Metizol

Leaflet attached to the packaging: patient information

Warning! Keep the leaflet! Information on the immediate packaging in a foreign language.

Metizol, 5 mg, tablets

Thiamazolum

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 necessary.
• In case of any doubts, you should consult a doctor or pharmacist.
• This medicine has been prescribed to a specific person. It should not be given to others. The medicine may harm another person, even if the symptoms of their disease 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 Metizol and what is it used for
• 2. Important information before taking Metizol
• 3. How to take Metizol
• 4. Possible side effects
• 5. How to store Metizol
• 6. Package contents and other information

1. What is Metizol and what is it used for

Metizol is a medicine that inhibits the production of thyroid hormones. However, it does not affect the amount of hormones already produced or their release, so the effects of its action appear only after a few days of use.
Thanks to its properties, Metizol is used in hyperthyroidism (regardless of its type), in thyroid crisis, in preparation for thyroidectomy, and as a supportive agent in the treatment with radioactive iodine.

2. Important information before taking Metizol

When not to take Metizol

• if the patient is allergic to thiamazole, substances with a similar structure to thiamazole (thionamide derivatives) or any of the other ingredients of this medicine (listed in section 6);
• if the patient has been diagnosed with a decrease in the number of certain blood cells (granulocytopenia);
• if, before starting treatment with Metizol, the patient has been diagnosed with bile stasis;
• if, in the past, the patient has experienced bone marrow damage after treatment with thiamazole or carbimazole;
• if, in the past, the patient has experienced pancreatitis (acute pancreatitis) after administration of thiamazole or carbimazole.

Thiamazole should not be taken at the same time as thyroid hormones in pregnant women.

Warnings and precautions

Before starting to take Metizol, you should discuss it with your doctor.
If, in the past, there have been mild allergic reactions to thiamazole, such as allergic rashes or skin itching, you should tell your doctor - the doctor will decide whether you can take Metizol.
In the case of a large thyroid goiter that makes breathing difficult, you should talk to your doctor, as the goiter may enlarge during treatment with Metizol. The doctor may decide to use the medicine for a shorter period and regularly monitor you during treatment.
Before starting treatment, the doctor will order blood morphology tests.
You should immediately consult a doctor if you experience symptoms such as oral mucosa inflammation, sore throat, fever. These symptoms may indicate a serious side effect of the medicine - agranulocytosis (a significant decrease in the number of certain types of white blood cells responsible for immune reactions in the body). They usually occur within the first few weeks of treatment, but may appear even after a few months of therapy or during the restart of treatment. If such symptoms occur, the doctor will order a blood morphology test and may decide to stop taking Metizol.
You should immediately consult a doctor if you experience fever or abdominal pain, as these may be symptoms of pancreatitis (acute pancreatitis). It may be necessary to stop taking Metizol.
In the case of the need to use very high doses of Metizol (about 120 mg per day), the doctor will order control blood tests, as bone marrow damage is possible. If the medicine has a toxic effect on the bone marrow, the doctor may decide to interrupt treatment and, if necessary, prescribe another medicine.
If, during treatment with Metizol, the goiter enlarges or thyroid function is excessively weakened, the doctor may modify the dose of Metizol, and if necessary, also prescribe thyroid hormones.
Metizol may harm the unborn child. If the patient may become pregnant, she should use a reliable method of contraception from the start of treatment and during therapy.
During treatment, there may also be an occurrence or exacerbation of a eye disease called endocrine orbitopathy, which is not related to treatment with Metizol.
During treatment with Metizol, it is possible to increase body weight. This is a normal reaction of the body. Metizol affects thyroid hormones, which control energy consumption in the body.

Children and adolescents

The safety and efficacy of Metizol in children under 2 years of age have not been studied.
Metizol can be used in children and adolescents from 3 to 17 years old (see section 3). For additional information, you should consult a doctor.

Metizol and other medicines

You should tell your doctor or pharmacist about all medicines you are currently taking or have recently taken, as well as medicines you plan to take, including those that are available without a prescription.
The effect of thiamazole is reduced by:

• iodine;
• medicines containing iodine (e.g., amiodarone - a medicine used to treat heart rhythm disorders);
• radiological contrast agents. Thiamazole reduces the uptake of radioactive iodine by the thyroid gland. If you are taking anticoagulant medicines (preventing blood clotting), you should tell your doctor, as the normalization of thyroid function under the influence of Metizol may affect the action of these medicines. This may also apply to other medicines. As the thyroid hormone levels in the blood return to normal under the influence of Metizol treatment, the blood levels of some medicines taken at the same time may change. Therefore, it may be necessary to change the dosage of the medicines taken at the same time.

Metizol with food and drink

Metizol can be taken regardless of meals.

Pregnancy, breastfeeding, and fertility

Metizol may harm the unborn child.
If the patient may become pregnant, she should use a reliable method of contraception from the start of treatment and during therapy.
If the patient is pregnant, suspects she may be pregnant, or plans to have a child, she should immediately consult a doctor.
It may be necessary to continue treatment with Metizol during pregnancy if the potential benefits outweigh the risk to the mother and fetus.
During pregnancy, you should not take Metizol and thyroid hormones at the same time.
During breastfeeding, Metizol can be used only in small doses, up to 10 mg per day. However, you should not take thyroid hormones at the same time. The child of a patient treated with Metizol who is breastfeeding should be regularly examined by a doctor who will monitor the child's thyroid function.
Patients who take high doses of Metizol should not breastfeed.

Driving and using machines

Metizol has a minor effect on the ability to drive and use machines.
This medicine may cause dizziness (see section 4). Patients who experience this side effect should not drive vehicles or operate machines until it has completely resolved.

Metizol contains lactose monohydrate

If you have been diagnosed with intolerance to some sugars, you should contact your doctor before taking the medicine.

3. How to take Metizol

This medicine should always be taken according to the doctor's recommendations. In case of doubts, you should consult a doctor or pharmacist.

Recommended dose

The dosage is determined individually by the doctor for each patient, depending on the severity of hyperthyroidism and the size of the goiter.
The initial daily dose is usually 40 mg to 60 mg (8 to 12 tablets) and is given in 3 or 4 divided doses. This dosage is maintained until thyroid function is inhibited (usually 2-3 weeks, although sometimes it is necessary to maintain such a dosage for 8 weeks or even longer). Then, the doses of the medicine should be gradually reduced to a maintenance dose, usually 5 mg to 20 mg (1 to 4 tablets) per day. This dose is given in a single daily dose or in 2 divided doses.
In the treatment of thyroid crisis, the medicine is initially given in a dose of 100 mg (20 tablets), and then every 8 hours in a dose of 30 mg (6 tablets).
Treatment of hyperthyroidism with Metizol usually lasts from 6 months to 2 years.
In preparation for thyroidectomy, the medicine is usually taken for 3-4 weeks before the surgery.
Patients of advanced age:
There is no need to change the dosage.
Use in children and adolescents (from 3 to 17 years old):
In children and adolescents over 3 years of age, the dose is adjusted according to the patient's body weight.
Usually, at the beginning of treatment, 0.5 mg/kg of body weight is used, divided into 2 or 3 equal doses.
Later, the doctor may recommend reducing the dose. The total daily dose should not exceed 40 mg.
It is not recommended to use in children under 2 years of age.
Patients with renal impairment:
There is no need to change the dosage.
Patients with hepatic impairment:
In case of liver dysfunction or liver disease, you should tell your doctor. In such cases, it may be necessary to reduce the dose of Metizol.
Metizol should be taken regularly.

Using a higher dose of Metizol than recommended

In case of taking a higher dose of Metizol than recommended, you should consult a doctor, who will implement appropriate procedures, including inducing vomiting, gastric lavage, and administration of activated charcoal, as well as symptomatic treatment.
In case of overdose, the following may occur: nausea, vomiting, muscle pain, constipation, headache, menstrual disorders in women, decreased body temperature, goiter enlargement or appearance, excessive drowsiness or lethargy, and fatigue, weight gain, excessive dryness of the skin, and insomnia.

Missing a dose of Metizol

In case of missing a dose of Metizol at the scheduled time, you should take it as soon as possible. However, if the time for the next dose is approaching, you should skip the missed dose.
You should not take a double dose to make up for the missed dose.

Stopping treatment with Metizol

In case of premature termination of treatment with Metizol, hyperthyroidism may worsen.
In case of doubts related to the use of the medicine, you should consult a doctor or pharmacist.

4. Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.
Side effects may occur:
Very common (may occur more often than 1 in 10 people)
Common (may occur in no more than 1 in 10 people)
Uncommon (may occur less often than 1 in 100 people)
Rare (may occur in no more than 1 in 1000 people)
Very rare (may occur in no more than 1 in 10,000 people)
Frequency not known (frequency cannot be estimated from the available data)

If you experience one of the following side effects, you should stop taking the medicine and immediately consult a doctor:

• Symptoms such as oral mucosa inflammation, sore throat, fever, which may indicate an uncommon side effect - agranulocytosis (a significant decrease in the number of certain types of white blood cells). These symptoms may occur within the first few weeks of treatment or even after a few months of therapy.

In addition, the following side effects may occur:

Very common side effects:

• Allergic skin reactions of varying severity (itching, rash, urticaria) - usually have a mild course and resolve during continued use of the medicine;

Common side effects:

• Joint pain, which may occur even after several months of therapy with Metizol;

Rare side effects:

• Taste disorders (altered taste perception, loss of taste) - these symptoms may resolve after the end of treatment, although it may take several weeks;
• Fever;

Very rare side effects:

• Thrombocytopenia (decrease in platelet count; may manifest as excessive bleeding, e.g., after procedures, nosebleeds; frequent bruising; presence of blood in stool or urine; pinpoint bleeding on the skin);
• Pancytopenia (decrease in the number of all blood cells);
• Generalized lymphadenopathy (enlargement of lymph nodes), decreased blood glucose levels (caused by disorders of glucose regulation in the blood);
• Nerve inflammation, polyneuropathy (nerve damage, may manifest as numbness and tingling in the hands, feet, and face);
• Salivary gland swelling;
• Cholestatic jaundice (manifesting as yellowing of the skin, mucous membranes, and eye whites) and toxic hepatitis - these symptoms usually resolve after the end of treatment with the medicine;
• Severe forms of allergic skin reactions, including generalized skin inflammation;
• Hair loss;
• Drug-induced lupus erythematosus (an immune-related disease; may manifest as fatigue, loss of appetite, and a characteristic butterfly-shaped rash on the face).

Frequency not known:

• Dizziness;
• Pancreatitis (acute pancreatitis).

Children and adolescents
The type, frequency, and severity of side effects in children 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, Al. Jerozolimskie 181C, 02-222 Warsaw, tel.: +48 22 49 21 301, fax: +48 22 49 21 309;
website: https://smz.ezdrowie.gov.pl.
By reporting side effects, you can help gather more information on the safety of the medicine.

5. How to store Metizol

Store in the original packaging.
The medicine should be stored in a place that is out of sight and reach of children.
Do not use this medicine after the expiry date stated on the packaging. The expiry date refers to the last day of the month.
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. Package contents and other information

What Metizol contains

• The active substance of the medicine is thiamazole.
• The other ingredients of the medicine are: lactose monohydrate, potato starch, povidone, talc, magnesium stearate.

What Metizol looks like and what the package contains

Metizol is a white, round, flat tablet with the inscription "M" on one side and a smooth surface on the other.
The package contains 50 tablets in PVC/Al blisters in a cardboard box.
For more detailed information, you should consult the marketing authorization holder or the parallel importer.

Marketing authorization holder in Bulgaria, the country of export:

Mylan EOOD
Office building "Serdika Offices"
Sitnyakovo Blvd., No.48, fl. 7
1505 Sofia, Bulgaria

Manufacturer:

ICN Polfa Rzeszów S.A.
ul. Przemysłowa 2
35-959 Rzeszów
Poland

Parallel importer:

InPharm Sp. z o.o.
ul. Strumykowa 28/11
03-138 Warsaw

Repackaged by:

InPharm Sp. z o.o. Services sp. k.
ul. Chełmżyńska 249
04-458 Warsaw
Marketing authorization number in Bulgaria, the country of export:9900341

Parallel import authorization number: 188/22 Date of approval of the leaflet: 28.04.2022

[Information about the trademark]