Allobarbital

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

Recommendation (from TRS)

Substance identification
Allobarbital (INN, CAS-52-43-7), chemically 5,5-diallybarbituric acid, is also known as allobarbitone, diallylbarbitone, diallylbarbituric acid, diallylmalonylurea, and diallymalum.

Similarity to known substances and effects on the CNS
Allobarbital has been classified pharmacologically as an intermediate-acting 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 and 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
With the exception of one clinical report on a single patient, there is no information on the ability of allobarbital to induce physical or psychic dependence, in. either animals or man in controlled laboratory studies.

Actual abuse and or/evidence of likelihood of abuse
A number of cases involving the abuse of allobarbital have been reported from Belgium and the Federal Republic of Germany, while Austria and Czechoslovakia have reported sporadic cases of abuse. These reports have mainly concerned combination preparations. No government has reported on any public health or social problems caused by this substance. There have been reports of seizures of small amounts of the drug from the Republic of Korea and the United States of America. The Federal Republic of Germany, too, has reported a notable number of cases of forged prescriptions and’ thefts involving allobarbital.

Therapeutic usefulness
Allobarbital is used as a. sedative and hypnotic. It is also combined in analgesic preparations, although the enhanced efficacy of such mixtures has not been firmly established. The drug or

combinations containing it have been reported to be registered and or available on the market in 26 countries..Over the past few years only modest amounts of the drug have been used. The Committee considered the therapeutic usefulness of this drug to be relatively low.

Recommendation
The Committee found that there was sufficient evidence (sections 3.1.2-3.1.5) that allobarbital 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 in the Convention on Psychotropic Substances. On the basis of its pharmacological profile, dependence potential, and on limited evidence of actual abuse, the Committee rated thelikelihood of abuse of allobarbital as moderate. The degree of seriousness of the public health and social problems associated with its abuse was also found to be moderate and its therapeutic usefulness relatively low. In the light of this assessment, the Committee recommended that allobarbital be placed in Schedule IV.

ECDD Recommendation

Inclusion in Schedule IV of the 1971 Convention on Psychotropic Substances