSA-N Y
N(what is this?)  (verify)

Methylphenobarbital (INN), also known as mephobarbital (USAN, JAN) and mephobarbitone (BAN), marketed under brand names such as Mebaral, Mephyltaletten, Phemiton, and Prominal, is a drug which is a barbiturate derivative and is used primarily as an anticonvulsant, but also as a sedative and anxiolytic. It is the N-methylated analogue of phenobarbital and has similar indications, therapeutic value, and tolerability.

Approval History

• 1935 Mebaral was introduced by Winthrop Pharmaceuticals.
• 2001 Methylphenobarbital discontinued in the UK.
• 2003 Mebaral acquired by Ovation Pharmaceuticals (a specialty pharmaceutical company that acquired underpromoted branded pharmaceutical products).
• 2009 Ovation was acquired by Lundbeck, which now markets Mebaral. However, Lundbeck recently announced that they are abandoning the product because, under the FDA unapproved-drug campaign, FDA is no longer willing to allow it to be grandfathered. A new drug application was never submitted to the FDA to gain marketing approval. The drug will no longer be available when supplies are depleted, which is anticipated by the end of 2011.

Overdose

Symptoms of overdose of mephobarbital include confusion, decrease in or loss of reflexes, somnolence, fever, irritability, hypothermia, poor judgment, shortness of breath or slow/troubled breathing, slow heartbeat, slurred speech, staggering, trouble in sleeping, unusual movements of the eyes, weakness.

Chemistry

Mephobarbital (5-ethyl-1-methyl-5-phenylbarbituric acid) is synthesized according to one of the diagrams used for the phenobarbital synthesis, except one uses methylurea instead.

• W. Kropp, L. Taub, DE 537366  (1929).

See also

• Barbiturate

References

• The Treatment of Epilepsy 2nd Ed by S. D. Shorvon (Editor), David R. Fish (Editor), Emilio Perucca (Editor), W. Edwin Dodson (Editor). Published by Blackwell 2004. ISBN 0-632-06046-8