Euthyrox 75 mcg 100 tablets
Merck
Merck
Composition
Each tablet contains
75 microgram levothyroxine sodium.
Excipients
Maize starch, citric acid, croscarmellose sodium, gelatin, magnesium stearate, mannitol.
Description
Euthyrox contains levothyroxine sodium, a synthetic thyroid hormone used for replacement therapy, suppression therapy, prevention of goiter recurrence, and diagnostic thyroid suppression testing.
Tablets are available in a wide dosage range (25-200 micrograms) for individualized daily dosing.
Indications for Use
Euthyrox 25-200 micrograms
- Treatment of benign euthyroid goiter
- Prevention of relapse after surgery for euthyroid goiter
- Replacement therapy in hypothyroidism
- Suppression therapy in thyroid cancer.
Euthyrox 25-100 micrograms
Concomitant supplementation during antithyroid drug treatment of hyperthyroidism.
Euthyrox 100/150/200 micrograms
Thyroid suppression testing (diagnostic use).
Dosage and Method of Administration
- Tablets contain 25-200 micrograms of levothyroxine; most patients require only one daily tablet.
- Dose must be individualized based on laboratory results, especially serum TSH.
General rules
- Start with a low dose; increase every 2-4 weeks.
- TSH is the most reliable parameter for dose adjustment.
Neonates and infants with congenital hypothyroidism
10-15 micrograms/kg/day for the first 3 months; thereafter dose adjustments based on TSH and clinical status.
Elderly, cardiac disease, long-standing hypothyroidism: Initial dose: 12.5 micrograms/day. Increase slowly at long intervals (e.g., 12.5 micrograms every 2 weeks).
Recommended daily doses (micrograms/day)
- Benign euthyroid goiter: 75-200
- Relapse prophylaxis: 75-200
- Hypothyroidism in adults: initial 25-50, maintenance 100-200
- Hypothyroidism in children: initial 12.5-50, maintenance 100-150 micrograms/m²
- Concomitant use with antithyroid drugs: 50-100
- Thyroid cancer suppression: 150-300.
Administration
- Once daily, in the morning on an empty stomach, 30 minutes before breakfast, with water.
- Infants: disperse the tablet in water and give before first feeding.
- Duration of therapy: lifelong in hypothyroidism and post-surgery cases.
Contraindications
- Hypersensitivity to active substance or excipients
- Untreated adrenal insufficiency
- Untreated pituitary insufficiency
- Untreated thyrotoxicosis
- Acute myocardial infarction, myocarditis, pancarditis
- Combination of levothyroxine and antithyroid drugs during pregnancy.
Precautions
- Exclude coronary disease, hypertension, atherosclerosis, pituitary insufficiency before therapy
- Treat adrenal insufficiency before starting levothyroxine
- Start with low dose in patients at risk of psychotic disorders
- Avoid drug-induced hyperthyroidism in cardiac patients
- Monitor hemodynamics in very low birth weight neonates
- In postmenopausal women avoid supraphysiological doses
- Levothyroxine must not be used for weight loss
- High doses combined with sympathomimetics may cause severe adverse effects
- Close monitoring required when switching brand
- Orlistat may reduce levothyroxine absorption
- Biotin interferes with thyroid tests → lab must be informed
- Contains <1 mmol sodium per tablet (“sodium-free”).
Side Effects
Symptoms of hyperthyroidism may occur in overdose or excessive dosing:
- Cardiac arrhythmias, tachycardia, palpitations, angina
- Headache, muscle weakness, cramps
- Tremor, restlessness, insomnia, sweating
- Weight loss, diarrhoea, vomiting
- Menstrual disorders
- Pseudotumor cerebri
- Allergic reactions: rash, urticaria, respiratory involvement, angioedema.
Pregnancy and Breastfeeding
Pregnancy
Levothyroxine should be continued during pregnancy.
Dose may need to be increased.
TSH should be checked each trimester.
Postpartum dosage should return to pre-pregnancy levels.
Thyroid suppression tests contraindicated during pregnancy.
Breastfeeding
Excreted into breast milk, but therapeutic doses are safe for infants.
Storage Conditions
Store below 30°C.
Keep an outer carton to protect from light.
Keep out of reach of children.
Packaging
Carton box containing 4 blisters (aluminum/aluminum), each with 25 tablets, plus leaflet.
Total: 100 tablets.