Iodine : Safety

by MedlinePlus

(Page 4 of 5)

Allergies

Some individuals are allergic/hypersensitive to iodide or to organic preparations containing iodine. Hypersensitivity reactions may involve rash, angioedema (throat swelling), cutaneous/mucosal hemorrhage (bleeding), fever, arthralgias (joint pains), eosinophilia (abnormal blood counts), urticaria (hives), thrombotic thrombocytopenic purpura, or severe periarteritis (inflammation around blood vessels). Reactions can be severe and deaths have occurred with exposure. Iodine-based products should be avoided if there is known allergy/hypersensitivity to iodine.

Topical use of iodine preparations may irritate/burn tissues and cause sensitization in some individuals.

This review does not comprehensively cover the use of iodine-based intravenous contrast media for CT scan imaging, although serious life-threatening allergic reactions have been associated with use. Individuals with known or suspected iodine hypersensitivity should inform their physician prior to receiving contrast media.

Side Effects and Warnings

Note: This review does not cover adverse effects associated with intravenous iodine-based contrast agents used for CT scan imaging, or radioactive iodine.

General: Iodine preparations used orally (by mouth) or topically (on the skin) are generally considered to be safe in healthy non-allergic individuals when used in recommended amounts, not exceeding tolerated upper limits. Higher amounts taken acutely or chronically may result in adverse effects.

Acute toxicity: Acute iodine poisoning is rare and generally occurs only with doses of many grams. Symptoms may include burning of the mouth, throat, and stomach, fever, nausea, vomiting, diarrhea, cardiovascular compromise, and loss of consciousness/coma.

Chronic toxicity (iodism, intoxication):Chronic iodism, also known as iodide intoxication, may cause eye irritation, eyelid swelling, unpleasant/metallic taste, burning or swelling of the mouth/throat, soreness of the gums/teeth, increased salivation, gastrointestinal upset, diarrhea, anorexia, flu-like symptoms, sneezing, cough, pulmonary edema (fluid in the lungs), confusion, headache, fatigue, depression, numbness, tingling, pain, weakness, muscle aches, easy bruising, irregular heart beat, or acne-like skin lesions. Prolonged excess intake of iodides can lead to thyroid gland dysfunction including hypo- or hyperthyroidism, parotiditis, thyroid gland hyperplasia (enlargement), thyroid adenoma, goiter, autoimmunity, and elevated thyroid stimulating hormone (TSH) levels.

Endocrine (thyroid effects): Prolonged excess intake of iodides can lead to thyroid gland dysfunction including hypo- or hyperthyroidism, thyroid gland hyperplasia (enlargement), thyroid adenoma, goiter, autoimmunity, and elevated thyroid stimulating hormone (TSH) levels. Individuals with autoimmune thyroid disease (AITD) may have increased sensitivity to adverse effects of iodine. Those with previous iodine deficiency or nodular goiter may be particularly susceptible.

Dermatologic: Topical cadexomer iodine has been associated with local burning sensation in clinical trials. Cutaneous (skin) intolerance may develop with the topical use of iodinated polyvidone. Other reported reactions to tinctures include rash, blistering, crusting, irritation, itching, or erythema (reddening) of skin. Topical use of iodine may stain the skin.

Ocular/Otic: Eyelid edema may result from administration of povidone-iodine.

Genitourinary: Povidone-iodine bladder irrigation has been associated with increased risk of urinary tract infection.

Renal: Sodium iodide should be used cautiously in those with renal failure. Lugol solution and saturated solution of potassium iodide (SSKI, PIMA) should be avoided in those with hyperkalemia. (Note: This review does not cover adverse effects associated with intravenous iodine-based contrast agents used for CT scan imaging. However, such contrast agents can cause impairment of kidney function including permanent damage. Individuals with a history of kidney disease or diabetes may be particularly susceptible. This concern should be discussed with the patient's physician prior to receiving intravenous contrast.)

Gastrointestinal: Sodium iodide should be used cautiously in those with gastrointestinal obstruction.

Pulmonary: Lugol solution and saturated solution of potassium iodide (SSKI, PIMA) should be avoided in patients with pulmonary edema, bronchitis, or known tuberculosis.

Immunologic: It has been suggested thatapplication of povidone-iodine to wounds (particularly surgical wounds) may locally suppress immune cells and wound healing, and increase susceptibility to local infection.

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