Iodotope

In the U.S.

• Iodotope

Available Dosage Forms:

• Capsule
• Kit
• Solution

Therapeutic Class: Diagnostic Agent, Thyroid Function

Sodium iodide I 131 is used to treat hyperthyroidism (an overactive thyroid) and certain kinds of thyroid cancer. This medicine is taken up mainly by the thyroid gland. In the treatment of overactive thyroid gland, the radiation from the radioactive iodine damages the thyroid gland to bring its activity back down to normal. Larger doses of radioiodide are usually used after thyroid cancer surgery to destroy any remaining diseased thyroid tissue or to destroy thyroid cancer that has spread to other tissues.

When very small doses are given, a measure of the radioactivity taken up by the gland helps your doctor decide whether your thyroid gland is working properly or to locate tumors caused by certain types of thyroid cancers.

This medicine is to be given only by or under the direct supervision of a doctor with specialized training in nuclear medicine or radiation oncology.

Before receiving this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.

A nurse or other trained health professional will give you this medicine in a hospital or clinic. It is given by mouth.

Your doctor may have special instructions for you to get ready for your treatment. If you have not received such instructions or you do not understand them, check with your doctor ahead of time.

Your doctor will check your progress closely while you are receiving this medicine. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to receive it. Blood and urine tests may be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. If you are a woman who can bear children, your doctor may give you a pregnancy test before you start receiving this medicine to make sure you are not pregnant. You must use two forms of birth control together for at least 6 months after using this medicine. Use birth control pills together with another form of birth control, such as a condom, diaphragm, or contraceptive foam or jelly. If you think you have become pregnant while using the medicine, tell your doctor right away.

If you are receiving sodium iodide I 131 for an overactive thyroid or cancer of the thyroid, your doctor may tell you to follow some or all of these guidelines for 48 to 96 hours after receiving the medicine, to help reduce the chance of contaminating other persons:

• Do not kiss anyone, or handle or use another person's eating or drinking utensils, toothbrush, or bathroom glass.
• Do not have sex.
• Do not sit close to others, especially pregnant women, and do not hold children in your lap for long periods of time.
• Sleep alone.
• Wash the tub and sink after each use (including after brushing teeth).
• Wash your hands after using or cleaning the toilet.
• Use a separate towel and washcloth.
• Wash your clothes, bed linens, and eating utensils separately.
• Sodium iodide I 131 is passed in the urine. To prevent contamination of your home, flush the toilet twice after you urinate.

If you were treated with sodium iodide I 131 for an overactive thyroid, your doctor may want to check the level of thyroid hormone in your blood every 2 to 3 months during the first year, and once a year thereafter. This is to make sure that your thyroid has not become underactive.

This medicine may cause allergic reactions. Check with your doctor right away if you have a rash, hives, itching, fast heartbeat, shortness of breath, or swelling of the eyes, face, lips after receiving the medicine.

This medicine may increase your risk for cancer or thyroid problems. Talk with your doctor about these risks. You may need to take other medicine with this medicine to prevent thyroid problems.

You will be exposed to dangers of radiation while using this medicine. Talk to your doctor about this risk and the precautions that you might need to take.

This medicine might cause temporary infertility in both men and women. Discuss this with your doctor if you plan to have children.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

• Changes in menstrual periods
• clumsiness
• coldness
• drowsiness
• dry, puffy skin
• headache
• listlessness
• muscle aches
• thinning of the hair (temporary)
• unusual tiredness or weakness
• weight gain

• Excessive sweating
• fast, irregular, pounding, or racing heartbeat or pulse
• fever
• unusual irritability

• Black, tarry stools
• blood in the urine or stools
• cough or hoarseness
• fever or chills
• lower back or side pain
• painful or difficult swallowing
• painful or difficult urination
• pinpoint red spots on the skin
• unusual bleeding or bruising

• Chest pain
• fast, pounding, or irregular heartbeat or pulse
• hives, itching, and rash
• nervousness
• sensitivity to heat
• sweating
• tenderness of salivary glands
• trouble sleeping
• weight loss

• Abdominal or stomach cramps
• bleeding gums
• bone pain
• diarrhea
• feeling of discomfort
• loss of appetite
• nausea
• sore throat
• unusual tiredness or weakness
• vomiting
• weakness

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Neck tenderness or swelling
• sore throat

• Loss of taste (temporary)
• nausea and vomiting (temporary)
• tenderness of the salivary glands

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Therapeutic • Oral

Iodine 131 decays by beta emission and associated gamma emission with a physical half-life of 8.04 days.1 Photons that are useful for detection and imaging are listed in Table 1.

External Radiation

The specific gamma ray constant for iodine 131 is 2.2 R/hour-millicurie at 1 cm. The first half-value thickness of lead (Pb) for iodine 131 is 0.24 cm. A range of values for the relative attenuation of the radiation emitted by this radionuclide that results from interposition of various thicknesses of Pb is shown in Table 2. For example, the use of 2.55 cm of Pb will decrease the external radiation exposure by a factor of about 1,000.

To correct for physical decay of iodine 131, the fractions that remain at selected intervals after the time of calibration are shown in Table 3.

Sodium iodide I 131 is readily absorbed from the gastrointestinal tract. Following absorption, the iodide is primarily distributed within the extracellular fluid of the body. It is trapped and rapidly converted to protein bound iodine by the thyroid; it is concentrated, but not protein bound, by the stomach and salivary glands. It is also promptly excreted by the kidneys. About 90 percent of the local irradiation is caused by beta radiation and 10 percent is caused by gamma radiation.

Iodotope (Sodium Iodide I 131 Capsules USP) blue/buff therapeutic capsules containing 37 to 4810 megabecquerels (1 to 130 millicuries) sodium iodide I 131 at the time of calibration are available in packages of 37 to 5550 megabecquerels (1 to 150 millicuries) at the time of calibration.

Storage

Sodium Iodide I 131 Capsules should be stored as supplied at 25 °C (77 °F), excursions permitted to 15-30 °C (59-86 °F) [See USP Controlled Room Temperature].

   The U.S. Nuclear Regulatory Commission has approved this prepared
   radiopharmaceutical for distribution to persons licensed to use byproduct
   material identified in §35.300 of 10 CFR Part 35, to persons who
   hold an equivalent license issued by an Agreement State, and, outside
   the United States, to persons authorized by the appropriate authority.

Manufactured for
Bracco Diagnostics Inc.
Princeton, NJ 08543

by DRAXIMAGE, a division of
DRAXIS Specialty Pharmaceuticals Inc.
Kirkland Quebec H9H 4J4 Canada

Printed in Canada
Revised December 2006
43-8300A

Applies to sodium iodide-i-131: oral capsule, oral kit, oral solution

Along with its needed effects, sodium iodide-i-131 (the active ingredient contained in Iodotope) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking sodium iodide-i-131:

• Changes in menstrual periods
• clumsiness
• coldness
• drowsiness
• dry, puffy skin
• headache
• listlessness
• muscle aches
• thinning of the hair (temporary)
• unusual tiredness or weakness
• weight gain

• Excessive sweating
• fast, irregular, pounding, or racing heartbeat or pulse
• fever
• unusual irritability

• Black, tarry stools
• blood in the urine or stools
• cough or hoarseness
• fever or chills
• lower back or side pain
• painful or difficult swallowing
• painful or difficult urination
• pinpoint red spots on the skin
• unusual bleeding or bruising

• Chest pain
• fast, pounding, or irregular heartbeat or pulse
• hives, itching, and rash
• nervousness
• sensitivity to heat
• sweating
• tenderness of salivary glands
• trouble sleeping
• weight loss

• Abdominal or stomach cramps
• bleeding gums
• bone pain
• diarrhea
• feeling of discomfort
• loss of appetite
• nausea
• sore throat
• unusual tiredness or weakness
• vomiting
• weakness

Some side effects of sodium iodide-i-131 may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Neck tenderness or swelling
• sore throat

• Loss of taste (temporary)
• nausea and vomiting (temporary)
• tenderness of the salivary glands