The antithyroid drug, methimazole (1-methyl-2-thiolimidazole), is a powerful chelator of cupric ion. This is reflected in
its ability to selectively inhibit certain copper oxidases. Uricase, ascorbic oxidase and monoamine oxidase are not affected.
Ceruloplasmin oxidase is slightly inhibited and tyrosinase is markedly inhibited by methimazole.
This work was supported in part by Dartmouth Medical School grant No. RR-05392 and USPHS grant No. GM-15549.