Clomethiazole

Clomethiazole

Systematic (IUPAC) name
5-(2-Chloroethyl)-4-methyl-1,3-thiazole
Clinical data
AHFS/Drugs.com	International Drug Names
Pregnancy cat.	?
Legal status	POM (UK)
Routes	Oral
Identifiers
CAS number	533-45-9 N
ATC code	N05CM02
PubChem	CID 10783
ChemSpider	10327 Y
UNII	0C5DBZ19HV Y
KEGG	D07330 Y
ChEMBL	CHEMBL315795 Y
Chemical data
Formula	C6H8ClNS
Mol. mass	161.653 g/mol
SMILES	eMolecules & PubChem
InChI InChI=1S/C6H8ClNS/c1-5-6(2-3-7)9-4-8-5/h4H,2-3H2,1H3 Y Key:PCLITLDOTJTVDJ-UHFFFAOYSA-N Y
N(what is this?)  (verify)

Clomethiazole (also called chlormethiazole) is a sedative and hypnotic originally developed by Hoffmann-Le Roche in the 1930s^[1]. The drug is used in treating and preventing symptoms of acute alcohol withdrawal.

It is a drug which is structurally related to thiamine (vitamin B₁) but acts like a sedative, hypnotic, muscle relaxant and anticonvulsant. It is also used for the management of agitation, restlessness, short-term insomnia and Parkinson's disease in the elderly. In the U.K, it is sold under the brand Heminevrin (AstraZeneca Pharmaceuticals). Another brand name includes Nevrin (in Romania). The drug is marketed either as a free base in an oily suspension containing 192 mg in capsule form, or as clomethiazole edisylate (ethane disulfonate) syrup.

Pharmacology

Chlomethiazole acts as a positive allosteric modulator at the barbiturate/picrotoxin site of the GABA-A receptor. It works to enhance the action of the neurotransmitter GABA at this receptor.^{[citation needed]}GABA is the major inhibitory neurotransmitter in the brain and produces anxiolytic, anticonvulsant, sedative, and hypnotic effects. Chlomethiazole appears to also have another mechanism of action mediating some of its hypothermic and neuroprotective effects.^{[citation needed]}

Adverse effects

Long term and frequent use of chlomethiazole can cause tolerance and physical dependence. Abrupt withdrawal may result in symptoms similar to those of sudden withdrawal of alcohol or benzodiazepines.^[2]

Overdose

Chlomethiazole is particularly toxic and dangerous in overdose and can be potentially fatal.^[3]

References

1. ^ CH patent 200248, "Verfahren zur Darstellung von 4-Methyl-5-B-chloräthylthiazol" 
2. ^ Reilly, T. M. (1976). "Physiological dependence on, and symptoms of withdrawal from, chlormethiazole". The British journal of psychiatry : the journal of mental science 128: 375–378. PMID 1260235.  edit
3. ^ Reith, D. M.; Fountain, J.; McDowell, R.; Tilyard, M. (2003). "Comparison of the fatal toxicity index of zopiclone with benzodiazepines". Journal of toxicology. Clinical toxicology 41 (7): 975–980. PMID 14705844.  edit