Thiopental sodium

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

Recommendation (from TRS)

Substance identification
Thiopental sodium (INN, CAS~-71—73> 8), chemically 5-ethyl-5-(1-methylbutyl)-2-thiobarbituric acid sodium salt, is also known as penthiobarbital, penthiopental sodium, thiomebumal sodium, thiomebumalum, thiomebutal, thiopental, and thiopentone sodium.

Similarity to known substances and effects on the CNS
Thiopental sodium has been classified pharmacologically as an ultra-short-acting barbiturate used as an intravenous anaesthetic agent. Barbiturates of this type have not been scheduled. Dose related 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 other short-acting barbiturates, thiopental sodium 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
In studies of barbiturate-reinforced responding in animals trained to self-administer the drugs, responding was shown to be increased and was maintained by thiopental sodium, indicating that the drug could potentially cause psychic dependence. There are no reports on the ability of thiopental to induce physical dependence in’ animals or man.

Actual abuse and or/evidence of likelihood of abuse
There are isolated reports of abuse from Austria, Czechoslovakia, and Norway. The substance has occasionally been used for committing suicide. There are a small number of reports of seizures from the Republic of Korea and the United States of America. Nine countries have reported that the substance has been put under national control. No government has reported on any public health or social problems caused by this substance.

Therapeutic usefulness
Thiopental is very widely used as an intravenous anaesthetic and to a lesser extent in status epilepticus and in cerebral oedema and cerebral ischaemia. It is available and’or registered in 71 countries, mainly for hospital use. It is effective, and relatively safe to use if administered by skilled health personnel. The Committee rated the therapeutic usefulness of thiopental sodium as an intravenous anaesthetic agent as high.

The Committee found that there was insufficient evidence that thiopental sodium 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 thiopental sodium as moderate. The degree of the public health and social problems associated with the drug was found 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