Sodium Iodide I 131

1 INDICATIONS AND USAGE Sodium Iodide I 131 Capsules Diagnostic is indicated for use in adults for: Assessment of thyroid function using radioactive iodine (RAI) uptake test Imaging the thyroid (scintigraphy) Sodium Iodide I 131 Capsules Diagnostic is a radioactive diagnostic agent indicated for the assessment of thyroid function and for thyroid imaging.

2 DOSAGE AND ADMINISTRATION Use careful handling with appropriate safety measures to minimize radiation exposure to patients and healthcare workers. ( 2.1 , 5.2 ) Follow suitable radioactivity calibration prior to administration. ( 2.1 ) In an adult patient, recommended doses are ( 2.2 ): Thyroid Function: 0.185 to 1.1 megabecquerels (MBq) [5 to 30 microcuries (microCi)] Thyroid Imaging: 1.85 to 3.70 MBq (50 to 100 microCi) 2.1 Radiation Safety Sodium Iodide I 131 Capsules Diagnostic is a radioactive drug and should be handled with appropriate safety measures to minimize radiation exposure to the patient and healthcare worker [see Warnings and Precautions ( 5.2 ) ]. Use waterproof gloves during the entire handling and administration procedure. Maintain adequate shielding during the life of the product. Open the capsule-containing vial in a well ventilated hood to avoid exposure to trace levels of volatile I-131 which may be present. Measure patient dose by a suitable radioactivity calibration system immediately prior to administration. 2.2 Recommended Dosage and Administration Instructions Administer Sodium Iodide I 131 Capsules Diagnostic orally prior to scanning. The recommended dose of Sodium Iodide I 131 Capsules Diagnostic for an adult patient is the following: Thyroid Function: 0.185 to 1.1 megabecquerels (MBq) [5 to 30 microcuries (microCi)]. Administer 24 hours before uptake measurement. Thyroid Imaging (Scintigraphy): 1.85 to 3.70 MBq (50 to 100 microCi). Administer 16 -24 hours before imaging. Consult the color-coded decay calendar that is updated in January of every year to determine which colored capsule(s) correspond to the prescribed dose: https://www.draximage.com/products/us/draximage-i-131-diagnostic-capsules/ or calculate the correct dose from the date and time of calibration provided on the container label. Prior to Sodium Iodide I 131 Capsules Diagnostic Administration Obtain a pregnacy test in females of reproductive potential prior to administration to verify the absence of pregnancy [see Contraindications ( 4 ) and Use in Specific Populations ( 8.1, 8.3 ) ]. Advise patients to maintain a low-iodine diet two weeks prior to radioiodine administration and continue for several days during the uptake or imaging process [see Drug Interactions ( 7 ) ]. Advise patients to fast at least 2 hours before and 2 hours after administration to ensure absorption. Advise patients to hydrate before and after administration of radioiodine and void frequently to ensure rapid excretion. 2.3 Radiation Dosimetry The biokinetic and radiation dose distributions associated with thyroid uptake of iodide I 131 depend on dietary intake of stable iodine. A range of uptake percentages in an average adult (73.7 kg) are shown in Table 1. For a thyroid blocked from iodide uptake in the production of hormones, the effective half-life of iodide I 131 is approximately 1.4 hours; for "low" to "high" uptake, the effective half-life of I 131 ranges from approximately 80 to 90 hours. Table 1 Absorbed dose per unit activity sodium iodide I 131 administered orally (mGy/MBq) in adult (73.7-kg reference model) Organ Thyroid uptake of I 131 (% administered activity A 0 ) 24 h after oral administration Blocked thyroid (0% A 0 ) Low uptake (16% A 0 ) Medium uptake (26% A 0 ) High uptake (36% A 0 ) Adrenals 0.044 0.051 0.055 0.059 Bone surfaces 0.030 0.089 0.12 0.16 Brain 0.021 0.093 0.13 0.17 Breast 0.020 0.038 0.048 0.058 Gallbladder wall 0.037 0.043 0.046 0.049 Gastrointestinal tract Stomach wall 0.87 0.77 0.71 0.66 Small intestine wall 0.035 0.033 0.032 0.032 Colon wall 0.14 0.14 0.14 0.14 (Upper large intestine wall) 0.12 0.12 0.12 0.12 (Lower large intestine wall) 0.17 0.17 0.17 0.16 Heart wall 0.062 0.089 0.10 0.12 Kidneys 0.27 0.27 0.27 0.27 Liver 0.050 0.093 0.12 0.14 Lungs 0.053 0.10 0.13 0.15 Muscles 0.026 0.084 0.12 0.15 Oesophagus 0.024 0.10 0.14 0.19 Ovaries 0.038 0.037 0.036 0.035 Pancreas 0.060 0.064 0.066 0.068 Red marrow 0.031 0.072 0.095 0.12 Salivary glands 0.27 0.22 0.19 0.16 Skin 0.019 0.043 0.057 0.071 Spleen 0.064 0.069 0.072 0.075 Testes 0.025 0.024 0.023 0.22 Thymus 0.024 0.10 0.14 0.19 Thyroid 2.2 280 430 580 Urinary bladder wall 0.54 0.45 0.39 0.34 Uterus 0.045 0.042 0.040 0.038 Remaining organs 0.029 0.84 0.11 0.15 Effective dose per administered activity (mSv/MBq) 0.28 14 22 29

6 ADVERSE REACTIONS The following adverse reaction has been described elsewhere in the labeling: Hypersensitivity Reactions [see Warnings and Precautions ( 5.4 ) ] The following adverse reactions have been identified during post-approval use from Sodium Iodide I 131 Capsules Diagnostic. Because these reactions are voluntarily reported from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Adverse reactions associated with the administration of Sodium Iodide I 131 Capsules Diagnostic are: Gastrointestinal disorders: vomiting, nausea, and diarrhea General disorders and administration site conditions: local thyroid swelling Immune system disorders: hypersensitivity reactions Skin and subcutaneous tissue disorders: itching, rash, hives, and erythema Common adverse reactions reported with diagnostic doses of sodium iodide I 131 include nausea, vomiting, itching, rash and hives. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Jubilant DraxImage Inc. at 1-888-633-5343 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

12.3 Pharmacokinetics Absorption Following oral administration of Sodium Iodide I 131 Capsules Diagnostic, 90% of the administered radioactivity of sodium iodide I 131 is systemically absorbed in the first 60 minutes. Distribution Following absorption, sodium iodide I 131 is distributed within the extra-cellular space. It is actively transported by the sodium-iodide symporter (NIS) protein and binds to thyroglobulin resulting in accumulation in the thyroid. The thyroid uptake of iodide is usually increased in hyperthyroidism and in goiter, and is decreased in hypothyroidism. Sodium iodide I 131 also accumulates in the stomach, choroid plexus, salivary glands breast, liver, gall bladder, and kidneys. Elimination Metabolism In thyroid follicular cells, iodide is oxidized through the action of thyroid peroxidase to iodinium (I + ) which in turn iodinates tyrosine residues of thyroglobulin. Excretion Sodium iodide I 131 is excreted in urine and feces. The normal range of urinary excretion is 37% to 75% of the administered dose, varying with the thyroid and renal function of the patient. Fecal excretion is about 10%.