Phenylbutyrate

Sodium phenylbutyrate

Clinical data
AHFS/Drugs.com	Consumer Drug Information
License data	EU EMA: Ammonaps US FDA: Sodium_phenylbutyrate
Pregnancy category	US: C (Risk not ruled out)
ATC code	A16AX03 (WHO)
Legal status
Legal status	US: ℞-only
Pharmacokinetic data
Metabolism	Hepatic and renal to phenylacetic acid
Biological half-life	0.8 hours (phenylbutyrate), 1.15-1.29 hours (phenylacetate)
Excretion	Urine (80-100% as phenylacetylglutamine)
Identifiers
IUPAC name Sodium 4-phenylbutanoate
CAS Number	1716-12-7 N
PubChem CID	5258
ChemSpider	5068 N
ChEBI	CHEBI:75316 N
ChEMBL	CHEMBL1746 N
ECHA InfoCard	100.130.318
Chemical and physical data
Formula	C10H11NaO2
Molar mass	186.2 g/mol
3D model (Jmol)	Interactive image
SMILES [Na+].[O-]C(=O)C(c1ccccc1)CC
InChI InChI=1S/C10H12O2.Na/c1-2-9(10(11)12)8-6-4-3-5-7-8;/h3-7,9H,2H2,1H3,(H,11,12);/q;+1/p-1 Y Key:RHLFTMGPBSLHRS-UHFFFAOYSA-M Y
NY (what is this?)

Sodium phenylbutyrate is a salt of an aromatic fatty acid, 4-phenylbutyrate (4-PBA) or 4-phenylbutyric acid. The compound is used to treat urea cycle disorders, because its metabolites offer an alternative pathway to the urea cycle to allow excretion of excess nitrogen. It is an orphan drug, marketed by Ucyclyd Pharma under the trade name Buphenyl, by Swedish Orphan International (Sweden) as Ammonaps, and by Fyrlklövern Scandinavia as triButyrate.

Sodium phenylbutyrate is also a histone deacetylase inhibitor and chemical chaperone, leading respectively to research into its use as an anti-cancer agent and in protein misfolding diseases such as cystic fibrosis.

Sodium phenylbutyrate is a sodium salt of an aromatic fatty acid, made up of an aromatic ring and butyric acid. The chemical name for sodium phenylbutyrate is 4-phenylbutyric acid, sodium salt. It forms water-soluble off-white crystals.

Sodium phenylbutyrate is taken orally or by nasogastric intubation as a tablet or powder, and tastes very salty and bitter. It treats urea cycle disorders, genetic diseases in which nitrogen waste builds up in the blood plasma as ammonia glutamine (a state called hyperammonemia) due to deficiences in the enzymes carbamoyl phosphate synthetase I, ornithine transcarbamylase, or argininosuccinic acid synthetase. Uncontrolled, this causes mental retardation and early death. Sodium phenylbutyrate metabolites allows the kidneys to excrete excess nitrogen in place of urea, and coupled with dialysis, amino acid supplements and a protein-restricted diet, children born with urea cycle disorders can usually survive beyond 12 months. Patients may need treatment for all their life. The treatment was introduced by researchers in the 1990s, and approved by the FDA on 13 May 1996.