Potassium Iodide Side Effects
Potassium iodide (KI) can cause potentially serious side effects including life-threatening anaphylaxis, and should only be used when specifically indicated for radioiodine exposure protection, not as a general antiradiation drug. 1
Common Side Effects
- Swelling of salivary glands 2
- Gastrointestinal disturbances: nausea, vomiting, diarrhea, stomach ache 2
- Fever, headache, and metallic taste 2
- Joint pain when accompanied by fever 2
Serious Side Effects
Allergic reactions ranging from skin rashes to severe manifestations 2
Thyroid-related complications 2
High-Risk Populations
- Patients with pre-existing thyroid disease are more susceptible to thyroid-related side effects 2
- Pregnant women - KI should be used cautiously, especially after the first trimester when it can affect the fetal thyroid 1
- Infants under 1 month - higher risk of developing hypothyroidism 2
- Individuals with history of iodine allergy - may experience severe allergic reactions 1
When to Stop Taking KI and Seek Medical Attention
Stop KI and call a doctor if you experience: 2
- Swelling of face, hands, or feet
- Fever with joint pain
- Skin rash
Stop KI and get immediate medical help for: 2
- Breathing difficulties
- Swelling of lips, tongue, or throat
- Irregular heartbeat or chest pain
Important Considerations
- KI is not a general antiradiation drug and should only be used when radioiodine exposure is confirmed 1
- KI offers protection by reducing radioiodine uptake by approximately 50% when administered within 4 hours of exposure 1
- Administration should be as soon as possible after radioiodine exposure (≤6 hours) 1
- Long-term use may lead to more significant adverse effects than short-term use 2, 4
Special Populations
- In pregnant women, KI protection is critical for both mother and fetus, particularly in the second and third trimesters 1
- Children and adolescents are particularly vulnerable to radioiodine-induced thyroid cancer and require appropriate KI dosing 1
- Animal studies have shown developmental toxicity with high doses of KI, affecting growth and neurological development 5
Remember that KI should only be used when specifically indicated for radioiodine exposure protection, and patients should be monitored for side effects, particularly those affecting thyroid function and allergic manifestations.