Inhibition of multiplication of Mycobacterium leprae by several antithyroid drugs

Multiplication of Mycobacterium leprae in the mouse footpad was inhibited when mice were fed, mixed in their diet, 0.05 per cent methimazole, 0.066 per cent USP thyroid powder, methimazole plus thyroid powder, 0.15 per cent 5-n-heptyl-2-thioxo-4-thiazolidinone, 0.1 per cent propylthiouracil, and 0.1 per cent thambutosine for 154 days, beginning on the day of inoculation. All of the treatment regimens, except for the 2 containing thyroid powder, decreased the plasma concentrations of thyroxine and protein-bound iodine. It is suggested that the 2 antithyroid drugs, methiomazole and propylthiouracil, and the 2 antimicrobial agents, heptylthioxothiazolidinone and thiambutosine, all of which possess structural features in common, may exert the antithyroid and antimicrobial effects through a common mechanisms.