potassium iodide

What is potassium iodide, and how does it work (mechanism of action)?

Potassium iodide is a iodine-containing liquid that is used to protect the thyroid gland and to loosen secretions in the lungs (expectorant) so that they can be more easily coughed up (expectorated). Procedures that involve the use of radioactive iodine can damage the thyroid gland because the gland accumulates iodine. Non-radioactive potassium iodide can protect the thyroid gland by blocking uptake of radioactive iodine into the thyroid gland. Potassium iodide works as an expectorant by increasing secretion of thinner mucus by the lungs.

What brand names are available for potassium iodide?

SSKI, Pima syrup, ThyroSafe, ThyroShield.

Is potassium iodide available as a generic drug?


Do I need a prescription for potassium iodide?


What are the side effects of potassium iodide?

Common side effects of potassium iodide are stomach upset, diarrhea, nausea, vomiting, skin rash, weakness, numbness, fever, and swelling of throat or neck.

What is the dosage for potassium iodide?

Adults and children over 12 years of age and weight 150 lbs or greater:

  • Prevention of thyroid gland injury due to radiation: 130 mg by mouth once dailywith a maximum of one dose per day.
  • Expectorant: 300 – 600 mg by mouth every 6 to 8 hours.


Prevention of thyroid gland injury due to radiation:

  • Infants of less than 1 month: 16.25 mg by mouth once daily. Maximum one dose per day.
  • Infants of 1 month to children of 3 years of age: 32.5 mg by mouth once daily. Maximum one dose per day.
  • Children of 3 to 12 years of age: 65 mg by mouth once daily. Maximum one dose per day.

Expectorant: 60 – 250 mg by mouth every 6 hours.

Which drugs or supplements interact with potassium iodide?

Potassium iodide should not be given together with sodium iodide I-131 (radioactive iodide) that is being used to treat thyroid disease, because potassium iodide can prevent the absorption of sodium iodide I-131 into the thyroid gland. Potassium iodide should be discontinued at least 3 to 4 days prior to using sodium iodide I-131.

Potassium iodide should be used with caution with lithium because concurrent use of both medications can lead to hypothyroidism.


Hyperthyroidism: Symptoms, Treatment, Medication See Slideshow

Is potassium iodide safe to take if I'm pregnant or breastfeeding?

There is increased risk of thyroid suppression in the newborn with potassium iodide. Potassium iodide should not be used during pregnancy.

Potassium iodide is excreted in breast milk. Use in nursing mothers can cause skin rash and thyroid suppression in nursing infants. Therefore, potassium iodide should not be used in nursing mothers.

What else should I know about potassium iodide?

What preparations of potassium iodide are available?

Tablet: 65 and 130 mg. Solution: 65 and 325 mg/5 ml. Concentrated Solution: 1 g/ml

How should I keep potassium iodide stored?

Potassium iodide should be stored between 15 C - 30 C (59 F - 86 F). The solution should be kept in a tightly closed bottle protected from light.

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Medically reviewed by John P. Cunha, DO, FACOEP; Board Certified Emergency Medicine


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Potassium iodide – Medscape