PHENOBARBITAL

First marketed in 1912

Details

Stereochemistry	ACHIRAL
Molecular Formula	C12H12N2O3
Molecular Weight	232.2353
Optical Activity	NONE
Defined Stereocenters	0 / 0
E/Z Centers	0
Charge	0

SHOW SMILES / InChI

Structure Search

SMILES

CCC1(C(=O)NC(=O)NC1=O)C2=CC=CC=C2

InChI

InChIKey=DDBREPKUVSBGFI-UHFFFAOYSA-N

InChI=1S/C12H12N2O3/c1-2-12(8-6-4-3-5-7-8)9(15)13-11(17)14-10(12)16/h3-7H,2H2,1H3,(H2,13,14,15,16,17)

HIDE SMILES / InChI

Description
Sources: https://www.drugs.com/monograph/phenobarbital.html
Curator's Comment: description was created based on several sources, including https://www.drugbank.ca/drugs/DB01174

Phenobarbital is a barbiturate derivative used to treat insomnia and anxiety, seizures, hyperbilirubinemia in neonates and cholestasis. Phenobarbital promotes binding to inhibitory gamma-aminobutyric acid subtype receptors, and modulates chloride currents through receptor channels.

CNS Activity

Originator

Approval Year

Targets

Primary Target	Pharmacology	Condition	Potency
GABA-A receptor; anion channel 202 Target ID: CHEMBL2093872 Sources: https://www.ncbi.nlm.nih.gov/pubmed/16981722	Positive Allosteric Modulator 179

Conditions

Condition	Modality	Highest Phase	Product
Insomnia 108 Sources: https://www.drugs.com/monograph/phenobarbital.html	Primary	Approved 8429	LUMINAL Approved Use Short-term treatment of insomnia. However, generally not used orally as a hypnotic because several hours are required to achieve maximal effectsa and barbiturates have decreased effectiveness for sleep induction and maintenance after 2 weeks.
Anxiety 267 Sources: https://www.drugs.com/monograph/phenobarbital.html	Primary	Approved 8429	LUMINAL Approved Use Relief of anxiety, tension, and apprehension. However, barbiturates used infrequently for routine sedation, since there are few clinical situations in which oral barbiturates provide a safety or efficacy advantage over nonbarbiturate sedatives/hypnotics.
Tonic-clonic seizures 7 Sources: https://www.drugs.com/monograph/phenobarbital.html	Primary	Approved 8429	LUMINAL Approved Use Management of tonic-clonic seizures and partial seizures; used alone (particularly in infants and young children) or, more commonly, in combination with phenytoin or other anticonvulsants.
Febrile seizures 6 Sources: https://www.drugs.com/monograph/phenobarbital.html	Preventing	Approved 8429	LUMINAL Approved Use Prevention of febrile seizures in infants and young children.
Status epilepticus 12 Sources: https://www.drugs.com/monograph/phenobarbital.html	Primary	Approved 8429	LUMINAL Approved Use Second-line agent in the termination of status epilepticus; may be useful to prevent seizure recurrence after seizures are initially terminated with other anticonvulsants (e.g., diazepam, phenytoin) or for termination of status epilepticus that does not respond to initial therapy with other anticonvulsants. Usefulness of parenteral phenobarbital in terminating acute seizure episodes is limited by its slow onset of action
Epilepsy 121 Sources: https://www.drugs.com/monograph/phenobarbital.html	Preventing	Approved 8429	LUMINAL Approved Use Prophylactic management of epilepsy.
Hyperbilirubinemia 6 Sources: https://www.drugs.com/monograph/phenobarbital.html	Primary	Approved 8429	LUMINAL Approved Use Prevention and treatment of hyperbilirubinemia in neonates
Cholestasis 12 Sources: https://www.drugs.com/monograph/phenobarbital.html	Primary	Approved 8429	LUMINAL Approved Use Has been used to reduce bilirubin concentrations in patients with congenital nonhemolytic unconjugated hyperbilirubinemia or chronic intrahepatic cholestasis. Has been used in the management of hyperlipemia associated with intrahepatic and extrahepatic cholestasis

PubMed

Title	Date	PubMed
Enhancement of GABAergic inhibition: a mechanism of action of benzodiazepines, phenobarbital, valproate and L-cycloserine in the cat spinal cord.	1982	6130936
General anaesthetic actions on ligand-gated ion channels.	1999 Aug 15	10487207
On the mechanism of alleviation by phenobarbital of the malfunction of an epilepsy-linked GABA(A) receptor.	2006 Sep 26	16981722

Patents

Sample Use Guides

In Vivo Use Guide

Phenobarbital is administered orally or by IM or slow IV injection. For treatment of anxiety, phenobarbital is administered orally 6 mg/kg daily or 180 mg/m2 daily, in 3 equally divided doses. For treatment of seizure disorders, the drug is administered orally 15–50 mg 2 or 3 times daily. Alternatively, 3–5 mg/kg or 125 mg/m2 daily; IV or IM 4–6 mg/kg daily for 7–10 days to reach therapeutic blood concentrations; alternatively, 10–15 mg/kg daily.

Route of Administration: Other

In Vitro Use Guide

Potentiation of the GABAA by phenobarbital was evaluated in HEK293 cells expressing recombinant rat GABAA receptors. Currents were recorded using the cell-flow technique and corrected for receptor desensitization. Co-application of phenobarbital with 300uM GABA lead to 20-30 amplification of chloride currents with EC50 of 100-200 uM

Name

Type

Language

PHENOBARBITAL

Official Name

English

PHENOBARBITALUM

Common Name

English

TEDRAL SUSPENSION

Common Name

English

phenobarbital [INN]

Common Name

English

THEOPHED

Common Name

English

GARDEPANYL

Common Name

English

PHENOBARBITAL [USP MONOGRAPH]

Common Name

English

PHENOBARBITAL [EP MONOGRAPH]

Common Name

English

LUMINAL

Brand Name

English

PHENOBARBITAL [JAN]

Common Name

English

5-Ethyl-5-phenylbarbituric acid

Systematic Name

English

5-ETHYL-5-PHENYLPYRIMIDINE-2,4,6(1H,3H,5H)-TRIONE

Systematic Name

English

2,4,6(1H,3H,5H)-PYRIMIDINETRIONE, 5-ETHYL-5-PHENYL-

Systematic Name

English

NSC-9848

Code

English

METHYLPHENOBARBITAL IMPURITY A [EP IMPURITY]

Common Name

English

PHENOBARBITAL [WHO-IP]

Common Name

English

PHENOBARBITAL CIV [USP-RS]

Common Name

English

PRIMATENE

Common Name

English

PRIMIDONE IMPURITY B [EP IMPURITY]

Common Name

English

VERSOMNAL

Common Name

English

Phenobarbital [WHO-DD]

Common Name

English

PHENOBARBITAL [MART.]

Common Name

English

GARDENAL

Brand Name

English

PHENOBARBITAL CIV

Common Name

English

PHENOBARBITONE

Common Name

English

PHENOBARBITALUM [HPUS]

Common Name

English

PHENOBARBITAL [IARC]

Common Name

English

PHENOBARBITAL [MI]

Common Name

English

TRIPHENATOL

Common Name

English

PHENOBARBITALUM [WHO-IP LATIN]

Common Name

English

TEDRIGEN

Common Name

English

PHENOBARBITAL [EP IMPURITY]

Common Name

English

NSC-128143

Code

English

SEDOPHEN

Common Name

English

TEDRAL

Common Name

English

PHENOBARBITAL [HSDB]

Common Name

English

Classification Tree Code System Code

WHO-VATC

QN03AA02