Euthyrox 100 Tab

EUTHYROX 100 TAB by MERCK LTD

Euthyrox 100 Tablet is a widely prescribed medication for thyroid hormone replacement therapy, manufactured by Merck Ltd. It is crucial for individuals with thyroid dysfunctions to maintain metabolic balance and overall well-being.

• Name

  • Brand Name: EUTHYROX 100 TAB
  • Common Name: Levothyroxine sodium

• Composition

  • Active Ingredient: Each tablet contains 100 micrograms (mcg) of Levothyroxine sodium.
  • Inactive Ingredients: Mannitol, maize starch (corn starch), gelatin, croscarmellose sodium, citric acid (anhydrous), and magnesium stearate.

• Uses Euthyrox 100 Tablet is primarily used to treat a variety of thyroid conditions:

  • Hypothyroidism: As a replacement therapy for an underactive thyroid gland, whether primary, secondary, or tertiary, congenital or acquired.
  • Goitre: Treatment of benign euthyroid goitre (enlarged thyroid gland) and prophylaxis of its recurrence after surgery.
  • Thyroid Cancer: As a suppression therapy for thyrotropin-dependent well-differentiated thyroid cancer.
  • Hyperthyroidism: Concomitant supplementation during anti-thyroid drug treatment to balance hormone levels.
  • Myxedema Coma: Used in the management of this severe complication of hypothyroidism.
  • Diagnostic Aid: Can be used for thyroid suppression testing.
  • Important Note: Euthyrox 100 Tablet should not be used for weight loss or to treat obesity.

• Dosage and Administration

  • Administration: Administer orally as a single daily dose on an empty stomach, typically 30 minutes to 1 hour before breakfast, with a full glass of water.
  • Individualization: Dosage is highly individualized based on age, body weight, medical condition, and regular thyroid function tests.
  • Initial Dosing: For adults with uncomplicated hypothyroidism, an average full replacement dose is approximately 1.6 mcg/kg/day, with adjustments in 12.5 mcg to 25 mcg increments every 4-6 weeks. Elderly patients, those with cardiac conditions, or severe longstanding hypothyroidism may start with lower doses (12.5 mcg to 25 mcg per day) and increase gradually.
  • Pediatric Use: For infants and children unable to swallow tablets, crush the tablet and mix with 1-2 teaspoons (5-10 ml) of water for immediate administration. Do not mix with soy infant formula or prepare in advance.
  • Consistency: Take the medication at the same time each day to maintain stable hormone levels. Do not discontinue without medical advice, as thyroid replacement therapy is usually lifelong.

• Side Effects

  • Common Side Effects: Headache, nervousness, sleeplessness (insomnia), irritability, diarrhea, muscle spasm/cramps/weakness, weight loss, heat intolerance, menstrual irregularities, skin rash, tremors, increased appetite, and temporary hair loss during the initial months of treatment.
  • Serious Side Effects (Seek immediate medical attention): Chest pain, rapid or irregular heartbeats (tachycardia, palpitations, arrhythmia), shortness of breath, fever, increased sweating, mood swings, and signs of an allergic reaction (hives, difficulty breathing, swelling of the face, lips, tongue, or throat). Overdosing can lead to symptoms of hyperthyroidism or even a thyrotoxic crisis (convulsions, cardiac arrhythmia, heart failure, coma).

• Precautions

  • Contraindications: Do not take Euthyrox if you have untreated adrenal insufficiency, untreated pituitary insufficiency, untreated thyrotoxicosis (overactive thyroid), acute myocardial infarction, acute myocarditis, or acute pancarditis.
  • Cardiac Conditions: Use with caution in patients with heart disease (e.g., angina pectoris, heart failure, high blood pressure, atherosclerosis). Close monitoring of thyroid function is essential.
  • Diabetes: Euthyrox may affect blood glucose control, requiring adjustments to antidiabetic medications or insulin.
  • Pregnancy & Breastfeeding: Generally considered safe during pregnancy, but dose adjustments are often necessary. Levothyroxine passes into breast milk but is unlikely to harm a nursing infant.
  • Drug Interactions:
    • Reduced Absorption: Avoid taking Euthyrox at the same time as aluminum-containing products (antacids, sucralfate), iron-containing medicines, calcium salts/supplements, soy products, bile acid sequestrants (e.g., cholestyramine, colestipol), ion exchange resins, proton pump inhibitors, and orlistat. Administer Euthyrox at least 2 hours before these, or 4-5 hours before bile acid sequestrants/ion exchange resins.
    • Altered Efficacy: Medications such as sertraline, chloroquine/proguanil, tyrosine kinase inhibitors, and protease inhibitors may influence the effect of levothyroxine, potentially requiring dose adjustments.
    • Increased Euthyrox Effect: Salicylates, dicumarol, high doses of furosemide, clofibrate, and phenytoin may intensify the effect of Euthyrox.
    • Other: Euthyrox can interact with oral anticoagulants, digitalis glycosides, antidepressants, ketamine, and sympathomimetics.
  • Other Considerations: Postmenopausal women on Euthyrox should have regular thyroid function checks due to an increased risk of osteoporosis. The mannitol content may have a laxative effect.

• Storage

  • Store in a cool and dry place, away from direct sunlight.
  • Maintain storage temperature at or below 30°C.
  • Keep the tablets in their original blister packaging or outer carton to protect them from light.
  • Keep out of the sight and reach of children.