Iodine, Strong (Systemic)


VA CLASSIFICATION
Primary: HS852
Secondary: AD900; TN499

Another commonly used name is
Lugol"s solution .
Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).



Category:


Antihyperthyroid agent—

radiation protectant (thyroid gland)—

iodine replenisher{11}

Indications

Note: Bracketed information in the Indications section refers to uses that are not included in U.S. product labeling.

Accepted

[Hyperthyroidism (treatment adjunct)]1—Strong iodine is used as an adjunct in the treatment of hyperthyroidism. {03}

[Radiation protection, thyroid gland]1—Strong iodine is used as a radiation protectant (thyroid gland) prior to and following administration of radioactive isotopes of iodine or in radiation emergencies. {03}

[Thyroid involution, preoperative (treatment adjunct)]1—Strong iodine is used concurrently with an antithyroid agent to induce thyroid involution prior to thyroidectomy. {03}

[Thyrotoxic crisis (treatment adjunct)]1—Strong iodine is used as an adjunct in the treatment of thyrotoxic crisis. {03} {13}

[Iodine deficiency (treatment)]—Strong iodine is used in the treatment of iodine deficiency {11}

1 Not included in Canadian product labeling.



Pharmacology/Pharmacokinetics

Physicochemical characteristics:
Molecular weight—
    Iodine: 126.90
    Potassium iodide: 166.00

Mechanism of action/Effect:

Antihyperthyroid agent—In hyperthyroid patients, strong iodine produces rapid remission of symptoms by inhibiting the release of thyroid hormone into the circulation. The effects of strong iodine on the thyroid gland include reduction of vascularity, a firming of the glandular tissue, shrinkage of the size of individual cells, reaccumulation of colloid in the follicles, and increases in bound iodine. These actions may facilitate thyroidectomy when the medication is given prior to surgery. {04}

Radiation protectant—Prior to and following administration of radioactive isotopes and in radiation emergencies, strong iodine protects the thyroid gland by blocking the thyroidal uptake of radioactive isotopes of iodine. {02} {03}


Precautions to Consider

Pregnancy/Reproduction

Iodides cross the placenta; use during pregnancy may result in abnormal thyroid function and/or goiter in the infant. {05} {07}

Breast-feeding

Iodides are distributed into breast milk; use by nursing mothers may cause skin rash and thyroid suppression in the infant. {05} {07}

Pediatrics

Iodides may cause skin rash and thyroid suppression in infants. {01}


Geriatrics


Appropriate studies on the relationship of age to the effects of strong iodine have not been performed in the geriatric population. However, geriatrics-specific problems that would limit the usefulness of this medication in the elderly are not expected.


Dental

Strong iodine may cause salivary swelling or tenderness, burning of mouth or throat, metallic taste, soreness of teeth and gums, and unusual increase in salivation. {06}

Drug interactions and/or related problems
The following drug interactions and/or related problems have been selected on the basis of their potential clinical significance (possible mechanism in parentheses where appropriate)—not necessarily inclusive (» = major clinical significance):


Note: Combinations containing any of the following medications, depending on the amount present, may also interact with this medication.

» Antithyroid agents    (concurrent use of these medications with strong iodine may potentiate the hypothyroid and goitrogenic effects of antithyroid agents or strong iodine; baseline thyroid status should be determined at periodic intervals to detect changes in the thyroid-pituitary response)


Captopril or
Enalapril or
Lisinopril    (concurrent use of captopril, enalapril, or lisinopril with strong iodine may result in hyperkalemia; serum potassium concentrations should be monitored {12} {20})


» Diuretics, potassium-sparing    (concurrent use with strong iodine may increase the effects of potassium, possibly resulting in hyperkalemia and cardiac arrhythmias or cardiac arrest; serum potassium concentrations should be monitored {10} {21} {22})


» Lithium    (concurrent use with strong iodine may potentiate the hypothyroid and goitrogenic effects of either medication; baseline thyroid status should be determined at periodic intervals to detect changes in the thyroid-pituitary response {03} {10})


Sodium iodide I 131, therapeutic    (strong iodine solution may decrease thyroidal uptake of I 131 {17})



Laboratory value alterations
The following have been selected on the basis of their potential clinical significance (possible effect in parentheses where appropriate)—not necessarily inclusive (» = major clinical significance):

With diagnostic test results
Thyroid function studies and
Thyroid imaging, radionuclide and
Thyroid uptake tests    (strong iodine solution may decrease thyroidal uptake of I 131, I 123 {12} and sodium pertechnetate Tc 99m {19} {17})


Medical considerations/Contraindications
The medical considerations/contraindications included have been selected on the basis of their potential clinical significance (reasons given in parentheses where appropriate)— not necessarily inclusive (» = major clinical significance).


Risk benefit should be considered when the following medical problems exist
» Bronchitis, acute or{02}
» Edema, pulmonary or{05}
Tuberculosis, pulmonary{02}{05}    (may cause irritation and increase secretions {14} {15})


» Hyperkalemia{13}    (condition may be exacerbated)


Hyperthyroidism—for use other than thyroid inhibitor    (prolonged use of iodine may cause thyroid gland hyperplasia, thyroid adenoma, goiter, or hypothyroidism {16})


» Renal function impairment    (may cause excessive serum potassium concentrations)


Sensitivity to iodine or potassium iodide

Patient monitoring
The following may be especially important in patient monitoring (other tests may be warranted in some patients, depending on condition; » = major clinical significance):

Potassium, serum, concentrations    (determinations recommended at periodic intervals during therapy in patients with renal function impairment {13})




Side/Adverse Effects
The following side/adverse effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parentheses where appropriate)—not necessarily inclusive:

Those indicating need for medical attention
Incidence less frequent
    
Allergic reactions, specifically angioedema (swelling of the arms, face, legs, lips, tongue, and/or throat){02}, arthralgia (joint pain), eosinophilia
swelling of lymph nodes
urticaria (hives)

With prolonged use
    
Iodism (burning of mouth or throat; gastric irritation; increased watering of mouth; metallic taste; severe headache; soreness of teeth and gums; symptoms of head cold){02}{08}
    
potassium toxicity (confusion; irregular heartbeat; numbness, tingling, pain, or weakness in hands or feet; unusual tiredness; weakness or heaviness of legs){01}{08}



Those indicating need for medical attention only if they continue or are bothersome
Incidence less frequent
    
Diarrhea
    
nausea or vomiting {09}
    
stomach pain {09}





Patient Consultation
As an aid to patient consultation, refer to Advice for the Patient, Strong Iodine (Systemic)

In providing consultation, consider emphasizing the following selected information (» = major clinical significance):

Before using this medication
»   Conditions affecting use, especially:
Sensitivity to iodine or potassium iodide

Pregnancy—May cause thyroid problems or goiter in the newborn infant





Breast-feeding—May cause skin rash and thyroid problems in nursing babies





Use in children—May cause skin rash and thyroid problems in infants

Other medications, especially antithyroid agents, potassium-sparing diuretics, or lithium
Other medical problems, especially bronchitis, hyperkalemia, or renal function impairment

Proper use of this medication
» Taking after meals or with food or milk to minimize gastrointestinal irritation

Proper administration technique for oral liquids

» Taking medication by mouth even if dispensed in a dropper bottle

Not using if solution turns brownish yellow

Taking medication in a full glass (240 mL) of water or in fruit juice, milk, or broth to improve taste and lessen gastric upset; drinking full dose

If crystals form in solution, warming closed container in warm water and gently shaking container

» Proper dosing
Missed dose: Taking as soon as possible; not taking if almost time for next dose; not doubling doses

» Proper storage

For use as a radiation protectant (thyroid gland)
Taking medication only upon instructions from state or local health authorities

» Taking medication daily for 10 days, unless otherwise instructed; not taking more medication or more often than instructed

Precautions while using this medication
Regular visits to physician to check progress during therapy

» Caution in patients on potassium-restricted diet


Side/adverse effects
» Signs of potential side effects, especially allergic reactions, iodism, or potassium toxicity


General Dosing Information
The potassium content is 0.6 mEq (23.4 mg) per mL of strong iodine. {02}

To protect against possible gastrointestinal injury, which has been associated with the oral ingestion of concentrated potassium salt preparations, and to improve the taste {02}, it is recommended that the oral solution be administered in a full glass (240 mL) of water or in fruit juice, milk, or broth.


Oral Dosage Forms

Note: Bracketed uses in the Dosage Forms section refer to categories of use and/or indications that are not included in U.S. product labeling.

STRONG IODINE SOLUTION USP

Usual adult and adolescent dose
[Antihyperthyroid agent]1
Oral, 1 mL three times a day, the first dose being given at least one hour after the initial dose of antithyroid agent. {02}

[Thyroid involution, preoperative]1
Prior to thyroidectomy: Oral, 3 to 5 drops (approximately 0.1 to 0.3 mL) three times a day for ten days before surgery, usually administered concurrently with an antithyroid agent. {02}

[Radiation protectant (thyroid gland)]1
Oral, 130 mg a day for ten days. {03} {17} {18}

[Iodine replenisher]
Oral, 0.3 to 1 mL three or four times a day. {11}


Usual pediatric dose
[Thyroid involution, preoperative]1
See Usual adult and adolescent dose .

[Radiation protectant (thyroid gland)]1
Oral, 65 mg per day for ten days. {03} {17} {18}


Strength(s) usually available
U.S.—


50 mg of iodine and 100 mg of potassium iodide per mL (Rx)[Generic]

Canada—


50 mg of iodine and 100 mg of potassium iodide per mL (OTC)[Generic]

Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), unless otherwise specified by manufacturer. Store in a tight container. Protect from freezing.

Stability:
Crystallization may occur under normal conditions of storage, especially if refrigerated; however, on warming and shaking, the crystals will redissolve.

Free iodine may be liberated by oxidation of the strong iodine, causing the solution to turn brownish yellow in color. If this occurs, the solution should be discarded.

Auxiliary labeling:
   • For oral use only.



Revised: 08/10/1994



References
  1. Drug-induced goiters in the fetus and in children and adults. Medical Letter 7/24/70.
  1. American Hospital Formulary Service 1990, pp 1461–1463.
  1. AMA DE, 6th Edition, 1986, pp 150, 807.
  1. Goodman and Gilman's The Pharmacological Basis of Therapeutics, 7th Edition. 1985, p 1405.
  1. Handbook of Clinical Drug Data, 6th Edition, 1988, p 175.
  1. Accepted Dental Therapeutics, 40th Edition, 1984, p 115.
  1. Niebyl J. Drug use in pregnancy. 1982, p 54.
  1. Potassium iodide product information, Lilly, rev 6/88, rec 1/89, U.S.
  1. Potassium iodide solution, Lyne Labs, rec 2/86, rev 2/84, U.S.
  1. Drug Information Facts, 1990.
  1. Reviewer comment, 1992 revision.
  1. Drug interaction review, 1985.
  1. Panel consensus, 1991 revision cycle.
  1. Panel comment, 1991 revision cycle.
  1. Panel comment, 1991 revision cycle.
  1. Panel comment, 1991 revision cycle.
  1. Panel comment, 1991 revision cycle.
  1. Becker D et al. The use of iodine as a thyroidal blocking agent in the event of a reactor accident. JAMA, 1984, 25[5]: 659–661.
  1. Reviewer comment, 1991 revision cycle.
  1. Capoten product information, Squibb, 1991, PDR p 2142.
  1. Aldactone product information, Searle, Canada, rec 1/90, rev 9/89.
  1. Dyrenium product information, SKF, rec 5/89, rev 1/88, U.S.
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