clomethiazole at a glance
Medicine class
Sedative and hypnotic with anticonvulsant effects
Licensed roles
Selected symptoms in older people and supervised alcohol withdrawal
Alcohol
Do not drink alcohol during treatment because breathing and consciousness may be dangerously suppressed
Driving
Do not drive or operate machinery during treatment
What is clomethiazole used for?
Selected UK products are licensed for:
Restlessness and agitation in older people.
Severe insomnia in older people.
Alcohol-withdrawal symptoms under close hospital supervision.
How does clomethiazole work?
Clomethiazole enhances signalling through GABA-A receptors, reducing neuronal activity and producing sedative, hypnotic, muscle-relaxant and anticonvulsant effects. It does not act through the benzodiazepine binding site.
clomethiazole preparations and strengths
Capsule
Route: Oral
Strengths: 192 mg
Syrup
Route: Oral
Strengths: 31.5 mg/mL
How to take clomethiazole
Take clomethiazole exactly as directed on the dispensing label. Do not drink alcohol, drive or operate machinery during treatment.
Swallow capsules whole with water; do not chew, crush or break them.
Dilute syrup with water or juice and take it immediately; do not save the mixture.
Minimise contact between diluted syrup and plastic because clomethiazole can bind to some plastics.
clomethiazole side effects
Common or expected effects
- Blocked or irritated nose, sometimes with increased nasal or bronchial secretions
- Eye irritation
- Headache
- Drowsiness or excessive sedation
- Stomach upset
- Occasional next-day effects in older people
Get urgent medical advice
- Severe allergic reaction, including swelling, wheezing or breathing difficulty
- Blistering skin eruption
- Marked sedation, reduced consciousness or respiratory depression
- Paradoxical severe excitement or confusion
- Dependence and withdrawal after inappropriate prolonged or excessive use
clomethiazole in pregnancy
Clomethiazole should generally not be used during pregnancy, particularly in the first and last trimesters, unless there are compelling clinical reasons. Discuss individual risks and benefits with the prescriber rather than stopping prescribed treatment without advice.
clomethiazole while breastfeeding
Clomethiazole passes into breast milk, and its effects on a breastfed infant are uncertain. Use requires an individual assessment of benefit and potential infant risk.
clomethiazole interactions
Clomethiazole has important sedative and metabolic interactions. Check prescribed, non-prescription and recreational substances before use.
Alcohol
Can markedly increase sedation and respiratory depression; fatal reactions have been reported, particularly with alcohol-related liver disease.
Benzodiazepines and other central nervous system depressants
Sedative and cardiorespiratory effects can be additive or increased.
Cimetidine
May increase clomethiazole concentration and sedative effects.
Common questions about clomethiazole
Answers are fully visible for fast scanning and source review.
Is clomethiazole a benzodiazepine?
No. It is pharmacologically distinct from benzodiazepines, although both can enhance inhibitory GABA signalling and cause sedation.
Can I drink alcohol while taking clomethiazole?
No. Alcohol can dangerously intensify sedation and suppress breathing.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.