Sodium Iodide-i-131 Side Effects

Medically reviewed by Drugs.com. Last updated on Jan 26, 2025.

Applies to sodium iodide-i-131: oral kit.

Precautions

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.

Common side effects of sodium iodide-i-131

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:

After treatment of cancer of the thyroid

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

Serious side effects of sodium iodide-i-131

Along with its needed effects, sodium iodide-i-131 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:

After treatment of overactive thyroid

Symptoms of an underactive thyroid

• 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

After treatment of cancer of the thyroid

• 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

After treatment of cancer of the thyroid

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

For healthcare professionals

Applies to sodium iodide-i-131: compounding powder, oral capsule, oral liquid.

Cardiovascular adverse events

Cardiovascular side effects have included chest pain and tachycardia.^[Ref]

Dermatologic

Dermatologic side effects have included itching skin, rash, and hives.^[Ref]

Endocrine

Endocrine side effects have included acute thyroid crisis.^[Ref]

Gastrointestinal

Gastrointestinal side effects have included nausea and vomiting.^[Ref]

Hematologic

Hematologic side effects have included blood dyscrasia, leukopenia, thrombocytopenia, depression of hematopoietic system, and anemia.^[Ref]

Local

Local side effects have included tenderness and swelling of the neck, pain on swallowing, sore throat, and cough (usually around the third day after treatment).^[Ref]

Oncologic

Oncologic side effects have included acute leukemia.^[Ref]

Other

Other side effects have included temporary thinning of the hair (may occur 2 to 3 months after treatment), chromosomal abnormalities, radiation sickness, and death.^[Ref]

See also:

Further information

Sodium iodide-i-131 side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer