Current Scheduling Status
Year(s) and type of review / ECDD meetings
Drug Class
Recommendation (from TRS)
Substance identification
Butalbital - GNN, CAS-77-26-9), chemically 5-allyl-5-isobutylbarbituric acid, is also known as alisobumal, alisobumalum, allylbarbital, allylbarbituric acid, itobarbital; and tetrallobarbital.
It is a racemic mixture.
Similarity to known substances and effects on the CNS
Butalbital 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. Butalbital produces a typical barbiturate-like depression of the central nervous system. As it is a hypnotic, it is presumed that tolerance, both natural and functional, may occur. Cross-tolerance may occur to other barbiturates, ethanol, and other sedative—hypnotic agents.
Dependence potential
With the exception of a single case report, there is no specific information available on the ability of butalbital to induce physical or psychic dependence, in either animals or man in controlled laboratory studies. One case has been reported of severe withdrawal symptoms in an infant after intrauterine exposure to butalbital. The withdrawal manifestations, including seizures, were relieved by phenobarbital.
Actual abuse and or/evidence of likelihood of abuse
There have been reports in the literature of actual abuse of butalbital and urine samples positive for butalbital use have been found among probationary prisoners and methadone maintenance patients. Seven countries have reported some abuse of butalbital, with most cases involving combination products. One government reported that this abuse caused some public health and social problems. Eight countries reported that the drug is under national control. There have been reports of illicit trafficking from seven countries.
Therapeutic usefulness
Butalbital has been used as both a sedative and as a hypnotic. It is one component of a number of preparations containing nonsteroidal anti-inflammatory agents (e.g., one combination
preparation contains butalbital, acetylsalicylic acid, phenacetin, and caffeine), which are widely used for the treatment of headache. There is no convincing evidence that barbiturates contribute significantly to the analgesic activity of these preparations. The drug and/or its preparations are reported to be marketed or are available in 27 countries. Over the past two years, significant amounts of butalbital have been sold in several countries. The Committee rated the therapeutic usefulness of butalbital as relatively low.
Recommendation
The Committee found sufficient evidence that butalbital has been,
and 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 evidence of actual abuse, the Committee rated the likelihood of abuse of butalbital as moderate. The degree of the seriousness of the public health and social problems associated with its abuse was found to be high and its therapeutic usefulness relatively low. In the light of this assessment, the Committee recommended that butalbital be placed in Schedule III.
Butalbital - GNN, CAS-77-26-9), chemically 5-allyl-5-isobutylbarbituric acid, is also known as alisobumal, alisobumalum, allylbarbital, allylbarbituric acid, itobarbital; and tetrallobarbital.
It is a racemic mixture.
Similarity to known substances and effects on the CNS
Butalbital 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. Butalbital produces a typical barbiturate-like depression of the central nervous system. As it is a hypnotic, it is presumed that tolerance, both natural and functional, may occur. Cross-tolerance may occur to other barbiturates, ethanol, and other sedative—hypnotic agents.
Dependence potential
With the exception of a single case report, there is no specific information available on the ability of butalbital to induce physical or psychic dependence, in either animals or man in controlled laboratory studies. One case has been reported of severe withdrawal symptoms in an infant after intrauterine exposure to butalbital. The withdrawal manifestations, including seizures, were relieved by phenobarbital.
Actual abuse and or/evidence of likelihood of abuse
There have been reports in the literature of actual abuse of butalbital and urine samples positive for butalbital use have been found among probationary prisoners and methadone maintenance patients. Seven countries have reported some abuse of butalbital, with most cases involving combination products. One government reported that this abuse caused some public health and social problems. Eight countries reported that the drug is under national control. There have been reports of illicit trafficking from seven countries.
Therapeutic usefulness
Butalbital has been used as both a sedative and as a hypnotic. It is one component of a number of preparations containing nonsteroidal anti-inflammatory agents (e.g., one combination
preparation contains butalbital, acetylsalicylic acid, phenacetin, and caffeine), which are widely used for the treatment of headache. There is no convincing evidence that barbiturates contribute significantly to the analgesic activity of these preparations. The drug and/or its preparations are reported to be marketed or are available in 27 countries. Over the past two years, significant amounts of butalbital have been sold in several countries. The Committee rated the therapeutic usefulness of butalbital as relatively low.
Recommendation
The Committee found sufficient evidence that butalbital has been,
and 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 evidence of actual abuse, the Committee rated the likelihood of abuse of butalbital as moderate. The degree of the seriousness of the public health and social problems associated with its abuse was found to be high and its therapeutic usefulness relatively low. In the light of this assessment, the Committee recommended that butalbital be placed in Schedule III.
ECDD Recommendation
Inclusion in Schedule III of the 1971 Convention on Psychotropic Substances
Link to full TRS
who_trs_741.pdf2.21 MB