L-Tyroxine 50 Berlin Chemi, tablets 50 mcg 50 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 is monodeiodized 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 sodium50 mcg

Ancillary substances:

calcium hydrophosphate dihydrate,

cellulose microcrystalline,

p> sodium carboxymethyl starch (type A),

dextrin,

long-chain incomplete glycerides.

How to take, the dosage

The daily dose of the drug is set and controlled individually on the basis of laboratory and clinical data.

Prescribed 50 to 100 mcg/day.

The daily dose of the drug is 150-300 mcg.

The average daily maintenance dose of the drug is shown in the table.

Patient groupHypothyroidismNyborns12.5 µg4 µg/kgBabies at 3 months25-37.5 µg25 µgBabies at 6 months25-37.5 µg37.5 µgChildren at 1 year old25-37.5 µg37.5 µgChildren at 5 years old25-62.5 mcg50 mcgChildren 7 years of age50-100 mcg75-100 mcgChildren 12 years of age100-150 mcg100 mcgAdults75-200 mcg125-250 mcg

The daily dose is taken in the morning on an empty stomach at least 30 minutes before breakfast, without chewing and with a small amount of liquid.

The pills should be taken regularly. If the next dose is missed, do not take the missed dose and continue as directed.

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

Consultation with a physician is necessary if other iodine-containing medications need to be prescribed. It is recommended to periodically determine blood levels of TSH, an elevated level of which indicates an insufficient dose. The adequacy of suppressive thyroid therapy is also assessed by suppression of radioiodine uptake. In long-standing multinodular goiter, a thyrotropin-releasing hormone stimulation test should be performed before starting treatment. In most cases of hypothyroidism the metabolic status should be restored gradually, especially in elderly patients and patients with cardiovascular pathology. For elderly patients the initial dose should not exceed 50 mcg. When used in the second and third trimesters of pregnancy, the dose is usually increased by 25%.

With caution is administered in severe long-term hypothyroidism. Prior to treatment, the possibility of pituitary or hypothalamic hypothyroidism should be excluded.

Contraindications

Side effects

Allergic reactions (skin rash, skin itching).

When used 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 insufficiently effective doses:

Hypothyroidism (dysmenorrhea, constipation, dryness, puffiness of the skin, headache, lethargy, myalgia, drowsiness, weakness, apathy, weight gain).

Overdose

Symptoms: Thyrotoxic crisis, sometimes delayed for several days after administration.

Treatment: Application of beta-adrenoblockers, intravenous GCS, plasmapheresis.

Pregnancy use

In pregnancy and during lactation (breastfeeding) the drug should be continued. During pregnancy, the need for thyroid hormones increases, so it is necessary to adjust the dose of the drug.

However, levothyroxine is not recommended for use during pregnancy at the same time as thyroid medications, which penetrate through the placenta and may cause hypothyroidism in the fetus.

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

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