Induction of Lung Tumors and Malignant Lymphomas in Mice by Metronidazole2

Abstract

Metronidazole, the drug used in the treatment of Trichomonas infections, was tested for carcinogenicity in a lifetime study in Swiss mice. The drug was administered orally at levels of either 0.5, 0.3, 0.15, or 0.06% of the powdered diet. At all dose levels the incidence of lung tumors, predominantly adenomas, was elevated. An increased incidence of malignant lymphomas was observed in the 2 highest dosage groups of female mice but not in the males.