• Home
  • A-B index
  • Pharmacological Index
  • Drug Classes
  • Active Ingredients
  • Companies
  • News
  • Synthroid
    / Abbott

    Active Ingredient
    Levothyroxine Sodium 50 mcg, 100 mcg

    Status in Israel

    Presentation and Status in Health Basket

    Presentation Basket Yarpa Pharmasoft


    90 X 50 mcg

    full basket chart 50793 19958


    90 X 100 mcg

    full basket chart 50790 19959

    Related information


    The dose should be adjusted by the doctor only, personally for each patient. For full details see prescribing information.
    Pediatric Dosage: The dose should be adjusted based on clinical response and laboratory parameters of the child.
    0-3 months-10-15 mcg/kg/day
    3-6 months-8-10 mcg/kg/day
    6-12 months-6-8 mcg/kg/day
    1-5 years-5-6 mcg/kg/day
    6-12 years- 4-5 mcg/kg/day
    > 12 years but growth and puberty incomplete -1.7 mcg/kg/day
    Growth and puberty complete1.7 mcg/kg/day
    Adults: The average full replacement dose of levothyroxine sodium is approximately 1.7 mcg/kg/day (e.g., 100-125 mcg/day for a 70 kg adult).
    For full details see prescribing information.


    Hypothyroidism, Pituitary TSH Suppression.


    Hypersensitivity to any of the inactive ingredients, in patients with untreated subclinical (suppressed serum TSH level with normal T3 and T4 levels) or overt thyrotoxicosis of any etiology and in patients with acute myocardial infarction. Patients with uncorrected adrenal insufficiency since thyroid hormones may precipitate an acute adrenal crisis by increasing the metabolic clearance of glucocorticoids.

    Special Precautions

    Should not be used for the treatment of obesity or for weight loss and in the treatment of male or female infertility unless this condition is associated with hypothyroidism.
    For full details see prescribing information.

    Side Effects

    Adverse reactions associated with levothyroxine therapy are primarily those of hyperthyroidism due to therapeutic overdose. They include the following: Fatigue, increased appetite, weight loss, heat intolerance, fever, excessive sweating, Headache, hyperactivity, nervousness, anxiety, irritability, emotional liability, insomnia, palpitations, tachycardia, arrhythmias, increased pulse and blood pressure, hair loss, flushing decreased bone mineral density, menstrual irregularities, impaired fertility.
    For full details see prescribing information.

    Drug interactions

    Dopamine/Dopamine Agonists ,Glucocorticoids,Octreotide: Use of these agents may result in a transient reduction in TSH secretion when administered at the following doses: Dopamine (≥ 1 mcg/kg/min); Glucocorticoids (hydrocortisone ≥ 100 mg/day or equivalent); Octreotide (> 100 mcg/day). Drugs that may decrease thyroid hormone secretion, which may result in hypothyroidism: Aminoglutethimide, Amiodarone, Iodide (including iodine-containing radiographic contrast agents), Lithium, Methimazole, Propylthiouracil (PTU), Sulfonamides, Tolbutamide.
    Drugs that may increase thyroid hormone secretion, which may result in hyperthyroidism: Amiodarone, Iodide (including iodine-containing radiographic contrast agents).
    Drugs that may decrease T4 absorption, which may result in hypothyroidism: Antacids – Aluminum & Magnesium Hydroxides, Simethicone, Bile Acid Sequestrants- Cholestyramine, Colestipol, Calcium Carbonate, Cation Exchange Resins- Kayexalate ,Ferrous Sulfate Orlistat, Sucralfate.
    Oral Anticoagulants: Levothyroxine increases the response to oral anticoagulant therapy. Therefore, a decrease in the dose of anticoagulant may be warranted with correction of the hypothyroid state or when the drug dose is increased. Prothrombin time should be closely monitored to permit appropriate and timely dosage adjustments.
    Digitalis Glycosides: The therapeutic effects of digitalis glycosides may be reduced by levothyroxine. Serum digitalis glycoside levels may be decreased when a hypothyroid patient becomes euthyroid, necessitating an increase in the dose of digitalis glycoside.
    For full details see prescribing information.

    Pregnancy and Lactation

    Pregnancy: Studies in women taking levothyroxine sodium during pregnancy have not shown an increased risk of congenital abnormalities. Therefore, the possibility of fetal harm appears remote. This drug should not be discontinued during pregnancy and hypothyroidism diagnosed during pregnancy should be promptly treated.
    Nursing Mothers: Although thyroid hormones are excreted only minimally in human milk, caution should be exercised when Synthroid is administered to a nursing woman. However, adequate replacement doses of levothyroxine are generally needed to maintain normal lactation.
    For full details see prescribing information.


    The signs and symptoms of overdose are those of hyperthyroidism. In addition, confusion and disorientation may occur. Cerebral embolism, shock, coma, and death have been reported. Seizures have occurred in a child ingesting 18 mg of levothyroxine. Symptoms may not necessarily be evident or may not appear until several days after ingestion of levothyroxine sodium.
    Treatment of Overdose: Levothyroxine sodium should be reduced in dose or temporarily discontinued if signs or symptoms of overdose occur.
    Acute Massive Overdose: This may be a life-threatening emergency, therefore, symptomatic and supportive therapy should be instituted immediately. If not contraindicated (e.g., by seizures, coma, or loss of the gag reflex), the stomach should be emptied by emesis or gastric lavage to decrease gastrointestinal absorption. Activated charcoal or cholestyramine may also be used to decrease absorption. Central and peripheral increased sympathetic activity may be treated by administering β-receptor antagonists, e.g., propranolol, provided there are no medical contraindications to their use. Provide respiratory support as needed; control congestive heart failure and arrhythmia; control fever, hypoglycemia, and fluid loss as necessary. Large doses of antithyroid drugs (e.g., methimazole or propylthiouracil) followed in one to two hours by large doses of iodine may be given to inhibit synthesis and release of thyroid hormones. Glucocorticoids may be given to inhibit the conversion of T4 to T3. Plasmapheresis, charcoal hemoperfusion and exchange transfusion have been reserved for cases in which continued clinical deterioration occurs despite conventional therapy. Because T4 is highly protein bound, very little drug will be removed by dialysis.
    For full details see prescribing information.

    Abbvie Inc., USA