It is structurally related to thiamine (vitamin B1), but acts like a sedative, hypnotic, muscle relaxant and anticonvulsant, having the same mechanism of action as traditional barbiturates.

It is also rarely used for the management of agitation, restlessness, short-term insomnia and Parkinson's disease in the elderly, when all other treatment options have failed.

As opposed to barbiturates, clomethiazole doesn't affect the electrophysiological responses to excitatory aminoacids, and additionally, it also directly acts on chloride ion channels.

When clomethiazole is administered via IV in addition to carbamazepine, its clearance is increased by 30%, which results in a proportional reduction in plasma concentration.

As the drug can be fatal in high doses, prescribing clomethiazole outside of a controlled environment, for example a hospital, is not recommended, especially because there are much less toxic alternatives, such as diazepam.