L-Tiroxine (levothyroxine sodium) 75 tablets 75 mcg. №50

Description

L-Tiroxine Composition
active substance: levothyroxine sodium;

1 tablet contains 75 mcg levothyroxine;

excipients: calcium hydrogen phosphate dihydrate, microcrystalline cellulose, dextrin, sodium starch (type A), long-chain partial glycerides.

L-Tiroxine Dosage form
Pills.

Basic physical and chemical properties: round, slightly convex tablets from white to slightly beige, with a dividing line on one side and embossing “75” on the other.

The tablet can be divided into equal parts.

Pharmacotherapeutic group
Thyroid therapy, thyroid hormones. ATX code Н03А А01.

L-Tiroxine Pharmacodynamics

Mechanism of action

Synthetic levothyroxine, which is found in the preparation L-thyroxin 75 Berlin-Chemie, is identical in its action to the natural thyroid hormone produced mainly by the thyroid gland. There is no disagreement between endogenously formed and exogenous levothyroxine for the body.

Pharmacodynamic effects

After partial conversion to liothyronine (T3), mainly in the liver and kidneys, and the transition to the cells of the body, the characteristic effects of thyroid hormones are observed on the development, growth and metabolism through the activation of T3 receptors.

Clinical efficacy and safety

Substitution of thyroid hormones leads to the normalization of metabolic processes. For example, taking levothyroxine leads to a significant reduction in high cholesterol levels associated with hypothyroidism.

Pharmacokinetics
Suction.

The absorption of orally taken levothyroxine occurs mainly in the upper part of the small intestine, the degree of absorption of which depends mainly on the galenic form of the drug and can be up to 80% when taken on an empty stomach. If the drug is taken with food, its absorption is significantly reduced.

The maximum concentration in blood plasma is reached 2-3 hours after ingestion.

The effect of the drug is observed 3-5 days after the start of oral therapy.

Distribution

The volume of distribution is approximately 10-12 liters. Levothyroxine binds to specific plasma proteins by about 99.97%. The binding of proteins to hormones is not covalent, thus there is a constant and very rapid exchange between free and bound hormone.

Excretion

The metabolic clearance for levothyroxine is approximately 1.2 liters of plasma per day. Cleavage occurs mainly in the liver, kidneys, brain, and muscles. Metabolites are excreted in urine and feces. The half-life is about 7 days with hyperthyroidism, this period is reduced (up to 3-4 days), and with hypothyroidism, it increases (up to about 9-10 days).

Pregnancy and breastfeeding

Levothyroxine crosses the placenta only in small amounts. In the case of taking the drug in usual doses, levothyroxine is excreted into breast milk only in small amounts.

Impaired renal function

Due to the high level of protein binding, neither hemodialysis nor hemoperfusion affects the level of levothyroxine.

Indications

replacement therapy for hypothyroidism of various etiologies;
prevention of recurrence of goiter after resection of goiter with euthyroid state of thyroid function;
benign goiter with euthyroid state of thyroid function;
adjuvant for thyreostatic therapy of hyperthyroidism after reaching the euthyroid functional state;
suppressive and replacement therapy for malignant tumors of the thyroid gland, mainly after thyroidectomy.

Contraindications
Hypersensitivity to the active substance or to any of the excipients. Untreated hyperthyroidism of any origin. Untreated adrenal insufficiency. Untreated pituitary insufficiency (this leads to insufficiency of the adrenal cortex, requires treatment). Acute myocardial infarction. Acute myocarditis. Acute pancarditis.
During pregnancy, the simultaneous use of levothyroxine and any thyreostatic agent is contraindicated (for more information on use during pregnancy and lactation, see the section “Use during pregnancy or lactation”).