Current Scheduling Status
Year(s) and type of review / ECDD meetings
Drug Class

Recommendation (from TRS)

Substance identification
Thiobutabarbital (CAS—2095-57-0, and the sodium salt CAS 947-08-0), 5-(1-methylpropyl)-5-ethyl-2-thiobarbituric acid, is also known as thibutabarbital, and venobarbital. It is a racemic


Similarity to known substances and effects on the CNS
Thiobutabarbital has been classified pharmacologically as an ultra-short-acting barbiturate used as an intravenous anaesthetic agent. Barbiturates of this type have not been scheduled. Doserelated drowsiness, vertigo, confusion, and incoordination do occur. The drug, like other barbiturates, is metabolized by hepatic microsomal enzymes and stimulates the production of these enzymes. Like the other short-acting barbiturates, thiobutabarbital produces a dose-related depression of the central nervous system, ranging from mild sedation to general anaesthesia and coma. Tolerance, both natural and functional, can occur. Cross-tolerance may occur to other barbiturates. ethanol, and other sedative—hypnotic drugs.

Dependence potential
There is no information on the ability of thiobutabarbital to induce physical or psychic dependence in either animals or man in controlled laboratory studies.

Actual abuse and or/evidence of likelihood of abuse
There are no reports of abuse, seizures, or illicit trafficking. Six countries have reported that the substance is under national control.

Therapeutic usefulness
Thiobutabarbital is used as an intravenous anaesthetic. It is available or registered in twelve countries, but is used less extensively than thiopental (see section 3.29). The Committee rated the therapeutic usefulness of thiobutabarbital as an intravenous anaesthetic agent as high.

The Committee found that there was insufficient evidence that thiobutabarbital is being, or is likely to be, abused so as to constitute a public health and social problem warranting the placing of the substance under international control. Based on the data concerning its pharmacological profile, dependence potential, and actual abuse, the Committee rated the likelihood of abuse of thiobutabarbital as indeterminate. The degree of the public health and social problems associated with the drug wasfound to be low and its‘therapeutic usefulness high. In the light of this assessment; the Committee recommended against scheduling of the drug..

ECDD Recommendation

Scheduling/control not currently recommended