(Group 3)

For definition of Groups, see Preamble Evaluation.

VOL.: 66 (1996) (p. 161)

CAS No: 846-50-4
Chem. Abstr. Name: 7-Chloro-1,3-dihydro-3-hydroxy-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-one

5. Summary of Data Reported and Evaluation

5.1 Exposure data

Temazepam is a benzodiazepine prescribed widely since the 1970s for short-term management of insomnia. Temazepam is a minor metabolite of diazepam.

5.2 Human carcinogenicity data

No data were available to the Working Group.

5.3 Animal carcinogenicity data

Temazepam was tested for carcinogenicity in one experiment in mice and in one experiment in rats by oral administration in the diet. A slight increase in the incidence of liver adenomas was found in female mice.

5.4 Other relevant data

Temazepam is absorbed rapidly and completely in humans from appropriate oral formulations. It is eliminated mainly in urine as the glucuronide conjugate; oxazepam is a minor metabolite. The mean elimination half-life is about 10 h.

Conjugation and N-demethylation to oxazepam are the major metabolic pathways recognized in mice and dogs.

Chronic administration of pharmacological doses does not induce organ toxicity. Repeated-dose toxicity studies lasting up to six months did not reveal specific organ toxicity in dogs, rats or mice.

No data were available on teratogenic effects of temazepam.

Few data on genetic effects of temazepam were available. It did not produce DNA strand breaks in the livers of rats.

5.5 Evaluation

There is inadequate evidence in humans for the carcinogenicity of temazepam.

There is inadequate evidence in experimental animals for the carcinogenicity of temazepam.

Overall evaluation

Temazepam is not classifiable as to its carcinogenicity to humans (Group 3).

For definition of the italicized terms, see Preamble Evaluation.


Last updated 05/22/97

    See Also:
       Toxicological Abbreviations
       Temazepam (PIM 683)