antithyroid agent

Prior to 1940, iodides were the predominant antithyroid agents.

An antithyroid agent is a hormone antagonist acting upon thyroid hormones.

Potassium perchlorate can be used as an antithyroid agent used to treat hyperthyroidism, usually in combination with one other medication.

Of note, the drug is approximately 70% protein-bound and significantly ionized at normal physiologic pH, while the antithyroid agent methimazole is substantially less protein bound.