Possible Interaction: Iodides and Methimazole

“The iodide organification step can be inhibited by propylthiouracil and methimazole , which are TPO enzyme inhibitors.”

“These results indicate that in our patient population 15 mg MMI had a longer inhibitory effect on the organification of iodide than did 300 mg PTU, and that MMI was more rapidly effective in the treatment of Graves' hyperthyroidism.”

“ Iodide inhibited TSH- and thyroid-stimulating immunoglobulin-activated cAMP accumulation and this effect was reduced by methimazole , showing that, in this tissue, iodide, through an oxidized derivative, depresses the TSH-cAMP system.”

“We have found that stimulation by TSH (5 and 50 mU/ml) of cAMP formation in thyroid slices from patients preoperatively treated with methimazole and iodide is significantly less than in slices from patients treated with methimazole alone.”

“ Iodide therapy resulted in a striking diminution in urinary radioiodine excretion in one patient receiving Tapazole , with a concomitant slowing in the decrease of thyroidal radioiodine without a reciprocal effect...”

“ Iodide inhibited the cellular release of H(2)O(2) and NADPH oxidase activity, effects prevented by methimazole.”

“Incubation with methimazole and PTU resulted in a 20% and 25% decrease of iodide accumulation, respectively, whereas potassium iodide suppressed iodide accumulation by approximately 50%.”

“On the contrary, LBI increased as a function of iodide concentration up to 100 microM. Methimazole (MMI) inhibited the incorporation of iodide into both LBI and PBI, but higher concentrations of MMI were required to depress LBI as compared to PBI.”

“Protein binding of iodide was inhibited by methimazole (10(-3) M) in all experiments.”

“The effects of iodide on basal and agonist-stimulated thyroid metabolism were blocked by methimazole (10(-3) M).”