Euthyrox tablets 125 mcg blister No. 100

Instructions Euthyrox tablets 125 mcg blister No. 100

Composition

active ingredient: levothyroxine sodium;

1 tablet contains 125 mcg of levothyroxine sodium;

excipients: mannitol (E 421); corn starch; gelatin; croscarmellose sodium; anhydrous citric acid, magnesium stearate.

Dosage form

Pills.

Main physicochemical properties: almost white round, flat on both sides, with beveled edges tablets, with a score line on both sides, with engraving on one side "EM + dosage".

Pharmacotherapeutic group

Hormone preparations for systemic use (except sex hormones and insulin). Preparations for the treatment of thyroid diseases. Thyroid preparations. Levothyroxine sodium. ATX code H03A A01.

Pharmacological properties

Pharmacodynamics

Synthetic levothyroxine, which is contained in the drug Euthyrox, has effects identical to those of the hormone secreted by the thyroid gland. It is converted to T3 (triiodothyronine) in peripheral organs, and as an endogenous hormone affects T3 receptors. There is no difference between the functions of the endogenous hormone and exogenous levothyroxine.

Pharmacokinetics

After oral administration, levothyroxine is almost completely absorbed in the upper small intestine. Depending on the galenic form of the drug, up to 80% of the dose is absorbed. The maximum concentration (Tmax) is reached after approximately 5-6 hours.

The clinical effect of the drug is manifested 3-5 days after oral administration. Levothyroxine quickly binds to specific transport proteins in the blood (up to 99.97%). The connection with proteins is not covalent, so the bound hormone in the plasma is able to constantly and quickly exchange with fractions of the free hormone.

Due to its high level of protein binding, levothyroxine is not amenable to either hemodialysis or hemoperfusion.

The half-life of the drug is 7 days. In hyperthyroidism, this period is reduced to 3-4 days, and in hypothyroidism it is extended to 9-10 days. The volume of distribution is 10-12 l. About 1/3 of the total amount of levothyroxine administered accumulates in the liver, which quickly interacts with levothyroxine in the blood serum. Thyroid hormones are metabolized mainly in the liver, kidneys, brain and muscles. Metabolites are excreted in urine and feces. The total metabolic clearance of levothyroxine is approximately 1.2 l of plasma/day.

Indication

Euthyrox 25–200 mcg

Treatment of benign euthyroid goiter; prevention of relapses after surgical treatment of euthyroid goiter, depending on the hormone level in the postoperative period; as replacement therapy for hypothyroidism; suppressive therapy for thyroid cancer.

Euthyrox 25–100 mcg

As an adjunct to antithyroid therapy for hyperthyroidism.

Euthyrox 100/150/200 mcg

As a diagnostic tool when performing a thyroid suppression test.

Contraindication

Hypersensitivity to any component of the drug; untreated adrenal insufficiency, pituitary insufficiency, thyrotoxicosis; acute myocardial infarction, acute myocarditis, acute pancarditis; combined therapy with levothyroxine and antithyroid drugs is not prescribed during pregnancy (see section "Use during pregnancy or breastfeeding").

Interaction with other medicinal products and other types of interactions

Hypoglycemic agents. Levothyroxine may reduce the effect of hypoglycemic agents. It is recommended to monitor blood glucose levels frequently at the beginning of thyroid hormone treatment and, if necessary, adjust the dose of hypoglycemic agents.

Coumarin derivatives. Levothyroxine enhances the effect of anticoagulant drugs, displacing them from plasma protein binding, which increases the risk of bleeding, for example, spinal and cerebral hemorrhage or gastrointestinal bleeding, especially in the elderly. Therefore, regular laboratory monitoring of coagulation parameters should be carried out at the beginning and during concomitant therapy and, if necessary, the daily dose of anticoagulant drugs should be adjusted.

Protease inhibitors (e.g. ritonavir, indinavir, lopinavir) may interfere with the action of levothyroxine. Close monitoring of thyroid hormone levels is required. If necessary, the dose of levothyroxine should be adjusted.

Phenytoin may interfere with the action of levothyroxine by displacing it from plasma protein binding, resulting in increased levels of free thyroxine (fT4) and free triiodothyronine (fT3). On the other hand, phenytoin increases the hepatic metabolism of levothyroxine. Close monitoring of thyroid hormone levels is recommended.

Preparations containing aluminum, iron and calcium salts. According to the data provided in the relevant literature, preparations containing aluminum (antacids, sucralfate) can potentially reduce the effect of levothyroxine. Therefore, levothyroxine should be taken at least 2 hours before the use of preparations containing aluminum. This also applies to medicines containing iron and calcium salts.

Salicylates, dicumarol, furosemide in high doses (250 mg), clofibrate and other substances can displace levothyroxine sodium from its binding to plasma proteins, leading to an increase in the fT4 fraction.

Orlistat: Concomitant use of orlistat and levothyroxine may lead to the development of hypothyroidism and/or worsening of hypothyroidism control. This may be due to reduced absorption of iodine salts and/or levothyroxine.

Sevelamer may reduce the absorption of levothyroxine. In this regard, it is recommended to monitor changes in thyroid function tests at the beginning and end of concomitant treatment. If necessary, the dose of levothyroxine should be adjusted. Tyrosine kinase inhibitors (e.g. imatinib, sunitinib) may reduce the effectiveness of levothyroxine. In this regard, it is recommended to monitor changes in thyroid function tests at the beginning and end of concomitant treatment. If necessary, the dose of levothyroxine should be adjusted.

Propylthiouracil, glucocorticoids, beta-sympatholytics, amiodarone and iodinated contrast media inhibit peripheral conversion of T4 to T3. Due to its high iodine content, amiodarone can contribute to the development of both hyperthyroidism and hypothyroidism. The drug should be prescribed with particular caution to patients with nodular goiter of unknown etiology.

Sertraline, chloroquine/proguanil reduce the effectiveness of levothyroxine and increase the level of laboratory indicators of TSH in serum.

Enzymes induced by drugs (barbiturates, carbamazepine) may increase the hepatic clearance of levothyroxine.

Estrogens: Women taking contraceptives containing estrogens, as well as postmenopausal women taking hormone replacement drugs, may require higher doses of levothyroxine.

Soy-containing products may inhibit the intestinal absorption of levothyroxine. Therefore, the dose of Euthyrox should be adjusted, especially at the beginning and after the end of taking soy-containing supplements.

Application features

Before starting thyroid hormone treatment or performing tests for thyroid suppression, the presence of diseases such as coronary insufficiency, angina pectoris, atherosclerosis, arterial hypertension, pituitary insufficiency, adrenal insufficiency should be excluded or previously treated. Functional autonomy of the thyroid gland should also be excluded or previously treated before starting thyroid hormone therapy.

Levothyroxine therapy in patients at risk of developing psychotic disorders should be initiated with low doses of the drug, gradually increasing the dosage at the beginning of therapy. It is recommended to monitor the patient's condition. In case of development of psychotic disorders, the possibility of adjusting the dose of levothyroxine should be considered.

The possibility of even minor manifestations of hyperthyroidism caused by the use of the drug should be avoided in patients with coronary insufficiency, heart failure, tachyarrhythmia. When treating such patients, it is necessary to regularly monitor the level of thyroid hormones.

In the case of secondary hypothyroidism, the cause should be identified before replacement therapy is prescribed. If necessary, a course of replacement therapy should be carried out to compensate for the insufficiency of the adrenal cortex.

If functional autonomy of the thyroid gland is suspected, TSH levels should be determined or thyroid scintigraphy should be performed before starting treatment with the drug.

In postmenopausal women with hypothyroidism, who are at increased risk of osteoporosis, very high serum levothyroxine levels above physiological levels should be avoided. Therefore, laboratory values of thyroid function should be carefully monitored.

Levothyroxine should not be prescribed to patients with hyperthyroidism who are receiving antithyroid drug therapy for hyperthyroidism.

Thyroid hormones should not be used for weight loss. Levothyroxine doses do not result in weight loss in euthyroid patients. Higher doses may result in serious or even life-threatening adverse reactions. Levothyroxine in high doses should not be used in combination with certain substances intended for weight loss (e.g. sympathomimetics) (see section 4.4).

Concomitant use of orlistat and levothyroxine may lead to the development of hypothyroidism and/or worsening of hypothyroidism control (see section “Interaction with other medicinal products and other forms of interaction”). Patients taking levothyroxine should consult their doctor before starting, stopping or changing their treatment with orlistat, as orlistat and levothyroxine need to be taken at different times and the dose of levothyroxine needs to be adjusted. Monitoring of serum hormone levels in patients is recommended in the future.

Use the drug with caution in patients with diabetes mellitus and patients taking anticoagulant drugs (see section "Interaction with other medicinal products and other types of interactions").

Ability to influence reaction speed when driving vehicles or other mechanisms

There is no data on the possible effect on the ability to drive or operate complex mechanisms. However, since levothyroxine is identical in action to the natural thyroid hormone, the effect of Euthyrox on the reaction speed when driving or operating other mechanisms is not expected.

Use during pregnancy or breastfeeding

During pregnancy or breastfeeding, treatment with the drug prescribed for hypothyroidism should be continued. During pregnancy, the dose of the drug may need to be increased. Since an increase in serum TSH levels can occur as early as 4 weeks of pregnancy, pregnant women taking levothyroxine should have their TSH levels checked during each trimester. Serum TSH levels in pregnant women should be within the appropriate limits established for each trimester. The dose of levothyroxine should be increased to correct elevated serum TSH levels. Since postnatal TSH levels correspond to values present before conception, the dose of levothyroxine should be adjusted immediately after delivery to the pre-pregnancy dose. The required serum TSH level should be established 6-8 weeks after delivery.

Pregnancy

There is no evidence of teratogenicity and/or fetotoxicity when taking the drug at recommended therapeutic doses. Taking very high doses of levothyroxine during pregnancy may adversely affect the fetus and postnatal development of the child.

Combination therapy with levothyroxine and antithyroid drugs is not recommended for the treatment of hyperthyroidism during pregnancy because this combination requires higher doses of antithyroid drugs, which can cross the placenta and cause hypothyroidism in the infant. Thyroid suppression testing is not performed during pregnancy because the use of radioactive substances is contraindicated during pregnancy.

Breast-feeding

Levothyroxine passes into breast milk, however, when using the drug in recommended therapeutic doses, the concentration level of the drug in breast milk is insufficient to develop hyperthyroidism or suppress TSH secretion in the infant.

Method of administration and doses

Dosage

To treat each individual patient, depending on their individual needs, Euthyrox is available in tablets containing from 25 mcg to 150 mcg of levothyroxine sodium. Therefore, patients are usually prescribed only 1 tablet per day.

Dosage information is for guidance only.

The daily dose is determined individually, depending on laboratory parameters and the clinical picture of the disease.

Since a number of patients have experienced increases in T4 and fT4 concentrations during levothyroxine therapy, the basal serum concentration of thyroid-stimulating hormone is a more reliable indicator for subsequent dose adjustment.

Thyroid hormone therapy should be started at a low dose and gradually increased (every 2-4 weeks) to the required therapeutic dose.

In elderly patients, patients with coronary heart disease, patients with severe or long-term hypothyroidism, treatment should be started with special caution, with low doses (12.5 mcg per day), the dose should be increased to the maintenance dose at longer intervals (gradually by 12.5 mcg every 2 weeks), regularly monitoring the level of thyroid hormones. It should be noted that the appointment of doses less than the optimal one, which provides full replacement therapy, does not lead to complete correction of TSH levels.

Experience shows that lower doses are sufficient for patients with low body weight and for patients with large nodular goiter.

The daily dose can be taken in one dose.

The daily dose of the drug should be taken in the morning on an empty stomach, 30 minutes before meals, with a small amount of water (half a glass of water).

Euthyrox should be used throughout life as replacement therapy for hypothyroidism, after surgical interventions (strumectomy or thyroidectomy), and to prevent relapses after removal of a euthyroid goiter. Complex therapy with thyreostatics should be prescribed after achieving a euthyroid state.

In the case of benign euthyroid goiter, the duration of treatment is from 6 months to 2 years. If the condition does not improve after treatment, surgery or radioactive iodine therapy should be prescribed.

Children

For newborns and infants with congenital hypothyroidism, where rapid therapeutic response is essential, the recommended initial dose is 10 to 15 mcg/kg body weight per day for the first 3 months. Thereafter, the dose is adjusted individually, depending on clinical response and thyroid-stimulating hormone (TSH) levels.

Infants should be given the daily dose of the drug in one dose 30 minutes before the first feeding. Dissolve the tablet in water to obtain a suspension, which should be prepared immediately before taking the drug and used after adding a small amount of liquid.

Overdose

Elevated T3 (triiodothyronine) levels are a more reliable indicator of drug overdose than elevated serum T4 and fT4 (free).

Overdose may result in symptoms characteristic of increased metabolism (see section "Adverse reactions").

In case of overdose, the drug should be discontinued and laboratory tests should be performed.

Beta-blockers are prescribed for symptoms that manifest as pronounced beta-sympathomimetic effects, such as tachycardia, anxiety, nervous excitability, hyperkinesia. In case of significant overdose, plasmapheresis is recommended.

In some cases, patients prone to seizures may develop seizures when the individual permissible dose of the drug has been exceeded.

Overdose with levothyroxine can cause symptoms of hyperthyroidism and lead to acute psychosis, especially in patients at risk of developing psychotic disorders.

There are several reports of sudden coronary death in patients who have abused (exceeded the recommended dosage) levothyroxine for many years.

Adverse reactions

Clinical symptoms of hyperthyroidism may occur in case of overdose, if the dose of levothyroxine exceeds the individual tolerance, if the dose is increased rapidly at the beginning of treatment.

Symptoms:

Cardiovascular system: cardiac arrhythmias (atrial fibrillation, extrasystole), tachycardia, angina pectoris, palpitations, hot flashes; Nervous system: headache, insomnia, anxiety, pseudotumor cerebri, tremor; Gastrointestinal tract: vomiting, diarrhea, weight loss; Skin and musculoskeletal system: increased sweating, muscle weakness and cramps; General disorders: increased body temperature, menstrual disorders.

In such cases, the daily dose of the drug should be reduced or treatment should be interrupted for several days. After the disappearance of adverse reactions, treatment can be continued.

In case of hypersensitivity to the components of the drug, allergic reactions on the skin and respiratory tract may occur, including skin rashes, itching, urticaria, shortness of breath. There have been reports of cases of angioedema (Quincke's edema).

Expiration date

3 years.

Storage conditions

Store at a temperature not exceeding 25 °C in the original packaging. Keep out of the reach of children!

Packaging

25 tablets in a blister. 4 blisters in a cardboard box.

Vacation category

According to the recipe.

Producer

Merck Healthcare KGaA, Germany.

Location of the manufacturer and its business address

Frankfurter Strasse 250, 64293 Darmstadt, Germany.