Sodium iodide [131I] (Natrii iodidum [131I])

Pharmacodynamics Pharmacokinetics Indications Carefully Contraindications Dosing and Administration Side effects
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Clinical and pharmacological group: & nbsp

Other diagnostic tools

Included in the formulation
  • Sodium iodide Na131I
    solution in / in 
    National Center for Nuclear Research     Poland
  • Sodium iodide, 131-I
    capsules inwards 
    Federal State Unitary Enterprise "Federal Center for Design and Development of Nuclear Medicine Facilities" FMBA of Russia     Russia
  • Sodium iodide, 131-I
    solution inwards 
    NIFHI them. LYKARPOVA     Russia
  • Sodium iodide, 131-I
    capsules inwards 
    Federal State Unitary Enterprise "Federal Center for Design and Development of Nuclear Medicine Facilities" FMBA of Russia     Russia
  • Sodium iodide, 131-I in isotonic solution
    solution inwards in / in 
    NIFHI them. LYKARPOVA     Russia
  • Sodium iodide, 131I
    solution inwards 
    Medradiopreparat plant FSUE FMBA of Russia     Russia
    • АТХ:

    V.09.F.X   Other radiopharmaceuticals for diagnosing thyroid diseases

    Pharmacodynamics:

    In the diagnostic application, radioactive iodine (131I: half-life 8.08 days; the decay constant is 0.00358 h-1; type of β decay; emitted radiation: β-radiation with an energy of 191 keV, gamma radiation with an energy of 364.5 keV; the average number of emissions / decay - 0.90 for β-radiation, 0.81 for γ-radiation) is selectively captured by the thyroid gland, since it is necessary for the synthesis of thyroid hormones. This allows you to quantify and visualize the anatomical distribution 131I in the gland tissues. Sodium iodide 131I also accumulates in functioning nodes of papillary, follicular and mixed (papillary-follicular) cancer and in metastases, although to a lesser extent than in normal thyroid tissue. Ingestion of large doses 131I leads to its selective accumulation in pathological tissues (hyperthyroidism or malignant tumors) of the thyroid gland and their destruction.

    Pharmacokinetics:

    The drug is injected on an empty stomach, absorbed into the stomach and enters the blood. The half-life is 8-10 minutes. When you introduce into the body the radioactive isotope of iodine 131I accumulates mainly in the thyroid gland. Absorption kinetics 131I of the thyroid gland (relative to the administered amount) is on average: after 2 hours - 14%, after 4 hours - 9%, after 24 hours - 27%. It is excreted in urine and feces (60% within 24 hours). Accumulation and speed of excretion of the drug are individual and depend on the state of the thyroid gland, sex and age of the patient.

    Indications:

    Scanning and scintigraphy of the thyroid gland:

    - assessment of the functional state and topography of the thyroid gland for the diagnosis of disteardosis;

    - diagnosis of A-cell thyroid cancer and metastases;

    - diagnostics of thyroid diseases in adults.

    Treatment:

    - thyrotoxicosis;

    - thyroid cancer.

    ICD-10

    IV.E00-E07.E05   Thyrotoxicosis [hyperthyroidism]

    II.C73-C75.C73   Malignant neoplasm of thyroid gland

    XXI.Z00-Z13.Z03   Medical surveillance and evaluation in case of suspected disease or pathological condition

    Contraindications:

    - individual intolerance;

    - thyrotoxic adenoma;

    - nodular goiter;

    - vaginal goiter;

    - euthyroid goiter;

    - mild forms of thyrotoxicosis;

    - mixed toxic goiter;

    - kidney failure;

    - violations of hemopoiesis (leukopoiesis and thrombocytopoiesis);

    - severe hemorrhagic syndrome;

    - peptic ulcer of the stomach and duodenum (in the stage of exacerbation);

    - pregnancy and the period of breastfeeding;

    - age younger than 20 years.

    Carefully:

    Age from 20 to 40 years.

    Pregnancy and lactation:

    FDA recommendations for category C for diagnostic use (the risk and benefits of the study should be correlated), category X for therapeutic use (use in pregnancy is contraindicated). 131I penetrates the placenta and can cause severe irreversible hypothyroidism in the fetus. Thyroid absorbs iodine starting from the 12th week of gestation. Before the start of treatment or before the study, it is necessary to exclude the possibility of pregnancy. In a study of 627 women treated with sodium [131I] iodide for various types of thyroid cancer, there are no signs of impaired fertility.

    Dosing and Administration:

    Treatment of hyperthyroidism: inside 148-370 MBq (4-10 mCi) (according to other data, the minimum dose is 111 MBq); The dose is usually adjusted based on the weight of the thyroid gland and the measurements of the daily accumulation of the isotope.

    With nodular goiter and other severe thyroid diseases, you can increase the dose to 555-1110 MBq (15-30 mCi).

    Treatment of thyroid cancer (functioning papillary or follicular).

    Suppression of the functioning of normal thyroid tissue: inside at 1.85 GBq (according to other data, 1.1-3.7 GBq) (30-100, an average of 50 mCi).

    Subsequent metastatic therapy: inside at 3.7-7.4 GBq (100-200 mCi).

    Treatment of metastases of thyroid cancer: inside 1.85-3.7 GBq 1 time in 3 months. Before each re-appointment of the drug, a study is made of the iodine absorption activity of metastases (by scintigraphy or radioisotope scanning after the administration of 37-74 MBq of the drug). Duration of treatment can reach 2 years, and the total dose 131I - 18.5-25.9 GBq.

    Scintigraphy of the thyroid gland (evaluation of the functional state of the thyroid gland, diagnosis and confirmation of hyperthyroidism, determination of the effectiveness of treatment with radioactive iodine, visualization of the functions and form of the thyroid gland, focal formations, including cancer, and sublingual, neck and mediastinal structures, evaluation of treatment effectiveness and monitoring patients with thyroid cancer in the pre- and postoperative period).

    Assessment of only the accumulation of the radionuclide in the thyroid gland: inside 0,185-0,55 MBq (5-15 μCi). With a well-founded suspicion of the presence of hyperthyroidism or retrosternal nodes, a dose increase of up to 3.7 MBq (100 μCi) may be required.

    Visualization of the thyroid gland: inside 1.85-3.7 MBq (50-100 μCi).

    Localization of metastases of thyroid cancer: inside 37-370 MBq (1-10 mCi).

    When scintigraphy of the thyroid gland, especially in children, sodium iodide 123I or sodium pertechnetate 99mTc is preferable to sodium iodide 131I due to a lower radiation load on the patient and the possibility of obtaining images of better quality.

    When used for all indications, intravenous administration is possible.

    To study the accumulation of a radionuclide: a minimum dose of 0.037 mBq (1 μCi); the maximum dose is 0.55 MBq (15 μCi).

    For visualization of the thyroid gland: a minimum dose of 0.185 mBq (5 μCi); the maximum dose is 1.3 MBq (35 μCi).

    For visualization of mediastinal formations: a minimum dose of 0.55 mBq (15 μCi); the maximum dose is 3.7 MBq (100 μCi).

    Side effects:

    Blood: leukopenia, thrombocytopenia.

    Digestive system: nausea and vomiting, a temporary lack of taste sensations, radiation gastritis, radiation sialadenitis.

    Nervous system: headache.

    Leather: skin itching, skin rashes, alopecia, reactive skin changes in the thyroid gland, pharyngeal mucosa and larynx.

    Carcinogenicity / mutagenicity: in animals 131I can induce the development of adenomas and thyroid cancer, but studies in humans have yielded conflicting results; does not increase the incidence of acute leukemia in humans compared to other hyperthyroid patients; the induction of chromosomal abnormalities in laboratory studies, hypothyroidism (the frequency of hypothyroidism after treatment of hyperthyroidism 15-25% during the first year after completion of treatment,increases by ~ 2-3% in each subsequent year; the risk rises with an increase in life expectancy; can develop within a few years after the successful treatment of hyperthyroidism; a regular annual study of thyroid hormones is recommended), the increase in the phenomena of hyperthyroidism, radiation thyroiditis, exophthalmos, ulcerous cystitis.

    Overdose:Not described, treatment is symptomatic.
    Interaction:

    Amiodarone, antithyroid agents (thiomide derivatives or aromatic compounds), benzodiazepines, iodine-containing radiopaque agents, glucocorticoids, zobogenous products (eg cabbage, turnips), iodine-containing foods, iodine-containing agents, bromides containing traces of iodine, iodine, monovalent anions (for example, perchlorate, thiocyanate), pyrazolone derivatives (eg, phenylbutazone), salicylates, iodized table salt (in large amounts), sodium thiopental, blocking agents (for example, concentrated iodine solution, potassium iodide, potassium perchlorate), thyroid hormones (natural or synthetic) - the accumulation may decrease 131I.It is recommended to cancel these funds for the next period of time before the introduction of sodium [131I] iodide: several months for amiodarone, 1 week for glucocorticoids, 4 weeks for benzodiazepines, 2-4 weeks for intravascular injection of iodine-containing radiopaque agents, at least 4 weeks for radiocontrast agents for cholecystography, 2-4 weeks for iodine-containing drugs vitamins, expectorants, antitussives and topical preparations), 1-2 weeks for pyrazolone derivatives, 1 week for sodium thiopental, 4-6 weeks for thyroxine preparations, 2-3 weeks for triiodothyronine preparations.

    Antithyroid drugs - it is possible to develop a recoil effect when abruptly canceling antithyroid drugs with very high thyroid iodine uptake during the first 5 days. It is recommended to cancel antithyroid drugs 1 week before the introduction of sodium [131I] iodide. For studies of early absorption (15-30 minutes) for the detection of iodide (not distribution in the body), therapy with thioamide drugs should not be interrupted.

    Myelodepressants showing predictable dose-dependent myelotoxicity [abacavir, azathioprine, aldesleukin, alemtuzumab, altretamine, amphotericin B (with systemic application), amphotericin B a liposome complex, anastrozole, busulfan, valganciclovir, vidarabin (with systemic use in high doses), vinblastine, vincristine, vinorelbine, ganciclovir, gemcitabine, hydroxycarbamide, dacarbazine, dactinomycin, daunorubicin, daunorubicin liposomal, didanosine, doxorubicin, doxorubicin liposomal, docetaxel, zidovudine, zoledronic acid, idarubicin, imatinib, interferons α, irinotecan, ifosfamide, capecitabine, carboplatin, carmustine (with systemic application), clozapine, colchicine, lamivudine, lomustine, melphalan, mercaptopurine, methotrexate, mitoxantrone, mitomycin, sodium P32 phosphate, oxaliplatinum, paclitaxel, plikamycin, procarbazine, pegasgas, strontium 89Sr chloride, streptozocin, temozolomide, teniposide, thioguanine, thiotepa, topotecan, fludarabine, flucytosine, fluorouracil (with systemic application), chlorambucil, chloramphenicol, cyclophosphamide, cisplatin, cytarabine, epirubicin, etoposide] - in rare cases, it is possible to enhance myelosuppression with parallel application; it may be necessary to reduce the dose of myelo-depressants (only with sodium [131I] iodide for medical purposes).

    Salicylates (with prolonged use) can inhibit the functions of the thyroid gland. It should be canceled 1-2 weeks before the introduction of sodium [131I] iodide. It is possible to develop a recoil effect after the abolition of salicylates with an increase in iodine uptake by the thyroid gland within 3-10 days.

    Special instructions:

    The study of the functional state of the thyroid gland should be conducted no earlier than 4-6 weeks after the withdrawal of preparations of iodine-containing radiocontrast agents, fluoride, bromine, triiodothyronine, stable iodine, iodine and iodinated foods and multivitamin preparations, thyroxine, thyroidin, 6-methylthiouracil and other similar antithyroid drugs, glucocorticosteroids.

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