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Details

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

SHOW SMILES / InChI
Structure of CHLORMEZANONE, (-)-

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).

Approval Year

Conditions

Conditions

ConditionModalityTargetsHighest PhaseProduct
Primary
Unknown

Approved Use

Unknown
Cmax

Cmax

ValueDoseCo-administeredAnalytePopulation
4.62 mg/L
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

AUC

ValueDoseCo-administeredAnalytePopulation
224.93 mg × h/L
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
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
T1/2

T1/2

ValueDoseCo-administeredAnalytePopulation
40.5 h
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
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

Doses

DosePopulationAdverse events​
4 g single, oral
Overdose
Dose: 4 g
Route: oral
Route: single
Dose: 4 g
Sources:
healthy, 46
Health Status: healthy
Age Group: 46
Sex: M
Sources:
Disc. AE: Coma...
AEs leading to
discontinuation/dose reduction:
Coma (grade 5)
Sources:
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:
unhealthy
Health Status: unhealthy
Sources:
Disc. AE: Muscular weakness, Ataxia...
AEs leading to
discontinuation/dose reduction:
Muscular weakness
Ataxia
Stumbling
Tachycardia
Sources:
800 mg single, oral
Studied dose
Dose: 800 mg
Route: oral
Route: single
Dose: 800 mg
Sources:
unhealthy
Health Status: unhealthy
Sources:
AEs

AEs

AESignificanceDosePopulation
Coma grade 5
Disc. AE
4 g single, oral
Overdose
Dose: 4 g
Route: oral
Route: single
Dose: 4 g
Sources:
healthy, 46
Health Status: healthy
Age Group: 46
Sex: M
Sources:
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:
unhealthy
Health Status: unhealthy
Sources:
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:
unhealthy
Health Status: unhealthy
Sources:
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:
unhealthy
Health Status: unhealthy
Sources:
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:
unhealthy
Health Status: unhealthy
Sources:
PubMed

PubMed

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

Patents

Sample Use Guides

In Vivo Use Guide
Unknown
Route of Administration: Oral
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 23:10:46 GMT 2025
Edited
by admin
on Mon Mar 31 23:10:46 GMT 2025
Record UNII
C14WB33Y0S
Record Status Validated (UNII)
Record Version
  • Download
Name Type Language
(-)-CHLORMEZANONE
Preferred Name English
CHLORMEZANONE, (-)-
Common Name English
(-)-FENAROL
Common Name English
4H-1,3-THIAZIN-4-ONE, 2-(4-CHLOROPHENYL)TETRAHYDRO-3-METHYL-, 1,1-DIOXIDE, (-)-
Systematic Name English
Code System Code Type Description
FDA UNII
C14WB33Y0S
Created by admin on Mon Mar 31 23:10:46 GMT 2025 , Edited by admin on Mon Mar 31 23:10:46 GMT 2025
PRIMARY
CAS
102818-67-7
Created by admin on Mon Mar 31 23:10:46 GMT 2025 , Edited by admin on Mon Mar 31 23:10:46 GMT 2025
PRIMARY
Related Record Type Details
RACEMATE -> ENANTIOMER