Thyrozole,10 mg 50 pcs

Irozole has an antithyroid effect.

Pharmacodynamics

The antithyroid drug disrupts the synthesis of thyroid hormones by blocking the enzyme peroxidase involved in thyronine iodination in the thyroid gland to form triiodine and tetraiodothyronine. This property allows for symptomatic therapy of thyrotoxicosis, except in cases of thyrotoxicosis due to release of hormones after destruction of thyroid cells (after treatment with radioactive iodine or in thyroiditis). Thyrozole does not affect the process of release of synthesized thyronines from thyroid follicles. This explains the latent period of varying duration, which may precede the normalization of plasma levels of T3 and T4, i.e. improvement of the clinical picture.

Decreases basic metabolism, accelerates iodide excretion from the thyroid gland, increases reciprocal activation of thyroid hormone synthesis and secretion by the pituitary gland, which may be accompanied by some thyroid hyperplasia.

The duration of action of a single dose is almost 24 hours.

Pharmacokinetics

Tyrosol is quickly and almost completely absorbed when taken orally. Cmax in plasma is reached within 0.4-1.2 hours. It is practically not bound to blood plasma proteins. Thyrozole cumulates in the thyroid gland, where it is slowly metabolized. Small amounts of thiamazole are detected in breast milk. T1/2 is about 3-6 hours; in hepatic insufficiency it increases. No dependence of kinetics on the functional state of the thyroid gland has been revealed. Metabolism of Thyrozole is carried out in kidneys and liver, excretion is carried out by kidneys and with bile. The kidneys excrete 70% of Thyrozole within 24 hours, and 7-12% – in unchanged form.

Indications

Active ingredient

Composition

How to take, the dosage

Overly, after meals, without chewing, with enough liquid.

The daily dose is given as a single dose or divided into 2-3 single doses. At the start of treatment, single doses are taken at specific times during the day.

The maintenance dose should be taken in 1 sitting after breakfast.

Thyrotoxicosis: depending on the severity of the disease, 20-40 mg/day of Thyrozole for 3-6 weeks. After normalization of thyroid function (usually after 3-8 weeks) we switch to receiving a maintenance dose of 5-20 mg/day. From this time, additional intake of levothyroxine is recommended.

In preparation for surgical treatment of thyrotoxicosis: administer 20-40 mg/day until euthyroid state is achieved. From that time, additional levothyroxine administration is recommended.

In order to reduce the time required to prepare for surgery, beta-adrenoblockers and iodine preparations are additionally prescribed.

In preparation for radioactive iodine treatment: 20-40 mg/day until euthyroidism is achieved.

Therapy in the latent period of radioiodine action: depending on the severity of the disease – 5-20 mg until the onset of radioiodine action (4-6 months).

Long-term thyrostatic maintenance therapy: 1.25; 2.5; 10 mg/day with additional administration of small doses of levothyroxine. In the treatment of thyrotoxicosis the duration of therapy is 1.5 to 2 years.

The prophylaxis of thyrotoxicosis when prescribing iodine preparations (including cases of iodine containing radiopaque agents) in the presence of latent thyrotoxicosis, autonomous adenomas or history of thyrotoxicosis: 10-20 mg/day of Thirozole and 1 g potassium perchlorate daily for 8-10 days before administration of iodine containing agents.

Dosage in children. It is not recommended for use in children from 0 to 3 years old. In children from 3 to 17 years old the preparation Tirozol is prescribed in initial dose of 0.3-0.5 mg/kg of body weight divided into 2-3 equal doses daily; the maximum recommended dose for children with body weight over 80 kg is 40 mg/day.

The maintenance dose is 0.2-0.3 mg/kg; if necessary, levothyroxine is prescribed additionally.

Dosage in pregnant women. Pregnant women are prescribed in the lowest possible dose: a single dose of 2.5 mg, a daily dose of 10 mg.

In case of hepatic insufficiency the lowest effective dose of the drug is prescribed under close medical supervision.

In preparation for surgery in patients with thyrotoxicosis, treatment with the drug is carried out until euthyroidism is achieved within 3-4 weeks prior to the planned day of surgery (longer in some cases) and ends the day before surgery.

Interaction

The effect of thiamazole may be impaired if it is administered after high-dose iodine-containing radiopaque agents.

Iodine deficiency increases the effect of thiamazole.

In patients taking thiamazole for the treatment of thyrotoxicosis, after achieving an euthyroid state, i.e. After achieving a normal serum thyroid hormone level, it may be necessary to decrease the doses of cardiac glycosides (digoxin and digitoxin), aminophylline, and to increase the doses of warfarin and other anticoagulants – coumarin and indandion derivatives (pharmacodynamic interaction).

Lithium drugs, beta-adrenoblockers, reserpine, amiodarone increase the effect of thiamazole (requires dose adjustment).

Concomitant use with sulfonamides, sodium methamisole and myelotoxic drugs increases the risk of leukopenia.

Leukogen and folic acid when used concomitantly with thiamazole decrease the risk of leukopenia.

Gentamicin increases the antithyroid effect of thiamazole.

There are no data on the effect of other drugs on pharmacokinetics and pharmacodynamics of the drug. However, it should be borne in mind that in thyrotoxicosis the metabolism and elimination of substances is accelerated. Therefore, in some cases it is necessary to adjust the dose of other drugs.

Special Instructions

Patients with significant thyroid gland enlargement narrowing the tracheal lumen, Thyrozole is administered short-term in combination with sodium levothyroxine, since prolonged use may increase goiter and further tracheal compression. It is necessary to monitor the patient carefully (control of TSH level, tracheal lumen). Regular control of peripheral blood picture is necessary during treatment with the drug.

Thiamazole and thiourea derivatives may decrease the sensitivity of thyroid tissue to radiation therapy. If during treatment with the drug, sore throat, difficulty swallowing, elevated body temperature, signs of stomatitis or furunculosis (possible symptoms of agranulocytosis) suddenly appear, stop taking the drug and see a physician immediately.

In case of subcutaneous hemorrhage or bleeding of unclear genesis, generalized skin rash and itching, persistent nausea or vomiting, jaundice, severe epigastric pain and marked weakness during treatment, the drug should be discontinued. In case of early discontinuation of treatment, relapse of the disease is possible. Appearance or worsening of endocrine ophthalmopathy is not a side effect of the treatment with Thyrozole properly carried out. Late hypothyroidism may occur in rare cases after the end of treatment, which is not a side effect of the drug, but is associated with inflammatory and destructive processes in the thyroid tissue, occurring as part of the underlying disease.

Impact on the ability to drive vehicles and mechanisms. Tiamazole has no effect on the ability to drive vehicles and mechanisms.

Contraindications

Side effects

The incidence of side effects of the drug is rated as follows: very frequent (≥1/10), frequent (≥1/100,

Hematological and lymphatic system disorders: infrequent – agranulocytosis (its symptoms (see “Special indications”). “Particular indications”) may appear even weeks and months after the start of treatment and lead to the need to withdraw the drug); very rare – generalized lymphadenopathy, thrombocytopenia, pancytopenia.

Endocrine system disorders: very rarely – insulin autoimmune syndrome with hypoglycemia.

Nervous system disorders: rare – reversible change in sense of taste, dizziness, very rare – neuritis, polyneuropathy.

Gastrointestinal system disorders: very rare – increase of salivary glands, vomiting.

Liver and biliary tract: very rare – cholestatic jaundice and toxic hepatitis.

Skin and subcutaneous tissue disorders: very common – allergic skin reactions (itching, redness, rashes); very rare – generalized skin rash, alopecia, lupus-like syndrome.

Musculoskeletal and connective tissue disorders: often – slowly progressive arthralgia without clinical signs of arthritis.

General complications and reactions at the site of administration: rarely – fever, weakness, weight gain.

Overdose

In long-term administration of high doses of the drug, subclinical and clinical hypothyroidism may develop, as well as an increase in the size of the thyroid gland due to increased levels of TSH. This can be avoided by reducing the dose of the drug until euthyroidism is achieved or, if necessary, by additional prescription of levothyroxine sodium. There is usually a spontaneous recovery of thyroid function after discontinuation of Thyrozole. Taking very high doses of Thiamazole (about 120 mg per day) may lead to the development of myelotoxic effects. These doses of the drug should be used only for special indications (severe forms of the disease, thyrotoxic crisis).

The treatment: cancellation of the drug, gastric lavage, symptomatic therapy, if necessary – transfer to an antithyroid drug of another group.

Pregnancy use

Lack of treatment of thyroid hyperfunction during pregnancy can lead to serious complications such as premature delivery and fetal malformations. Thiamazole penetrates the placental barrier and can reach the same concentration in fetal blood as in the mother. Due to the fact that the effect of thiamazole on the fetus cannot be completely excluded, in pregnancy the drug should be prescribed after a full assessment of the benefits and risks of its use in the lowest effective dose without additional levothyroxine administration.

Doses of thiamazole significantly higher than recommended may cause goiter and hypothyroidism in the fetus, as well as low birth weight.

The treatment of thyrotoxicosis with Thyrozole may be continued during lactation if necessary. Since thiamazole penetrates into breast milk and may reach concentrations in it corresponding to its level in blood of the mother, the newborn may develop hypothyroidism. Therefore, if it is necessary to continue treatment of thyrotoxicosis during breastfeeding, Thyrozole should be taken in low doses (up to 10 mg/day) without additional levothyroxine administration.