PACKAGE LEAFLET: INFORMATION FOR THE PATIENT

Warning! Keep this leaflet. The information on the immediate packaging is in a foreign language!
Metizol
5 mg, tablets
Thiamazolum
Please read this leaflet carefully before taking this medicine, as it contains important information for you.

Keep this leaflet so that you can read it again if necessary.
If you have any questions, please consult your doctor or pharmacist.
This medicine has been prescribed for a specific individual. Do not give it to others. This medicine may harm someone else, even if their symptoms are the same.
If you experience any adverse effects, including any not listed in this leaflet, inform your doctor or pharmacist. See section 4.

Contents of the leaflet:

What Metizol is and what it is used for
Important information before taking Metizol
How to take Metizol
Possible side effects
How to store Metizol
Contents of the pack and other information

1. What Metizol is and what it is 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; therefore, its effects become apparent only after several days of treatment.
Due to these properties, Metizol is used in hyperthyroidism (regardless of type), in thyroid storm, in preparation for thyroidectomy, and as an adjunctive treatment during radioactive iodine therapy.

2. Important information before using Metizol

When not to use Metizol

if the patient is allergic to thiamazole, substances structurally related to thiamazole (thionamide derivatives), or any of the other ingredients of this medicine (listed in section 6);
if the patient has a reduced number of certain blood cells (granulocytopenia);
if the patient has cholestatic jaundice before starting treatment with Metizol;
if the patient previously experienced bone marrow damage during treatment with thiamazole or carbimazole;
if the patient previously developed pancreatitis (acute pancreatitis) after administration of thiamazole or carbimazole.

Concomitant use of thiamazole and thyroid hormones should not be used in pregnant women.
Warnings and precautions
Before starting to take Metizol, discuss this with your doctor.
If the patient previously experienced mild allergic reactions to thiamazole, such as skin rashes or
itching, inform the doctor – the doctor will decide whether the patient can take Metizol.
In case of a large goitre causing breathing difficulties, discuss this with the doctor, as the goitre may
enlarge during treatment with Metizol. The doctor may decide to use the medicine for a shorter period
and monitor the patient regularly during treatment.
Before starting treatment, the doctor will order blood morphology tests.
Immediately consult a doctor if symptoms such as oral mucosal inflammation, sore throat, or fever
occur. These symptoms may indicate a serious adverse effect of the medicine – agranulocytosis (a
marked deficiency of certain types of white blood cells responsible for immune responses in the
body). These symptoms usually occur within the first weeks of treatment, but may appear even after
several months of therapy or when restarting treatment. If such symptoms occur, the doctor will order
a blood morphology test and may decide to discontinue treatment with Metizol.
Immediately consult a doctor if the patient develops fever or abdominal pain, as these may be
symptoms of pancreatitis (acute pancreatitis). Discontinuation of Metizol may be necessary.
If high doses of Metizol (approximately 120 mg per day) are required, the doctor will order regular
blood tests, as bone marrow damage may occur. If toxic effects on the bone marrow occur, the doctor
may decide to discontinue treatment and, if necessary, prescribe another medicine.
If the goitre enlarges during treatment with Metizol or if thyroid function becomes excessively
reduced, the doctor may adjust the dose of Metizol and, if necessary, additionally prescribe thyroid
hormones.
Metizol may harm the unborn child. If the patient could become pregnant, she should use a reliable
contraceptive method from the start of treatment and during therapy.
During treatment, the occurrence or worsening of an eye disease called endocrine orbitopathy may
occur, which is unrelated to treatment with Metizol.
During treatment with Metizol, weight gain may occur. This is a normal body reaction. Metizol affects
thyroid hormones, which regulate energy consumption in the body.
Children and adolescents
The safety and efficacy of Metizol have not been studied in children under 2 years of age.
Metizol can be used in children and adolescents aged 3 to 17 years (see section 3). For additional
information, consult a doctor.
Metizol with other medicines
Inform your doctor or pharmacist about all medicines currently taken or recently taken, as well as
any medicines planned for use, including those available without a prescription.
The effect of thiamazole is reduced by:

iodine;
medicines containing iodine (e.g. amiodarone – a medicine used to treat cardiac arrhythmias);
radiographic contrast agents. Thiamazole reduces the uptake of radioactive iodine by the thyroid gland. If anticoagulant medicines (preventing blood clotting) are used, inform the doctor, as normalization of thyroid function due to Metizol may affect the action of these medicines. This may also apply to other medicines. As thyroid hormone levels return to normal due to treatment with Metizol, blood concentrations of certain concomitantly administered medicines may change. Therefore, dosage adjustment of concomitantly used medicines may be necessary.

Metizol with food and drink
Metizol can be taken independently of meals.
Pregnancy, breastfeeding, and fertility
Metizol may harm the unborn child.
If the patient could become pregnant, she should use a reliable contraceptive method 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.
Continuation of treatment with Metizol during pregnancy may be necessary if potential benefits
outweigh the risks to the mother and fetus.
During pregnancy, concomitant use of Metizol and thyroid hormones is not allowed.
During breastfeeding, Metizol may be used only in low doses, up to 10 mg per day. However, thyroid
hormones must not be taken concomitantly. The child of a patient treated with Metizol who is
breastfeeding should be regularly examined by a doctor monitoring thyroid function in the child.
Patients receiving high doses of Metizol must not breastfeed.
Driving and operating machinery
Metizol has a minor influence on the ability to drive and operate machinery.
This medicine may cause dizziness (see section 4). Patients experiencing this adverse effect should
not drive or operate machinery until the effect has completely subsided.
Metizol contains monohydrate lactose
If the patient has previously been diagnosed with intolerance to certain sugars, the patient should
consult a doctor before taking the medicine.

3. How to use Metizol

This medicine should always be taken as directed by the physician. In case of doubt, consult a doctor or pharmacist.
Recommended dose
The physician determines the dose individually for each patient, depending on the severity of hyperthyroidism and the size of the goitre.
The initial daily dose is usually 40 mg to 60 mg (8 to 12 tablets), administered in 3 or 4 divided doses. This dosage is maintained until thyroid function is suppressed (usually 2–3 weeks, although sometimes this dosage must be continued for up to 8 weeks or longer). Subsequently, the dose should be gradually reduced to a maintenance dose, usually 5 mg to 20 mg (1 to 4 tablets) per day. This dose may be given as a single daily dose or in 2 divided doses.
In the treatment of thyroid storm, the medicine is initially administered at a dose of 0.1 g (20 tablets), followed by 30 mg (6 tablets) every 8 hours.
Treatment of hyperthyroidism with Metizol usually lasts from 6 months to 2 years. In preparation for thyroidectomy, the medicine is usually administered for 3–4 weeks prior to surgery.
Elderly patients:
Dosage adjustment is not necessary.
Use in children and adolescents (aged 3 to 17 years)
In children and adolescents aged 3 years and older, the dose is adjusted according to body weight.
Initially, a dose of 0.5 mg/kg body weight is usually administered, divided into 2 or 3 equal doses.
Later, the physician may recommend reducing the dose. The total daily dose should not exceed 40 mg.
Use in children under 2 years of age is not recommended.
Patients with renal function impairment:
Dosage adjustment is not necessary.
Patients with hepatic function impairment:
In case of impaired liver function or liver disease, inform the physician. In such cases, a reduction in the dose of Metizol may be necessary.
Metizol should be taken regularly.
Administration of a higher than recommended dose of Metizol
If a higher than recommended dose of Metizol is administered, consult a physician immediately. The physician will initiate appropriate management, including, among others, induction of emesis, gastric lavage, administration of activated charcoal, and symptomatic treatment.
In case of overdose, symptoms may include, among others: nausea, vomiting, muscle pain, constipation, headache, in women menstrual disturbances, decrease in body temperature, enlargement or appearance of goitre (swelling in the front of the neck), excessive drowsiness or lethargy, fatigue, weight gain, excessive dryness of the skin, and insomnia.
Missed dose of Metizol
If a dose of Metizol is missed at the scheduled time, take it as soon as possible. However, if the time for the next dose is approaching, skip the missed dose.
Do not take a double dose to make up for a missed dose.
Discontinuation of Metizol
Premature discontinuation of Metizol treatment may result in worsening of hyperthyroidism.
In case of any doubts regarding the use of the medicine, consult a doctor or pharmacist.

4. Possible adverse reactions

Like all medicines, this medicine can cause adverse reactions, although they do not occur in everyone.
Adverse reactions may occur:
Very common (may affect more than 1 in 10 people)
Common (may affect up to 1 in 10 people)
Uncommon (may affect less than 1 in 100 people)
Rare (may affect up to 1 in 1,000 people)
Very rare (may affect up to 1 in 10,000 people)
Frequency not known (frequency cannot be estimated from the available data)

If any of the following adverse reactions occur, stop taking the medicine and
contact your doctor immediately:

Symptoms such as: inflammation of the mucous membrane of the mouth, sore throat, fever, which may indicate an uncommon adverse reaction – agranulocytosis (a marked decrease in the number of certain types of white blood cells). These symptoms may appear within the first weeks of treatment or only after several weeks or months of taking the medicine.

In addition, the following adverse reactions may occur:
Very common adverse reactions:

Allergic skin reactions of varying severity (itching, rash, urticaria) – usually mild and resolve during continued use of the medicine.

Common adverse reactions:

Joint pain, which may occur even after several months of therapy.

Uncommon adverse reactions:

Taste disturbances (altered sense of taste, loss of taste) – these symptoms may resolve after discontinuation of treatment, although this may take several weeks;
Fever.

Very rare adverse reactions:

Thrombocytopenia (reduced number of blood platelets; may manifest as excessive bleeding, e.g. after procedures, nosebleeds, frequent bruising, presence of blood in stool or urine, petechiae on the skin);
Pancytopenia (reduction in the number of all blood cells);
Generalized lymphadenopathy (enlargement of lymph nodes), decreased blood glucose concentration (caused by disturbances in glucose regulation processes);
Neuritis, 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 whites of the eyes) and toxic hepatitis – these symptoms usually resolve after discontinuation of the medicine;
Severe forms of skin allergic reactions, including generalized skin inflammation;
Hair loss;
Drug-induced systemic lupus erythematosus (an immunologically based disease; may manifest, among others, as fatigue, loss of appetite, and development of a characteristic butterfly-shaped rash on the face).

Frequency not known:

Dizziness;
Pancreatitis (acute inflammation of the pancreas).

Children and adolescents
The type, frequency, and severity of adverse reactions in children are similar to those observed in adults.

Reporting of adverse reactions
If any adverse reactions occur, including any adverse reactions not listed in this leaflet, inform your doctor or pharmacist. Adverse reactions can be reported directly to the Department of Monitoring Adverse Reactions of Medicinal Products at 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.
Reporting adverse reactions helps to collect more information on the safety of using the medicine.

5. How to store Metizol

Do not store above 25°C.
Keep the blister in the outer packaging to protect from light.
Keep the medicine out of the 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 indicated.
Medicines must not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. This will help protect the environment.

6. Contents of the package and other information

What Metizol contains

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

What Metizol looks like and contents of the pack
Metizol is a white, round, biconvex tablet, with the imprint "M" on one side and smooth on the other side.
The pack contains 50 tablets (2 blisters of 25 tablets each).
For more detailed information, please contact the responsible party or the parallel importer.
Marketing Authorisation Holder in Lithuania, the country of export:
Viatris Healthcare Limited
Damastown Industrial Park
Mulhuddart
Dublin 15
Dublin
Ireland
Manufacturer:
ICN Polfa Rzeszów S.A.
Przemysłowa 2
35-959 Rzeszów
Poland
Parallel Importer:
Medezin Sp. z o.o.
Zbąszyńska 3
91-342 Łódź
Repackaged in:
Medezin Sp. z o.o.
Zbąszyńska 3
91-342 Łódź
Marketing Authorisation number in Lithuania, the country of export: LT/1/95/2571/001
Parallel Import authorisation number: 374/19