Difebarbamate

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

Recommendation (from TRS)

Substance identification
Difebarbamate (INN, CAS-15687-09-9), chemically 1,3-bis (3- butoxy-2-2 hydroxy-propyl)-5 phenylbarbituric acid dicarbamate, has no common names. The substance is a racemic mixture.

Similarity to known substances and effects on the CNS
Difebarbamate is a derivative of phenobarbital in which both nitrogens are substituted with bulky butoxycarbamyolpropyl groups, which are allegedly hard to split. Because of these substitutions the compound loses its barbiturate-like pharmacological profile. It is not similar to other barbiturates that are already scheduled. The pharmacology of difebarbamate cannot be evaluated. No consistent data are available. In fifteen different tests, the substance was found to be completely inactive; in thirteen of those fifteen tests the drug was found to have no effects on the central nervous system. It must be remembered, however, that in these tests difebarbamate was administered only orally and the amount of the substance absorbed from the gastrointestinal tract was unknown.

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

Actual abuse and or/evidence of likelihood of abuse
Isolated cases of abuse have been reported from France, but it is not clear whether these refer to difebarbamate or to tetrabamate, which is a complex containing one molecule of difebarbamate. There was one report of illicit trafficking, and the drug was reported to be under national control in five countries.

Therapeutic usefulness
There is no claim for the therapeutic use of the substance as a single preparation. It is a constituent of tetrabamate, a complex containing 50% febarbamate, 35.7% difebarbamate, and 14.3% phenobarbital. Information on tetrabamate is insufficient to judge its usefulness. However, tetrabamate is available in several countries and large amounts of the drug are sold, especially in France. The Committee rated the therapeutic usefulness of difebarbamate as low.

Recommendation
The Committee found that there was insufficient evidence at this

time that difebarbamate 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 limited data concerning its pharmacological profile, dependence potential, and actual abuse, the Committee rated the likelihood of abuse of difebarbamate as low. 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