What is the treatment for iodine toxicity?

Treatment of Iodine Toxicity

The primary treatment for iodine toxicity is immediate discontinuation of the iodine source, followed by supportive care for vital functions and electrolyte management, with close monitoring of thyroid function and urinary iodine excretion. 1

Immediate Management

Source Identification and Removal

• Identify and immediately discontinue all sources of excess iodine, including iodinated contrast agents, topical povidone-iodine disinfectants, amiodarone, Lugol's solution, iodine-containing supplements, and iodized salt 1
• Common non-nutritional sources include chemicals for photography, engraving dyes and inks, and radioactive iodine used for medical procedures 1

Acute Poisoning Protocol

• In acute iodine poisoning, provide support of vital functions and aggressive electrolyte management 1
• Monitor for clinical signs including abdominal pain, loss of appetite, metallic taste, coughing, fever, delirium, diarrhea, gum and tooth soreness, and vomiting 1
• In case of allergic reaction (difficulty breathing, speaking or swallowing, wheezing, shortness of breath, or swelling of mouth/throat), call emergency services immediately 2

Monitoring and Assessment

Laboratory Evaluation

• Measure 24-hour urinary iodine excretion combined with assessment of thyroid function (TSH, free T4, T3) and thyroid size 1
• This is particularly critical in patients exposed to prolonged povidone-iodine disinfection or topical applications, regardless of wound size 1

High-Risk Populations Requiring Intensive Monitoring

• Patients with reduced kidney function and unexplained acidosis require heightened suspicion, as excess iodine may alter renal function 1
• Patients with nodular thyroid disease, especially those with heart disease, are at particular risk and should avoid further iodine exposure 2
• Pregnant or breastfeeding women require immediate medical evaluation, with thyroid function checks recommended for babies less than 1 month of age exposed to excess iodine 2

Management of Thyroid Dysfunction

Iodine-Induced Hypothyroidism

• Excess iodine intake is most commonly associated with elevated TSH, lower thyroid hormone levels, increased thyroid autoimmunity, leading to hypothyroidism and goiter 1
• Chronic exposure induces autoimmune thyroiditis because highly iodinated thyroglobulin is more immunogenic 1, 3
• Treat hypothyroidism symptomatically while the excess iodine clears from the system 1

Iodine-Induced Hyperthyroidism (Jod-Basedow Phenomenon)

• Patients with nodular thyroid disease can develop hyperthyroidism when exposed to excess iodine, particularly those with autonomous thyroid nodules 1, 3
• This occurs because excess iodine establishes excessive thyroid hormone synthesis and release, inducing autonomous thyroid function 1
• Monitor closely and treat hyperthyroidism according to standard protocols 3

Timeline and Prognosis

Clearance Period

• Water-soluble contrast agents generally clear in 4-8 weeks in most patients 3
• Thyroid dysfunction can occur at a median of 9 months post-administration of iodinated contrast 3
• Free iodine interferes with thyroid iodide uptake, affecting diagnostic nuclear procedures like thyroid scintigraphy and radioactive iodine treatment for 2 months or more after contrast use 3

Critical Pitfalls to Avoid

• Do not administer additional iodine-containing medications or supplements during the recovery period 1, 4
• Avoid repeat dosing in pregnant/breastfeeding women and infants unless absolutely necessary, with mandatory thyroid function monitoring 2
• Do not overlook topical iodine sources (povidone-iodine disinfectants, surgical preparations) in patients with major burns, fasciotomies, or mediastinitis treatment, as these can cause significant systemic absorption 1
• Be aware that there is no specific antidote for iodine toxicity—treatment is entirely supportive and focused on source removal 1