de la Provincia de Buenos Aires

Ioduro de Potasio

Pharmacologic Category

Antithyroid Agent;
Expectorant

Dosing: Adult

RDA: 150 mcg (iodine)

Expectorant: Oral: SSKI®: 300-600 mg 3-4 times/day

Preoperative thyroidectomy (unlabeled use): Oral: 50-250 mg (1-5 drops SSKI®) 3 times/day; administer for 10 days before surgery

To reduce risk of thyroid cancer following nuclear accident (Iosat™, ThyroSafe™, ThyroShield™): Oral: Adults (including pregnant/lactating women): Oral: 130 mg once daily. Note: Dosing should continue until risk of exposure has passed or other measures have are implemented.

Thyroid gland protection during radiopharmaceutical use (unlabeled use): Oral: Tablet: 130 mg once daily or Solution (SSKI®): 4 drops 3 times/day. Note: Begin at 1-48 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 (unlabeled use): Oral: 250 mg (5 drops SSKI®) every 6 hours (Nayak, 2006)

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

Dosing: Pediatric

(For additional information see "Potassium iodide: Pediatric drug information")

Preoperative thyroidectomy (unlabeled use): Refer to adult dosing.

To reduce risk of thyroid cancer following nuclear accident (Iosat™, ThyroSafe™, ThyroShield™): Oral:

Neonates: 16.25 mg once daily

Children 1 month to 3 years: 32.5 mg once daily

Children 3-18 years: 65 mg once daily

Children >68 kg: Refer to adult dosing

Note: Dosing should continue until risk of exposure has passed or other measures are implemented.

Thyroid gland protection during radiopharmaceutical use (unlabeled use): Oral (Olivier, 2003; Giammarile, 2008):

Neonates: 16 mg once

Infants <5 kg: 16 mg once daily

Children 1 month to 3 years or 5-15 kg: 32 mg once daily

Children 3-13 years or 15-50 kg: 65 mg once daily

Children >13 years or >50 kg: 130 mg once daily

Note: Begin at 1-48 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 (unlabeled use): Oral:

Infants: 100 mg (2 drops SSKI®) 4 times/day (Hassoun, 2008)

Children: Refer to adult dosing.

Dosing: Geriatric

Refer to adult dosing.

Dosage Forms: U.S.

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Solution, oral:

SSKI®: 1 g/mL (30 mL, 237 mL)

Thyroshield™: 65 mg/mL (30 mL) [black raspberry flavor]

Tablet, oral:

iOSAT™: 130 mg [scored]

ThyroSafe™: 65 mg [scored; equivalent to iodine 50 mg]

Administration

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

Use

Expectorant for the symptomatic treatment of chronic pulmonary diseases complicated by mucous; block thyroidal uptake of radioactive isotopes of iodine in a radiation emergency

Use - Unlabeled/Investigational

Lymphocutaneous and cutaneous sporotrichosis; reduce thyroid vascularity prior to thyroidectomy; management of thyrotoxic crisis; block thyroidal uptake of radioactive isotopes of iodine after therapeutic or diagnostic exposure to radioactive iodine

Adverse Reactions Significant

Frequency not defined.

Cardiovascular: Irregular heart beat

Central nervous system: Confusion, tiredness, fever

Dermatologic: Skin rash

Endocrine & metabolic: Goiter, salivary gland swelling/tenderness, thyroid adenoma, swelling of neck/throat, myxedema, lymph node swelling, hyper-/hypothyroidism

Gastrointestinal: Diarrhea, gastrointestinal bleeding, metallic taste, nausea, stomach pain, stomach upset, vomiting

Neuromuscular & skeletal: Joint pain, numbness, tingling, weakness

Miscellaneous: Chronic iodine poisoning (with prolonged treatment/high doses); iodism, hypersensitivity reactions (angioedema, cutaneous and mucosal hemorrhage, serum sickness-like symptoms)

Contraindications

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

Warnings/Precautions

Concerns related to adverse effects:

• Hypothyroidism: Prolonged use can lead to hypothyroidism.

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

Disease-related concerns:

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

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

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

• Cystic fibrosis: May have an exaggerated response.

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

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

• Thyroid disease: Use with caution in patients with a history of hyperthyroidism; use is contraindicated in patients with nodular thyroid condition and heart disease.

• Tuberculosis: Use with caution in patients with tuberculosis.

Concurrent drug therapy issues:

• Potassium-altering therapies: Use with caution in patients receiving concomitant medications or therapies that increase potassium (eg, ACEI, potassium-sparing diuretics, potassium containing salt substitutes).

Other warnings/precautions:

• Appropriate use: Thyroid gland protection (radiopharmaceutical use): Potassium iodide must be administered prior to receiving radiopharmaceuticals that require thyroid gland protection.

Drug Interactions

(For additional information: Launch Lexi-Interact™ Drug Interactions Program )

ACE Inhibitors: Potassium Salts may enhance the hyperkalemic effect of ACE Inhibitors. Risk C: Monitor therapy

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

Eplerenone: May enhance the hyperkalemic effect of Potassium Salts. Management: This combination is contraindicated in patients receiving eplerenone for treatment of hypertension. Risk D: Consider therapy modification

Lithium: Potassium Iodide may enhance the adverse/toxic effect of Lithium. Specifically the hypothyroid/goiter-potentiating effects. Risk C: Monitor therapy

Potassium-Sparing Diuretics: Potassium Salts may enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Risk D: Consider therapy modification

Sodium Iodide I131: Antithyroid Agents may diminish the therapeutic effect of Sodium Iodide I131. Management: Discontinue antithyroid therapy 3-4 days prior to sodium iodide I-131 administration. Risk X: Avoid combination

Vitamin K Antagonists (eg, warfarin): Antithyroid Agents may diminish the anticoagulant effect of Vitamin K Antagonists. Risk D: Consider therapy modification

Pregnancy Risk Factor

D (show table)

Pregnancy Implications

Iodide crosses the placenta (may cause hypothyroidism and goiter in fetus/newborn). Use as an expectorant during pregnancy is contraindicated by the AAP. 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. Repeat dosing should be avoided if possible. Refer to Iodine for additional information.

Lactation

Enters breast milk/use caution (AAP rates “compatible”)

Breast-Feeding Considerations

AAP considers this drug compatible, but recommends avoiding breast-feeding following radioactive iodine exposure unless no alternative is available. May cause skin rash in nursing infant. Refer to Iodine for additional information.

Dietary Considerations

SSKI®: Take with food to decrease gastric irritation.

Pricing: U.S. (www.drugstore.com)

Solution (SSKI)

1 g/mL (237): $70.34

Monitoring Parameters

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

International Brand Names

Cato-Bell (IN);
Iodid (BE);
Iodure de Potassium (FR);
Ioduro Potasico Rovi (ES);
Jodam (PL);
Jodetten Henning (DE);
Jodgamma (DE);
Jodid (DE, HU, LU, PL);
Jodid Merck (AT);
Jodid Verla (DE);
Jodid-ratiopharm (DE);
Jodix (FI);
Jodostin (PL);
Jodox (PL);
Kalium jodatum (DE);
Kaliumiodid (CH);
Kaliumiodid BC (DE);
Kaliumjodid Lannacher (AT);
Kaliumjodid Recip (SE);
Kaliumjodid ”Dak” (DK);
Mono-Jod (DE);
Tarjod (PL);
Thyroprotect (DE)

Mechanism of Action

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 uptake of radioiodine by the thyroid, reducing the risk of thyroid cancer.

Pharmacodynamics/Kinetics

Onset of action: Hyperthyroidism: 24-48 hours

Peak effect: 10-15 days after continuous therapy

Duration: Radioactive iodine exposure: ~24 hours

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REFERENCES

“American Academy of Pediatrics Committee on Drugs. The Transfer of Drugs and Other Chemicals Into Human Milk,” Pediatrics, 2001, 108(3):776-89.
“American Academy of Pediatrics Committee on Environmental Health. Radiation Disasters and Children,” Pediatrics, 2003, 111(6 Pt 1):1455-66.
Briggs GG, Freeman RK, and Yaffe SJ, Drugs in Pregnancy and Lactation, 6th ed, Philadelphia, PA: Lippincott Williams & Wilkins, 2002.
Giammarile F, Chiti A, Lassmann M, et al, “EANM Procedure Guidelines for 131I-meta-iodobenzylguanidine (131I-mIBG) Therapy,” Eur J Nucl Med Mol Imaging, 2008, 35(5):1039-47. [PubMed 18274745]
Hassoun A and Oberfield SE, “Renal, Endocrine, and Metabolic Disorders,” in Roger’s Textbook of Pediatric Intensive Care, 3rd ed, David G Nichols, ed, Philadelphia, PA: Lippincott, Williams, & Wilkins, 2008; p.1658.
Kauffman CA, Bustamante B, Chapman SW, et al, “Clinical Practice Guidelines for the Management of Sporotrichosis: 2007 Update by the Infectious Diseases Society of America,” Clin Infect Dis, 2007, 45(10):1255-65. [PubMed 17968818]
Kauffman CA, Hajjeh R, and Chapman SW, “Practice Guidelines for the Management of Patients With Sporotrichosis. For the Mycoses Study Group. Infectious Diseases Society of America,” Clin Infect Dis, 2000, 30(4):684-7.
Nayak B and Burman K, “Thyrotoxicosis and Thyroid Storm,” Endocrinol Metab Clin North Am, 2006,35(4):663-86, vii. [PubMed 17127140]
Olivier P, Colarinha P, Fettich J, et al, “Guideline for Radioiodinated MIBG Scintigraphy in Children,” Eur J Nucl Med Mol Imaging, 2003, 30(5):B45-50. [PubMed 12658506]
“Potassium Iodide as a Thyroid Blocking Agent in a Radiation Emergency: Final Recommendations on Use,” Washington DC, Bureau of Radiological Health and Bureau of Drugs, Food and Drug Administration, 1982.
U.S. Food and Drug Administration, “FDA's Guidance on Protection of Children and Adults Against Thyroid Cancer in Case of Nuclear Accident,” FDA Talk Paper. Available at