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Potassium Iodide

Medically reviewed by Drugs.com. Last updated on July 27, 2020.

Pronunciation

(poe TASS ee um EYE oh dide)

Index Terms

  • KI
  • Saturated Potassium Iodide Solution
  • Saturated Solution of Potassium Iodide

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Solution, Oral:

SSKI: 1 g/mL (30 mL, 237 mL)

Generic: 65 mg/mL (30 mL)

Tablet, Oral:

iOSAT: 130 mg [scored]

ThyroSafe: 65 mg [scored]

Brand Names: U.S.

  • iOSAT [OTC]
  • SSKI
  • ThyroSafe [OTC]

Pharmacologic Category

  • Antidote
  • Antithyroid Agent
  • Expectorant

Pharmacology

Reduces viscosity of mucus by increasing respiratory tract secretions; inhibits secretion of thyroid hormone, fosters colloid accumulation in thyroid follicles. Following radioactive iodine exposure, potassium iodide blocks the uptake of radioactive iodine by the thyroid, reducing the risk of thyroid cancer.

Onset of Action

Hyperthyroidism: 24 to 48 hours (Nayak 2006); Peak effect: ~2 weeks after continuous therapy (Nayak 2006)

Duration of Action

Radioactive iodine exposure: Each dose has a duration of ~24 hours

Use: Labeled Indications

Antidote: Block thyroidal uptake of radioactive isotopes of iodine in a nuclear radiation emergency.

Expectorant: Expectorant for the symptomatic treatment of chronic pulmonary diseases complicated by mucous.

Off Label Uses

Graves hyperthyroidism (following radioactive iodine therapy)

Data from a retrospective study suggest that potassium iodide may be beneficial in select patients with Graves hyperthyroidism (eg, those who would be candidates for but are allergic to antithyroid drugs) in order to shorten the duration of hyperthyroidism after receiving radioactive iodine therapy [Ross 1983]. Additional data may be necessary to further define the role of potassium iodide in this condition.

Sporotrichosis (cutaneous, lymphocutaneous)

Based on the Infectious Diseases Society of America (IDSA) Clinical Practice Guidelines for the Management of Sporotrichosis: 2007 update, potassium iodide is recommended as alternative therapy for nonpregnant adults with cutaneous or lymphocutaneous sporotrichosis who do not respond to or otherwise cannot receive itraconazole.

Thyroidectomy preparation in patients with Graves disease

Based on the American Thyroid Association and American Association of Clinical Endocrinologists guidelines for the management of hyperthyroidism and other causes of thyrotoxicosis, potassium iodide is recommended in the immediate preoperative period in patients with Graves disease undergoing thyroidectomy to reduce thyroid blood flow, vascularity, and intraoperative blood loss. Potassium iodide is not recommended in the preoperative setting in patients with thyrotoxicosis caused by a toxic adenoma or toxic multinodular goiter due to the risk of exacerbating hyperthyroidism [Ross 2016].

Thyroid gland protection during radiopharmaceutical use

Based on the European Association of Nuclear Medicine (EANM) procedure guidelines for 131 I-meta-iodobenzylguanidine (131 I-mIBG) therapy, potassium iodide is effective and recommended when given as thyroid gland protection during radiopharmaceutical use.

Thyrotoxic crisis/thyroid storm

Based on the American Thyroid Association and American Association of Clinical Endocrinologists guidelines for the diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis, potassium iodide given to adults for thyrotoxic crisis/thyroid storm is effective and recommended in the management of this condition.

Contraindications

Hypersensitivity to iodide, iodine, or any component of the formulation; dermatitis herpetiformis; hypocomplementemic vasculitis, nodular thyroid condition with heart disease

Dosing: Adult

Expectorant (SSKI): Oral: 300 to 600 mg (0.3 to 0.6 mL) 3 to 4 times daily.

Antidote [thyroid block following nuclear radiation emergency (iOSAT, ThyroSafe, ThyroShield)]: Includes pregnant/lactating women: Oral: 130 mg once daily, continue for 10 to 14 days or as directed by public officials (until risk of exposure has passed or other measures are implemented).

Thyroidectomy preparation in patients with Graves disease (off-label use): Oral: 50 to 100 mg (1 to 2 drops or 0.05 to 0.1 mL SSKI) 3 times daily; administer for 10 days before surgery; if not euthyroid prior to surgery, consider concurrent beta-blockade (eg, propranolol) in the immediate preoperative period to reduce the risk of thyroid storm (Ross 2016).

Sporotrichosis (cutaneous, lymphocutaneous; off-label use) (SSKI): Oral: Initial: 5 drops 3 times daily; increase to 40 to 50 drops 3 times daily as tolerated until 2 to 4 weeks after lesions have resolved (usual duration 3 to 6 months) (Kauffman 2007).

Thyroid gland protection during radiopharmaceutical use (off-label use): Oral: Tablets or SSKI solution: 130 to 300 mg (~3 to 6 drops SSKI) per day (ACR-ACNM [Subramaniam 2017]; ACR-SPR 2015; Bombardier 2010; Taïeb 2012).

Note: Begin at 1 to 48 hours prior to exposure. Continue potassium iodide after radiopharmaceutical administration until risk of exposure has diminished (treatment duration and time of initiation is dependent on the radiopharmaceutical, consult specific protocol).

Thyrotoxic crisis/thyroid storm (off-label use): Oral: Note: Administer at least 1 hour after antithyroid drug administration (eg, propylthiouracil, methimazole): SSKI 250 mg (5 drops or 0.25 mL) every 6 hours (Ross 2016).

Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Note: Doses may be presented as drops, mL, or mg depending on indication and/or product. SSKI contains 1 g/mL; 1 drop = 0.05 mL = 50 mg (ATA [Ross 2016]). Use caution to ensure the proper dose is ordered and administered.

Sporotrichosis, cutaneous: Note: Alternative agent: Limited data available: Children and Adolescents: SSKI 1 g/mL: Oral: Initial: 1 drop (50 mg or 0.05 mL) 3 times daily; increase dose as tolerated; maximum dose: 1 drop/kg/dose or 50 drops/dose, whichever is lowest; continue at the maximum tolerated dosage for several weeks after lesions have resolved (IDSA [Kauffman 2007]; Red Book [AAP 2018]).

Thyroid block following nuclear radiation emergency: Iosat, ThyroSafe, ThyroShield: Oral: Note: Continue treatment until the risk of exposure no longer exists (FDA 2001).

Infants and Children ≤3 years: 32.5 mg once daily.

Children >3 to 12 years: 65 mg once daily.

Adolescents:

Weight <68 kg: 65 mg once daily.

Weight ≥68 kg: 130 mg once daily.

Thyroid gland protection during radiopharmaceutical use: Limited data available; Note: Begin at 1 to 48 hours prior to exposure; continue potassium iodide after radiopharmaceutical administration until risk of exposure has diminished (treatment duration and time of initiation is dependent on the radiopharmaceutical; consult specific protocol): Oral:

Age-directed dosing (Olivier 2003):

Infants and Children <3 years: 32 mg once daily.

Children and Adolescents 3 to 13 years: 65 mg once daily.

Adolescents >13 years: 130 mg once daily.

Weight-directed dosing (Giammarile 2008):

<5 kg: 16 mg once daily.

5 to <15 kg: 32 mg once daily.

15 to <50 kg: 65 mg once daily.

≥50 kg: 130 mg once daily.

Thyroidectomy in Graves disease, preoperative preparation: Limited data available:

Patients receiving methimazole: Children and Adolescents: SSKI 1 g/mL: Oral: 1 to 2 drops (50 to 100 mg or 0.05 to 0.1 mL) 3 times daily; administer for 10 days prior to surgery (ATA [Ross 2016]).

Patients unable to take or intolerant to methimazole or need for urgent thyroidectomy: Children and Adolescents: SSKI 1 g/mL: Oral: 3 to 7 drops (150 to 350 mg or 0.15 to 0.35 mL) 3 times daily; administer for 10 days before surgery in combination with beta-blockade (ATA [Ross 2016]).

Thyrotoxic crisis/thyroid storm: (Eyal 2008): Note: Administer at least 1 hour after antithyroid drug (eg, methimazole) administration:

Infants: SSKI 1 g/mL: Oral: 2 drops (100 mg or 0.1 mL) 4 times daily.

Children and Adolescents: SSKI 1 g/mL: Oral: 5 drops (250 mg or 0.25 mL) 2 to 4 times daily.

Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.

Extemporaneously Prepared

Note: A potassium iodide oral solution (65 mg/mL) is commercially available.

16.25 mg/5 mL Oral Solution

A 16.25 mg/5 mL oral solution may be made with tablets. Crush one 130 mg tablet and reduce to a fine powder. Add 20 mL of water and mix until powder is dissolved. Add an additional 20 mL of low-fat milk (white or chocolate), orange juice, flat soda, raspberry syrup, or infant formula. Stable for 7 days under refrigeration. Discard any unused portion.

Iosat 130 mg tablet (potassium iodide) [prescribing information]. Williamsburg, VA: Anbex Inc; August 2017.

8.125 mg/5 mL Oral Solution

To prepare an 8.125 mg/5 mL oral solution, crush one 65 mg tablet and reduce to a fine powder. Add 20 mL of water and mix until powder is dissolved. Add an additional 20 mL of low-fat milk (white or chocolate), orange juice, flat soda, raspberry syrup, or infant formula. Stable for 7 days under refrigeration. Discard any unused portion.

Iosat 65 mg tablet (potassium iodide) [prescribing information]. Williamsburg, VA: Anbex Inc; August 2017.

Administration

Oral:

SSKI: Dilute in a glassful of water, fruit juice, or milk. Administer with food or milk to decrease gastric irritation.

iOSAT, ThyroSafe, ThyroShield: Administer as soon as possible after instructed to do so by public officials. Do not take more than 1 dose in 24 hours. Tablets may be administered whole or crushed and then mixed with water, low fat milk (white or chocolate), orange juice, soda (flat), raspberry syrup, or infant formula. Raspberry syrup disguises the taste best; low-fat white milk or water do not hide the salty taste well) (AAP 2003). See Extemporaneously Prepared.

Storage

Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F). Protect from light. Keep tightly closed.

SSKI: If exposed to cold, crystallization may occur. Warm and shake to redissolve. If solution becomes brown/yellow, it should be discarded.

iOSAT, ThyroSafe: Keep dry and intact in foil.

Drug Interactions

Aliskiren: Potassium Salts may enhance the hyperkalemic effect of Aliskiren. Monitor therapy

Angiotensin II Receptor Blockers: Potassium Salts may enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Monitor therapy

Angiotensin-Converting Enzyme Inhibitors: Potassium Salts may enhance the hyperkalemic effect of Angiotensin-Converting Enzyme Inhibitors. Monitor therapy

Cardiac Glycosides: Antithyroid Agents may increase the serum concentration of Cardiac Glycosides. Monitor therapy

Drospirenone: Potassium Salts may enhance the hyperkalemic effect of Drospirenone. Monitor therapy

Eplerenone: May enhance the hyperkalemic effect of Potassium Salts. Management: This combination is contraindicated in patients receiving eplerenone for treatment of hypertension. Potassium supplements may be needed to treat/prevent hypokalemia in selected patients with heart failure receiving eplerenone and high dose loop diuretics. Consider therapy modification

Heparin: May enhance the hyperkalemic effect of Potassium Salts. Monitor therapy

Heparins (Low Molecular Weight): May enhance the hyperkalemic effect of Potassium Salts. Monitor therapy

Lithium: Potassium Iodide may enhance the hypothyroid effect of Lithium. Monitor therapy

Nicorandil: May enhance the hyperkalemic effect of Potassium Salts. Monitor therapy

Potassium-Sparing Diuretics: Potassium Salts may enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Management: Avoid coadministration of a potassium-sparing diuretic and a potassium salt. This combination should only be used in cases of significant hypokalemia, and only if serum potassium can be closely monitored. Consider therapy modification

Sodium Iodide I131: Potassium Iodide may diminish the therapeutic effect of Sodium Iodide I131. Management: Discontinue potassium iodide at least 3 weeks before sodium iodide I-131 administration, and avoid concurrent use. Avoid combination

Theophylline Derivatives: Antithyroid Agents may increase the serum concentration of Theophylline Derivatives. Monitor therapy

Vitamin K Antagonists (eg, warfarin): Antithyroid Agents may diminish the anticoagulant effect of Vitamin K Antagonists. Monitor therapy

Test Interactions

Iodide may alter thyroid function tests.

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.

Frequency not defined.

Cardiovascular: Cardiac arrhythmias, numbness, vasculitis

Central nervous system: Confusion, fatigue, fever, numbness, tingling sensation

Dermatologic: Acne vulgaris, dermatitis, urticaria

Endocrine & metabolic: Goiter, hyperthyroidism (prolonged use), hypothyroidism (prolonged use), myxedema

Gastrointestinal: Diarrhea, enlargement of salivary glands, gastric distress, gastrointestinal hemorrhage, gingival pain, metallic taste, nausea, stomach pain, toothache, vomiting

Hematologic & oncologic: Eosinophilia, lymphedema, thyroid adenoma

Hypersensitivity: Hypersensitivity reaction (angioedema, cutaneous and mucosal hemorrhage, serum sickness-like symptoms)

Neuromuscular & skeletal: Arthralgia, weakness

Respiratory: Dyspnea, rhinitis, wheezing

Miscellaneous: Iodine poisoning (with prolonged treatment/high doses)

Warnings/Precautions

Concerns related to adverse effects:

• Hypersensitivity: Iodide hypersensitivity may occur, manifesting as angioedema, cutaneous/mucosal hemorrhage, and serum sickness-like symptoms (fever, arthralgia, lymph node enlargement, and eosinophilia).

• Skin reactions: Can cause acne flare-ups and/or dermatitis.

• Thyroid adverse effects: Prolonged use may lead to hypothyroidism. Iodide may cause underactive or overactive thyroid; thyroid enlargement may also occur. Use with caution in patients with a history of hyperthyroidism; use is contraindicated in patients with nodular thyroid condition (goiter) with heart disease. Iodism or chronic iodide poisoning may occur with high doses or prolonged treatment; symptoms include burning of mouth/throat, sore teeth/gums, severe headache, metallic taste, eye irritation/eye lid swelling, increased salivation, acneform skin lesions, and (rarely) severe skin lesions; withhold potassium iodide treatment and manage with supportive care.

Disease-related concerns:

• Adrenal insufficiency: Use with caution in patients with Addison disease.

• Bronchitis: Use with caution in patients with acute bronchitis.

• Cardiac disease: Use with caution in patients with cardiac disease.

• Myotonia congenita: Use with caution in patients with myotonia congenita.

• Renal impairment: Use with caution in patients with renal impairment

• Tuberculosis: Use with caution in patients with tuberculosis.

Special populations:

• Pediatric: In a nuclear radiation emergency, infants and children are more likely to experience thyroid damage. Neonates <1 month are at higher risk for hypothyroidism with potassium iodide use; evaluate thyroid function if repeat dosing is required in this patient population.

Other warnings/precautions:

• Appropriate use: For thyroid gland protection (radiopharmaceutical use), potassium iodide must be administered prior to receiving radiopharmaceuticals that require thyroid gland protection. For nuclear radiation emergency, take only when instructed by public health officials; do not take more or more often than instructed; follow other emergency measures recommended by officials.

Monitoring Parameters

Thyroid function tests (thyroid function should be monitored in pregnant or breast-feeding women, neonates, and young infants if repeat doses are required following radioactive iodine exposure); signs/symptoms of hypo- or hyperthyroidism

Pregnancy Risk Factor

D

Pregnancy Considerations

Iodide crosses the placenta (may cause hypothyroidism and goiter in fetus/newborn). Use as an expectorant during pregnancy is contraindicated by the AAP (AAP 1976). Use for protection against thyroid cancer secondary to radioactive iodine exposure is considered acceptable based upon risk:benefit, keeping in mind the dose and duration (AAP 2003). In general, medications used as antidotes should take into consideration the health and prognosis of the mother; antidotes should be administered to pregnant women if there is a clear indication for use and should not be withheld because of fears of teratogenicity (Bailey, 2003). Pregnant women should take as instructed by public officials and contact their physician. Repeat dosing should be avoided if possible (AAP 2003). Refer to Iodine monograph for additional information.

Patient Education

What is this drug used for?

• It is used to prevent thyroid cancer from radiation.

• It is used to thin mucus so it can be taken from the body by coughing.

• It is used to aid diet needs.

• It may be given to you for other reasons. Talk with the doctor.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Nausea

• Vomiting

• Abdominal pain

• Diarrhea

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Trouble swallowing

• Trouble speaking

• Wheezing

• Cough

• Shortness of breath

• Abnormal heartbeat

• Chest pain

• Joint pain

• Swelling of neck

• Swelling of arms or legs

• Sensation of heaviness in extremities

• Black, tarry, or bloody stools

• Vomiting blood

• Burning or numbness feeling

• Severe loss of strength and energy

• Confusion

• Severe headache

• Metallic taste

• Teeth or gingival changes

• Burning of mouth or throat

• Eye irritation

• Eyelid swelling

• Increased saliva

• Skin irritation

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

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