The Influence of the Antithyroid Drug, Tapazole, on Reproduction in Rats

The antithyroid drug, Tapazole (methamazole, or imidazole-2-thio, 1-methyl), when fed to female rats at the dietary level of 0.1 % had a slight effect on the average number of young and weight per litter if administered during the preconception period. If given during the gestation period the results were harmful. Tapazole treatment of mothers during lactation resulted in lethargic cretin-like young, although survival rates during lactation and after weaning were good