L-Tyroxine 150 Berlin Chemi, tablets 150 mcg 100 pcs

Pharmacodynamics

The synthetic left-handed isomer of thyroxine. After partial conversion to triiodothyronine (in the liver and kidneys) and transfer to body cells, it influences tissue development and growth and metabolism.

In low 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 the CNS. In high doses it inhibits hypothalamic and pituitary TTH production.

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

Pharmacokinetics

Intake

After oral administration, levothyroxine is absorbed almost exclusively in the upper small intestine. Up to 80% of the dose taken is absorbed. Food intake reduces absorption of levothyroxine. Cmax in blood serum is reached approximately 5-6 hours after oral administration.

Distribution

After absorption, more than 99% of the drug is bound to serum proteins (thyroxine-binding globulin, thyroxine-binding prealbumin and albumin). In various tissues approximately 80% of levothyroxine is monodeiodized to form triiodothyronine (T3) and inactive products.

Metabolism

The 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).

The metabolites are excreted in the urine and bile. T1/2 is 6-7 days. Pharmacokinetics in special clinical cases In thyrotoxicosis T1/2 is shortened to 3-4 days and in hypothyroidism it is prolonged to 9-10 days.

Indications

Active ingredient

Composition

1 tablet

levothyroxine sodium150 mcg

Supplementary substances:

calcium hydrophosphate dihydrate,

cellulose microcrystalline,

Sodium carboxymethyl starch (type A),

dextrin,

long-chain partial glycerides.

How to take, the dosage

The daily dose is determined individually depending on the indication.

The daily dose of L-Tyroxine Berlin-Chemie is taken orally in the morning on an empty stomach at least 30 min before a meal, with a small amount of liquid (half a glass of water) and without chewing.

In hypothyroidism replacement therapy, patients under 55 years of age in the absence of cardiovascular disease L-Tyroxine Berlin-Chemie is prescribed at a daily dose of 1.6-1.8 mcg/kg body weight; patients over 55 years or with cardiovascular disease – 0.9 mcg/kg body weight. In case of significant obesity the calculation should be made on the “ideal body weight”.

The initial stage of substitution therapy in hypothyroidismPatients without cardiovascular disease younger than 55 yearsThe initial dose:
women – 50-100 mcg/day,
men – 50-150 mcg/dayPatients with cardiovascular disease or older than 55 yearsThe initial dose is 25 mcg/day.
Increase by 25 mcg at 2-month intervals until normalization of the TSH level in blood.

In case of appearance or worsening of cardiovascular symptoms, correct cardiovascular therapy.

Recommended thyroxine doses for the treatment of congenital hypothyroidism

Age Daily dose of thyroxine (µg) Dose of thyroxine per body weight (µg/kg)0-6 months25-5010-156-24 months50-758-10 from 2 to 10 years75-1254-6 from 10 to 16 years100-2003-4> 16 years100-2002-3

The indications

Recommended doses of L-Tyroxine Berlin-Chemie (mcg/day)

The treatment of euthyroid goiter50-200

Prevention of relapse after surgical treatment of euthyroid goiter50-200

In the complex therapy of thyrotoxicosis50-100

Thyroid cancer suppressive therapy150-300

Thyroid suppression test4 weeks before test3 weeks before test2 weeks before test1 week before test50-7575-100150-200150-200

The most appropriate dosage of L-Tyroxine Berlin-Chemie (50, 75, 100, 125, or 150 mcg) should be used for accurate dosing.

In severe long-term hypothyroidism, treatment should be started with extreme caution, with low doses of 25 mcg/day, the dose should be increased to maintenance at longer intervals – by 25 mcg/day every 2 weeks and blood TSH levels should be determined more frequently. For hypothyroidism, L-Tyroxine Berlin-Chemie is usually taken for life.

In case of thyrotoxicosis L-Tyroxine Berlin-Chemie is used in combination therapy with thyreostatics after achieving euthyroidism. In all cases, the duration of treatment with the drug is determined by the doctor.

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

Side effects

Allergic reactions (in case of hypersensitivity to the drug).

When used properly under the supervision of a physician, side effects are not observed.

Overdose

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

Treatment: Decrease in daily dosage of the drug, a few days’ treatment break, and administration of beta-adrenoblockers may be recommended. After side effects have disappeared, treatment should be started with caution at a lower dose.

Pregnancy use

Treatment with levothyroxine sodium prescribed for hypothyroidism should be continued during pregnancy and breastfeeding. During pregnancy, an increase in the dose of the drug is required due to increased levels of thyroxine-binding globulin. The amount of thyroid hormone secreted with breast milk (even when treated with high doses of the drug) is not enough to cause any disorders in the baby during breastfeeding.

The use in pregnancy in combination with thyreostatics is contraindicated because the administration of levothyroxine sodium may require increasing doses of thyreostatics. Since thyreostatics, unlike sodium levothyroxine, can pass through the placenta, the fetus may develop hypothyroidism.

The FDA fetal category of action is A.

Pediatric use

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

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