Medicines affecting the functions of the thyroid and parathyroid glands

Content

• 1 Antithyroid drugs 1.1 Thiamazole (Mercazolil)
• 1.2 Iodine
• 1.3 Potassium iodide

Antithyroid drugs[edit | edit code]

In case of hyperfunction of the thyroid gland, substances with thyreostatic action are used. These drugs inhibit various parts of the biosynthesis of thyroid hormones. They are prescribed for the conservative treatment of thyrotoxicosis.

Thiamazole (mercazolyl)[edit | edit code]

Pharmacokinetics

: onset of action after 20-30 minutes, half-life is 6 hours.

Pharmacodynamics

: reduces the synthesis of thyroxine in the thyroid gland; removes iodides from it, reduces the enzymatic activity of enzymes that promote the transition of iodides to iodine; delays the conversion of monoiodotyrosine to diiodotyrosine; inhibits the activity of cytochrome oxidase and peroxidase; The drug contains sulfur, which blocks enzyme systems. Indications for use: various forms of toxic goiter. The drug is prescribed orally after meals 3-4 times a day.

Iodine[edit | edit code]

In small doses, it has an antithyroid effect due to its inhibitory effect on the formation of thyroid-stimulating hormone in the anterior lobe of the pituitary gland, which leads to a decrease in the synthesis of thyroxine; disrupts feedback in the adenohypophysis-thyroid system. It has an expectorant and slight anti-atherosclerotic effect (increases lecithin/blood cholesterol ratio).

Pharmacokinetics

: onset of action - after 12-24 hours.

Indications for use

: hyperthyroidism, but in some cases can also be used for hypothyroidism.

Side effects:

in case of overdose - the phenomenon of iodism.

Potassium iodide[edit | edit code]

Potassium iodide is an antithyroid drug that inhibits the activity of gland enzymes, disrupts the synthesis of triiodothyronine (T3) and tetraiodothyronine (T4), and prevents the accumulation of radioactive iodine in the thyroid gland. After oral administration, the effect develops within 12-24 hours.

Indications for use, contraindications and side effects are similar to those for iodine. Given the irritating effect on the gastrointestinal tract, potassium iodide tablets should be washed down with milk or jelly.

Suppresses thyroid activity

Home Medical Encyclopedia Medicines Hormones, their analogues and antihormonal medicines

PROPYLIOURACIL

Synonyms: Propicil 50.

Pharmachologic effect. It has a pronounced thyreostatic effect (suppresses the functional activity of the thyroid gland). Interferes with the process of iodization of thyroglobulin (a complex consisting of thyroid hormone and protein), reduces the formation of the active form of iodine in the thyroid gland, blocking the peroxidases system (enzymes involved in the iodization of thyroid hormones).

Indications for use. Graves' disease (a disease characterized by diffuse enlargement of the thyroid gland and increased function), Hashimoto's disease (a disease characterized by enlargement of the thyroid gland due to the accumulation of a large number of lymphocytes in its body - lymphocytic goiter) with hyperthyroidism (increased function of the thyroid gland), preoperative preparation and postoperative therapy, preparation for treatment with radioactive iodine.

Method of administration and dose. Doses are set individually depending on the severity of hyperthyroidism. The average single dose is 0.1-0.3 g, the frequency of administration is 3-6 times a day, after meals. The average daily dose for children from 6 to 10 years old is 0.05-0.15 g per day, over 10 years old - 0.15-0.3 g per day. Treatment lasts on average 1-1.5 years.

Treatment with the drug should be carried out under the control of the level of thyroid hormones, the morphological picture of the blood (cellular composition of the blood), the level of transaminae, bilirubin, and alkaline phosphatase.

Side effect. Itching, paresthesia (feeling of numbness in the limbs), alopecia (partial or complete hair loss), anorexia (lack of appetite), nausea, vomiting, rarely - hyperthermia (increased body temperature), periarteritis (inflammation of the outer lining of the artery), very rarely - agranulocytosis (a sharp decrease in the number of granulocytes in the blood), pancytopenia (low content of all formed elements in the blood). Goitrogenic effect (action aimed at increasing the volume of the thyroid gland). Drug-induced hyperthyroidism (increased thyroid function associated with taking a drug).

Contraindications. Absolute: pregnancy, breastfeeding, hypersensitivity to the drug, leukopenia (decrease in the level of leukocytes in the blood), agranulocytosis, active hepatitis (inflammation of the liver tissue), cirrhosis of the liver. Relative: persistent hepatitis (long-term hepatitis /inflammation of liver tissue/), fatty liver (impaired liver function due to the accumulation of fat in its cells), nodular goiter (nodular enlargement of the thyroid gland).

Propylthiouracil should not be prescribed simultaneously with drugs that inhibit leukopoiesis (the process of formation of white blood cells).

Release form. Tablets of 0.05 g in packs of 20 and 100 pieces.

Storage conditions. List B. In a dry place, protected from light.

TIAMAZOL (Thiamazolc)

Synonyms: Antiroid, Bazolan, Danantizol, Favistan, Mercazol, Mercazolil, Methimazole, Methotyrine, Tapazol, Ticapzol, Timidazole, etc.

Pharmachologic effect. Antithyroid drug - inhibits the synthesis of thyroid hormones of the thyroid gland. It blocks the peroxidase enzyme involved in the iodization of thyroid hormones, which disrupts their synthesis (formation in the body).

Indications for use. Thyrotoxicosis (a disease associated with increased levels of thyroid hormones in the body); preparation for surgical treatment of thyrotoxicosis; preparation for treatment of thyrotoxicosis with radioactive iodine; prevention of hyperthyroidism (increased thyroid function) during treatment with iodine preparations.

Method of administration and dose. For thyrotoxicosis, depending on the severity of the disease, 0.02-0.04 g of the drug per day is prescribed for 3-6 weeks. After normalization of thyroid function (usually after 3-8 weeks), they switch to taking maintenance doses of the drug (2.5-10 mg per day). During this period, it is recommended to additionally prescribe thyroid hormones. The duration of use is usually '/2-2 years.

In preparation for surgery for thyrotoxicosis, 0.02-0.04 g of the drug per day is prescribed until the symptoms of hyperfunction (increased function) of the thyroid gland are eliminated. In order to reduce the time required to prepare for surgery, beta-blockers and iodine preparations are additionally prescribed.

Before using radioactive iodine, 0.02-0.04 g of the drug per day is prescribed. After radiation treatment, 0.005-0.02 g of the drug per day is prescribed until the onset of radiation therapy.

The tablets are swallowed whole with a small amount of liquid. The daily dose is prescribed in one dose or divided into 3 equal parts.

During pregnancy, the drug is used with caution, if possible, in a small dose (2.5-10 mg) and not combined with thyroid hormones. During breastfeeding, use the drug with caution, in a small dose (no more than 0.01 g/day). Children - 0.3-0.5 mg/kg body weight, maintenance doses - 0.2-0.3 mg/kg.

During treatment with the drug, it is necessary to regularly monitor the peripheral blood picture. In case of significant enlargement of the thyroid gland, narrowing the lumen of the trachea, the drug is used for a short time (with long-term treatment, growth of the thyroid gland is possible). During treatment with the drug, you should immediately consult a doctor if you suddenly develop a sore throat, difficulty swallowing, fever, signs of stomatitis (inflammation of the oral mucosa) or furunculosis (multiple purulent inflammation of the skin) - possible symptoms of agranulocytosis (a sharp decrease in the number of granulocytes in the blood ).

Side effect. Allergic skin rashes, skin pigmentation disorders (very rare); leukopenia (decrease in the level of leukocytes in the blood), agranulocytosis - rarely; dyspepsia (digestive disorders), liver dysfunction - rarely, cholestatic jaundice (yellowing of the skin and mucous membranes of the eyeballs due to stagnation of bile in the bile ducts) - very rarely. Headaches, neuritis (inflammation of a nerve) and polyneuritis (inflammation of several nerves) - very rare, taste disturbances - rare. Arthralgia (joint pain), fever (sharp increase in body temperature), generalized lymphadenopathy (multiple enlargement of lymph nodes).

Contraindications. History of hypersensitivity to the drug (medical history); granulocytopenia (decrease in the content of granulocytes in the blood) during previous therapy with thiamazole.

Release form. Tablets of 0.005 g in packs of 50 and 100 pieces.

Storage conditions. List B. In a dry place, protected from light.

Antithyroid drugs[edit | edit code]

Source:
Clinical Pharmacology by Goodman and Gilman, Volume 4
.
Editor
: Professor A.G.
Gilman Ed.
: Practice, 2006.

The chemical structure of the antithyroid drugs used today is thioureylene. belonging to the broader group of thionamides. The main drug in this group is propylthiouracil.

Historical background[edit | edit code]

The study of goitrogenic substances began with the observation that in rabbits eating mainly cabbage. Goiter often develops. This was probably due to the fact that cabbage leaves contain thiocyanate precursors (see below). It was later discovered that goiter is caused by two substances - sulfaguanidine and phenylthiourea.

Administration of thiourea derivatives to rats leads to hypothyroidism and, at the same time, to hyperplasia of the thyroid gland, characteristic of an increase in TSH secretion. The synthesis of thyroid hormones stops. If thiourea derivatives are administered simultaneously with thyroid hormones or after removal of the pituitary gland, then no changes occur in the thyroid gland. Based on these observations, it was concluded that goiterogenic substances disrupt the synthesis of thyroid hormones, and goiter formation is a compensatory reaction to hypothyroidism caused by these substances (Astwood, 1945). Such substances were called antithyroid, and they began to be used to treat thyrotoxicosis.

Structural-functional dependence[edit | edit code]

The first goitrogenic substances were obtained in the 1940s. Subsequently, antithyroid properties were discovered in many substances. Modern antithyroid drugs belong to thioureylenes (Fig. 57.8)

Figure 57.8. Thionamid antithyroid drugs.

. In addition, several substances with antithyroid properties have been found among aniline derivatives, most of which are sulfonamides. Polyhydric phenols, including resorcinol (1,3-dihydroxybeneol), can cause goiter if they come into contact with damaged skin. Some other substances also have antithyroid properties (see below). Most antithyroid drugs active in humans are aliphatic and heterocyclic thiourea derivatives. They usually contain a thioureylene group, but in some of them one nitrogen atom is replaced by oxygen or sulfur, so that only the gionamide group is common to all of these agents. Among heterocyclic compounds, sulfur-containing derivatives of imidazole, oxazole, hydantoin, thiazole, thiadiazole, uracil and barbituric acid have antithyroid activity.

Table 57.4. antithyroid drugs and drugs that interfere with the action of thyroid hormones.

Eating turnips and the seeds and green parts of cruciferous vegetables may cause goiter caused by L-5-vinyl-2-thiooxazolidone (goitrin) contained in these plants. Cows also eat these plants, and in areas of Finland where goiter is endemic, goitrin is found in cow's milk. In humans, goitrin has approximately the same activity as propylthiouracil.

Antithyroid properties of many substances have been found in toxicological studies, clinical trials, and in studies of compounds used in industry (De Rosa et al., 1998). Thiopental and sulfonylurea derivatives have a weak antithyroid effect in animal experiments, but this effect is not observed in humans at normal doses. In humans, dimercaprol, aminoglutethimide and lithium have this effect. Polychlorinated biphenyls have structural similarities to thyroid hormones and may act as thyroid hormone receptor stimulants or blockers (De Rosa et al., 1998). There is evidence that polychlorinated biphenyls can alter plasma concentrations of thyroid hormones and TSH, as well as impair the development of the central nervous system (Porterfield and Hendry, 1998; Sher et al., 1998). The iodine-rich anti-arrhythmic drug amiodarone has variable effects on thyroid function (Haijai and Licata, 1997). In areas with sufficient iodine in food and water, amiodarone often causes hypothyroidism due to excess iodine intake, while in areas with iodine deficiency, amiodarone mainly causes thyrotoxicosis, which can be caused by both excess iodine intake and amiodarone-induced thyroiditis. In addition, amiodarone and its metabolite desethylamiodarone are potent inhibitors of iodothyronine deiodination, inhibiting the conversion of T4 to T3. Desethylamiodarone also reduces the binding of T3 to intracellular receptors. Recommendations have recently been issued to identify substances that disrupt thyroid function or alter thyroid hormone activity (DeVito et al., 1999).

Mechanism of action[edit | edit code]

This issue is discussed in a recently published review (Taurog, 2000). Thionamides disrupt the synthesis of thyroid hormones by blocking iodination of tyrosine residues of thyroglobulin; in addition, they prevent the condensation of iodotyrosines to form iodothyronines. Antithyroid drugs are thought to inhibit iodide peroxidase, thereby preventing the oxidation of iodide and iodogyrosine to their respective active forms. These agents bind to iodide peroxidase and inactivate it only when the enzyme's heme is in its oxidized form. Suppression of the synthesis of thyroid hormones leads to the fact that the reserves of iodinated thyroglobulin are gradually depleted as it is broken down and thyroid hormones are released. Only after the supply of iodinated thyroglobulin is depleted, the concentration of thyroid hormones in the blood decreases, and the effect of antithyroid drugs manifests itself clinically.

According to some data, antithyroid drugs such as propylthiouracil inhibit iodotyrosine condensation more strongly than tyrosine iodination (Taurog, 2000). This may be why thyrotoxicosis can often be treated with doses at which iodination of the tyrosine residues of thyroglobulin is only partially suppressed.

When treating toxic goiter with antithyroid drugs, the concentration of thyroid-stimulating antibodies in plasma often decreases. It is possible that these agents have immunosuppressive properties. However, the level of thyroid-stimulating antibodies also decreases under the influence of perchlorate, the mechanism of action of which is completely different (Burman and Baker, 1985). This suggests that treatment of thyrotoxicosis itself helps eliminate immune disorders.

In addition to its effect on the synthesis of thyroid hormones, propylthiouracil suppresses the deiodination of T4 to T3 in peripheral tissues. Thiamazole does not have this property and can even interfere with the effect of propylthiouracil on deiodination. Although the degree of suppression of deiodination has not yet been quantitatively assessed, theoretically this effect gives grounds to consider propylthiouracil as the drug of choice in severe thyrotoxicosis and thyrotoxic crises, when suppression of the conversion of T4 to T3 in the blood is highly desirable.

Pharmacokinetics[edit | edit code]

In the United States, only two antithyroid drugs are used: propylthiouracil (6-and-propyl-thiouracil) and thiamazole (1-methyl-2-mercaptoimidazole).

In Europe, a thiamazole derivative is also used - carbimazole (carbethoxythiamazole), which after absorption is converted into thiamazole. Some pharmacokinetic properties of thiamazole and propylthiouracil are given in table. 57.5.

Table 57.5. Pharmacokinetics of antithyroid drugs

The inclusion of radioactive iodine in thyroglobulin decreases within 20-30 minutes after oral administration of propylthiouracil. Studies with radioactive iodine have also shown that the duration of action of currently used antithyroid drugs is short. The effect of propylthiouracil after taking a dose of 100 mg begins to decrease within 2-3 hours, and after taking a dose of 500 mg, complete suppression of the synthesis of thyroid hormones is observed only within 6-8 hours. A dose of thiamazole, to the same extent suppresses the incorporation of radioactive iodine into thyroglobulin is only 0.5 mg, but in order for the effect to last 24 hours, a single dose of 10-25 mg of the drug is required.

T1/2 of propylthiouracil is approximately 75 minutes, and thiamazole is 4-6 hours. Both drugs (including thiamazole, formed from carbimazole) accumulate in the thyroid gland. Propylthiouracil and thiamazole are excreted mainly by the kidneys, both unchanged and in the form of metabolites.

Both drugs, but to a greater extent thiamazole, penetrate the placenta and into milk. The use of these drugs during pregnancy is discussed below.

Side effects[edit | edit code]

According to available data, propylthiouracil and thiamazole rarely cause side effects. The overall risk of these effects, based on previously published data, is 3% for propylthiouracil and 7% for thiamazole; the most severe reaction, agranulocytosis, develops in 0.44 and 0.12% of cases, respectively (Meyer-Gessner et al., 1994). The risk of agranulocytosis when taking thiamazole depends on the dose, while no such dependence was found for propylthiouracil. Further studies showed that these drugs cause almost the same side effects, and the risk of agranulocytosis does not exceed 1:500. Agranulocytosis is usually observed during the first weeks or months of treatment, but may occur later. Because it sometimes develops rapidly, periodic white blood cell counts are not helpful for early diagnosis. The first signs of agranulocytosis are often a sore throat and fever, so patients should immediately tell their doctor if these symptoms occur. After discontinuation of the drug, agranulocytosis usually resolves on its own, but this process can be accelerated by the administration of recombinant G-CSF preparations (Magneret al., 1994). Mild neutropenia can be both a symptom of thyrotoxicosis and a sign of incipient agranulocytosis. In this situation, it is necessary to carefully monitor the patient and frequently count the number of leukocytes.

The most common side effect is a mild urticarial (occasionally hemorrhagic) rash. It often disappears without stopping treatment, but sometimes it is necessary to prescribe H2-blockers, glucocorticoids or change the antithyroid drug, since cross-sensitivity is rare. Less common side effects are joint pain and stiffness, paresthesia, headache, nausea, skin pigmentation and alopecia. Drug fever and liver and kidney damage are rare, although the activity of liver enzymes often increases when taking propylthiouracil.

Application[edit | edit code]

Antithyroid drugs for thyrotoxicosis are used as follows: 1) as the main method of treatment, in anticipation of spontaneous remission in diffuse toxic goiter, 2) in combination with radioactive 1311, to accelerate recovery in anticipation of the effect of radiation, 3) in preparation for surgery. There is no consensus on the optimal treatment method (Toning et al., 19%), so many factors are taken into account when choosing a particular method (see below).

Propylthiouracil is usually started with a dose of 100 mg 3 times a day or 150 mg 2 times a day. If the dose exceeds 300 mg/day, it is advisable to divide it into 4-6 doses. Thiamazole can be taken once a day, since its T)/2 and duration of action are quite long. The ineffectiveness of propylthiouracil at doses of 300-400 mg/day and thiamazole at doses of 30-40 mg/day is usually associated with non-compliance with the treatment regimen. In addition, a delayed reaction to these drugs is sometimes observed with a very large goiter or with prior use of iodine in any form. Once euthyroidism is achieved, which usually occurs within 12 weeks, the dose of the antithyroid drug is reduced.

Treatment effectiveness[edit | edit code]

The cause of thyrotoxicosis can be diffuse toxic goiter, multinodular toxic goiter or toxic thyroid adenoma. Antithyroid drugs are equally effective in all these cases. Improvement usually occurs 3-6 weeks after the start of treatment. The success of treatment depends on the dose of the drug, the size of the goiter and the level of T3 in the serum before treatment (Benker et al., 1995). The speed of onset of the effect is determined by the reserves of thyroid hormones in the thyroid gland, the rate of release of hormones, their T | n in plasma and the degree of inhibition of their synthesis under the influence of the prescribed dose of antithyroid drugs. With prolonged use of large and sometimes regular doses of antithyroid drugs, hypothyroidism can develop. At the first signs of hypothyroidism, the dose should be reduced; If hypothyroidism has reached such a degree that it makes you feel unwell, you can temporarily prescribe thyroid hormones (for example, levothyroxine in regular doses). After achieving euthyroidism, the dose of antithyroid drugs is reduced to maintenance. According to a study conducted in Japan, simultaneous administration of an antithyroid drug and levothyroxine increases the remission rate in diffuse toxic goiter (Hashizume et al., 1991). However, in more recent studies, combination therapy with levothyroxine and thiamazole did not increase the rate of remission (Mclver, 19%; Rittmaster et al., 1998) or reduce serum levels of thyroid-stimulating antibodies (Rittmaster et al., 1996).

During treatment, estimated free T4 and total T3 should be determined every 2-4 months. Once euthyroidism is achieved, this can be done every 4-6 months.

Elimination of thyrotoxicosis is usually accompanied by a decrease in the size of the goiter. If the goiter increases, then hypothyroidism may have occurred, caused by an overdose of an antithyroid drug. In this case, the doses of these drugs are significantly reduced, and if hypothyroidism is confirmed, then levothyroxine is prescribed.

Remissions[edit | edit code]

Antithyroid drugs are widely used for diffuse toxic goiter to eliminate the manifestations of thyrotoxicosis before remission occurs. The first studies reported that 50% of patients experienced long-term remission after a year of treatment, and even a complete cure was possible. However, in more recent studies, the likelihood of remission after such treatment was significantly lower (Maugendre et al., 1999; Benker et al., 1998). It is assumed that the decrease in the likelihood of remission may be associated with an increase in iodine intake from food.

Unfortunately, it is impossible to predict in advance which patients will achieve long-term remission and which will experience relapses. It is only clear that the long course of the disease, the large size of the goiter and the failure of other treatment methods indicate a low probability of remission. The situation is further complicated by the fact that apparent remission resulting in hypothyroidism may reflect the natural course of the disease.

A sign of a possible remission during treatment is a decrease in the size of the goiter. If the goiter does not decrease and hypothyroidism is excluded, remission most likely has not occurred. Another favorable sign is the absence of all symptoms of thyrotoxicosis against the background of a low maintenance dose of antithyroid drugs. Finally, the onset of remission can be thought of when the level of thyroid-stimulating antibodies decreases, the absorption of radioactive iodine by the thyroid gland decreases with a suppressive test with T3 and normal results of the test with thyrotropin-releasing hormone; however, these studies are not carried out for all patients.

Choice of treatment method[edit | edit code]

For diffuse toxic goiter, treatment with antithyroid drugs, radioactive iodine and sub-total resection of the thyroid gland are equally successful, so there is no consensus among endocrinologists on the preferred method of treatment (Franklyn, 1994; Klein et al., 1994; Toning et al., 19%). Long-term treatment with antithyroid drugs in anticipation of remission is most justified for small goiters and mild thyrotoxicosis. Large goiters and severe thyrotoxicosis usually require treatment or surgery. In the USA, many endocrinologists prefer 131I (Soloman et al., 1990). Some authors consider Graves' ophthalmopathy to be a relative contraindication for T1 treatment, as worsening of ophthalmopathy has been reported with such treatment (Bartalena et al., 1998). However, there is an opinion that the main risk factor for the progression of ophthalmopathy, regardless of the treatment method, is hypothyroidism developing after treatment (Manso et al., 1998). Elderly patients are prescribed antithyroid drugs before treatment 131 to deplete the reserves of thyroid hormones in the thyroid gland, since otherwise radiation thyroiditis can lead to a sharp increase in thyrotoxicosis. Subtotal resection of the thyroid gland is performed in young patients with large goiters, children and pregnant women (usually in the 11th trimester) with allergies to antithyroid drugs, as well as patients who prefer surgical treatment (Zimmerman, 1999; Mestman, 1997). For toxic multinodular goiter, surgical treatment or 1311 is indicated, since there are no remissions in these patients during treatment with antithyroid drugs.

Thyrotoxicosis in pregnant women[edit | edit code]

Thyrotoxicosis occurs in approximately 0.2% of pregnant women and is usually caused by diffuse toxic goiter. The best treatment is antithyroid drugs; 1311 is contraindicated. Previously, preference was given to propylthiouracil because it crosses the placenta less readily than thiamazole. However, according to recent data, both drugs are equally safe during pregnancy (Momotani et al., 1997; Mortimer et al., 1997; Mestman, 1997).

Doses of antithyroid drugs should be minimal; it is enough to maintain the level of estimated free T4 closer to the upper limit of normal or even slightly above it. As pregnancy progresses, thyrotoxicosis may become less severe. In this regard, towards the end of pregnancy, the dose of antithyroid drugs is often significantly reduced until completely discontinued. Low doses of antithyroid drugs and frequent assessment of maternal thyroid function can reduce the risk of fetal hypothyroidism. After childbirth, thyrotoxicosis often recurs or intensifies, so the woman is carefully monitored. It is better for nursing mothers to prescribe propylthiouracil, since it hardly passes into milk and, according to available data, does not affect the function of the baby's thyroid gland. However, it has been shown that administration of thiamazole to nursing mothers at a dose of up to 20 mg/day does not affect thyroid function in children (Azizi, 1996).

Auxiliary means[edit | edit code]

Some drugs that do not have antithyroid properties are used for the symptomatic treatment of thyrotoxicosis. Thus, β-blockers (Chapter 10) help cope with such manifestations of thyrotoxicosis as tachycardia, tremor, widening of the palpebral fissures, palpitations, anxiety and nervous tension. Typically, propranolol is prescribed, 20-40 mg 4 times a day, or atenolol, 50-100 mg 1 time a day. Propranolol and esmolol are administered intravenously if necessary. In addition to its main action, propranolol slightly inhibits the conversion of T4 to T3 in peripheral tissues. For tachycardia and supraventricular tachyarrhythmias, calcium antagonists, for example diltiazem, 60-120 mg 4 times a day can be used (Chapter 35). Once euthyroidism is achieved, these drugs are discontinued.

In severe thyrotoxicosis, to quickly achieve an effect, agents are used that disrupt the conversion of T4 to T3 in peripheral tissues. During preoperative preparation, dexamethasone (0.5-1 mg 2-4 times a day) and iodine-containing radiopaque agents, such as iopanic acid (500-1000 mg once a day) or sodium salt of iopodic acid (500 mg) are prescribed. —1000 mg 1 time per day); These drugs should not be used for a long time. Recently, the sale of sodium iopodic acid was discontinued in the United States. There is evidence of the use of cholestyramine in severe thyrotoxicosis to suppress the enterohepatic circulation of thyroid hormones (Mercardo et al., 1996).

Preoperative preparation[edit | edit code]

To reduce the surgical risk, before subtotal resection of the thyroid gland, they try to achieve euthyroidism. This can almost always be achieved; surgical mortality in such patients when the operation is performed by an experienced surgeon is negligible. Euthyroidism can usually be achieved with the help of antithyroid drugs. To reduce vascularization of the thyroid gland, iodide is prescribed 7-10 days before surgery. This makes the gland less fragile, making the surgeon's task easier. In case of allergy to antithyroid drugs or non-compliance with the treatment regimen, euthyroidism can be achieved by prescribing iopanic acid, dexamethasone and propranolol 5-7 days before surgery. After surgery, all these drugs are discontinued.

Thyrotoxic crisis[edit | edit code]

This is a rare but very dangerous condition, representing a sharp increase in thyrotoxicosis, usually caused by concomitant diseases (Abend and Braverman, 1999). Thyrotoxic crisis occurs with untreated or poorly treated thyrotoxicosis. Precipitating factors may include infection, stress, trauma, surgery on the thyroid gland or other organs, diabetic ketoacidosis, childbirth, heart disease, and, in rare cases, treatment with 1311.

During a thyrotoxic crisis, all manifestations of thyrotoxicosis intensify. The main symptoms are hyperthermia (usually a temperature above 38.5°C) and severe tachycardia that does not correspond to body temperature. Nausea, vomiting, diarrhea, agitation and confusion are common. In 20% of cases, thyrotoxic crisis ends in coma and death. The function of the thyroid gland during thyrotoxic crisis is changed in the same way as in uncomplicated thyrotoxicosis, therefore thyrotoxic crisis is primarily a clinical diagnosis.

Supportive measures include infusion therapy, antipyretic and sedatives, and cold wraps. Large doses of antithyroid drugs are prescribed. Preference is given to propylthiouracil, since it not only disrupts the synthesis of thyroid hormones in the thyroid gland, but also blocks the conversion of T4 to T3 in peripheral tissues. The initial dose of propylthiouracil is 200-400 mg every 4 hours. If necessary, propylthiouracil or thiamazole can be administered through a nasogastric tube or rectally; There are no forms for parenteral administration in the United States.

Iodides are prescribed intravenously or orally after the first dose of antithyroid drugs. Iodine-containing radiocontrast agents, due to the release of iodide, disrupt the release of thyroid hormones and suppress the conversion of T4 to T3. To combat tachyarrhythmias, β-blockers (propranolol or esmolol) and calcium antagonists are used. Dexamethasone, 0.5-1 mg IV every 6 hours, is used to prevent relative adrenal insufficiency; in addition, it disrupts the conversion of T4 to T3. Finally, the factor that provoked the thyrotoxic crisis should be eliminated.

Medicines affecting the functions of the thyroid and parathyroid glands

Home Medical Encyclopedia Medicines Hormones, their analogues and antihormonal medicines

MEDICINES USED FOR THYROID DISEASES

See also potassium iodide. Thyroid hormone medications

LEVOTHYROXINE SODIUM (Levothyroxinesodium)

Synonyms: L-Thyroxine 25/50/100 Berlin Hemi, L-Thyroxine Henning, Euthyrox, Eferox.

Pharmachologic effect. Synthetic levorotatory isomer of thyroxine (thyroid hormone). In small doses it has an anabolic (increasing protein synthesis) effect. In medium doses, it stimulates growth and development, increases the need for oxygen in tissues, stimulates the metabolism (metabolism in the body) of proteins, fats and carbohydrates, and increases the functional activity of the cardiovascular and central nervous systems. In large doses, it inhibits the production of thyrotropin releasing hormone of the hypothalamus and thyroid-stimulating hormone of the pituitary gland (hormones produced by the endocrine glands located in the brain). The drug is slowly absorbed, the therapeutic effect is observed after 7-12 days, and is also slowly excreted.

Indications for use. Primary and secondary hypothyroidism (decreased thyroid function), complex treatment of Graves' disease (a disease characterized by diffuse enlargement of the thyroid gland and increased function), euthyroid hyperplasia (pathological enlargement) of the thyroid gland, prevention of relapses (re-development) after surgical treatment of nodular and malignant thyroid tumors, cretinism (congenital deficiency of thyroid function, characterized by a sharp decrease in mental and physical development). A dose of 1 mg is used to conduct a differential diagnostic test for thyroid suppression (suppression of thyroid function).

Method of administration and dose. Doses are selected individually depending on the indications. Treatment begins with small doses - 12.5-25 mcg per day. The average daily dose is 25-200 mcg. Frequency of administration: 1 time per day, 20-30 minutes before meals. Maintenance dose - 25-200 mcg per day. For congenital hypothyroidism, children under 6 months are prescribed 25-50 mcg, up to 12 months - up to 60 mcg, 1-5 years - up to 100 mcg, 6-12 years - 1 up to 150 mcg, over 12 years - up to 150 mcg,

up to 200 mcg per day. During treatment with the drug, constant medical supervision is required. Levothyroxine sodium enhances the effect of antidepressants and anticoagulants.

Side effect. In case of overdose, signs of hyperthyroidism (increased thyroid function), worsening of coronary heart disease, diabetes mellitus, Addison's disease (insufficient adrenal function), rarely - cardiac arrhythmias, diarrhea, vomiting, insomnia. In the first 2-3 days after taking the diagnostic dose (3 mg), sweating, palpitations, and weakness are possible.

Contraindications. Absolute contraindications for the use of the drug for a differential diagnostic test are acute myocardial infarction, acute myocarditis (inflammation of the heart muscles), untreated Addison's disease, severe cardiac arrhythmias, severe hyperthyroidism (a disease characterized by increased thyroid function). There are no absolute contraindications for carrying out replacement therapy (introducing into the body a substance (thyroxine), the natural formation of which is reduced or stopped). Relative contraindications are severe forms of coronary heart disease, general atherosclerosis, severe arterial hypertension (increased blood pressure), circulatory failure.

Release form. Tablets containing 25, 50, 75, 100, 125, 150, 175, 200 mcg of sodium levothyroxine.

Storage conditions. List B. In a dry place, protected from light.

Jodthyrox

Pharmachologic effect. A combined preparation containing levothyroxine and an inorganic iodine preparation. Iodotirox is intended for the treatment and prevention of euthyroid goiter (pathological enlargement of the thyroid gland) in conditions of iodine deficiency. With a lack of iodine, the synthesis of thyroxine by the thyroid gland decreases, which increases the content of thyroid-stimulating hormone of the pituitary gland in the blood, which regulates the function of the thyroid gland) with the subsequent development of hyperplasia (tissue growth) of the thyroid gland. Isolated intake of iodine preparations blocks the secretion (release) of thyroid-stimulating hormone, which can lead to inhibition of thyroxine synthesis. The addition of levothyroxine compensates for the deficiency of thyroxine and also suppresses excess synthesis of thyroid-stimulating hormone. In addition, the combined use of levothyroxine and iodine preparations for the treatment and prevention of relapse (reappearance) of endemic goiter (disease of the thyroid gland, accompanied by its enlargement due to low iodine content in water) can reduce the undesirable effects of long-term use of iodides that occur in some cases (in particular , inhibition of the synthesis of thyroid hormones /thyroid hormones/, changes in the sensitivity of the thyroid gland to thyroid-stimulating hormone).

Indications for use. Treatment and prevention of endemic goiter, diffuse non-toxic goiter (increase in the volume of the thyroid gland); prevention of goiter recurrence after its surgical removal (with iodine deficiency in the environment).

Method of administration and dose. The drug is taken on an empty stomach, usually 30 minutes before breakfast, and washed down with a small amount of liquid. Usually the initial dose of the drug is 1/2 tablet per day. After 2-4 weeks, the dose, if necessary, depending on the condition of the patients, as well as taking into account body weight, is increased to 1 tablet per day. During pregnancy, 1-1!/2 tablets of the drug per day are prescribed.

Side effect. Associated with potassium iodide - hypersensitivity reactions: skin reactions, eosinophilia (increased levels of eosinophils in the blood), in very rare cases - shock; rapid heartbeat, trembling, increased nervousness, insomnia, increased sweating, diarrhea (in patients over 40 years of age). Related to levothyroxine - see levothyroxine.

The development of chest pain or other symptoms indicating worsening cardiovascular disease should be a reason to reduce the dose of the drug. The use of the drug (due to the presence of levothyroxine in its composition) in patients with diabetes mellitus or adrenal insufficiency can lead to an increase in the severity of these diseases. During this period of time, careful selection of drugs for the treatment of these diseases is required.

Contraindications. Hypersensitivity to iodine, clinically pronounced hyperthyroidism (a disease characterized by increased function of the thyroid gland), adenomatous goiter (nodular enlargement of the thyroid gland), tumors of the thyroid gland. The drug is prescribed with caution to patients suffering from cardiovascular diseases, including arterial hypertension (high blood pressure), angina pectoris, myocardial infarction, heart rhythm disturbances, myocarditis (inflammation of the heart muscle), as well as nursing mothers. During pregnancy, the use of the drug in combination with thyreostatic (suppressing thyroid function) drugs is contraindicated.

Release form. Tablets containing 100 mcg of levothyroxine sodium and 130.8 mcg of potassium iodide, in packs of 50 and 100 pieces.

Storage conditions. List B. In a cool, dry place.

NOVOTHYRAL

Pharmachologic effect. Replenishment of thyroid hormone deficiency.

Indications for use. Treatment and prevention of relapse (reappearance) of euthyroid goiter (pathological enlargement of the thyroid gland); hypothyroidism (low thyroid function); thyroidectomy (condition after surgical removal of the thyroid gland).

Method of administration and dose. For hypothyroidism, adults are usually prescribed 1/3 tablet containing 100 mcg of levothyroxine or 1/2 tablet containing 75 mcg of levothyroxine. The dose is increased every 2-4 weeks. until the effect is achieved. Maintenance dose - 1-2 tablets. (100 mg of levothyroxine). In children with congenital hypothyroidism, tablets containing 75 mcg of levothyroxine are used (daily dose: at the age of 3-6 months - 1/3 tablet, 6-12 months - 2-2/3 tablet, 1-3 years 2/3 tab., 3-7.5 years - 1 tab., 7.5-12 years - 1-1'/3 tab.). After thyroidectomy - 1-2 tablets. 100 mcg of levothyroxine or 2-3 tablets. 75 mcg of levothyroxine. The daily dose is taken once in the morning 30 minutes before meals, without chewing and washed down with water. For euthyroid goiter in adults '/2 tab. (100 mcg of levothyroxine), adolescents - '/2-1 tablet. (7.5 mcg of levothyroxine), children Uz-2/z tab. (75 mcg of levothyroxine).

Side effect. Hyperfunction of the thyroid gland: palpitations, irregular heart rhythm, tremors (trembling limbs), internal restlessness, insomnia, excessive sweating, weight loss, diarrhea (diarrhea).

Contraindications. Hyperfunction of the thyroid gland.

Release form. Tablets in packs of 50 and 100 pieces. One tablet contains: levothyroxine sodium - 100 or 75 mcg; liothyronine sodium - 20 or 15 mcg, respectively.

Storage conditions. List B In a place protected from light.

THYREOIDIN (Thyreoidlnum)

Synonyms: Tyrant, Thyroid, Tirotan.

A hormonal preparation obtained by grinding the defatted and dried thyroid glands of slaughter cattle,

Pharmachologic effect. In small doses it gives an anabolic effect (increases protein synthesis), in large doses it leads to increased protein breakdown, inhibits the thioreotropic activity of the pituitary gland (regulation of thyroid function by pituitary hormones) and reduces thyroid function.

The action of thyroidin is associated with the presence of two hormones in it: thyroxine and triiodothyronine. Both hormones have a similar multifaceted effect on the body, increase the need of tissues for oxygen, enhance energy processes, stimulate growth and differentiation of tissues, affect the functional state of the nervous and cardiovascular systems, liver, kidneys and other organs and systems, enhance the absorption of glucose and its utilization (assimilation). The effect of thyroid hormones may vary depending on the dose. Thus, small doses of thyroxine have an anabolic effect, while large doses lead to increased protein breakdown. In large doses, thyroid hormones inhibit the thyroid-stimulating activity of the pituitary gland.

Indications for use. Primary hypothyroidism (decreased thyroid function) and myxedema (severe depression of thyroid function, accompanied by edema); cretinism (congenital deficiency of thyroid function, characterized by a sharp decrease in mental and physical development); cerebral-pituitary diseases (a combined disease of the brain tissue and pituitary gland, usually characterized by a decrease in the release of hormones by the pituitary gland) and obesity, occurring with hypothyroidism (decreased thyroid function); endemic goiter (disease of the thyroid gland, accompanied by its enlargement, due to low iodine content in water) and sporadic goiter (enlargement of the thyroid gland, usually without significant impairment of its function, developing in individuals outside endemic goiter areas / areas with low iodine content in water/); thyroid cancer.

Method of administration and dose. Thyroidin is prescribed orally. Doses should be carefully individualized taking into account the age of the patient, the nature and course of the disease. Take orally in the first half after meals.

Adults with myxedema and hypothyroidism are initially prescribed 0.05-0.2 g per day, then the dose is adjusted to achieve normalization of pulse, basal metabolism, and blood cholesterol. For diffuse euthyroid sporadic and endemic goiter, the dose is from 0.1 to 0.2 g per day, then during treatment, as the size of the gland decreases, the daily dose is reduced to 0.05-0.1.

Patients with thyroid cancer (after surgical removal of the tumor and radiation therapy) are prescribed 0.2-0.3 g of thyroidin per day (for distant metastases /spread of the tumor to other organs and tissues due to the transfer of tumor cells from the primary site with blood and lymph/ - up to 1 g or more per day). For toxic goiter (a disease characterized by an enlargement of the thyroid gland and an increase in its function, manifested by exophthalmos / forward displacement of the eyeball with widening of the palpebral fissure - “bulging eyes” /, rapid heartbeat, weight loss) take from 0.05 g every other day to 0.15- 0.2 g per day (together with antithyroid drugs).

Higher doses for adults orally: single - 0.3 g, daily - 1 g; for children under 6 months of age: one-time - 0.01 g, daily - 0.03 g; from 6 months up to 1 year: one-time -

0.02 g, daily - 0.06 g; at the age of 2 years: one-time - 0.03 g, daily - 0.09 g; 3-4 years: one-time - 0.05 g, daily -0.15 g; 5-6 years: one-time -0.075 g, daily - 0.25 g; 7-9 years: one-time - 0.1 g, daily - 0.3 g; 10-14 years: one-time - 0.15 g, daily - 0.45 g.

Children under 1 year of age are prescribed in the form of granules (mixed with 2-3 tablespoons of water or jelly).

For myxedema and hypothyroidism, children are prescribed doses close to the highest, specifying them depending on the clinical course of the disease and the effectiveness of therapy.

Typically, the effect of thyroidin is observed after 2-3 days of treatment, the final effect is observed after 3-4 weeks.

Side effect. In case of an overdose, thyrotoxicosis (a disease associated with an increased content of thyroid hormones in the body), angina pectoris, worsening of diabetes mellitus, and allergic reactions are possible.

Contraindications. Thyrotoxicosis (thyroid disease), diabetes mellitus, Addison's disease (insufficient adrenal function), general exhaustion, severe forms of coronary insufficiency (discrepancies between the heart's need for oxygen and its delivery).

Release form. Powder; film-coated tablets, 0.05 g and 0.1 g each, in a package of 50 pieces.

Storage conditions. List B. In a dry, cool place, protected from light.

TRIIODOTHYRONINE HYDROCHLORIDE (Triiodthyroninihydrochloridum)

Synonyms: Liothyronine, Trionine, Tibon, etc.

A synthetic drug corresponding to natural thyroid hormone.

The pharmacological action and indications for use are the same as for thyroidin. However, triiodothyronine is absorbed faster and more completely than thyroidin and has a more rapid effect; Since in hypothyroidism (decreased thyroid function) absorption processes are usually impaired, the use of triiodothyronine is especially advisable in the first stage of treatment. The initial manifestations of the drug's action in hypothyroidism are observed after 4-8 hours. It is often effective in cases of resistance (resistance) to thyroidin and does not cause allergic reactions. Triiodothyronine is especially indicated for myxedema coma (the most severe form of hypothyroidism).

Method of administration and dose. Prescribed orally 1-3 times a day. Doses are set individually, taking into account the age of the patient, the nature and course of the disease. The drug can be used in conjunction with thyroidin. When replacing thyroidine with triiodothyronine, it is assumed that 20-40 mcg (0.02-0.04 mg) of triiodothyronine corresponds to 0.1 g of thyroidine.

Adults are prescribed starting from 5-25 mcg per day. If necessary, the dose is gradually increased to 40-60 mcg, sometimes up to 100 mcg (0.1 mg) per day (in a hospital setting - up to 150 mcg per day).

For the treatment of myxedematous coma that occurs without coronary disorders (impaired blood flow through the vessels of the heart), 100 mcg is prescribed 2 times a day, then the dose is reduced.

With euthyroid endemic goiter (a disease of the thyroid gland, accompanied by its enlargement, due to a low iodine content in water, without a pronounced impairment of its function) or sporadic goiter (an enlargement of the thyroid gland, usually without a pronounced impairment of its function, developing in individuals outside of endemic goiter areas /areas with low iodine content in water/), as well as lymphomatous thyroiditis (inflammation of the thyroid gland caused by impaired immune processes in the body,

manifested by an enlargement of the thyroid gland and a decrease in its function - Hashimoto's goiter), it is advisable to add triiodothyronine to the intake of thyroidine in a dose of 10-20 mcg. For diffuse toxic goiter (a disease characterized by a diffuse enlargement of the thyroid gland and an increase in its function, manifested by exophthalmos / forward displacement of the eyeball with widening of the palpebral fissure - “bulging eyes” /, rapid heartbeat, weight loss), triiodothyronine is used after the onset of stable remission (temporary weakening or disappearance manifestations of the disease) in doses not exceeding 20 mcg, in combination with antithyroid drugs. For children with hypothyroidism (decreased thyroid function) and myxedema (severe depression of thyroid function, accompanied by edema), it is advisable to add 5-10 mcg of triiodothyronine during treatment with thyroidin.

Side effect. The same as when used with thyroidin.

Contraindications. The same as when using thyroidin. In addition, caution is required in case of coronary cardiosclerosis (replacement of the heart muscle with connective tissue due to impaired blood flow through its arteries) and secondary hypothyroidism in the presence of adrenal insufficiency (to avoid exacerbation, doses should not exceed 10-20 mcg per day).

Release form. Tablets of 20 mcg and 50 mcg in a package of 50 pieces.

Storage conditions. List B. In a cool, dark place.

Thyreocomb

Pharmachologic effect. A combined preparation of thyroid hormones and potassium iodide.

Indications for use. Hypothyroidism (decreased thyroid function), thyroiditis (inflammation of the thyroid gland), endocrine exophthalmos (confusion

eyeball forward, accompanied by widening of the palpebral fissure (“bulging eyes”/ associated with metabolic disorders), prevention of recurrent goiter (prevention of re-development of goiter).

Method of administration and dose. Adults with hypothyroidism: 1 tablet 1 time a day, gradually increasing the dose to 2 tablets 3 times a day; for thyroiditis and for the prevention of recurrent goiter after surgery on the thyroid gland, 1 tablet daily.

Side effect. Anxiety, insomnia, weight loss, increased heart rate, increased blood pressure.

Contraindications. The same as when using thyroidin.

Release form. Tablets in a package of 40 pieces. One tablet contains triiodothyronine 0.01 mg, thyroxine 0.07 mg, potassium iodide 0.15 mg.

Storage conditions. In a place protected from light.

THYREOTOM

Pharmachologic effect. Combined preparation of thyroid hormones.

Indications for use. Hypothyroidism (decreased thyroid function), euthyroid goiter (pathological enlargement of the thyroid gland, not accompanied by disturbances in its function), prevention and treatment of relapse (re-development) after resection (removal) of goiter.

Method of administration and dose. Doses must be individualized depending on the age of the patient, the nature and course of the disease; adults are usually prescribed 1-3 tablets per day.

Side effects and contraindications are the same as for thyroidin.

Release form. Tablets of 0.05 mg in a package of 60 pieces. One tablet contains triiodothyronine 0.01 mg, thyroxine 0.04 mg.

Storage conditions. List B. In a place protected from light.

Antithyroid drugs

PROPILTHIOURACILL (Propilthiouracil)

Synonyms: Propicil 50.

Pharmachologic effect. It has a pronounced thyreostatic effect (suppresses the functional activity of the thyroid gland). Interferes with the process of iodization of thyroglobulin (a complex consisting of thyroid hormone and protein), reduces the formation of the active form of iodine in the thyroid gland, blocking the peroxidases system (enzymes involved in the iodization of thyroid hormones).

Indications for use. Graves' disease (a disease characterized by diffuse enlargement of the thyroid gland and increased function), Hashimoto's disease (a disease characterized by enlargement of the thyroid gland due to the accumulation of a large number of lymphocytes in its body - lymphocytic goiter) with hyperthyroidism (increased function of the thyroid gland), preoperative preparation and postoperative therapy, preparation for treatment with radioactive iodine.

Method of administration and dose. Doses are set individually depending on the severity of hyperthyroidism. The average single dose is 0.1-0.3 g, the frequency of administration is 3-6 times a day, after meals. The average daily dose for children from 6 to 10 years old is 0.05-0.15 g per day, over 10 years old - 0.15-0.3 g per day. Treatment lasts on average 1-1.5 years.

Treatment with the drug should be carried out under the control of the level of thyroid hormones, the morphological picture of the blood (cellular composition of the blood), the level of transaminae, bilirubin, and alkaline phosphatase.

Side effect. Itching, paresthesia (feeling of numbness in the limbs), alopecia (partial or complete hair loss), anorexia (lack of appetite), nausea, vomiting, rarely - hyperthermia (increased body temperature), periarteritis (inflammation of the outer lining of the artery), very rarely - agranulocytosis (a sharp decrease in the number of granulocytes in the blood), pancytopenia (low content of all formed elements in the blood). Goitrogenic effect (action aimed at increasing the volume of the thyroid gland). Drug-induced hyperthyroidism (increased thyroid function associated with taking a drug).

Contraindications. Absolute: pregnancy, breastfeeding, hypersensitivity to the drug, leukopenia (decrease in the level of leukocytes in the blood), agranulocytosis, active hepatitis (inflammation of the liver tissue), cirrhosis of the liver. Relative: persistent hepatitis (long-term hepatitis /inflammation of liver tissue/), fatty liver (impaired liver function due to the accumulation of fat in its cells), nodular goiter (nodular enlargement of the thyroid gland).

Propylthiouracil should not be prescribed simultaneously with drugs that inhibit leukopoiesis (the process of formation of white blood cells).

Release form. Tablets of 0.05 g in packs of 20 and 100 pieces.

Storage conditions. List B. In a dry place, protected from light.

TIAMAZOL (Thiamazolc)

Synonyms: Antiroid, Bazolan, Danantizol, Favistan, Mercazol, Mercazolil, Methimazole, Methotyrine, Tapazol, Ticapzol, Timidazole, etc.

Pharmachologic effect. Antithyroid drug - inhibits the synthesis of thyroid hormones of the thyroid gland. It blocks the peroxidase enzyme involved in the iodization of thyroid hormones, which disrupts their synthesis (formation in the body).

Indications for use. Thyrotoxicosis (a disease associated with increased levels of thyroid hormones in the body); preparation for surgical treatment of thyrotoxicosis; preparation for treatment of thyrotoxicosis with radioactive iodine; prevention of hyperthyroidism (increased thyroid function) during treatment with iodine preparations.

Method of administration and dose. For thyrotoxicosis, depending on the severity of the disease, 0.02-0.04 g of the drug per day is prescribed for 3-6 weeks. After normalization of thyroid function (usually after 3-8 weeks), they switch to taking maintenance doses of the drug (2.5-10 mg per day). During this period, it is recommended to additionally prescribe thyroid hormones. The duration of use is usually '/2-2 years.

In preparation for surgery for thyrotoxicosis, 0.02-0.04 g of the drug per day is prescribed until the symptoms of hyperfunction (increased function) of the thyroid gland are eliminated. In order to reduce the time required to prepare for surgery, beta-blockers and iodine preparations are additionally prescribed.

Before using radioactive iodine, 0.02-0.04 g of the drug per day is prescribed. After radiation treatment, 0.005-0.02 g of the drug per day is prescribed until the onset of radiation therapy.

The tablets are swallowed whole with a small amount of liquid. The daily dose is prescribed in one dose or divided into 3 equal parts.

During pregnancy, the drug is used with caution, if possible, in a small dose (2.5-10 mg) and not combined with thyroid hormones. During breastfeeding, use the drug with caution, in a small dose (no more than 0.01 g/day). Children - 0.3-0.5 mg/kg body weight, maintenance doses - 0.2-0.3 mg/kg.

During treatment with the drug, it is necessary to regularly monitor the peripheral blood picture. In case of significant enlargement of the thyroid gland, narrowing the lumen of the trachea, the drug is used for a short time (with long-term treatment, growth of the thyroid gland is possible). During treatment with the drug, you should immediately consult a doctor if you suddenly develop a sore throat, difficulty swallowing, fever, signs of stomatitis (inflammation of the oral mucosa) or furunculosis (multiple purulent inflammation of the skin) - possible symptoms of agranulocytosis (a sharp decrease in the number of granulocytes in the blood ).

Side effect. Allergic skin rashes, skin pigmentation disorders (very rare); leukopenia (decrease in the level of leukocytes in the blood), agranulocytosis - rarely; dyspepsia (digestive disorders), liver dysfunction - rarely, cholestatic jaundice (yellowing of the skin and mucous membranes of the eyeballs due to stagnation of bile in the bile ducts) - very rarely. Headaches, neuritis (inflammation of a nerve) and polyneuritis (inflammation of several nerves) - very rare, taste disturbances - rare. Arthralgia (joint pain), fever (sharp increase in body temperature), generalized lymphadenopathy (multiple enlargement of lymph nodes).

Contraindications. History of hypersensitivity to the drug (medical history); granulocytopenia (decrease in the content of granulocytes in the blood) during previous therapy with thiamazole.

Release form. Tablets of 0.005 g in packs of 50 and 100 pieces.

Storage conditions. List B. In a dry place, protected from light.