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Iodotope Side Effects

Generic name: sodium iodide-i-131

Medically reviewed by Last updated on Jan 25, 2024.

Note: This document contains side effect information about sodium iodide-i-131. Some dosage forms listed on this page may not apply to the brand name Iodotope.

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

Serious side effects of Iodotope

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:

After treatment of overactive thyroid

Symptoms of an underactive thyroid


After treatment of overactive thyroid

After treatment of cancer of the thyroid

Incidence not known

After treatment of overactive thyroid

After treatment of cancer of the thyroid

Other side effects of Iodotope

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:

Less common

After treatment of overactive thyroid or cancer of the thyroid

After treatment of cancer of the thyroid

For Healthcare Professionals

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


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


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


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


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


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


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 side effects have included acute leukemia.[Ref]


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]


1. Product Information. Sodium Iodide 1-131 (sodium iodide I-131). Mallinckrodt Medical Inc. 2022.

2. Saha GB. Fundamentals of Nuclear Pharmacy. New York, NY: Springer-Verlag. 1998.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.