Potassium Iodide

Potassium iodide is a thyroid blocker indicated to help prevent radioactive iodine from getting into the thyroid gland during a nuclear radiation emergency. Potassium iodide is used along with other emergency measures recommended by public officials.

Potassium iodide is available under the following different brand names: Pima Syrup, SSKI, Iosat, ThyroSafe, and ThyroShield.

Adult and Pediatric Dosage Forms and Strengths

Tablet

• 65 mg
• 130 mg

Oral solution

• 65 mg/mL
• 325 mg/5mL

Oral solution (concentrated)

• 1 mg/mL

Dosage Considerations – Should be Given as Follows:

Radiation Emergency

Indicted during environmental radiation emergency to block uptake of radioactive iodine isotopes in thyroid and reduce risk of thyroid cancer

Adult: 130 mg orally once/day; not to exceed 1 dose/24 hours

Ideally initiate 1-48 hours prior to exposure

Continue daily dose until exposure risk has passed and/or until other measures (e.g., evacuation, sheltering, control of the food and milk supply) have been successfully implemented

Risk reduction with acute exposure

• Potassium iodide (KI) initiated shortly before or immediately after acute exposure: 90-99% risk reduction
• KI initiated within 3-4 hours after acute exposure: 50% risk reduction
• KI initiated up to 12 hours after acute exposure: limited benefit may be achieved

Pediatric:

Infants under 1 month: 16.25 mg orally once/day; not to exceed 1 dose/24 hours

Children 1 month-3 years: 32.5 mg orally once/day; not to exceed 1 dose/24 hours

Children 3-13 years: 65 mg orally once/day; not to exceed 1 dose/24 hours

Children over 13 years or adolescents weighing greater than 70 kg (154 lbs): 130 mg orally once/day; not to exceed 1 dose/24 hours

Ideally initiate 1-48 hours prior to exposure

Continue daily dose until exposure risk has passed and/or until other measures (e.g., evacuation, sheltering, control of the food and milk supply) have been successfully implemented

Risk reduction with acute exposure

• Potassium iodide (KI) initiated shortly before or immediately after acute exposure: 90-99% risk reduction
• KI initiated within 3-4 hours after acute exposure: 50% risk reduction
• KI initiated up to 12 hours after acute exposure: limited benefit may be achieved

Expectorant

• Adult: Super Saturated Potassium Iodide (SSKI): 300-600 mg orally every 6-8 hours
• Pediatric: SSKI: 60-250 mg orally every 6 hours

Thyrotoxic Crisis

• 250-500 mg (5-10 drops of 1 g/mL) orally every 4-6 hours

Preoperative Thyroidectomy

• 50-250 mg (1-5 drops of 1 g/mL) orally every 8 hours for 10-14 days

Neonatal Graves Disease

• Super Saturated Potassium Iodide (SSKI): 1 drop orally every 8 hours

Other Indications and Uses

• Cystic fibrosis, chronic sinusitis (adjunct)

Common side effects of Potassium Iodide include:

• Allergic reactions (skin rashes such as hives; swelling of various parts of the body such as the face, lips, tongue, throat, hands or feet; fever with joint pain, trouble breathing, speaking or swallowing, wheezing, or shortness of breath)
• Benign tumor of the thyroid gland
• Diarrhea
• Fever
• Gastrointestinal irritation or bleeding
• Goiter
• Headache
• Hyperthyroidism
• Hypothyroidism, may be severe (myxedema)
• Irregular heart rate (arrhythmia)
• Lymph node swelling
• Metallic taste
• Nausea
• Numbness and tingling
• Salivary gland swelling/tenderness
• Skin rash
• Stomachache
• Swelling or neck or throat
• Vomiting

This is not a complete list of side effects and other serious side effects may occur. Call your doctor for information and medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.

• Potassium Iodide has no known severe interactions with other drugs.
• Severe interactions of potassium_iodide include:
  • sodium iodide I-131
• Potassium iodide has no known serious interactions with other drugs.
• Moderate Interactions of potassium iodide include:
  • benazepril
  • captopril
• Mild Interactions of potassium iodide include:
  • amiloride
  • drospirenone
  • iodine (radioactive)
  • iodoquinol
  • lithium
  • methimazole
  • potassium acid phosphate
  • potassium chloride
  • potassium citrate
  • propylthiouracil
  • spironolactone
  • triamterene

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

Warnings

This medication contains potassium iodide. Do not take Pima Syrup, SSKI, Iosat, ThyroSafe, and ThyroShield if you are allergic to potassium iodide or any ingredients contained in this drug.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.

Contraindications

• Iodine sensitivity (although allergy to radio contrast media, contact dermatitis from iodine-containing antibacterials, allergy to seafood should NOT be considered evidence of potassium iodide allergy)
• Hyperthyroidism
• Respiratory failure

Effects of Drug Abuse

• None

Short-Term Effects

• See "What Are Side Effects Associated with Using Potassium Iodide?"

Long-Term Effects

• See "What Are Side Effects Associated with Using Potassium Iodide?"

Cautions

• Avoid repeat dosing in neonates or women who are pregnant or breastfeeding if possible; in acute radiation exposure, prioritize these individuals for evacuation; although these precautions should be taken, the benefits of short-term use of potassium iodide (KI) to block uptake of radioactive iodine by the thyroid gland far exceed its chances of side effects.
• Prescribe for radiation exposure only upon order from authorities.
• Caution in tuberculosis.
• Iodine poisoning (Iodism): Metallic taste, sore mouth, severe headache.

Pregnancy and Lactation

Use potassium iodide during pregnancy only in LIFE-THREATENING emergencies when no safer drug is available. There is positive evidence of human fetal risk.

The increased risk of thyroid suppression in the fetus and neonate leads to a specific recommendation that newborns and pregnant women be given priority with regard to evacuation, safe shelter, and safe food/milk during radiation emergency in order to obviate, as possible, the need for repeat dosing with potassium iodide (KI).

Potassium iodide is excreted in breast milk. Consult your doctor before breastfeeding.