L-Tyroxine-100 Berlin Chemi, 100 mcg tablets 100 pcs

After partial conversion to liothyronine (in the liver and kidneys) and transfer to body cells, it influences tissue development and growth and metabolism. In small doses it has an anabolic effect on protein and fat metabolism. In medium doses it stimulates growth and development, increases tissue oxygen demand, stimulates metabolism of proteins, fats and carbohydrates, increases functional activity of the cardiovascular system and CNS. At high doses it inhibits the production of thyrotropin-releasing hormone of the hypothalamus and thyrotropic hormone of the pituitary gland.

Pharmacodynamics

Therapeutic effect is observed in 7-12 days, during the same time the effect after discontinuation of the drug is maintained. Clinical effect in hypothyroidism is seen in 3-5 days. Diffuse goiter decreases or disappears within 3-6 months.

Pharmacokinetics

When taken orally levothyroxine is absorbed almost exclusively in the upper small intestine. Up to 80% of the dose taken is absorbed. Food intake reduces the absorption of levothyroxine. Cmax in blood serum is reached 6 hours after intake.

After absorption, more than 99% of the drug is bound to serum proteins. In various tissues levothyroxine monodeidation occurs with the formation of triiodothyronine and inactive products. Thyroid hormones are metabolized mainly in the liver, kidneys, brain and muscles.

A small amount of the drug undergoes deamination and decarboxylation as well as conjugation with sulfuric and glucuronic acids (in the liver). Metabolites are excreted in the urine and bile. T1/2 is 6-8 days.

Indications

Active ingredient

Composition

1 tabletlevothyroxine sodium100 mcg

Ancillary substances:

calcium hydrophosphate dihydrate,

microcrystalline cellulose,

p> sodium carboxymethyl starch (type A),

dextrin,

long-chain incomplete glycerides.

How to take, the dosage

Ingestion, on an empty stomach, at least 30 minutes before breakfast. The daily dose of the drug is set and controlled individually on the basis of laboratory and clinical examination data.

As experience has shown, a low dose is sufficient in low body weight and in the presence of a large nodular stricture.

Unless otherwise prescribed, the following dosing recommendations apply:

In hypothyroidism, the initial daily dose, adults – 25-100 mcg, then the dose is increased as prescribed by the doctor every 2-4 weeks by 25-50 mcg until the maintenance daily dose – 125-250 mcg; children – 12.5-50 mcg, with a long course of treatment the dose is determined by the body weight and height of the child (at the approximate rate of 100 to 150 mcg levothyroxine sodium per 1 m2 body surface area);

For prevention of goiter recurrence and in case of diffuse goiter in adults – 75-200 mcg/day;

As part of combined therapy in the treatment of thyroid hyperfunction with thyreostatics – 50-100 mcg/day;

In the treatment of malignant tumor, the daily dose is 150-300 mcg.

The approximate maintenance daily dose of levothyroxine sodium

. AgeDose in goiter, µg/kg/dayDose in hypothyroidism, µg/kg/dayInfants12.54Infants, 1/4 year25-37.525Infants, 1/2 year25-37.537.5Infants, 1 year25-37.537.5Early children, 5 years25-62.550School-age children, 7 years50-10075-100School-age children, 12 years100-150100Adults75-200125-250

The daily dose of the drug is set individually depending on the indication.

The need for thyroid hormones increases during pregnancy; therefore, it is necessary to inform the physician about the existing or initiated pregnancy during the course of treatment, so that the dose of the drug can be adjusted if necessary.

Interaction

Levothyroxine increases the effect of indirect anticoagulants, which may require reducing their dose.

The use of tricyclic antidepressants with levothyroxine may increase the effect of antidepressants.

The thyroid hormones may increase the need for insulin and oral hypoglycemic medications. More frequent monitoring of blood glucose levels is recommended during periods when levothyroxine treatment is initiated and also when the dose of the drug is changed.

Levothyroxine reduces the effect of cardiac glycosides. When used concomitantly, colestyramine, colestipol and aluminum hydroxide decrease the plasma concentration of levothyroxine by inhibiting its absorption in the intestine.

In concomitant use with anabolic steroids, asparaginase, tamoxifen there may be pharmacokinetic interaction at the level of protein binding.

Concomitant use with phenytoin, salicylates, clofibrate, furosemide in high doses increases unbound plasma protein levels of levothyroxine and T4.

Somatotropin when used concomitantly with levothyroxine may accelerate the closure of epiphyseal growth zones.

The administration of phenobarbital, carbamazepine and rifampicin may increase the clearance of levothyroxine and may require increasing the dose.

Estrogens increase the concentration of the thyroglobulin-bound fraction, which may decrease the effectiveness of the drug.

Amiodarone, aminoglutethimide, PASC, etionamide, antithyroid drugs, beta-adrenoblockers, carbamazepine, chloral hydrate, diazepam, levodopa, dopamine, metoclopramide, lovastatin, somatostatin have an effect on synthesis, secretion, distribution and metabolism of the drug.

Special Instructions

In hypothyroidism caused by pituitary lesions, it is necessary to find out whether there is simultaneously insufficiency of the adrenal cortex. In this case, GCS replacement therapy should be started before treatment of hypothyroidism with thyroid hormones to avoid development of acute adrenal insufficiency.

Impact on ability to drive and operate machinery

The drug does not affect the ability to drive vehicles and work requiring increased concentration.

Contraindications

With caution:

– in diseases of the cardiovascular system – CHD (atherosclerosis, angina, myocardial infarction in the history), arterial hypertension, arrhythmia;

– in diabetes; severe long-term hypothyroidism; malabsorption syndrome (dose adjustment is possible).

Side effects

Allergic reactions (skin rash, skin itching).

In case of use in excessive doses – hyperthyroidism (change in appetite, dysmenorrhea, chest pain, diarrhea, tachycardia, arrhythmia, fever, tremor, headache, irritability, muscle cramps of the lower extremities, nervousness, sweating, difficulty falling asleep, vomiting, weight loss).

When used in inadequate doses – hypothyroidism (dysmenorrhea, constipation, dryness, puffiness of the skin, headache, lethargy, myalgia, drowsiness, weakness, apathy, weight gain).

Overdose

Symptoms characteristic of thyrotoxicosis: palpitations, abnormal heart rhythm, heart pain, anxiety, tremors, sleep disturbances, increased sweating, decreased appetite, weight loss, diarrhea.

Treatment:A reduction in the daily dose of the drug, a break in treatment for several days, and the prescription of beta-adrenoblockers may be recommended. After side effects have disappeared, treatment should be started with caution at a lower dose. Antithyroid drugs are not recommended.

Pregnancy use

The treatment should be continued during pregnancy and breastfeeding. The use of the drug in combination with thyreostatics is contraindicated in pregnancy. Since thyreostatics, unlike levothyroxine, may pass through the placenta, the fetus may develop hypothyroidism.

In children, the starting daily dose is 12.5-50 mcg. With a long course of treatment the dose of the drug is determined at a guideline rate of 100-150 mcg/m2 body surface area.

Similarities