Probarbital sodium

Current Scheduling Status
None
Year(s) and type of review / ECDD meetings
Drug Class

Recommendation (from TRS)

Substance identification
Probarbital sodium (INN, CAS-143-82-8 sodium salt), chemically 5-ethyl-5-isopropylbarbituric acid, is also known as ethypropymalum (acid). It is a racemic mixture.

Similarity to known substances and effects on the CNS
Although there are only limited data available, probarbital sodium has been classified pharmacologically as an intermediateacting sedative-hypnotic barbiturate with a profile similar to that of pentobarbital. As it is a hypnotic, it is presumed that dose-related drowsiness, vertigo, confusion, and incoordination can occur. The drug, like other barbiturates, is metabolized by hepatic microsomal enzymes and stimulates the production of these enzymes. The drug produces typical barbiturate-like sedative-hypnotic effects on the central nervous system. As it is a hypnotic, it is presumed that 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 probarbital sodium 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 have been no reports of abuse, illicit trafficking, or clandestine manufacture. The drug is under national control in five countries.

Therapeutic usefulness
Sodium and calcium salts of the compound have been used as sedatives and hypnotics. Two countries reported that the drug is available for use. There is no indication that the drug has been marketed during the past five years. The Committee rated the therapeutic usefulness of probarbital sodium as relatively low.

Recommendation
The Committee found that there was insufficient evidence that probarbital 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. On the basis of the very limited data concerning its pharmacological profile, dependence potential, and actual abuse, the Committee rated the likelihood of abuse of probarbital sodium as indeterminate. The degree of the public health and social problems associated with the drug was found to be low as was its therapeutic usefulness. In the light of this assessment, the Committee recommended against scheduling of the drug.

ECDD Recommendation

Scheduling/control not currently recommended