Instructions for Mercazolil-Health tablets 5 mg container No. 100
Composition
active ingredient: 1 tablet contains thiamazole 5 mg;
excipients: potato starch, calcium stearate, refined sugar, talc.
Dosage form
Pills.
Main physicochemical properties: white or white with a yellowish tinge tablets, with a flat surface and a bevel.
Pharmacotherapeutic group
Antithyroid drugs. ATC code H03B B02.
Pharmacological properties
Pharmacodynamics
Antithyroid agent. The mechanism of thyrostatic action is due to inhibition of the activity of the peroxidase enzyme, which is involved in the iodination of thyroid hormones of the thyroid gland, which leads to a violation of the synthesis of thyroxine and triiodothyronine. This property allows for symptomatic treatment of thyrotoxicosis regardless of its etiology. Thiamazole does not affect the secretion of previously synthesized thyroid hormones, which explains the duration of the latent period before the normalization of the concentration of thyroxine and triiodothyronine in the blood serum, as a result of which the clinical picture of the disease improves. It does not affect thyrotoxicosis, which developed as a result of the release of hormones after the destruction of thyroid cells (after treatment with radioactive iodine or with thyroiditis).
Pharmacokinetics
After oral administration, it is rapidly and completely absorbed from the digestive tract. Cmax in blood plasma is reached after 40-80 minutes. It practically does not bind to blood plasma proteins. Thiamazole accumulates in the thyroid gland and is metabolized very slowly, due to which a concentration plateau is formed on the kinetic curve, which persists for 24 hours after taking a single dose of the drug. The kinetics of metabolism does not depend on the function of the thyroid gland. T½ is 3 hours; in patients with liver failure it is longer. It is excreted in urine and bile, to a small extent - in feces. It is excreted in the urine in the form of metabolites (70% within 24 hours) and unchanged substance.
Indication
Treatment of thyrotoxicosis.
– Conservative treatment of thyrotoxicosis, especially with absent or small goiter.
– Preparation for surgical treatment for all forms of thyrotoxicosis.
– Preparation for treatment of thyrotoxicosis with radioactive iodine.
– Therapy during the latent period of radioactive iodine exposure.
– Prevention of thyrotoxicosis when prescribing iodine preparations in the presence of latent thyrotoxicosis, autonomous adenomas, or a history of thyrotoxicosis.
Contraindication
Hypersensitivity to any of the components of the drug/other thionamide derivatives, moderate and severe blood count abnormalities (granulocytopenia), cholestasis before treatment, bone marrow damage during previous therapy with thiamazole or carbimazole, concomitant therapy with the drug and thyroid hormones during pregnancy is contraindicated (see section "Use during pregnancy or breastfeeding").
Interaction with other medicinal products and other types of interactions
Iodine deficiency increases the susceptibility of the thyroid gland to the drug, and iodine excess reduces it. Other direct interactions with other drugs are unknown. It should be borne in mind that the metabolism and excretion of other drugs may increase in hyperthyroidism. These indicators normalize when thyroid function is restored. If necessary, the dosage of the drug should be adjusted.
Application features
The drug is not recommended for use in patients with a history of hypersensitivity reactions (allergic rashes, itching).
Patients who have very large goiters and tracheal narrowing should use the drug with caution and for the shortest possible period.
Before starting treatment, special attention should be paid to the symptoms of agranulocytosis (stomatitis, pharyngitis, high body temperature). Symptoms usually occur at the beginning of treatment, but they may appear after a few months or during a repeated course of treatment. It is recommended to monitor blood counts before and after starting therapy, especially in patients suffering from moderate granulocytopenia. In case of development of any of the above symptoms, especially during the first week of treatment, you should immediately consult a doctor for a blood test. If agranulocytosis is confirmed, further therapy with the drug should be discontinued.
Excess of the drug in the body after taking very high doses may lead to the development of subclinical/clinical hypothyroidism or goiter growth due to increased secretion of thyroid-stimulating hormone. In this regard, the dose of the drug should be reduced immediately after the restoration of normal thyroid function, and if necessary, levothyroxine should be prescribed. It is not recommended to completely stop treatment with the drug and use only levothyroxine.
The increase in goiter during therapy with the drug, despite the suppression of thyroid-stimulating hormone secretion, occurs as a result of the disease itself and cannot be prevented by additional administration of levothyroxine.
Maintaining normal thyroid-stimulating hormone secretion is important to minimize the risk of developing or worsening endocrine ophthalmopathy. However, this pathology is often independent of the course of thyroid disease. Such complications are not a reason to change the treatment regimen and are not an adverse reaction when the course of treatment is correct.
In rare cases, late hypothyroidism has been observed after a course of antithyroid therapy without surgery. This is not an adverse reaction to the drug, but the result of inflammatory and destructive processes in the thyroid parenchyma caused by the underlying disease.
Due to the reduction of pathologically increased energy expenditure in hyperthyroidism, body weight may increase during treatment with the drug. Improvement in the clinical picture indicates normalization of energy metabolism.
If the patient has been diagnosed with an intolerance to some sugars, consult a doctor before taking this medicine.
Use during pregnancy or breastfeeding
Usually, thyroid function returns to normal during pregnancy. However, continued treatment of thyrotoxicosis is often necessary, especially in the first months of pregnancy. Overactive thyroid during pregnancy can lead to serious complications, such as premature birth or fetal malformations. The use of thiamazole in high doses for the treatment of thyrotoxicosis also increases the risk of miscarriage.
Thiamazole penetrates the placental barrier. In case of taking the drug in improper doses, there is a risk of growth of the thyroid gland and development of hypothyroidism in the fetus, as well as a decrease in fetal body weight. There are repeated reports of cases of partial skin aplasia in newborns from women who received thiamazole. Healing of the defect occurred spontaneously after a few weeks.
Also, the occurrence of various malformations, such as choanal atresia, esophageal atresia, nipple hypoplasia, as well as mental and motor development delay, associated with the use of high doses of thiamazole during the first weeks of pregnancy. However, a study of several cases of prenatal exposure to thiamazole did not reveal any abnormalities in morphological development and did not confirm the effect of the drug on the development of hypothyroidism or on the physical and mental development of children.
Due to the impossibility of completely excluding toxic effects on the fetus, the drug should be prescribed during pregnancy after a careful benefit/risk assessment. The drug should be used in the lowest effective dose, and additional hormones should not be prescribed.
Thiamazole penetrates into breast milk, where its concentration reaches the level of concentration in the mother's blood serum, which causes the risk of developing hypothyroidism in the child.
During breastfeeding, the drug should be prescribed in the lowest effective doses, not exceeding 10 mg per day, without additional hormone administration.
It is necessary to regularly monitor thyroid function in newborns.
Ability to influence reaction speed when driving vehicles or other mechanisms
The drug does not affect the ability to drive vehicles or other mechanisms.
Method of administration and doses
The daily dose should be administered as a single dose or divided into several doses during the day. At the beginning of treatment, single doses should be administered throughout the day, at equal intervals. The maintenance dose should be administered as a single dose, during or after breakfast.
Take the tablets without chewing, with sufficient liquid.
General dosage recommendations.
Adults. Depending on the severity of the disease and the intake of iodine into the body, the recommended dose for adults is 10-40 mg per day. In many cases, suppression of thyroid hormone production is achieved by taking 20-30 mg of the drug per day. In case of mild disease, the drug should be prescribed in a lower dosage, in case of severe disease, the drug should be used in an initial dose of 40 mg per day.
Dose adjustment should be carried out individually, taking into account the activity of metabolic processes caused by the level of thyroid hormone production.
The following dosage is recommended for maintenance therapy:
– a maintenance dose of the drug of 5-20 mg per day in combination with levothyroxine, for the prevention of hypothyroidism;
– as monotherapy, 2.5-10 mg of the drug per day.
In case of thyrotoxicosis caused by elevated iodine content, the drug may be used in higher doses.
After normalization of thyroid function, the dose should be gradually reduced to a maintenance dose, which is determined taking into account individual metabolic characteristics. If necessary, additionally prescribe levothyroxine.
Conservative treatment of thyrotoxicosis. The duration of therapy with the drug is from 6 months to 2 years (on average - within 1 year). The possibility of prolonging the remission period depends on the duration of therapy. In cases where remission cannot be achieved and other therapeutic measures are impossible, the drug can be used for long-term therapy in the lowest effective doses.
Patients with tracheal stenosis and very large goiters should be treated for a short period. Long-term therapy may lead to goiter growth.
Preparation for surgical treatment in all forms of thyrotoxicosis. Short-term preparatory therapy (for 3-4 weeks, in some cases the drug can be used longer) contributes to the restoration of a euthyroid state, thereby reducing the risks associated with surgical intervention.
Surgery is performed immediately after achieving a euthyroid state. Drug therapy can be terminated the day before surgery.
During the last 10 days before surgery, the surgeon may additionally prescribe high-dose iodine preparations to strengthen the thyroid tissue.
Preparation for treatment of thyrotoxicosis with radioactive iodine. The drug should be used to achieve a euthyroid state before starting therapy with radioactive iodine. Pre-treatment with the drug is especially necessary for patients with severe thyrotoxicosis, since isolated cases of thyrotoxic crisis have been observed after iodine treatment without prior thiamazole therapy.
It should be taken into account that thiourea derivatives may reduce the sensitivity of thyroid tissue to radiotherapy. When carrying out planned therapy with radioactive iodine in connection with autonomous adenomas, it is necessary to conduct preliminary therapy with the drug to prevent activation of paranodular tissue.
Therapy during the latent period of radioactive iodine action. The duration and dose of the drug are selected individually depending on the severity of the disease, as well as taking into account the period before the onset of radioactive iodine action (approximately 4-6 months).
Prevention of thyrotoxicosis when prescribing iodine preparations, in the presence of latent thyrotoxicosis, autonomous adenomas or thyrotoxicosis in history. The usually recommended dose is 10-20 mg of the drug per day and/or 1 g of perchlorate daily for 10 days (for example, if it is necessary to administer a radiopaque agent that is excreted by the kidneys). The duration of preventive treatment is determined taking into account the duration of the period during which iodine preparations are in the body.
Special patient groups. In patients with impaired liver function, the rate of thiamazole excretion is reduced. In this regard, the drug is recommended to be used in the lowest effective doses, and during therapy with the drug, it is necessary to monitor the patient's condition.
Individual dose adjustment and constant monitoring are recommended for patients with renal insufficiency, as there is insufficient data on the pharmacokinetic properties of the drug in this group of patients.
Elderly patients are recommended individual dose adjustment and constant monitoring, there is no data on the accumulation of the drug in the body. The drug is recommended to be used in the lowest effective doses.
Children. This dosage form of thiamazole should be prescribed to children aged 3 years and over. Recommendations for dosing the drug for children are given in the section “Method of administration and doses”.
Overdose
Overdose may lead to the development of hypothyroidism and, due to the effect of hormone deficiency, to activation of the adenohypophysis with subsequent growth of the goiter. In this case, the drug should be discontinued and, if necessary, additional thyroid hormones should be prescribed.
Adverse reactions
From the blood and lymphatic system: agranulocytosis (may appear weeks or months after the start of treatment, in most cases disappears on its own after discontinuation of the drug), thrombocytopenia, pancytopenia, generalized lymphadenopathy.
On the part of the endocrine system: insulin autoimmune syndrome with a sharp decrease in blood glucose concentration.
From the nervous system: taste disturbances (dysgeusia, ageusia), which resolve on their own after discontinuation of the drug (sometimes taste sensations are restored a few weeks after the end of the course of treatment); neuritis, polyneuropathy, fever.
On the part of the digestive system: acute inflammation of the salivary glands.
Hepatobiliary system: cholestatic jaundice or toxic hepatitis. Symptoms usually disappear after discontinuation of the drug. Clinically subtle symptoms of bile stasis during treatment should be distinguished from dysfunctions caused by hyperthyroidism, such as increased levels of γ-glutamyltransferase and alkaline phosphatase.
Musculoskeletal system: arthralgia, which develops gradually and may occur even after several months of therapy.
Expiration date
5 years.
Storage conditions
Store in the original packaging at a temperature not exceeding 25 °C.
Keep out of reach of children.
Packaging
Tablets No. 50, No. 100 in a container in a box; No. 50 (10x5), No. 100 (10x10) in blisters.
Vacation category
According to the recipe.
Producer
Limited Liability Company "Pharmaceutical Company "Zdorovya".
Location of the manufacturer and its business address
Ukraine, 61013, Kharkiv region, Kharkiv city, Shevchenko street, building 22.
