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Pronunciation
(poe TASS ee um EYE oh dide)
Generic Available (U.S.)
No
Index Terms
Brand Names: U.S.
Pharmacologic Category
Use: Labeled Indications
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
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
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. 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”; AAP 2001 update pending)
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.
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.
Adverse Reactions
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)
Metabolism/Transport Effects
None known.
Drug Interactions
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
Cardiac Glycosides: Antithyroid Agents may increase the serum concentration of Cardiac Glycosides. 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 hypothyroid effect of Lithium. 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
Theophylline Derivatives: Antithyroid Agents may increase the serum concentration of Theophylline Derivatives. Exceptions: Dyphylline. Risk C: Monitor therapy
Vitamin K Antagonists (eg, warfarin): Antithyroid Agents may diminish the anticoagulant effect of Vitamin K Antagonists. Risk D: Consider therapy modification
Storage
Store at controlled room temperature of 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.
Reconstitution
SSKI®: May be mixed in water, fruit juice, or milk.
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
Dosage
Oral:
Adults: RDA: 150 mcg (iodine)
Expectorant: Adults: SSKI®: 300-600 mg 3-4 times/day
Preparation for thyroidectomy (unlabeled use):
Children: 150-350 mg (3-7 drops or 0.15-0.35 mL SSKI®) 3 times/day; 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 (Bahn, 2011)
Adults: 50-100 mg (1-2 drops or 0.05-0.1 mL SSKI®) 3 times/day; 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 (Bahn, 2011)
To reduce risk of thyroid cancer following nuclear accident (Iosat™, ThyroSafe®, ThyroShield®): Dosing should continue until risk of exposure has passed or other measures are implemented:
Children 1 month to 3 years: 32.5 mg once daily
Children 3-18 years: 65 mg once daily
Children >68 kg and Adults (including pregnant/lactating women): 130 mg once daily
Thyroid gland protection during radiopharmaceutical use (unlabeled use):
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).
Children (Giammarile, 2008; Olivier, 2003):
Infants <5 kg: 16 mg once daily
1 month to 3 years or 5-15 kg: 32 mg once daily
3-13 years or 15-50 kg: 65 mg once daily
>13 years or >50 kg: 130 mg once daily
Adults: Tablet: 130 mg once daily or Solution (SSKI®): 4 drops 3 times/day
Thyrotoxic crisis/thyroid storm (unlabeled use): Note: Administer at least 1-2 hours after antithyroid drug administration:
Infants: 100 mg (2 drops or 0.1 mL SSKI®) 4 times/day (Eyal, 2008)
Children: 250 mg (5 drops or 0.25 mL SSKI®) 2-4 times/day (Eyal, 2008)
Adults: 250 mg (5 drops or 0.25 mL SSKI®) every 6 hours (Bahn, 2011)
Sporotrichosis (cutaneous, lymphocutaneous; unlabeled use): Adults: 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)
Administration: Oral
SSKI®: Dilute in a glassful of water, fruit juice, or milk. Take with food to decrease gastric irritation.
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
Test Interactions
May alter thyroid function tests.
Dietary Considerations
SSKI®: Take with food to decrease gastric irritation.
Patient Education
SSKI®: Dilute in water, fruit juice, or milk and take with meals to reduce gastric irritation. May cause metallic taste, nausea, or vomiting; soreness of teeth, gums, or glands; fever, headache, or sore joints; or confusion or tiredness. Discontinue and report if you experience any swelling of lips, mouth, or tongue; difficulty swallowing; chest pain or irregular heartbeat; unusual muscle weakness; eye irritation or eyelid swelling; or skin rash.
Additional Information
10 drops of SSKI® = potassium iodide 500 mg
Cardiovascular Considerations
Hypokalemia is highly arrhythmogenic, particularly in the setting of ischemia or digitalis toxicity. ECG evidence of hypokalemia includes flattening of the T wave. As the T wave shrinks, U waves may appear. There is no prolongation of the QT interval. Hyperkalemia may present as tall peaked symmetrical T waves. S-T elevation may present in severe hyperkalemia. QRS complex progressively widens with eventual apparent sine waves on the ECG. Hyperkalemia will also induce cardiac slowing and AV conduction abnormalities.
Dental Health: Effects on Dental Treatment
Key adverse event(s) related to dental treatment: Metallic taste.
Dental Health: Vasoconstrictor/Local Anesthetic Precautions
No information available to require special precautions
Mental Health: Effects on Mental Status
None reported
Mental Health: Effects on Psychiatric Treatment
Concurrent use with lithium may produce additive hypothyroid effects
Dosage Forms
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) [contains propylene glycol; black raspberry flavor]
Tablet, oral:
iOSAT™: 130 mg [scored]
ThyroSafe®: 65 mg [scored; equivalent to iodine 50 mg]
Pricing: U.S. (www.drugstore.com)
Solution (SSKI)
1 g/mL (237): $163.41
Extemporaneously Prepared
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.
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.
References
"Adverse Reactions to Iodide Therapy of Asthma and Other Pulmonary Diseases," Pediatrics, 1976, 57(2):272-4.
American Academy of Pediatrics Committee on Drugs, "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.
Bahn RS (Chair), Burch HB, Cooper DS, et al, “Hyperthyroidism and Other Causes of Thyrotoxicosis: Management Guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists,” Thyroid, 2011, 21(6):593-646.
Eyal O and Rose SR, “Thyroid Disease,” in Roger's Textbook of Pediatric Intensive Care, 4th ed, David G Nichols, ed, Philadelphia, PA: Lippincott, Williams, & Wilkins, 2008.
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.
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.
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.
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.
“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 http://www.fda.gov/Drugs/EmergencyPreparedness/BioterrorismandDrugPreparedness/ucm133711.htm
International Brand Names
Lexi-Comp.com
Last full review/revision February 2012
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