Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Additional information

Data source: European Directorate for the Quality of Medicines & HealthCare (EDQM) - Catalogue code: M1850000, USP Reference Standards - Catalog Number: 1442009, IARC, 1987. Overall Evaluations of Carcinogenicity. IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Humans, Supplement 7. Lyon, France: International Agency for Research on Cancer. 440 pp.; DailyMed Report on Carcinogens, Eleventh Edition, Muller J J A, Bos P M J, 2004. The occurrence of Carcinogenic, Mutagenic and Reprotoxic (CMR) substances in consumer preparations. RIVM report 320010001, pag. 63; EMEA, 1997. Committee for veterinary medicinal products Metronidazole. Summary Report; Data bank www.chemspider.com

Justification for classification or non-classification

Metronidazole has been shown to be carcinogenic (lung tumorigenesis and lymphoma) in mice and rats. An increased incidence of tumors in very young patients treated with metronidazole in the long term has raised the suspicion that the metronidazole is potentially carcinogenic in humans. According to the IARC SAFETY DATA SHEET METRONIDAZOLE Edition : 01 Revision: 02 Data: 08/22/2016 page 10 of 13

metronidazole is considered as a possible carcinogen to humans (Group 2B).

On the basis of existing data, it is appropriate to consider the MTZ as a potential human carcinogen, in the presence of sufficient experimental data and human data of limited value. The MTZ is mutagenic in bacterial systems, genotoxic in human cell lines and carcinogenic in animal studies.