Current Scheduling Status
Year(s) and type of review / ECDD meetings
Drug Class
ECDD Recommendation
Scheduling/control not currently recommended
Recommendation (from TRS)
Substance identification
Quazepam (INN; CAS 36735-22-5), chemically 7-chloro-5-(ofluorophenyl)-1,3-dihydro- 1 -(2,2,2-trifluoroethyl)-2 H-1,4-benzodiazepine-2-thione, is also known as Oniria, Quazium, Selepam, Prosedar,Dormalin, and Temodol. No stereoisomers are possible.

Similarity to known substances and effects on the CNS
Quazepam is a benzodiazepine possessing the full range of group-specific, CNS-depressant effects of these compounds, so that it is an anxiolytic, anticonvulsant, sedative-hypnotic, muscle relaxant, etc. In animal experiments, quazepam is as efficacious as diazepam in most of its pharmacological effects. Clinical studies suggest that the hypnotic effects of quazepam are approximately equivalent to those of flurazepam. Quazepam is soluble in methylene chloride and hexane, but insoluble in water. It has an elimination half-life of approximately 40 hours in humans.

Dependence potential
Quazepam has been demonstrated to have some reinforcing effects in monkeys. In physical-dependence studies in animals, it substituted for barbital and produced withdrawal signs typical of the sedative-hypnotic class. Drug-discrimination studies in monkeys indicated pentobarbital-like effects with quazepam. Human studies on dependence potential are not available.

Actual abuse and or/evidence of likelihood of abuse
There is at present no direct evidence of actual abuse or illicit trafficking, production or diversion of quazepam. The Committee noted the relatively short period of time since the drug was introduced into the market.

Therapeutic usefulness
Quazepam is currently available in 9 countries in 15-mg tablets for the treatment of sleep disturbances.

On the basis of the available data concerning its pharmacological profile and dependence potential, the Committee rated the abuse liability of quazepam as low to moderate and the therapeutic usefulness as moderate to high. No public health and social problems are currently associated with the use of quazepam. The Committee considered that the degree of seriousness of the public health and social problems associated with the abuse of this substance was not great enough to warrant international control. The Committee did not recommend scheduling of quazepam.