Mercazolil

General characteristics. Structure:

Deystvuyushche substance: 5 mg of Thiamazolum.

Excipients: lactose (sugar milk), potato starch, calcium stearate.

Pharmacological properties:

Pharmacodynamics. Anti-thyroid drug; breaks synthesis of hormones of a thyroid gland, blocking enzyme the peroxidase participating in iodination of a tironin in a thyroid gland with education triyod-and a tetrayodtironin, reduces incretion of thyroxine (T4).

This property allows to carry out symptomatic therapy of a thyrotoxicosis regardless of an etiology. Mercazolil does not influence process of release of the synthesized tironin of follicles of a thyroid gland. Stage of latency of various duration which can precede normalization of level of triiodothyronine (T3) and T4 in a blood plasma, i.e. to improvement of a clinical picture is explained by it. Mercazolil does not influence the thyrotoxicosis which developed owing to release of hormones after destruction of cells of a thyroid gland (after treatment by a radioiodine or at a tireoiodita).

Mercazolil reduces standard metabolism, accelerates removal from a thyroid gland of iodides, increases reciprocal activation of synthesis and allocation by a hypophysis of thyritropic hormone that is followed by some hyperplasia of a thyroid gland.

Duration of action of once accepted dose makes nearly 24 hours.

Pharmacokinetics. Drug is well soaked up at oral administration, meal does not influence quantity and speed of absorption. Bioavailability — 93%. Practically does not contact proteins of plasma. Concentrates in tissue of a thyroid gland. Small amounts are found in breast milk. The volume of distribution is 0,6 l/kg. Time of achievement of the maximum concentration in plasma makes 30-60 min. after administration of drug; the maximum concentration in plasma reaches 1,184 mkg/ml at peroral introduction of a dose of 60 mg. Metabolism is carried out in a liver with formation of inactive metabolites. An elimination half-life — 5-6 h. Less than 10% — in not changed look are brought out of an organism by kidneys, and.

Indications to use:

- thyrotoxicosis;
- preparation for surgical treatment of a thyrotoxicosis;
- preparation for treatment of a thyrotoxicosis radioiodine;
- therapy at stage of latency of action of a radioiodine. It is carried out prior to action of a radioiodine (within 4-6 months);
- in exceptional cases — a long maintenance therapy of a thyrotoxicosis when in connection with the general state or for the individual reasons it is impossible to execute radical treatment;
- prevention of a thyrotoxicosis at purpose of drugs of iodine (including cases of use of iodinated X-ray contrast means) in the presence of a latent thyrotoxicosis, autonomous adenomas or a thyrotoxicosis in the anamnesis.

Route of administration and doses:

Pill should be taken inside after food, without chewing, with enough liquid. The daily dose is appointed in one step or divided into two-three single doses. In an initiation of treatment single doses are accepted during the day in strictly certain time. The maintenance dose should be accepted in one step after a breakfast.

Thyrotoxicosis. At adults in an initiation of treatment, depending on severity of a thyrotoxicosis, Mercazolil is applied 3 times a day (each 8 hours) in the general dose:
- 15 mg/days (3 tablets) in case of a slight thyrotoxicosis;
- 20-30 mg/days (4-6 tablets) in case of moderately expressed thyrotoxicosis;
- 40 mg/days (8 tablets) in hard cases of a thyrotoxicosis.

After normalization of function of a thyroid gland appoint maintenance doses of drug — from 2,5 to 10 mg/days (½ - 2 tablets) in 1 or 2 receptions. At pregnancy drug is appointed in the lowest doses — 2,5-1 mg/days. To children in an initiation of treatment appoint usually 300-500 mkg/kg of weight bodies/days in 3 receptions; a maintenance dose — 200-300 mkg/kg of body weight a day in 2 receptions.

To children up to 3 years drug is dissolved in water to a thin suspension which is prepared just before reception. Treatment duration Mercazolil is defined by individual need of the patient. Experience of therapeutic use of drug shows that duration of treatment of a thyrotoxicosis at a diffusion toxic craw has to make 1,5-2 years.

By preparation for surgical treatment of a thyrotoxicosis appoint 20-40 mg/days before achievement of an euthyroid state within 3-4 weeks about the planned day of operation (in some cases — is longer); from now on additional reception of left thyroxine is recommended. Stop reception of Thiamazolum a day before operation.

For the purpose of reduction of time necessary for a preparation for surgery, in addition appoint beta adrenoblockers and drugs of iodine.

By preparation for treatment by a radioiodine: appoint 20-40 mg/days before achievement of an euthyroid state. Instruction: Thiamazolum and derivative thioureas can reduce sensitivity of tissue of thyroid gland to radiation therapy.

Therapy at stage of latency of action of a radioiodine: depending on disease severity appoint 5-20 mg/days before action of a radioiodine (4-6 months).

Long thyreostatic maintenance therapy: 2,5-10 mg/days with additional reception of small doses of left thyroxine.

Prevention of a thyrotoxicosis at purpose of drugs of iodine (including cases of use of iodinated X-ray contrast means) in the presence of a latent thyrotoxicosis, autonomous adenomas or a thyrotoxicosis in the anamnesis: appoint 10-20 mg/days of Thiamazolum and 1 g of potassium perchlorate a day within 8-10 days before reception of iodinated means.

At a liver failure appoint minimum effective dose of drug. In all cases treatment duration by drug is determined by the doctor.

Features of use:

During treatment it is necessary to carry out control of peripheral blood (at an interval of 1-2 weeks during selection of a dose and once a month — in the period of a maintenance therapy).

The patient with significant increase in the thyroid gland narrowing a trachea gleam, Mercazolil is appointed quickly in a combination with left thyroxine as at prolonged use increase in a craw and a bigger prelum of a trachea is possible. It is necessary to make careful observation of the patient (control of the TTG level, a tracheal gleam).

The patient to whom Mercazolil is appointed has to be warned about need of the obligatory address to the doctor at emergence of fever, a fever, cough, pharyngalgias, inflammations of a mucous membrane of an oral cavity, furuncles since these manifestations can be agranulocytosis symptoms.
Emergence during treatment of hypodermic hemorrhages or bleedings of not clear genesis, generalized skin rash and an itch, persistent nausea or vomiting, jaundice, severe epigastric pains and the expressed weakness demands drug withdrawal.

In case of the early termination of treatment the recurrence is possible.

Emergence or deterioration in a course of an endocrine ophthalmopathy is not side effect of the treatment by Mercazolil which is carried out properly. In rare instances after the end of treatment there can be a late hypothyroidism which is not side effect of drug, and is connected with the inflammatory and destructive processes in tissue of a thyroid gland proceeding within a basic disease.

Use during pregnancy and during breastfeeding. Thiamazolum gets through a placental barrier and in blood of a fruit reaches the same concentration, as at mother. Therefore, at pregnancy drug has to be used only in urgent cases in minimum effective dose without additional administration of drugs of hormones of a thyroid gland under strict observation of the doctor. The high dose of Thiamazolum can cause formation of a craw and a hypothyroidism in a fruit. Thiamazolum also gets into breast milk and can reach in it the concentration corresponding to level in blood at mother. In need of continuation of treatment of a thyrotoxicosis during breastfeeding, feeding by a breast should be stopped.

Side effects:

Allergic reactions (itch, rash, urticaria), suppression of a myelopoiesis (agranulocytosis, granulocytopenia, thrombocytopenia), aplastic anemia, medicinal fever, autoimmune syndrome with a hypoglycemia, a generalized limfoadenopatiya, a sialadenopatiya, neuritis, taste disturbances, an alopecia, a polyneuritis, a volchanochnopodobny syndrome, a prothrombinopenia (petechias, bleedings), a periarteritis, hepatitis, cholestatic jaundice, a skin itch, nausea, vomiting, pain in epigastriums, an arthralgia, a mialgiya, paresthesias, the expressed weakness, a headache, dizziness, a skin hyperpegmentation, hypostases, increase in body weight, it is rare — nephrite.

Subclinical and clinical гипотериоз can develop at reception of high doses of drug. Also the enlargement of the thyroid gland can begin that is connected with increase in maintenance of TTG in blood.

Interaction with other medicines:

Lithium drugs, beta adrenoblockers, Reserpinum, Amiodaronum increase effect of Thiamazolum (correction of its dose is required).

Streptocides, metamizole sodium increase risk of development of a leukopenia.

Myelotoxic medicines strengthen manifestations of a gematotoksichnost of drug.

The iodine deficiency raises, and surplus (for example, arising against the background of receptions of the medicines containing large amounts of iodine) weakens effect.

Leucogenum and folic acid at simultaneous use with Thiamazolum reduce risk of development of a leukopenia. Gentamycin strengthens anti-thyroid action of Thiamazolum.

The patients accepting Thiamazolum concerning a thyrotoxicosis after achievement of an euthyroid state can have a need of reduction of the accepted doses of cardiac glycosides (digoxin and digitoxin), Aminophyllinum, and also increase in the accepted doses of warfarin and other anticoagulants — derivative coumarin and an indandion (pharmakodinamichesky interaction).

Contraindications:

- hypersensitivity to Thiamazolum or to thiourea derivatives;
- an agranulocytosis during earlier carried out therapy by carbimazole or Thiamazolum;
- a granulocytopenia (including in the anamnesis);
- a cholestasia before an initiation of treatment;
- lactation period.

With care it is necessary to apply at pregnant women; at patients with a craw of very big sizes with a tracheostenosis (only short-term treatment in the period of a preparation for surgery); at a liver failure; at the patients receiving anticoagulants, cardiac glycosides, and also Aminophyllinum.

Overdose:

Symptoms: nausea, vomiting, pains in epigastriums, fever, an arthralgia, a skin itch, hypostases. Aplastic anemia (pancytopenia) or an agranulocytosis can demonstrate during the first hours. More rare — hepatitis, a nephrotic syndrome, exfoliative dermatitis, neuropathy, oppression or stimulation of the central nervous system.

Treatment: gastric lavage, absorbent carbon, symptomatic therapy. The chronic overdose of Thiamazolum leads to an enlargement of the thyroid gland and development of a hypothyroidism. In this case treatment by drug is stopped. Replacement therapy by left thyroxine is carried out if it comes true severity of a hypothyroidism. As a rule, after cancellation of Thiamazolum spontaneous recovery of function of a thyroid gland is observed.

Storage conditions:

List B. In the dry, protected from light place, at a temperature not above 25 °C.
To store in the place, unavailable to children. Not to use drug after a period of validity. A period of validity - 5 years.

Issue conditions:

According to the recipe

Packaging:

Tablets of 5 mg. On 10 tablets in a blister strip packaging. 5 or 10 blister strip packagings together with the application instruction in a pack from a cardboard.