Possible Interaction: Iodine and Propylthiouracil

“Patients pretreated with propylthiouracil had a higher rate of relapse during the first year after radioactive iodine than those pretreated with carbimazole, but the difference was not significant when combined with other pretreatment variables.”

“Formation of iodinated origin material is inhibited to a greater degree by azide, cyanide, and propylthiouracil than is deiodination.”

“Two drugs that inhibit the metabolism of iodine, propylthiouracil (PTU) and aminotriazole, reduced thyroidal infiltration and TgAb levels, although to a lesser extent.”

“These findings are similar to those found previously for PTU and show that ATZ, like PTU , not only interferes with organification of iodine but also inhibits the coupling of iodotyrosines to form iodothyronines.”

“It has long been known that treatment with propylthiouracil and other antithyroid drugs inhibits organic binding of iodine and leads to a reduction in total iodine in the thyroid (1).”

“ Propylthiouracil blocked organic binding of iodine in rats treated with Prominal as well as in untreated rats.”

“RECENT studies by Wollman and Scow (1953) on mice indicated that when binding of iodine was blocked by a single injection of propylthiouracil the ratio of the radioiodide concentrations in the thyroid gland and serum (T/S ratio) was greater than when binding was permitted.”

“The interaction of diiodine with selenium analogs of the antithyroid drug 6-n-propyl-2-thiouracil ( PTU ), of formulae RSeU (6-alkyl-2-Selenouracil) results in the formation of complexes with formulae [(RSeU)I2].”

“Supplementary iodine decreased goitrogenesis but increased the inhibitory effects of propylthiouracil on radioiodine uptake and on formation of diiodotyrosine and T4.”