Possible Interaction: Iodides and Thyrotropin-Releasing Hormone

“Iodide treatment did not affect basal plasma TSH levels but the mean integrated TSH response to TRH was increased from 801 ± 123 μU·min to 996 ± 135 μU·min ( P 4 and T 3 levels after iodide treatment.”

“Despite decreased FT(4)-I and/or FT(3)-… iodide treatment in all patients, the TSH response to TRH … iodide treatment was augmented in only 8 of 15 patients who had decreased serum T(3) (…) and in only 5 of 8 patients who had a normal serum T(3).”

“Large doses of iodide (500 mg three times a day) administered to normal men for 10--12 days caused a rise in basal serum TSH and a concomitant rise in the peak TSH response to TRH.”

“Administration of iodide (25 mg daily for two weeks) increased in healthy subjects the basal concentrations of TSH and the release of TSH in response to TRH (p less than 0.05-0.01).”

“Responses of T4 but not of T3 to TRH were also reduced after iodide.”

“The obtained data show that the prolonged ingestion of iodide induces a relatively hypothyroid state with an increased release of HTSH in response to the injection of TRH.”

“As evidence of the inhibitory effect of iodide on hormonal release, the increment in serum T3 at 120 min after TRH was significantly lessened during iodide administration (61+/-42 vs. 33+/-24 ng/100 ml).”

“ TRH also stimulated iodide binding to proteins, but not cyclic GMP accumulation.”