(Group 3)

For definition of Groups, see Preamble Evaluation.

VOL.: 66 (1996) (p. 105)

CAS No.: 29975-16-4
Chem. Abstr. Name: 8-Chloro-6-phenyl-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepine

5. Summary of Data Reported and Evaluation

5.1 Exposure data

Estazolam is a triazolobenzodiazepine used since the 1970s for short-term management of insomnia.

5.2 Human carcinogenicity data

No data were available to the Working Group.

5.3 Animal carcinogenicity data

Estazolam was tested for carcinogenicity in one experiment in mice and one experiment in rats by oral administration in the diet. No increase in the incidence of tumours was found.

5.4 Other relevant data

Estazolam is rapidly and almost completely absorbed in humans. It is extensively metabolized to at least 11 metabolites and excreted mainly in the urine. The elimination half-life is 14-19 h. Metabolism is extensive in various animal species. Rabbits and dogs excrete the metabolites principally in urine, while in mice, rats and guinea-pigs the excretion is mainly in faeces. Some metabolites are species-specific. There were no data available on reproductive effects of estazolam. The data available on genetic effects were negative.

5.5 Evaluation

There is inadequate evidencein humans for the carcinogenicity of estazolam.

There is evidence suggesting a lack of carcinogenicity in experimental animals for estazolam.

Overall evaluation

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

For definition of the italicized terms, see Preamble Evaluation


Last updated 22/05/97

    See Also:
       Toxicological Abbreviations
       Estazolam (PIM 925)