Thirozol

Leaflet attached to the packaging: information for the user

Thyrozol, 5 mg, coated tablets

Thyrozol, 10 mg, coated tablets

Thyrozol, 20 mg, coated tablets

Thiamazol

You should carefully read the contents of the leaflet before taking the medicine, as it contains important information for the patient.

• You should keep this leaflet, so that you can read it again if you need to.
• In case of any doubts, you should consult a doctor or pharmacist.
• This medicine has been prescribed specifically for you. Do not pass it on to others. The medicine may harm another person, even if their symptoms are the same.
• If the patient experiences any side effects, including any side effects not listed in this leaflet, they should tell their doctor or pharmacist. See section 4.

Table of contents of the leaflet

• 1. What is Thyrozol and what is it used for
• 2. Important information before taking Thyrozol
• 3. How to take Thyrozol
• 4. Possible side effects
• 5. How to store Thyrozol
• 6. Contents of the pack and other information

1. What is Thyrozol and what is it used for

The medicine contains thiamazole. It inhibits the excessive production of thyroid hormones in the thyroid gland, regardless of the cause.
Thyrozol is used to treat excessive production of thyroid hormones:

• when it is necessary to take the medicine to treat the thyroid gland that produces hormones in excess, especially in the case of a small goiter (swelling in the front of the neck) or no goiter,
• when thyroid surgery is planned,
• when treatment with radioactive iodine is planned, especially in cases of very high production of thyroid hormones,
• after treatment with radioactive iodine until the effects of the treatment become apparent. Thyrozol is used to prevent excessive production of thyroid hormones before planned exposure to iodine, for example, before a test using iodine-containing contrast agents:
• when there is a slight increase in thyroid hormone production without accompanying symptoms,
• when there are certain areas in the thyroid gland that produce hormones (autonomous nodules),
• when excessive production of thyroid hormones has occurred in the past.

2. Important information before taking Thyrozol

When not to take Thyrozol

Warnings and precautions

Before starting treatment with Thyrozol, you should discuss it with your doctor or pharmacist.
If you have had mild allergic reactions to thiamazole in the past, such as allergic rashes
or skin itching, you should talk to your doctor, who will decide whether you can take Thyrozol.
In the case of a large goiter (swelling in the front of the neck) that makes breathing difficult,
you should talk to your doctor, as the goiter may increase in size during treatment with Thyrozol.
The doctor may decide to use the medicine for a short period and with regular monitoring
during treatment.
You should immediately consult your doctor if you experience symptoms such as
fever, fatigue, weight loss, and muscle and joint pain. These may be symptoms of vasculitis (vasculitis). In this case, the doctor may stop the treatment if necessary.
These symptoms usually disappear after stopping the treatment.
You should stop taking Thyrozol and immediately consult your doctor if you experience
such symptoms as inflammation of the mucous membrane of the mouth, sore throat, or fever. The cause may be a serious decrease in the number of certain blood cells (agranulocytosis). This can happen especially in the first few weeks of treatment and can lead to serious consequences.
You should immediately consult your doctor if you experience fever or abdominal pain,
as these may be symptoms of pancreatitis (acute pancreatitis). It may be necessary to stop taking Thyrozol.
Thyrozol may harm the unborn child. If you can become pregnant, you should use a reliable method of contraception from the start of treatment and during therapy.
In the case of very high production of excess thyroid hormones, it may be necessary to take very high doses of Thyrozol (over 120 mg per day). In this situation, the doctor will periodically perform blood tests, as bone marrow damage is possible. If this happens, the doctor may decide to stop the treatment and, if necessary, prescribe another medicine.
If the goiter increases in size or the thyroid function is excessively weakened during treatment with Thyrozol, the doctor may modify the dose of Thyrozol. However, such situations can also occur in the natural course of the disease. Similarly, a certain type of eye disease (endocrine orbitopathy) may occur or worsen, which is not related to treatment with Thyrozol.
During treatment with Thyrozol, it is possible to gain weight. This is a normal reaction of the body. Thyrozol affects thyroid hormones, which control energy consumption in the body.

Thyrozol and other medicines

Iodine intake affects the action of Thyrozol. The doctor will determine the dose of Thyrozol, taking into account the iodine intake and thyroid function in individual patients.
In the case of using anticoagulant medicines (preventing blood clotting), you should tell your doctor, as the normalization of thyroid function under the influence of Thyrozol may affect the action of these medicines. The same applies to other medicines.
You should tell your doctor or pharmacist about all medicines you are currently taking or have recently taken, as well as any medicines you plan to take.

Pregnancy and breastfeeding

Thyrozol may harm the unborn child.
If you can become pregnant, you should use a reliable method of contraception from the start of treatment and during therapy.
If you are pregnant, think you may be pregnant, or plan to have a child, you should consult your doctor immediately. It may be necessary to continue treatment with Thyrozol during pregnancy if the potential benefits outweigh the risks to the mother and fetus.
Thyrozol passes into breast milk. The doctor will decide whether it is necessary to take Thyrozol while breastfeeding. If necessary, only a small dose of up to 10 mg of thiamazole can be taken.
The doctor will regularly monitor the thyroid function of the newborn.

Driving and using machines

Thyrozol does not affect the ability to drive and use machines.

Important information about some ingredients of Thyrozol

In case of intolerance to some sugars, you should tell your doctor, as Thyrozol contains lactose.
The medicine contains less than 1 mmol (23 mg) of sodium per tablet, which means the medicine is considered "sodium-free".

3. How to take Thyrozol

This medicine should always be taken as directed by your doctor. In case of doubts, you should consult your doctor.
Recommended dose
The doctor will determine the dose individually, depending on the severity of the disease. The following doses are usually recommended.

• Adults The initial dose is 10 mg to 40 mg of Thyrozol per day (or more in some patients) and is used until the thyroid gland starts to function properly. The maintenance dose is 5 mg to 20 mg of Thyrozol per day in combination with thyroid hormones or 2.5 mg to 10 mg of Thyrozol per day without thyroid hormones.*
• Use in children and adolescents (from 3 to 17 years) The initial dose is 0.5 mg of Thyrozol per kilogram of body weight per day. Then the doctor will decide whether a smaller maintenance dose is sufficient and whether additional use of thyroid hormones is necessary.* Use in children (under 2 years) Thyrozol is not recommended for use in children under 2 years.

If there is a risk of excessive production of thyroid hormones after a diagnostic test using an iodine-containing contrast agent, the doctor may recommend taking 10 mg to 20 mg of Thyrozol per day in combination with perchlorate for about 10 days (until the iodine-containing contrast agent is eliminated from the body).*
*If small doses are needed, 5 mg tablets are available.
Patients with liver disease
In case of liver function disorders or liver disease, you should tell your doctor.
In such cases, it will be necessary to reduce the dose of Thyrozol.
Patients with kidney disease
In case of kidney function disorders or kidney disease, you should tell your doctor. In such cases, it will be necessary to reduce the dose of Thyrozol.
Duration of treatment
The duration of treatment may vary depending on the reason for taking Thyrozol.
The doctor will explain how long you should take the medicine. Usually, the duration of treatment is as follows:

• treatment of excessive production of thyroid hormones (without surgery): from 6 months to 2 years,
• preoperative treatment: 3-4 weeks before surgery,
• treatment before administration of radioactive iodine: until thyroid function is normalized,
• treatment after administration of radioactive iodine: 4-6 months, until the effects of radioactive iodine therapy become apparent.

Administration
Tablets should be taken in the morning, after breakfast, and washed down with a small amount of liquid, e.g., half a glass of water. The tablet can be divided into equal doses.
In case of taking a larger number of tablets per day, they can also be divided into several portions and taken at regular intervals throughout the day.

Taking a higher dose of Thyrozol than recommended

In case of accidental ingestion of a higher dose of the medicine than recommended, there should be no problem. If ingestion of a higher dose occurs frequently, you should contact your doctor as soon as possible.
You may experience intolerance to cold, fatigue, dry skin, constipation, weight gain, slow heart rate, and goiter growth. The doctor may recommend changing the dose of Thyrozol or prescribing additional thyroid hormones to avoid goiter growth.

Missing a dose of Thyrozol

You should not take a double dose to make up for a missed dose. The next day, you should take the same dose as usual.
In case of any further doubts about taking this medicine, you should consult your doctor or pharmacist.

4. Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.
During treatment with Thyrozol, the following side effects may occur, in some cases even after several months of treatment.
Very common(may occur more often than in 1 in 10 people)

• Skin reactions of varying severity (rash, itching, itchy blisters). In most cases, they are mild and disappear during continued treatment with Thyrozol.

Common(may occur in up to 1 in 10 people)

• Joint pain. Uncommon(may occur in up to 1 in 100 people)
• In case of symptoms such as inflammation of the mucous membrane of the mouth, sore throat, or fever, you should immediately consult your doctor. These may be symptoms of a serious decrease in the number of certain blood cells (agranulocytosis). Rare(may occur in up to 1 in 1000 people)
• Taste disorders or loss of taste.
• Fever. Very rare(may occur in up to 1 in 10,000 people)
• Decreased platelet count (thrombocytopenia), decreased count of all blood cells (pancytopenia), lymph node disease (generalized lymphadenopathy).
• Disorders of hormones regulating blood sugar levels, manifested by decreased blood sugar levels (autoimmune insulin syndrome).
• Inflammation or irritation of nerves (neuritis, polyneuropathy).
• Salivary gland swelling.
• Liver function disorders or liver inflammation (cholestatic jaundice, toxic hepatitis). Symptoms usually disappear after stopping treatment.
• Acute allergic skin reactions that can occur all over the body, including blistering skin reactions (Stevens-Johnson syndrome), hair loss, inflammatory autoimmune skin and connective tissue disease (lupus erythematosus).

Frequency not known(frequency cannot be estimated from available data)

• Pancreatitis (acute pancreatitis).
• Vasculitis (vasculitis).

Children and adolescents

Side effects in children and adolescents are similar to those observed in adults.

Reporting side effects

If you experience any side effects, including any side effects not listed in this leaflet, you should tell your doctor or pharmacist. Side effects can be reported directly to the Department of Monitoring of Adverse Reactions to Medicinal Products of the Office for Registration of Medicinal Products, Medical Devices, and Biocidal Products;
Jerozolimskie Avenue 181C
02-222 Warsaw
tel.: +48 22 49 21 301
fax: +48 22 49 21 309
website: https://smz.ezdrowie.gov.pl
Side effects can also be reported to the marketing authorization holder.
Reporting side effects will help to gather more information on the safety of the medicine.

5. How to store Thyrozol

The medicine should be stored out of sight and reach of children.
Do not use this medicine after the expiry date stated on the carton after "EXP". The expiry date refers to the last day of the month.
Do not store above 25°C.
Medicines should not be disposed of via wastewater or household waste. You should ask your pharmacist how to dispose of medicines that are no longer needed. This will help protect the environment.

6. Contents of the pack and other information

What Thyrozol contains

• The active substance of the medicine is thiamazole. Each coated tablet contains 5 mg, 10 mg, or 20 mg of thiamazole.
• The other ingredients are: tablet core: colloidal silica, magnesium stearate, hypromellose, talc, maize starch, lactose monohydrate, sodium carboxymethylcellulose; coating: dimeticone 100, macrogol 400, hypromellose, titanium dioxide (E171), and iron oxide (E172).

What Thyrozol looks like and contents of the pack

Thyrozol 5 mg coated tablets are yellow, biconvex, round with a dividing line on both sides.
Thyrozol 10 mg coated tablets are gray-orange, biconvex, round with a dividing line on both sides.
Thyrozol 20 mg coated tablets are brown, biconvex, round with a dividing line on both sides.
Thyrozol 5 mg and 10 mg coated tablets are available in packs containing 20, 30, 50, or 100 tablets.
Thyrozol 20 mg coated tablets are available in packs containing 20, 30, or 50 tablets.
Not all pack sizes may be marketed.

Marketing authorization holder

Merck Sp. z o.o.
Jerozolimskie Avenue 142B
02-305 Warsaw, Poland
Logo of the marketing authorization holder

Manufacturer

Merck Healthcare KGaA
Frankfurter Strasse 250
64293 Darmstadt, Germany
P&G Health Austria GmbH & Co. OG
Hösslgasse 20
9800 Spittal/Drau, Austria

This medicine is authorized in the Member States of the European Economic Area under the following names:

Bulgaria: Thyrozol
Czech Republic: Thyrozol
Estonia: Thyrozol
France: Thyrozol
Germany: Thyrozol
Latvia: Thyrozol
Lithuania: Thyrozol
Poland: Thyrozol
Romania: Thyrozol
Slovakia: Thyrozol

Date of last revision of the leaflet: April 2023