Instruction for use: L-Thyrok

Active substance Levothyroxine sodium

ATX Code H03AA01 Calcitonin

Pharmacological groups

Synthetic thyroid hormone [Thyroid and parathyroid hormones, their analogs and antagonists (including antithyroid agents) / 67 /]

Nosological classification (ICD-10)

C73 Malignant neoplasm of thyroid

Thyroid cancer, Thyrotropin-Dependent Thyroid Carcinoma, Anaplastic thyroid cancer, Thyroid carcinoma, Medullary thyroid cancer, Thyroid tumors, Papillary thyroid cancer

E01 Thyroid gland diseases associated with iodine deficiency and similar conditions

Hormonal deficiency of the thyroid gland due to iodine deficiency in the body, Goiter endemic, Iodine deficiency alimentary state, Iodine deficiency disease, Iodine Deficiency, Endemic cretinism

E03 Other forms of hypothyroidism

hypothyroidism, Hypothyroid conditions, Thyroid hypothyroidism, Diagnosis of hypothyroidism, Myxedema, Primary hypothyroidism, Simple goitre,Spontaneous hypothyroidism, Iatrogenic hypothyroidism

Composition and form of production

1 tablet contains levothyroxine sodium 50, 100 or 150 μg; In the package 50 pcs.

Characteristic

Levothyroxine, the active substance of L-Thyrok, is a levorotatory isomer of thyroxine (L-T4). The activity of 100 μg L-Thyrok in the clinical value corresponds to the activity of 25 μg of triiodothyronine.

pharmachologic effect

Pharmacological action - replenishing deficiency of thyroid hormones.

Pharmacokinetics

Accepted on an empty stomach, absorbed by 70-80%, resorption decreases with admission with food. T1 / 2 is 8 days (approximately). One dose per day provides stable levels of triiodothyronine (in the body it is transformed into triiodothyronine).

Clinical Pharmacology

In the case of cardiac decompensation (as a result of hypothyroidism), L-Thyrok improves cardiac function.

Indications

Replacement therapy for all forms of congenital and with iatrogenic hypothyroidism, after irradiation of the thyroid gland, thyroidectomy, treatment with thyreostatics; Oppression of thyroid function in goiter, carcinoma, active adenoma (if thyroid function remains under the control of the pituitary gland).

Contraindications

No.

pregnancy and lactation

During the II and III trimesters of pregnancy to ensure adequate action, it is necessary to increase the dose by 25% under the control of L-T4. In the case of hyperthyroidism, a combination of L-Thyrok and antithyroidin is not prescribed, because Possibly the development of congenital hypothyroidism. During lactation, taking the drug can not be interrupted.

Side effects

Manifestations of hyperthyroidism: tachycardia, stenocardia, arrhythmia, nervousness, tremor, sweating, diarrhea, weight loss.

Interaction

You can combine with drugs that inhibit the secretion of the thyroid-stimulating hormone of the pituitary gland. Estrogens are reduced, and phenytoin increases the effect (by increasing or decreasing the L-Thyrok bond with thyroglobulin). Cholestyramine decreases absorption in the digestive tract, barbiturates accelerate the catabolism of the drug. Strengthens the effect of anticoagulants, reduces the activity of hyperglycemic agents and digitalis. When taken with tricyclic antidepressants, the effect is mutually reinforced.

Dosing and Administration

Inside, in the morning, on an empty stomach, half an hour before a meal - 1 time a day. Before starting treatment, the thyroid-stimulating hormone level should be normalized. Adults - begin with 25-50 mcg per day, gradually increasing the dose from 25 to 50 mcg per day for 2-4 weeks. The maintenance dose is increased to 100-200 μg per day. In severe hypothyroidism, angina pectoris, cardiac decompensation, arrhythmias begin with 25 mcg per day or for two days, increasing the dose gradually. Children - begin with 2.5-5 μg / kg per day, increasing the dose to achieve euthyroidism.

Overdose

Symptoms of acute intoxication (thyrotoxic crisis) - tachycardia, stenocardia, arrhythmia, anxiety, tremor, sweating, diarrhea, weight loss. Treatment - to reduce the dose or stop taking the drug for several days, then resume the reception, but in smaller doses. In severe cases, beta-blockers are used. At a hyperthermia lower temperature of the patient, use in / in corticosteroids for the prevention of adrenal insufficiency and plasmapheresis - at the expressed intoxication.

Precautionary measures

Before starting treatment, patients suffering from secondary hypothyroidism due to pituitary insufficiency should undergo a course of corticotherapy to prevent acute adrenal insufficiency. Patients with myxedema and cardiovascular diseases (the risk of developing a BP, angina pectoris, myocardial infarction, cardiac decompensation) begin treatment with lower doses followed by a very gradual increase.

L-Thyrok storage conditions

In the dark place at a temperature of no higher than 25 ° C.

Keep out of the reach of children.

Shelf life

2 years.

Do not use after the expiry date printed on the package.