12 August

L- thyroxine - instructions for use , indications, dosage

L-thyroxine - thyroid medication, thyroid hormone.

release form and composition

drug produced in the form of tablets (10 pieces in blisters, 2, 3, 4, 5, 6, 8 or 10 packs per carton box;.. 20 or 50 pieces inpolymeric containers 1 container in a cardboard bundle; 50 pcs. in blisters, 1, 2, 4, 5, 6, 8 or 10 packs in a carton box, 50 pcs. in blisters, 1 blister cartonpack).

1 tablet contains active substance: levothyroxine sodium - 50 or 100 micrograms.


  • euthyroid goiter;
  • Hypothyroidism;
  • period after resection of the thyroid gland (goiter in order to prevent recurrence and as replacement therapy);
  • thyroid cancer (after surgery);
  • diffuse toxic goiter (as monotherapy or as part of comprehensive treatment for achieving euthyroid state tireostatikami);
  • The test thyroid suppression (as a diagnostic tool).

Contraindications Absolute:

  • acute myocardial infarction, acute myocarditis;
  • Untreated hyperthyroidism;
  • Untreated adrenal insufficiency;
  • Hereditary lactase deficiency
    or lactose intolerance (malabsorption of glucose and galactose);
  • Hypersensitivity to levothyroxine.

Relative (drug must be taken with caution):

  • Diseases of the cardiovascular system: hypertension, arrhythmias, ischemic heart disease (myocardial infarction, atherosclerosis, angina pectoris);
  • Diabetes;
  • heavy (long-lived) hypothyroidism;
  • malabsorption syndrome (may require dose adjustment).

overdose of L-thyroxine is shown symptoms typical for hyperthyroidism: cardiac arrhythmias, palpitations, heart pain, tremor, anxiety, sleep disturbances, increased appetite, rash, diarrhea, weight loss.The doctor may recommend (depending on symptoms): decrease the daily dose, a few days break in treatment, the appointment of β-blockers.Therapy should proceed with caution after the passage of side effects with lower doses.

Dosage and Administration

tablets taken orally in the morning on an empty stomach, at least 1/2 hour before a meal without chewing and drinking a small amount (1/2 cup) of water.

daily dose of L-thyroxine is determined by the physician individually and depends on the evidence.

replacement therapy for hypothyroidism patients younger than 55 years, in the absence of cardiovascular disease, the recommended daily dose of L-thyroxine - 1.6-1.8 mg / kg body weight.Patients over 55 years, or in the presence of cardiovascular disease is determined by calculating the dose of 0.9 mg / kg body weight.Patients with severe obesity (BMI - body mass index ≥ 30 kg / m2), the calculation is made on the "ideal weight".

Initially replacement therapy in hypothyroidism the recommended dose of levothyroxine:

  • patients without cardiovascular disease before the age of 55 years: males - 100-150 mg / day, and women - 75-100 mg / day;
  • Patients older than 55 years and / or cardiovascular disease: regardless of gender - 25 mg / day with gradual increase in dose (25 mcg at intervals of 2 months), up to normalization of thyroid stimulating hormone (TSH) in the blood.

In the case of the emergence or worsening of symptoms of the cardiovascular system should be carried out correction treatment of cardiovascular diseases.

recommended daily dose of L-thyroxine therapy for congenital hypothyroidism, depending on the age of the child (levothyroxine dose / dose of levothyroxine per body weight):

  • From birth until 1/2 years - 25-50 mg / 10-15mkg/ kg;
  • From 1/2 to 1 year - 50-75 mg / 8.6 mg / kg;
  • From 1 to 5 years - 75-100 mg / 6.5 mg / kg;
  • From 6 to 12 years - 100-150 mg / 5.4 mg / kg;
  • over 12 years - 100-200 mg / 2.3 mg / kg.

recommended daily dose of L-thyroxine, depending on the condition / disease:

  • Therapy euthyroid goiter - 75-200 g;
  • Prevention of relapse after surgical treatment of euthyroid goiter - 75-200 g;
  • thyrotoxicosis (in the complex therapy) - 50-100 mg;
  • thyroid cancer (for the suppressive therapy) - 150-300 g;
  • The test thyroid suppression - 3-4 weeks before the test - 75 g, 1-2 weeks prior to the test - 150-200 mg.

children from birth to 3 years a daily dose of levothyroxine given 1/2 hour before the first feeding (at once).Immediately prior to use the tablet must be dissolved in water to form a thin slurry.

In the case of hypothyroidism, L-thyroxine take usually lifelong.For the treatment of hyperthyroidism drug used in combination with antithyroid drugs after reaching a euthyroid state.The duration of therapy with levothyroxine in all conditions / diseases is determined by the attending physician.

Side effects

In the application of L-thyroxine in compliance with all the recommendations and under medical supervision no side effects were noted.

In the case of hypersensitivity to levothyroxine possible allergic reactions.Other side-effects can only be developed with an overdose of the drug.


In the case of hypothyroidism caused by pituitary lesion, diagnosis should be carried out to find out whether both adrenal insufficiency.If a positive result to start replacement therapy corticosteroids (corticosteroids) is necessary to receive thyroid hormone for the treatment of hypothyroidism, in order to avoid the development of acute adrenal insufficiency.

Periodically monitor the TSH concentration in the blood, increase in this index indicates insufficient dose of L-thyroxine.

Levothyroxine does not affect the concentration of attention and quickness of psychomotor reactions, needed to manage the complex mechanisms and vehicles.

Drug Interactions

Mutual influence of the following substances / drugs and levothyroxine, while the application:

  • Insulin and oral hypoglycemic drugs - you may need to increase their dose (at the beginning of therapy, sodium levothyroxine, as in the case of changes in the dosing regimen, it should be more oftencheck the concentration of glucose in the blood);
  • indirect anticoagulants, tricyclic antidepressants - intensified their action (may require dose reduction);
  • Colestipol, cholestyramine, aluminum hydroxide - decrease in plasma concentration of sodium levothyroxine from the decrease of its rate of absorption in the gut;
  • Anabolic steroids, asparaginase, tamoxifen - there is a possibility of pharmacokinetic interactions at the level of protein binding;
  • Cardiac glycosides - reduced their effectiveness;
  • salicylate, clofibrate, furosemide (in high doses), phenytoin - increase in blood plasma content is not associated with proteins of levothyroxine sodium and free thyroxine (T4);phenytoin reduces the amount of levothyroxine associated protein 15%, the concentration of T4 - 25%;
  • estrogensoderjath drugs - increase the amount of thyroxine binding globulin, which may increase in some patients the need for levothyroxine;
  • Growth Hormone - may accelerate the closure of the epiphyseal growth zones;
  • Phenobarbital, carbamazepine and rifampicin - can increase the clearance of levothyroxine sodium, thereby possibly increasing the dose;
  • aminoglutethimide, amiodarone, p-aminosalicylic acid (PAS), antithyroid drugs, β-blockers, ethionamide, carbamazepine, chloral hydrate, levodopa, diazepam, dopamine, metoclopramide, somatostatin, lovastatin - affect the metabolism and distribution of L-thyroxine.

Terms and conditions of storage

Store in a dry, dark, place inaccessible to children at temperature not exceeding 25 ° C.

Shelf life - 3 years.

Latest Blog Post

Rovamycinum - instruction , the use during pregnancy , reviews
August 12, 2017

Rovamycinum - antibacterial medication from the group of macrolides. composition and the form of release Rovamycinum According to instruction...

Roaccutane - instructions for use , operation , reviews , analogs
August 12, 2017

Roaccutane - a synthetic drug for the treatment of acne. Mode of action The active ingredient Roaccutane improves in severe forms of acne, bu...

Rifampicin - instructions for use , testimonials, testimony
August 12, 2017

Rifampicin - anti-bacterial anti-TB drug. Pharmacological action Rifampicin inhibits Mycobacterium tuberculosis, Brucella, Chlamydia, Legio...