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June 19, 1967

Reduction of Thyroid Irradiation From 131I by Potassium Iodide

Author Affiliations

From the departments of medicine (Dr. Blum) and environmental medicine (Dr. Eisenbud), New York (NY) University Medical Center.

JAMA. 1967;200(12):1036-1040. doi:10.1001/jama.1967.03120250070012

The prophylactic administration of 100 to 200 mg of potassium iodide in anticipation of radioactive iodine exposure will largely prevent uptake by the thyroid gland, thereby reducing the irradiation dose delivered by more than 98%. The same amount given at intervals after131I absorption is progressively less effective, but still reduces uptake to less than half after a delay of three hours. The suppressive effect of one dose is of short duration and daily readministration of the agent is required for prolonged protection. The extent of uptake blockade may be estimated by measuring serum inorganic iodide; concentrations of greater than 10μg /100 cc correlate with marked uptake arrest. Toxicity is negligible for a single ingestion, as is required in this temporary measure for the reduction of the immediate thyroid irradiation hazard, but the drug must be avoided by those allergic to it.

 Proceedings of the Hanford Symposium on the Biology of Radioiodine ,  Health Phys 9:1081-1426 ( (Dec) ) 1963.Crossref
Eisenbud, M.:  Environmental Radioactivity , New York: McGraw-Hill Book Co., Inc., 1963.
Conrad, R.A.; Rall, J.E.; and Sutow, W.W.:  Thyroid Nodules as a Late Sequela of Radioactive Fallout ,  New Eng J Med 274: 1391-1399 ( (June 23) ) 1966.Crossref
Adams, C.A., and Bonnell, J.A.:  Administration of Stable Iodide as a Means of Reducing Thyroid Irradiation Resulting From Inhalation of Radioactive Iodine ,  Health Phys 7:127-149 ( (Feb) ) 1962.Crossref
Pochin, E.E., and Barnaby, C.F.:  The Effect of Pharmacologic Doses of Non-radioactive Iodide on the Course of Radioiodine Uptake by the Thyroid ,  Health Phys 7:125-126 ( (Feb) ) 1962.Crossref
Saxena, K.M.; Chapman, E.M.; and Pryles, C.V.:  Minimal Dosage of Iodide Required to Suppress Uptake of Iodine-131 by Normal Thyroid ,  Science 138:430-431 ( (Oct 19) ) 1962.Crossref
Eisenbud, M., et al:  Estimation of the Distribution of Thyroid Doses in a Population Exposed to I-131 From Weapons Testing ,  Health Phys 9:1281-1289 ( (Dec) ) 1963.Crossref
Brown-Grant, K.:  Extrathyroidal Iodide Concentration Mechanisms ,  Physiol Rev 41:198-212 ( (Jan) ) 1961.
Johnson, A.E.:  The Rate of Return of Radioiodine Uptake by the Normal Thyroid After Suppression by Pharmacological Doses of Stable Iodide ,  Health Phys 9:537-538 ( (May) ) 1963.Crossref
Taguchi, J.T.; Powell, C.P.; and Nickerson, N.F.:  Thyroidal I-131 Uptake Patterns Following Iodides ,  Arch Intern Med 112: 569-574 ( (Oct) ) 1963.Crossref
Mercer, C.J., et al:  Slowing of Thyroidal Secretion Rate by Iodide in Euthyroid People ,  Lancet 2:19-21 ( (July) ) 1960.Crossref
Yamada, T.; Iino, S.; and Schichijo, K.:  Inhibitory Effect of Excess Iodide on Thyroidal Radioiodine Return in the Rat ,  Endocrinology 72:83-90 ( (Jan) ) 1963.Crossref
Goodman, L.S., and Gilman, A.:  The Pharmacological Basis of Therapeutics , New York: Macmillan Co., 1965, pp 812-813.
 Iodide to Reduce Risks of Reactor Accidents , editorial,  Brit Med J 1:628 ( (March 9) ) 1963.
 Fallout of the Cold War , editorial,  New Eng J Med 274: 1422-1443 ( (June 23) ) 1956.