CHLORMEZANONE

US Previously Marketed

First approved in 1958

Details

Stereochemistry	RACEMIC
Molecular Formula	C11H12ClNO3S
Molecular Weight	273.736
Optical Activity	( + / - )
Defined Stereocenters	0 / 1
E/Z Centers	0
Charge	0

SHOW SMILES / InChI

Structure Search

SMILES

CN1C(C2=CC=C(Cl)C=C2)S(=O)(=O)CCC1=O

InChI

InChIKey=WEQAYVWKMWHEJO-UHFFFAOYSA-N

InChI=1S/C11H12ClNO3S/c1-13-10(14)6-7-17(15,16)11(13)8-2-4-9(12)5-3-8/h2-5,11H,6-7H2,1H3

HIDE SMILES / InChI

Molecular Formula	C11H12ClNO3S
Molecular Weight	273.736
Charge	0
Count

Stereochemistry	RACEMIC
Additional Stereochemistry	No
Defined Stereocenters	0 / 1
E/Z Centers	0
Optical Activity	( + / - )

Description
Sources: www.ncbi.nlm.nih.gov/mesh/68002720
Curator's Comment: description was created based on several sources, including http://www.who.int/medicines/publications/drugalerts/drug_alert53chlormezanone_serious_cutaneous_reactions.pdf | https://www.drugbank.ca/drugs/DB01178

Chlormezanone (TRANCOPAL®) is a non-benzodiazepine that is used in the management of anxiety. It has been suggested for use in the treatment of muscle spasm. It binds to central benzodiazepine receptors which interact allosterically with GABA receptors. This potentiates the effects of the inhibitory neurotransmitter GABA, increasing the inhibition of the ascending reticular activating system and blocking the cortical and limbic arousal that occurs following stimulation of the reticular pathways. Chlormezanone (TRANCOPAL®) was discontinued worldwide in 1996 by Sanofi due to confirmed serious and rare cutaneous reactions (toxic epidermal necrolysis also known as Stevens-Johnson syndrome).

CNS Activity

Originator

Approval Year

Conditions

Condition	Modality	Targets	Highest Phase	Product
Muscle spasm 41 Sources: https://www.ncbi.nlm.nih.gov/mesh/68002720	Primary		Withdrawn	Unknown Approved Use Unknown

C_max

Value	Dose	Co-administered	Analyte	Population
4.62 mg/L EXPERIMENT https://www.ncbi.nlm.nih.gov/pubmed/2399514	400 mg single, oral dose: 400 mg route of administration: Oral experiment type: SINGLE co-administered:		CHLORMEZANONE plasma	Homo sapiens population: HEALTHY age: ADULT sex: MALE food status: UNKNOWN

AUC

Value	Dose	Co-administered	Analyte	Population
224.93 mg × h/L EXPERIMENT https://www.ncbi.nlm.nih.gov/pubmed/2399514	400 mg single, oral dose: 400 mg route of administration: Oral experiment type: SINGLE co-administered:		CHLORMEZANONE plasma	Homo sapiens population: HEALTHY age: ADULT sex: MALE food status: UNKNOWN
164.19 mg × h/L EXPERIMENT https://www.ncbi.nlm.nih.gov/pubmed/2399514	400 mg 1 times / day steady-state, oral dose: 400 mg route of administration: Oral experiment type: STEADY-STATE co-administered:		CHLORMEZANONE plasma	Homo sapiens population: HEALTHY age: ADULT sex: MALE food status: UNKNOWN

T_1/2

Value	Dose	Co-administered	Analyte	Population
40.5 h EXPERIMENT https://www.ncbi.nlm.nih.gov/pubmed/2399514	400 mg single, oral dose: 400 mg route of administration: Oral experiment type: SINGLE co-administered:		CHLORMEZANONE plasma	Homo sapiens population: HEALTHY age: ADULT sex: MALE food status: UNKNOWN
37.14 h EXPERIMENT https://www.ncbi.nlm.nih.gov/pubmed/2399514	400 mg 1 times / day steady-state, oral dose: 400 mg route of administration: Oral experiment type: STEADY-STATE co-administered:		CHLORMEZANONE plasma	Homo sapiens population: HEALTHY age: ADULT sex: MALE food status: UNKNOWN

Doses

Dose	Population	Adverse events
4 g single, oral Overdose Dose: 4 g Route: oral Route: single Dose: 4 g Sources: https://pubmed.ncbi.nlm.nih.gov/1936060	healthy, 46 Health Status: healthy Age Group: 46 Sex: M Sources: https://pubmed.ncbi.nlm.nih.gov/1936060	Disc. AE: Coma... AEs leading to discontinuation/dose reduction: Coma (grade 5) Sources: https://pubmed.ncbi.nlm.nih.gov/1936060
400 mg 3 times / day multiple, oral Recommended Dose: 400 mg, 3 times / day Route: oral Route: multiple Dose: 400 mg, 3 times / day Sources: https://pubmed.ncbi.nlm.nih.gov/1936060	unhealthy Health Status: unhealthy Sources: https://pubmed.ncbi.nlm.nih.gov/1936060	Disc. AE: Muscular weakness, Ataxia... AEs leading to discontinuation/dose reduction: Muscular weakness Ataxia Stumbling Tachycardia Sources: https://pubmed.ncbi.nlm.nih.gov/1936060
800 mg single, oral Studied dose Dose: 800 mg Route: oral Route: single Dose: 800 mg Sources: https://pubmed.ncbi.nlm.nih.gov/1936060	unhealthy Health Status: unhealthy Sources: https://pubmed.ncbi.nlm.nih.gov/1936060	Sources: https://pubmed.ncbi.nlm.nih.gov/1936060

AEs

AE	Significance	Dose	Population
Coma	grade 5 Disc. AE	4 g single, oral Overdose Dose: 4 g Route: oral Route: single Dose: 4 g Sources: https://pubmed.ncbi.nlm.nih.gov/1936060	healthy, 46 Health Status: healthy Age Group: 46 Sex: M Sources: https://pubmed.ncbi.nlm.nih.gov/1936060
Ataxia	Disc. AE	400 mg 3 times / day multiple, oral Recommended Dose: 400 mg, 3 times / day Route: oral Route: multiple Dose: 400 mg, 3 times / day Sources: https://pubmed.ncbi.nlm.nih.gov/1936060	unhealthy Health Status: unhealthy Sources: https://pubmed.ncbi.nlm.nih.gov/1936060
Muscular weakness	Disc. AE	400 mg 3 times / day multiple, oral Recommended Dose: 400 mg, 3 times / day Route: oral Route: multiple Dose: 400 mg, 3 times / day Sources: https://pubmed.ncbi.nlm.nih.gov/1936060	unhealthy Health Status: unhealthy Sources: https://pubmed.ncbi.nlm.nih.gov/1936060
Stumbling	Disc. AE	400 mg 3 times / day multiple, oral Recommended Dose: 400 mg, 3 times / day Route: oral Route: multiple Dose: 400 mg, 3 times / day Sources: https://pubmed.ncbi.nlm.nih.gov/1936060	unhealthy Health Status: unhealthy Sources: https://pubmed.ncbi.nlm.nih.gov/1936060
Tachycardia	Disc. AE	400 mg 3 times / day multiple, oral Recommended Dose: 400 mg, 3 times / day Route: oral Route: multiple Dose: 400 mg, 3 times / day Sources: https://pubmed.ncbi.nlm.nih.gov/1936060	unhealthy Health Status: unhealthy Sources: https://pubmed.ncbi.nlm.nih.gov/1936060

Sourcing

Vendor/Aggregator	ID	URL
ChEBI	CHEBI:3619	https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:3619
ChemicalBook	CB8355331	https://www.chemicalbook.com/ChemicalProductProperty_EN_CB8355331
eMolecules	1934274	https://www.emolecules.com/cgi-bin/more?vid=1934274
MolPort	MolPort-003-666-762	https://www.molport.com/shop/molecule-link/MolPort-003-666-762
Selleck Chemicals	Chlormezanone(Trancopal)	http://www.selleckchem.com/products/Chlormezanone(Trancopal).html

PubMed

Title	Date	PubMed
Toxic epidermal necrolysis and Stevens-Johnson syndrome.	2010-12-16	21162721
Anesthetic management for emergent Cesarean section in a patient with toxic epidermal necrolysis -A case report-.	2010-12	21286431
Flupirtine in pain management: pharmacological properties and clinical use.	2010-10	20839897
[Retrospective analysis of the combined therapy of terazosin with chlormezanone for chronic prostatitis/chronic pelvic pain syndrome].	2009-08	19852273
Fixed drug eruption resulting from fluconazole use: a case report.	2009-07-06	19830193
Adjuvant laser acupuncture in the treatment of whiplash injuries: a prospective, randomized placebo-controlled trial.	2006-03	16703253
Biology and therapy of fibromyalgia. New therapies in fibromyalgia.	2006	16762044
Investigations of interactions of chlormezanone racemate and its enantiomers on human keratinocytes and human leucoytes in vitro.	2004-05-11	15897685
[New findings on the synthesis of the centrally acting muscle relaxant chlormezanone and its resolution of a gram scale using a Chiralcel OD column].	2003-02	12641322
Stimulatory effects of chlorzoxazone, a centrally acting muscle relaxant, on large conductance calcium-activated potassium channels in pituitary GH3 cells.	2003-01-03	12480161
Risk of serious skin disorders among users of oral antifungals: a population-based study.	2002-11-28	12456265
[Retrospective of national pharmacovigilance surveys on drug-induced bullous, vesicular eruptions: methods and results ].	2002-11-09	12422541
[Acute confusional syndrome associated to chlormezanone].	2002-11	12587517
[Acute confusional syndrome associated to Chlormezanone use].	2002-06	12194698
[Lyell syndrome in Senegal: responsibility of thiacetazone].	2001-12	11908132
[Important pharmaceutical-chemical characteristics of the central muscle relaxant chlormezanone].	2000-04	10798243
[Cleavage and biotransformation of the central muscle relaxant chlormezanone].	1998-09	9770210
Chlormezanone-induced fulminant hepatitis in a pregnant woman: successful delivery and liver transplantation.	1992-05-01	1611024
[Pharmacokinetics of chlormezanone in healthy volunteers].	1990-07-01	2399514
[Drug-induced hepatitis with cholestasis following therapy with chlormezanone].	1985-12	4090569
Drug-related gustatory disorders.	1978-01-01	623418

Patents

Sample Use Guides

In Vivo Use Guide

Unknown

Route of Administration: Oral

In Vitro Use Guide

The investigation was performed in order to investigate whether the racemic chlormezanone and both enantiomers differ in their potential cytotoxicty for human HaCaT keratinocytes. In the dosage range of 0.001 to 0.1 mg/ml chlormezanone, no antiproliferative effects were measured with the racemate and both enantiomers. At 1.0 mg/ml, a decrease of proliferative activity was seen after 48 h incubation time of about 50% for the enantiomers and of about 80% for the racemate (PicoGreen assay) and 50% (enantiomers) or 21% (racemate) in the ATP assay, respectively. Oxygen radicals production by human interleukin-3-stimulated leukocytes was significantly inhibited at concentrations < or =0.01 mg/ml by the racemate and the (+)-enantiomer, whereas the (-)-enantiomer was less effective.

Substance Class	Chemical Created by `admin` on `Mon Mar 31 18:23:57 GMT 2025` Edited by `admin` on `Mon Mar 31 18:23:57 GMT 2025`
Record UNII	GP568V9G19
Record Status	`Validated (UNII)`
Record Version

Download

Name

Type

Language

CHLORMEZANONE

Official Name

English

TRANCOPAL

Preferred Name

English

CHLORMEZANONE [VANDF]

Common Name

English

CHLORMEZANONE [HSDB]

Common Name

English

Chlormezanone [WHO-DD]

Common Name

English

NSC-169108

Code

English

chlormezanone [INN]

Common Name

English

CHLORMEZANONE [JAN]

Common Name

English

CHLORMEZANONE [MI]

Common Name

English

CHLORMEZANONE [ORANGE BOOK]

Common Name

English

CHLORMEZANONE [MART.]

Common Name

English

Classification Tree Code System Code

WHO-ATC

M03BB52