Potassium iodide (KI) and iodine (I2) are both chemical compounds that contain iodine. However, they have different properties and uses.

• Potassium Iodide (KI):
  • Chemical formula: KI
  • It is an inorganic compound.
  • It is composed of potassium cations (K+) and iodide anions (I-).
  • Potassium iodide is commonly used in medicine as a source of iodine. It is used to treat conditions such as iodine deficiency, thyroid disorders, and radiation emergencies.
  • In radiation emergencies, potassium iodide is used to protect the thyroid gland from absorbing radioactive iodine released during a nuclear accident or emergency. By saturating the thyroid gland with stable iodine, it can prevent the uptake of radioactive iodine, reducing the risk of thyroid cancer.
  • Potassium iodide is also used in analytical chemistry and in some photographic processes.
• Iodine (I2):
  • Chemical formula: I2
  • It is a diatomic molecule composed of two iodine atoms bonded together (I-I).
  • Iodine is a nonmetal element in the halogen group of the periodic table.
  • It is commonly used as a disinfectant in various forms such as iodine tincture or iodine solution. It is effective against bacteria, viruses, and some fungi.
  • Iodine is also used in the production of various organic compounds and in certain industrial processes.
  • In some cases, iodine is used as a supplement or dietary source of iodine, particularly in areas where there is a deficiency of iodine in the diet.

Lugols Solution contains elemental Iodine and Potassium iodide. It is used in the management of thyroid storm and thyrotoxic crises.

Potassium iodide and iodine Uses:

• Antiseptic:
  • Topical antiseptic
• Thyroidectomy preparation:
  • Treatment of hyperthyroidism in the immediate preoperative period in patients who are undergoing thyroidectomy.

Note:

• Iodine therapy 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.
• Thyroid storm:
  • Treatment of thyroid storm (as part of a multimodality treatment approach).

Note:

• The American Thyroid Association and American Association of Clinical Endocrinologists guidelines for the management of hyperthyroidism and other causes of thyrotoxicosis suggest potassium iodide and iodine (Lugol's solution) as an acceptable replacement to a saturated solution of potassium iodide (SSKI) in the treatment of adults with thyrotoxic crisis and thyroid storm.
• Off Label Use of Potassium iodide and iodine Adults:
  • Thyroid gland protection during radiopharmaceutical use

Lugols Solution Dose in Adults

Note:

• Lugol's 5% solution (potassium iodide 10% and iodine 5%) contains about ~6.25 mg iodine/iodide per drop.

Lugols Solution Dose as Antiseptic:

• How to Use: Apply directly to the area(s) needing antiseptic treatment.
• Dose: The amount applied depends on the specific need and area of application.

Lugols Solution Dose in treatment of Thyroidectomy preparation in patients with Graves disease: Lugol's 5% solution:

• How to Use: Administer orally.
• Dosage:
  • 5 to 7 drops (approximately 0.25 to 0.35 mL) three times daily.
  • Administer for 10 days before surgery.
• Additional Considerations:
  • If the patient is not euthyroid (normal thyroid function) prior to surgery, consider concurrent beta-blockade (e.g., propranolol) in the immediate preoperative period to reduce the risk of thyroid storm.

Lugols Solution Dose in the treatment of Thyroid gland protection during radiopharmaceutical use (off-label): Lugol's 5% solution:

• Solution Used: Lugol's 5% Solution
• Method of Administration: Oral
• Dosage:
  • General Protocol:
    • Approximately 100 mg/day of iodine/iodide is required for thyroid block.
    • This can be achieved with approximately 16 drops/day of Lugol's 5% solution.
  • Specific Recommendations Based on Radiopharmaceuticals:
    • Iodine I-123 Radiopharmaceuticals:
      • 100 mg/day of iodine/iodide.
    • Iodine I-125 and I-131 Radiopharmaceuticals:
      • 10 drops three times daily.
    • Note: Specific dosing recommendations for Azedra are not provided in the manufacturer's labeling.
• Initiation and Duration:
  • Initiate treatment 1 to 48 hours prior to radiopharmaceutical exposure.
  • Continue after radiopharmaceutical administration until the risk of exposure has diminished.
  • Treatment initiation time and duration depend on the radiopharmaceutical agent used; consult specific protocol or labeling for guidance.

Lugols Solution Dose in the treatment of Thyrotoxic crisis and thyroid storm: Lugol's 5% solution:

• Solution Used: Lugol's 5% Solution
• Method of Administration: Oral
• Dosage:
  • General Dosage:
    • 4 to 8 drops every 6 to 8 hours.
  • Initiation Timing:
    • Initiate therapy at least 1 hour following the initial dose of antithyroid drug therapy (e.g., propylthiouracil, methimazole).

Lugols Solution Dose in Childrens

Note:

• Dosing is listed in terms of drops/dose; check instructions carefully before dispensing or administering.

Lugols Solution Dose in the treatment of Thyrotoxic crisis and Thyroid storm:

Children and Adolescents

• Solution Used: Lugol's Solution
• Method of Administration: Oral
• Dosage:
  • General Dosage:
    • 4 to 10 drops three times daily.
  • Initiation Timing:
    • Begin therapy preferably 2 hours following the initial dose of either propylthiouracil or methimazole.
• Notes:
  • Dosing is listed in terms of drops per dose.
  • Check instructions carefully before dispensing or administering.

Lugols Solution Pregnancy Risk Factor D

• During pregnancy, Potassium Iodide carries a risk factor D, meaning it can pose potential harm to the fetus.
• Iodide from potassium iodide can pass through the placenta, which may lead to hypothyroidism and goiter in the fetus or newborn.
• However, in situations where there's a risk of thyroid cancer due to exposure to radioactive iodine, using potassium iodide for protection can be considered acceptable after carefully weighing the risks and benefits, while considering the dose and duration of treatment.
• It's advisable to avoid repeating doses if feasible.
• For more details, refer to information regarding iodine use during pregnancy.

Use of potassium iodide or iodine during breastfeeding

• Skin rash in nursing infants has been reported when mothers consume potassium iodide.
• For additional details, refer to the iodine monograph.

Lugols solution Dose in Kidney disease:

• The manufacturer's labeling does not provide any dosage adjustments for individuals with renal impairment.

Lugols Solution Dose in Liver disease:

• No dosage adjustments for hepatic impairment are provided in the manufacturer's labeling.

Side effects of Lugols solution:

• Cardiovascular:
  • Cardiac Arrhythmia
  • Myxedema
• Central Nervous System:
  • Confusion
  • Fatigue
  • Metallic Taste
  • Numbness
  • Tingling Sensation
• Dermatologic:
  • Skin Rash
• Endocrine & Metabolic:
  • Goiter
  • Hyperthyroidism
  • Hypothyroidism
• Gastrointestinal:
  • Diarrhea
  • Enlargement Of Salivary Glands
  • Gastric Distress
  • Gastrointestinal Hemorrhage
  • Nausea
  • Salivary Gland Disease (Tenderness)
  • Stomach Pain
  • Vomiting
• Hematologic & Oncologic:
  • Adenopathy
  • Thyroid Adenoma
• Hypersensitivity:
  • Hypersensitivity Reaction (Angioedema
  • Cutaneous And Mucosal Hemorrhage
  • Serum Sickness-Like Symptoms)
• Neuromuscular & Skeletal:
  • Arthralgia
  • Weakness
• Respiratory:
  • Pharyngeal Edema
• Miscellaneous:
  • Drug Overdose (With Prolonged Treatment/High Doses)
  • Fever
  • Iodism

Contraindications to Lugols Solution (Potassium iodide and iodine):

• Potassium iodide should not be used in individuals who have hypersensitivity to iodine or any component of the formulation, active tuberculosis, dermatitis herpetiformis, hypocomplementemic vasculitis, or nodular thyroid disease with heart disease.

Warnings and precautions

Hypothyroidism:

• Long-term use of potassium iodide can result in hypothyroidism, a condition where the thyroid gland doesn't produce enough thyroid hormone.

Reactions to skin:

• Potassium iodide can lead to skin reactions like acne flare-ups and/or dermatitis.

Insufficiency of the adrenals:

• It's important to be cautious when using potassium iodide in patients with Addison's disease, as it can potentially worsen adrenal insufficiency.

Bronchitis

• Be cautious when using potassium iodide in patients with acute bronchitis.

Cardiac disease

• Exercise caution when administering potassium iodide to patients with cardiac disease.

Myotonia congenita:

• Be cautious when using potassium iodide in patients with myotonia congenita.

Renal impairment

• Exercise caution when administering potassium iodide to patients with renal impairment.

Thyroid disease:

• Be cautious when using potassium iodide in patients with a history of hyperthyroidism, and it is contraindicated in individuals with nodular thyroid conditions who also have heart disease.

Tuberculosis

• Exercise caution when administering potassium iodide to patients with tuberculosis.

Potassium iodide and iodine (Lugol solution): Drug Interaction

Monitoring parameters:

• Thyroid Function Tests:
  • Regular thyroid function tests should be conducted.
  • This helps monitor the levels of thyroid hormones in the body.
• Signs/Symptoms of Hyperthyroidism:
  • Keep an eye out for any signs or symptoms of hyperthyroidism.
  • These may include weight loss, rapid heartbeat, and anxiety.
• Pregnant Women, Neonates, and Young Infants:
  • Especially in these groups, if repeat doses of potassium iodide are needed, thyroid function should be closely monitored.
  • Monitoring ensures that the thyroid gland is functioning properly and helps prevent any potential complications.

How to administer Lugols solution (Potassium iodide and iodine)?

• Topical Application:
  • Apply directly to the area(s) needing antiseptic treatment.
  • No dilution is necessary for topical use.
• Oral Administration:
  • Dilute with water or juice before ingestion.
  • This ensures proper mixing and easier consumption.
  • Follow dosage instructions carefully for oral administration.

Mechanism of action of Lugols Solution (Potassium iodide and iodine):

• In hyperthyroidism, iodine can temporarily slow down the production and release of thyroid hormones into the body.
• It also helps shrink the thyroid gland and reduces its blood supply.
• While using iodine, the levels of certain thyroid hormones in the blood can drop for a few weeks, but this effect doesn't last long-term.
• After exposure to radioactive iodine, potassium iodide can help protect the thyroid by blocking the absorption of the radioactive iodine, which lowers the risk of developing thyroid cancer.

The onset of action:

• It typically takes 24 to 48 hours for the effects to begin after starting treatment for hyperthyroidism.

Peak effect:

• The maximum impact of the treatment is usually seen around 10 to 15 days after starting continuous therapy.

International Brands of Potassium iodide and iodine:

• Gemstain

Potassium iodide and iodine Brands Names in Pakistan: