Sodium iodide is a nutritional supplement for addition to total parenteral nutrition (TPN) solutions. It is primarily indicated to prevent depletion of endogenous iodine stores and related iodine deficiency symptoms. Iodide is the ionized form of iodine, an essential trace element for humans and an integral part of the thyroid hormones, triiodothyronine (T3) and thyroxine (T4). Iodine was first discovered in 1811 and was noted to sublimate into a violet vapor when heated. Because of this, the element is named after the Greek word for violet, 'iodes'. Deficiency of iodine results in histological changes in thyroid gland and impaired thyroid function, which may cause goiter. Iodine deficiency in early stages of life has been reported to produce cretinism. To combat iodine deficiency and goiter, the United States begin iodizing salt in the 1920s. The typical diet supplies greater than twice the recommended daily amount of 150 mcg. Other dietary sources of iodide include seaweed (kelp, dulse, or sea lettuce), shellfish (clams, oysters, shrimp), and marine fish. Sodium iodide is also present in some multivitamin and mineral combination products. Goitrogens, which interfere with thyroid metabolism, are also present in the typical diet and include nitrates, broccoli, cabbage, brussel sprouts, cassava, and rutabagas.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Route-Specific Administration
Injectable Administration
-Visually inspect parenteral products for particulate matter and discoloration prior to administration whenever solution and container permit.
Intravenous Administration:
-Sodium iodide injection is a hypotonic solution and should be administered in admixtures only. Injections of undiluted sodium iodide into a peripheral vein can cause infusion phlebitis.
-Sodium iodide injection should be aseptically added to TPN solutions under a laminar flow hood. Iodine is physically compatible with electrolytes and other trace elements usually present in amino acid/dextrose solutions used for TPN.
Sodium iodide is administered in small amounts and is unlikely to produce symptoms of toxicity in normal patients. If iodine toxicity does occur, symptoms include metallic taste, soreness of the mouth, hypersalivation, coryza, sneezing, blepharitis, severe headache, pulmonary edema, tenderness of salivary glands, acneiform rash, and skin eruptions. Hypersensitivity reactions may occur and result in angioedema, cutaneous and mucosal hemorrhages, fever, arthralgia, lymphadenopathy, and eosinophilia. Iododerma, a rare but severe cutaneous eruption that can be fatal, may also occur with iodide therapy. If a patient develops a hypersensitivity reaction, TPN solutions containing iodide should be immediately discontinued and appropriate measures taken. Abundant fluids and salt intake helps in elimination of iodides.
Sodium iodide should be used with extreme caution in patients with iodine hypersensitivity. Sensitization to iodides and deaths due to anaphylactic shock following iodide administration have been reported. Evaluation for iodine hypersensitivity must be done prior to initiating therapy. Patients at an increased risk of developing adverse effects caused by iodine include those with hypocomplementemic vasculitis, goiter, or autoimmune thyroid disease.
The intravenous administration of undiluted sodium iodide into a peripheral vein is contraindicated due to the risk of irritation phlebitis.
As iodine is eliminated in the urine, supplement iodine cautiously in patients with renal impairment, renal disease, or renal failure. Iodine supplementation in TPN solutions may be adjusted, reduced, or omitted in patients with renal impairment.
An FDA pregnancy risk category has not been assigned for sodium iodide; however, other iodide preparations are classified as FDA pregnancy risk category D. Iodide readily crosses the placenta. Prolonged use or use close to term may cause fetal or newborn goiter and/or hypothyroidism. Many prescription and OTC medications contain iodide or iodine which can be absorbed. Sodium iodide is sometimes used during pregnancy as nutritional supplementation in total parenteral nutrition (TPN), to supply needed nutritional requirements.
Iodide is excreted into breast milk in amounts that reflect the maternal intake, with a mean varying from 44-80%. Extremely high concentrations in breast milk, resulting from exposure of the mother to excess iodide in medications, may cause thyrotoxicosis in a breast-fed infant. However, despite the fact that these drugs may affect thyroid activity, the American Academy of Pediatrics lists them as usually compatible with breast-feeding. If sodium iodide supplementation is used in a woman who is breast-feeding her child, closely monitor the child for any adverse effects. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, health care providers are encouraged to report the adverse effect to the FDA.
For use as nutritional supplementation in total parenteral nutrition (TPN):
Parenteral dosage:
Adults: 1 to 2 mcg iodine/kg/day (typically 75 to 150 mcg/day in a normal adult) added to TPN solution.
Pregnant and lactating female Adults: 2 to 3 mcg iodine/kg/day added to TPN solution.
Children: 2 to 3 mcg iodine/kg/day added to TPN solution.
Maximum Dosage Limits:
Dosage must be individualized based on patient age and clinical response.
Patients with Hepatic Impairment Dosing
Specific information is not available; however, it appears no dosage adjustment is needed.
Patients with Renal Impairment Dosing
Dosage should be modified depending on clinical response and degree of renal impairment.
*non-FDA-approved indication
Acetaminophen; Aspirin; Diphenhydramine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Acetaminophen; Caffeine; Pyrilamine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Acetaminophen; Chlorpheniramine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Acetaminophen; Chlorpheniramine; Dextromethorphan: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Acetaminophen; Chlorpheniramine; Phenylephrine : (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Acetaminophen; Dextromethorphan; Doxylamine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Acetaminophen; Diphenhydramine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Acetaminophen; Pamabrom; Pyrilamine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Acrivastine; Pseudoephedrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Anticoagulants: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Antithrombin III: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Apixaban: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Argatroban: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Betrixaban: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Bivalirudin: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Brompheniramine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Brompheniramine; Dextromethorphan; Phenylephrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Brompheniramine; Phenylephrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Brompheniramine; Pseudoephedrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Brompheniramine; Pseudoephedrine; Dextromethorphan: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Carbinoxamine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Chlophedianol; Dexbrompheniramine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Chlorcyclizine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Chlorpheniramine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Chlorpheniramine; Codeine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Chlorpheniramine; Dextromethorphan: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Chlorpheniramine; Hydrocodone: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Chlorpheniramine; Phenylephrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Chlorpheniramine; Pseudoephedrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Clemastine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Cyclobenzaprine: (Moderate) Because medications that decrease salivation increase the time of sodium iodide I-131 induced radiation exposure to salivary glands, consider discontinuing medications with antimuscarinic activity including cyclobenzaprine prior to sodium iodide I-131 administration.
Cyproheptadine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Dabigatran: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Dalteparin: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Dexbrompheniramine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Dexbrompheniramine; Pseudoephedrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Dexchlorpheniramine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Dimenhydrinate: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Diphenhydramine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Diphenhydramine; Ibuprofen: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Diphenhydramine; Naproxen: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Diphenhydramine; Phenylephrine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Doxylamine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Doxylamine; Pyridoxine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Edoxaban: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Enoxaparin: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Estradiol; Progesterone: (Moderate) Progesterone is known to decrease the uptake of iodide into thyroid tissue. In order to increase thyroid uptake and optimize exposure of thyroid tissue to the radionucleotide sodium iodide I-131, consider withholding progesterone prior to treatment with sodium iodide I-131.
Ethiodized Oil: (Moderate) Administration of non-ionic contrast media may interfere with thyroid uptake of radioactive sodium iodide (I-131) and decrease therapeutic and diagnostic efficacy in patients with carcinoma of the thyroid. The decrease in efficacy lasts for 6 to 8 weeks.
Fondaparinux: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Heparin: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Hydroxyzine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Iodine; Potassium Iodide, KI: (Contraindicated) Sodium iodide should not be used concurrently with antithyroid agents. These agents can increase the likelihood of hypothyroidism when used in combination with sodium iodide. (Contraindicated) The recent intake of antithyroid agents will affect the uptake of radioiodide from sodium iodide, I-131; patients must discontinue all medications and supplements that may interfere with iodide uptake into thyroid tissue prior to therapy with sodium iodide I-131. Various protocols are used. Many manufacturers state that concurrent antithyroid agents should be discontinued at least 3 to 4 days before administration of radioiodide. The following withdrawal timing recommendations were set forth in a procedure guideline published by the Society of Nuclear Medicine in February 2002. Antithyroid agents may affect iodide protein binding for an average of 5 days after administration; allow a 3 day wash out period for the antithyroid agent prior to sodium iodide I-131 administration. The antithyroid agent may be resumed 2 to 3 days after treatment.
Iodixanol: (Moderate) Administration of non-ionic contrast media may interfere with thyroid uptake of radioactive sodium iodide (I-131) and decrease therapeutic and diagnostic efficacy in patients with carcinoma of the thyroid. The decrease in efficacy lasts for 6 to 8 weeks.
Iohexol: (Moderate) Administration of non-ionic contrast media may interfere with thyroid uptake of radioactive sodium iodide (I-131) and decrease therapeutic and diagnostic efficacy in patients with carcinoma of the thyroid. The decrease in efficacy lasts for 6 to 8 weeks.
Iomeprol: (Moderate) Administration of non-ionic contrast media may interfere with thyroid uptake of radioactive sodium iodide (I-131) and decrease therapeutic and diagnostic efficacy in patients with carcinoma of the thyroid. The decrease in efficacy lasts for 6 to 8 weeks.
Ionic Contrast Media: (Major) Certain medications should not be administered prior to therapy with sodium iodide I-131 in order to reduce interference with diagnostic or therapeutic use of sodium iodide I-131. Although various protocols are used, the following withdrawal timing recommendations were set forth in a procedure guideline published by the Society of Nuclear Medicine in February 2002. Avoid intravenous radiopaque contrast agents for one month prior to treatment with sodium iodide I-131; patients with renal deficiency may require additional time to clear these agents. Iodide containing contrast agents may affect iodide protein binding for up to a year.
Iopamidol: (Moderate) Administration of non-ionic contrast media may interfere with thyroid uptake of radioactive sodium iodide (I-131) and decrease therapeutic and diagnostic efficacy in patients with carcinoma of the thyroid. The decrease in efficacy lasts for 6 to 8 weeks.
Iopromide: (Moderate) Administration of non-ionic contrast media may interfere with thyroid uptake of radioactive sodium iodide (I-131) and decrease therapeutic and diagnostic efficacy in patients with carcinoma of the thyroid. The decrease in efficacy lasts for 6 to 8 weeks.
Ioversol: (Contraindicated) Sodium iodide should not be used concurrently with antithyroid agents. These agents can increase the likelihood of hypothyroidism when used in combination with sodium iodide. (Moderate) Administration of non-ionic contrast media may interfere with thyroid uptake of radioactive sodium iodide (I-131) and decrease therapeutic and diagnostic efficacy in patients with carcinoma of the thyroid. The decrease in efficacy lasts for 6 to 8 weeks.
Isosulfan Blue: (Moderate) Administration of non-ionic contrast media may interfere with thyroid uptake of radioactive sodium iodide (I-131) and decrease therapeutic and diagnostic efficacy in patients with carcinoma of the thyroid. The decrease in efficacy lasts for 6 to 8 weeks.
Levothyroxine: (Major) In order to increase thyroid uptake and optimize exposure of thyroid tissue to the radionucleotide, patients must discontinue all medications and supplements that may interfere with iodide uptake into thyroid tissue prior to therapy with sodium iodide I-131, including thyroid hormones. Although various protocols are used, the following withdrawal timing recommendations were set forth in a procedure guideline published by the Society of Nuclear Medicine in February 2002. It is recommended to hold alll T4 thyroid hormones (e.g., levothyroxine) 4 to 6 weeks prior, and to hold all T3 thyroid hormones (e.g., liothyronine) 2 weeks prior, to sodium iodide I-131 therapy.
Levothyroxine; Liothyronine (Porcine): (Major) In order to increase thyroid uptake and optimize exposure of thyroid tissue to the radionucleotide, patients must discontinue all medications and supplements that may interfere with iodide uptake into thyroid tissue prior to therapy with sodium iodide I-131, including thyroid hormones. Although various protocols are used, the following withdrawal timing recommendations were set forth in a procedure guideline published by the Society of Nuclear Medicine in February 2002. It is recommended to hold alll T4 thyroid hormones (e.g., levothyroxine) 4 to 6 weeks prior, and to hold all T3 thyroid hormones (e.g., liothyronine) 2 weeks prior, to sodium iodide I-131 therapy.
Levothyroxine; Liothyronine (Synthetic): (Major) In order to increase thyroid uptake and optimize exposure of thyroid tissue to the radionucleotide, patients must discontinue all medications and supplements that may interfere with iodide uptake into thyroid tissue prior to therapy with sodium iodide I-131, including thyroid hormones. Although various protocols are used, the following withdrawal timing recommendations were set forth in a procedure guideline published by the Society of Nuclear Medicine in February 2002. It is recommended to hold alll T4 thyroid hormones (e.g., levothyroxine) 4 to 6 weeks prior, and to hold all T3 thyroid hormones (e.g., liothyronine) 2 weeks prior, to sodium iodide I-131 therapy.
Liothyronine: (Major) In order to increase thyroid uptake and optimize exposure of thyroid tissue to the radionucleotide, patients must discontinue all medications and supplements that may interfere with iodide uptake into thyroid tissue prior to therapy with sodium iodide I-131, including thyroid hormones. Although various protocols are used, the following withdrawal timing recommendations were set forth in a procedure guideline published by the Society of Nuclear Medicine in February 2002. It is recommended to hold alll T4 thyroid hormones (e.g., levothyroxine) 4 to 6 weeks prior, and to hold all T3 thyroid hormones (e.g., liothyronine) 2 weeks prior, to sodium iodide I-131 therapy.
Lithium: (Moderate) Concurrent administration of sodium iodide and lithium salts can potentiate the incidence of hypothyroidism and goiter. In general, this combination is not advised; however, if concomitant use is required, careful monitoring for signs and symptoms of hypothyroidism is indicated.
Mafenide: (Moderate) Sulfonamides may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Meclizine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Methimazole: (Contraindicated) The recent intake of antithyroid agents will affect the uptake of radioiodide from sodium iodide, I-131; patients must discontinue all medications and supplements that may interfere with iodide uptake into thyroid tissue prior to therapy with sodium iodide I-131. Various protocols are used. Many manufacturers state that concurrent antithyroid agents should be discontinued at least 3 to 4 days before administration of radioiodide. The following withdrawal timing recommendations were set forth in a procedure guideline published by the Society of Nuclear Medicine in February 2002. Antithyroid agents may affect iodide protein binding for an average of 5 days after administration; allow a 3 day wash out period for the antithyroid agent (e.g., PTU, methimazole) prior to sodium iodide I-131 administration. The antithyroid agent may be resumed 2 to 3 days after treatment. When patients are taking sodium iodide (non-radioiodide) for supplementation in TPN, the effect of the iodide on antithyroid therapy should be considered.
Non-Ionic Contrast Media: (Moderate) Administration of non-ionic contrast media may interfere with thyroid uptake of radioactive sodium iodide (I-131) and decrease therapeutic and diagnostic efficacy in patients with carcinoma of the thyroid. The decrease in efficacy lasts for 6 to 8 weeks.
Pentosan: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Potassium Iodide, KI: (Contraindicated) The recent intake of antithyroid agents will affect the uptake of radioiodide from sodium iodide, I-131; patients must discontinue all medications and supplements that may interfere with iodide uptake into thyroid tissue prior to therapy with sodium iodide I-131. Various protocols are used. Many manufacturers state that concurrent antithyroid agents should be discontinued at least 3 to 4 days before administration of radioiodide. The following withdrawal timing recommendations were set forth in a procedure guideline published by the Society of Nuclear Medicine in February 2002. Antithyroid agents may affect iodide protein binding for an average of 5 days after administration; allow a 3 day wash out period for the antithyroid agent prior to sodium iodide I-131 administration. The antithyroid agent may be resumed 2 to 3 days after treatment.
Prednisone: (Moderate) Corticosteroids, such as prednisone, are known to decrease the uptake of iodide into thyroid tissue. In order to increase thyroid uptake and optimize exposure of thyroid tissue to the radionucleotide sodium iodide I-131, consider withholding prednisone prior to treatment with sodium iodide I-131.
Progesterone: (Moderate) Progesterone is known to decrease the uptake of iodide into thyroid tissue. In order to increase thyroid uptake and optimize exposure of thyroid tissue to the radionucleotide sodium iodide I-131, consider withholding progesterone prior to treatment with sodium iodide I-131.
Propylthiouracil, PTU: (Contraindicated) The recent intake of antithyroid agents will affect the uptake of radioiodide from sodium iodide, I-131; patients must discontinue all medications and supplements that may interfere with iodide uptake into thyroid tissue prior to therapy with sodium iodide I-131. Various protocols are used. Many manufacturers state that concurrent antithyroid agents should be discontinued at least 3 to 4 days before administration of radioiodide. The following withdrawal timing recommendations were set forth in a procedure guideline published by the Society of Nuclear Medicine in February 2002. Antithyroid agents may affect iodide protein binding for an average of 5 days after administration; allow a 3 day wash out period for the antithyroid agent (e.g., PTU, methimazole) prior to sodium iodide I-131 administration. The antithyroid agent may be resumed 2 to 3 days after treatment.
Pseudoephedrine; Triprolidine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Rivaroxaban: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Sedating H1-blockers: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Sulfadiazine: (Moderate) Sulfonamides may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Sulfamethoxazole; Trimethoprim, SMX-TMP, Cotrimoxazole: (Moderate) Sulfonamides may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Sulfasalazine: (Moderate) Sulfonamides may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Sulfonamides: (Moderate) Sulfonamides may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Thyroid hormones: (Major) In order to increase thyroid uptake and optimize exposure of thyroid tissue to the radionucleotide, patients must discontinue all medications and supplements that may interfere with iodide uptake into thyroid tissue prior to therapy with sodium iodide I-131, including thyroid hormones. Although various protocols are used, the following withdrawal timing recommendations were set forth in a procedure guideline published by the Society of Nuclear Medicine in February 2002. It is recommended to hold alll T4 thyroid hormones (e.g., levothyroxine) 4 to 6 weeks prior, and to hold all T3 thyroid hormones (e.g., liothyronine) 2 weeks prior, to sodium iodide I-131 therapy.
Triprolidine: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Warfarin: (Moderate) Anticoagulants may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administrations.
Iodide is the ionized form of elemental iodine. Iodine is required by the body to produce thyroid hormones. In the thyroid gland, iodide is combined with the amino acid tyrosine to produce thyroxin (T4) and triiodothyronine (T3). These thyroid hormones control the body's basal metabolic rate and support normal development and growth. Overall thyroid function is modulated by the hypothalamic-pituitary axis through thyroid-releasing hormone and thyroid-stimulating hormone via negative feed back of thyroxine levels in plasma.
Deficiency of iodine (hypothyroidism) results in histological changes in thyroid gland and impaired thyroid function. Symptoms of iodine deficiency include fatigue, cold intolerance, myalgias, heavy or more frequent menstruation, low sex drive, brittle nails, weight gain, alopecia, muscle cramps, depression, constipation, elevated cholesterol, puffy face, dry skin and hair, inability to concentrate, poor memory, and goiter. Iodine deficiency in early stages of life has been reported to produce cretinism (physical and mental retardation). An excess of iodine (hyperthyroidism, Grave's Disease) may lead to symptoms such as insomnia, heat intolerance, diaphoresis, lighter or less frequent menstruation, hand tremors, rapid pulse, exophthalmos (bug eyes), weight loss, increased appetite, muscle weakness, frequent bowel movements, irritability, nervousness, and goiter.
Sodium iodide is administered intravenously as a component of total parenteral nutrition (TPN) solutions. In humans, the thyroid gland is estimated to contain 7-8 mg of iodine. Iodide is also taken up by other important organs including salivary glands and gastric mucosa, and, to a lesser extent, choroid plexus, skin, hair, mammary glands, and placenta. The iodine in saliva and gastric mucosal secretions is reabsorbed and recycled. In plasma, circulating iodine is hormonal thyroxine of which 30-70 mcg is protein bound and 0.5 mcg is free thyroxine. Estimated normal plasma inorganic iodide levels are between 0.5 and 1.5 mcg per 100 ml. The kidneys are the major route of excretion. Minor amounts of conjugated thyroid hormones are excreted via the bile.
-Route-Specific Pharmacokinetics
Intravenous Route
Once administered, iodide equilibrates in the extracellular fluid and is specifically concentrated by the thyroid gland.