SUMMARY OF THE TWO-YEAR FEED AND GENETIC TOXICOLOGY STUDIES OF NITROFURANTOIN 



Male F344/N Rats 



Female F344/N Rats 



Male B6C3F, Mice 



Female B6C3F, Mice 



Dietary concentrations 



1.300 or 2.500 ppm 

 nitrolurantoin 



600 or 1.300 ppm 

 nitrofurantom 



1.300 or 2,500 ppm 

 nitrofurantoin 



1.300 or 2,500 ppm 

 nitrofurantoin 



Survival rates in the 2-year study 



24/50; 27/50; 26/50 25/50; 26/50; 3 1/50 



Nonneoplastic effects 



Chronic nephropathy; 

 testicular degeneration 



None 



Neoplastic effects 



Renal tubular cell neoplasms None 



28/50; 29/50; 34/50 



Testicular degeneration 



None 



19/50; 37/.50; 37/50 



Ovarian atrophy; hyperplasia 

 of adrenal cortex spindle cells 



Tubular adenomas, benign 

 mixed tumors, and granulosa 

 cell tumors of the ovary 



Level of evidence of qiircinogenic activity 

 Some evidence No evidence 



No evidence 



Clear evidence 



Genetic toxicology 



Mutagenic in S. typhimunum strains TA98 and 'I'AIOO with and without metabolic activation; induced forward mutations in 

 mouse L5178Y lymphoma cells without activation; induced increased numbers of sister chromatid exchanges and chromosomal 

 aberrations in cultured Chinese hamster ovary cells with and without 89; did not induce sex-linlced recessive lethal mutations 

 in Drosophila 



Nitrofurantoin, NTPTH341 



