Background pattern
EUTIROX 125 micrograms TABLETS

EUTIROX 125 micrograms TABLETS

This page is for general information. Consult a doctor for personal advice. Call emergency services if symptoms are severe.
About the medicine

How to use EUTIROX 125 micrograms TABLETS

Introduction

Leaflet: information for the user

Eutirox 25microgram tablets

Eutirox 38microgram tablets

Eutirox 50microgram tablets

Eutirox 63microgram tablets

Eutirox 75microgram tablets

Eutirox 88microgram tablets

Eutirox 100microgram tablets

Eutirox 112microgram tablets

Eutirox 125microgram tablets

Eutirox 137microgram tablets

Eutirox 150microgram tablets

Eutirox 175microgram tablets

Eutirox 200microgram tablets

sodium levothyroxine

Read the entire leaflet carefully before starting to take this medication, as it contains important information for you.

  • Keep this leaflet, as you may need to read it again.
  • If you have any questions, consult your doctor or pharmacist.
  • This medication has been prescribed to you only and you should not give it to others, even if they have the same symptoms, as it may harm them.
  • If you experience side effects, consult your doctor or pharmacist, even if they are not listed in this leaflet. See section 4.

Contents of the leaflet

  1. What is Eutirox and what is it used for
  2. What you need to know before taking Eutirox
  3. How to take Eutirox
  4. Possible side effects
  5. Storage of Eutirox
  1. Contents of the pack and additional information

1. What is Eutirox and what is it used for

Levothyroxine, the active ingredient of Eutirox, is a synthetic thyroid hormone for the treatment of thyroid gland diseases and disorders. It has the same effect as naturally produced thyroid hormones.

Eutirox is used

  • to treat benign goiter in patients with normal thyroid function,
  • to prevent the recurrence of goiter after surgery,
  • to replace natural thyroid hormones when the thyroid gland does not produce them in sufficient quantity,
  • to stop the growth of tumors in patients with thyroid cancer.

Eutirox 25 micrograms, 38 micrograms, 50 micrograms, 63 micrograms, 75 micrograms, 88 micrograms, and 100 micrograms tablets are also used to balance thyroid hormone levels when excess hormone production is treated with antithyroid medications.

Eutirox 100 micrograms, 150 micrograms, and 200 micrograms tablets may also be used to test thyroid function.

2. What you need to know before taking Eutirox

Do not take Eutirox

in any of the following situations:

  • allergy (hypersensitivity) to the active ingredient or any of the other components of Eutirox (listed in section 6),
  • untreated adrenal gland, pituitary gland, or excessive thyroid hormone overproduction (thyrotoxicosis),
  • acute heart disease (myocardial infarction or heart inflammation).

Do not take Eutirox with other antithyroid medications if you are pregnant (see the "Pregnancy and breastfeeding" section below).

Warnings and precautions

Consult your doctor or pharmacist before taking Eutirox if you have any of the following heart diseases:

  • insufficient blood flow to the heart vessels (angina pectoris),
  • heart failure,
  • rapid and irregular heartbeats,
  • high blood pressure,
  • fat deposits in your arteries (arteriosclerosis).

These diseases must be under medical control beforeyou start taking Eutirox or before performing a thyroid suppression test. While taking Eutirox, you willneed to undergo frequent checks of your thyroid hormone levels. If you are not sure if you have any of the described diseases or if you are not receiving treatment, consult your doctor.

Your doctor will investigate if you have adrenal gland or pituitary gland dysfunction or uncontrolled thyroid gland dysfunction with excessive thyroid hormone production (thyroid autonomy), as this should be medically controlled before starting Eutirox or performing a thyroid suppression test.

Blood pressure should be regularly monitored when starting treatment with levothyroxine in premature neonates with very low birth weight, as a rapid drop in blood pressure (known as circulatory collapse) may occur.

If you need to change your medication to another one containing levothyroxine, a thyroid imbalance may occur. Talk to your doctor if you have any doubts about changing your medication. During the transition period, close monitoring (clinical and biological) is required. You should tell your doctor if you experience any side effects, as this may indicate that your dose needs to be adjusted by increasing or decreasing it.

Consult your doctor,

  • if you are in menopause or postmenopause; your doctor may need to periodically check your thyroid function due to the risk of osteoporosis.
  • before starting, stopping, or changing treatment with orlistat (a medication for treating obesity); you may need closer monitoring and dose adjustment.
  • if you experience signs of psychotic disorders (you may need closer monitoring and dose adjustment).

Thyroid hormones should not be used for weight loss. Taking thyroid hormones will not reduce your weight if your thyroid hormone levels are within the normal range. If you increase the dose without being specifically indicated by your doctor, you may experience serious side effects or even put your life at risk. High doses of thyroid hormones should not be taken with certain weight loss medications, such as amfepramone, clobenzorex, and fenilpropanolamine, as the risk of serious or life-threatening side effects may increase.

If you are going to undergo laboratory tests to check your thyroid hormone levels, you should inform your doctor or laboratory personnel that you are taking or have recently taken biotin (also known as vitamin H, vitamin B7, or vitamin B8). Biotin can affect laboratory test results. Depending on the test, the results may be falsely elevated or falsely reduced due to biotin. Your doctor may instruct you to stop taking biotin before undergoing the tests. You should also be aware that other products you may be taking, such as multivitamins or supplements for hair, skin, and nails, may also contain biotin. This could affect laboratory test results. Inform your doctor or laboratory personnel if you are taking these products (see the "Other medications and Eutirox" section).

Other medications and Eutirox

Inform your doctor or pharmacist if you are taking, have recently taken, or may need to take any of the following medications, as Eutirox may affect their effects:

  • Antidiabetic medications (medications to reduce blood sugar levels): Eutirox may reducethe effect of your antidiabetic medication, so you may need additional blood sugar level checks, especially when starting treatment with Eutirox. While taking Eutirox, it may be necessary to adjust the dose of your antidiabetic medication.
  • Coumarin derivatives (medications used to prevent blood clotting): Eutirox may enhancethe effect of these medications, which may increase the risk of bleeding, especially in elderly patients. You may need periodic checks of your blood coagulation values at the start and during treatment with Eutirox. While taking Eutirox, it may be necessary to adjust the dose of your coumarin medication.

Make sure to follow the recommended time intervals if you need to take any of the following medications:

  • Medications used to bind bile acids and reduce high cholesterol levels (such as cholestyramine or colestipol): make sure to take Eutirox 4-5 hours beforethese medications, as they may block the absorption of Eutirox from the intestine.
  • Antacids (for relief of acid indigestion), sucralfate (for stomach or intestinal ulcers), other medications containing aluminum, medications containing iron, medications containing calcium: make sure to take Eutirox at least 2 hours before these medications, as they may otherwise reduce the effect of Eutirox.

Inform your doctor or pharmacist if you are taking, have recently taken, or may need to take any of the following medications, as they may reducethe effect of Eutirox:

  • propylthiouracil (antithyroid medication),
  • glucocorticoids (anti-allergic and anti-inflammatory medications),
  • beta-blockers (medications to reduce blood pressure and used to treat heart diseases),
  • sertraline (antidepressant medication),
  • chloroquine or proguanil (medication to prevent or treat malaria),
  • medications that activate certain liver enzymes, such as barbiturates (sedatives, sleep medications), carbamazepine (antiepileptic medication, also used to relieve certain types of pain and control mood disorders), or products containing hypericum (a plant-based medication),
  • medications containing estrogens used in hormone replacement therapy during and after menopause or to prevent pregnancy,
  • sevelamer (medication that binds to phosphate, used to treat patients with chronic kidney failure),
  • tyrosine kinase inhibitors (anticancer and anti-inflammatory medications),
  • proton pump inhibitors (such as omeprazol, esomeprazol, pantoprazol, rabeprazol, and lansoprazol) used to reduce the amount of acid produced by the stomach, which may reduce the intestinal absorption of levothyroxine and make it less effective. If you are taking levothyroxine at the same time as a proton pump inhibitor, your doctor should monitor your thyroid function and may need to adjust the dose of Eutirox,
  • orlistat (medication for treating obesity).

Inform your doctor or pharmacist if you are taking, have recently taken, or may need to take any of the following medications, as they may enhancethe effect of Eutirox:

  • salicylates (medications used to relieve pain and reduce fever),
  • dicumarol (medication to prevent blood clotting),
  • furosemide in high doses of 250 mg (diuretic medication),
  • clofibrate (medication to reduce blood fat levels).

Inform your doctor or pharmacist if you are taking, have recently taken, or may need to take any of the following medications, as they may affect the effects of Eutirox:

  • ritonavir, indinavir, lopinavir (protease inhibitors, medications for treating HIV infection),
  • phenytoin (antiepileptic medication).

You may need periodic checks of your thyroid hormone levels. It may be necessary to adjust your dose of Eutirox.

Inform your doctor if you are taking amiodarone (medication used to treat irregular heartbeats), as this medication may affect your thyroid gland function and activity.

If you need to undergo a diagnostic examination or scan with iodinated contrast agents, inform your doctor that you are taking Eutirox, as you may be given an injection that can affect your thyroid function.

If you are taking or have recently taken biotin, you should inform your doctor or laboratory personnel when they are going to perform laboratory tests to check your thyroid hormone levels. Biotin can affect laboratory test results (see Warnings and precautions).

Inform your doctor or pharmacist if you are using or have recently used other medications, including those purchased without a prescription.

Taking Eutirox with food and drinks

Inform your doctor if you take products containing soy, especially if you modify the amount you consume. Soy products may reduce the absorption of Eutirox from the intestine and, therefore, may require a dose adjustment of Eutirox.

Pregnancy and breastfeeding

If you are pregnant, continue taking Eutirox. Inform your doctor, as the dose may need to be changed.

If you have taken Eutirox with an antithyroid medication to treat excessive thyroid hormone production, your doctor will advise you to stop taking Eutirox when you become pregnant.

If you are breastfeeding, continue taking Eutirox according to your doctor's instructions. The amount of medication excreted in breast milk is so small that it will not affect the baby.

Driving and using machines

No studies have been conducted on the effects on the ability to drive and use machinery. Since levothyroxine is identical to the naturally produced thyroid hormone, it is unlikely that Eutirox will interfere with the ability to drive and use machinery.

Important information about some of the components of Eutirox

This medication contains less than 23 mg of sodium (1 mmol) per tablet; it is essentially "sodium-free".

3. How to take Eutirox

Follow the administration instructions for Eutirox exactly as indicated by your doctor or pharmacist. If in doubt, consult your doctor or pharmacist again.

Your doctor will determine your individual dose based on the tests and laboratory analyses that have been performed. In general, a low dose is started, which will be increased every 2 - 4 weeks, until your final individual dose is reached. During the first few weeks of treatment, laboratory tests will be performed to adjust the dose.

If your baby was born with hypothyroidism, your doctor may recommend starting with a higher dose, as it is essential to achieve rapid replacement. The recommended initial dose is 10 to 15 micrograms per kilogram of body weight during the first three months. After that, your doctor will adjust the dose individually.

The following table indicates the usual dosage ranges. A lower individualized dose may be sufficient:

  • if you are an elderly patient,
  • if you have heart problems,
  • if you have severe or long-term hypothyroidism,
  • if your body weight is low or you have a large goiter.

Use of Eutirox

Recommended daily dose of Eutirox

  • to treat benign goiter in patients with normal thyroid function

75 – 200 micrograms

  • to prevent goiter recurrence after surgery

75 – 200 micrograms

  • to replace natural thyroid hormones when the thyroid gland does not produce them in sufficient quantity
  • initial dose
  • maintenance dose

adults

25 – 50 micrograms*

100 – 200 micrograms

children

12.5 – 50 micrograms*

100 – 150 micrograms per m2 of body surface area

  • to stop the growth of tumors in patients with thyroid cancer

150 – 300 micrograms

  • to balance thyroid hormone levels when hormonal overproduction is treated with antithyroid medications

50 – 100 micrograms

  • to test thyroid function

If you take Eutirox 100 micrograms:

200 micrograms (2 tablets), starting 2 weeks before the test

If you take Eutirox 150 micrograms:

Start 4 weeks before the analysis with 75 micrograms (1/2 tablet), for 2 weeks, then 150 micrograms (1 tablet) until the analysis

If you take Eutirox 200 micrograms:

200 micrograms (1 tablet), starting 2 weeks before the test

  • Eutirox 112 micrograms, 125 micrograms, 137 micrograms, 150 micrograms, 175 micrograms, and 200 micrograms tablets are not suitable for the lower dosage range indicated here; your doctor may prescribe lower-dose Eutirox tablets.

Administration

Eutirox is used orally. Take a single dose per day on an empty stomach in the morning (at least half an hour before breakfast), preferably with a little liquid, for example, with half a glass of water.

Children can take their entire daily dose of Eutirox at least half an hour before their first meal of the day. Immediately before administration, crush the tablet and mix it with a little water, and give it to the child with a little more liquid. Always prepare the mixture at the time of administration.

Duration of treatment

The duration of treatment may vary depending on the indication for which you use Eutirox. Therefore, your doctor will inform you about the duration of treatment. Most patients have to take Eutirox for the rest of their lives.

If you take more Eutirox than you should

If you have taken a dose higher than prescribed, you may experience symptoms such as rapid heartbeats, anxiety, agitation, or involuntary movements. In patients with neurological disorders such as epilepsy, seizures may occur in isolated cases. In patients at risk of psychotic disorders, symptoms of acute psychosis may occur. If this happens, consult your doctor.

In case of overdose or accidental ingestion, consult the Toxicology Information Service: Phone: 915 620 420.

If you forget to take Eutirox

Do not take a double dose to make up for forgotten doses; take the normal dose the next day.

If you have any other questions about the use of this product, ask your doctor or pharmacist.

4. Possible side effects

Like all medicines, Eutirox can cause side effects, although not everyone will experience them.

You may experience one or more of the following side effects if you take more Eutirox than indicated or if you do not tolerate the prescribed dose (for example, when the dose is increased rapidly): irregular or rapid heartbeats, chest pain, headache, muscle weakness or cramps, flushing (heat and redness of the face), fever, vomiting, menstrual changes, pseudotumor cerebri (increased cranial pressure), tremors, agitation, sleep disturbances, sweating, weight loss, and diarrhea.

Consult your doctor if you notice any of these effects. Your doctor may consider interrupting treatment for several days or reducing the daily dose until the side effects have disappeared.

You may suffer an allergic reaction to any of the components of Eutirox (see section 6 "Composition of Eutirox"). Allergic reactions can include rash, hives, and swelling of the face or throat (angioedema). If this occurs, consult your doctor immediately.

If you consider that any of the side effects you are experiencing is serious or if you notice any side effect not mentioned in this prospectus, inform your doctor or pharmacist.

Reporting side effects

If you experience any type of side effect, consult your doctor or pharmacist, even if it is a possible side effect not listed in this prospectus. You can also report them directly through the Spanish Pharmacovigilance System for Human Use Medicines: www.notificaRAM.es.

By reporting side effects, you can contribute to providing more information on the safety of this medicine.

5. Storage of Eutirox

Keep this medicine out of the sight and reach of children.

Do not use Eutirox after the expiration date stated on the packaging, after CAD. The expiration date is the last day of the month indicated.

Do not store above 25 °C. Store in the original packaging to protect it from light.

Medicines should not be disposed of through wastewater or household waste. Deposit the packaging and medicines you no longer need at the SIGRE collection point in your pharmacy. If in doubt, ask your pharmacist how to dispose of the packaging and medicines you no longer need. This will help protect the environment.

6. Package contents and additional information

Composition of Eutirox

The active ingredient is levothyroxine.

Each Eutirox 25 microgram tablet contains 25 micrograms of sodium levothyroxine.

Each Eutirox 38 microgram tablet contains 38 micrograms of sodium levothyroxine.

Each Eutirox 50 microgram tablet contains 50 micrograms of sodium levothyroxine.

Each Eutirox 63 microgram tablet contains 63 micrograms of sodium levothyroxine.

Each Eutirox 75 microgram tablet contains 75 micrograms of sodium levothyroxine.

Each Eutirox 88 microgram tablet contains 88 micrograms of sodium levothyroxine.

Each Eutirox 100 microgram tablet contains 100 micrograms of sodium levothyroxine.

Each Eutirox 112 microgram tablet contains 112 micrograms of sodium levothyroxine.

Each Eutirox 125 microgram tablet contains 125 micrograms of sodium levothyroxine.

Each Eutirox 137 microgram tablet contains 137 micrograms of sodium levothyroxine.

Each Eutirox 150 microgram tablet contains 150 micrograms of sodium levothyroxine.

Each Eutirox 175 microgram tablet contains 175 micrograms of sodium levothyroxine.

Each Eutirox 200 microgram tablet contains 200 micrograms of sodium levothyroxine.

The other components are cornstarch, citric acid, sodium croscarmellose, gelatin, magnesium stearate, and mannitol (E 421).

Appearance of the product and package contents

Eutirox tablets are white, round, flat on both sides, beveled, with a score line, and have the inscription "EM 25", "EM 38", "EM 50", "EM 63", "EM 75", "EM 88", "EM 100", "EM 112", "EM 125", "EM 137", "EM 150", "EM 175", or "EM 200" on one side.

Eutirox is available in packages of 20, 25, 30, 50, 60, 90, 100, or 500 tablets, or in calendar packages of 28 or 84 tablets.

Only some package sizes may be marketed.

Marketing authorization holder and manufacturer

Marketing authorization holder

Merck, S.L.

María de Molina, 40

28006, Madrid, Spain

Manufacturer

Merck Healthcare KGaA

Frankfurter Strasse 250

64293 Darmstadt, Germany

FAMAR HEALTH CARE SERVICES MADRID, S.A.U.

Avda. Leganés, 62

Alcorcón, 28923 Madrid, Spain

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

Austria: Euthyrox

Denmark: Euthyrox

Germany: Euthyrox

Greece: Euthyrox

Iceland: Euthyrox

Croatia: Euthyrox

Norway: Euthyrox

Portugal: Eutirox

Spain: Eutirox

Sweden: Euthyrox

Date of the last revision of this prospectus:07/2024

Other sources of information

You can access detailed and updated information about this medicine by scanning the QR code included in the packaging with your mobile phone (smartphone). You can also access this information at the following internet address:

Eutirox 25 micrograms: https://cima.aemps.es/info/64011

Eutirox 38 micrograms: https://cima.aemps.es/info/89799

Eutirox 50 micrograms: https://cima.aemps.es/info/64012

Eutirox 63 micrograms: https://cima.aemps.es/info/89800

Eutirox 75 micrograms: https://cima.aemps.es/info/64013

Eutirox 88 micrograms: https://cima.aemps.es/info/70044

Eutirox 100 micrograms: https://cima.aemps.es/info/64014

Eutirox 112 micrograms: https://cima.aemps.es/info/70042

Eutirox 125 micrograms: https://cima.aemps.es/info/64015

Eutirox 137 micrograms: https://cima.aemps.es/info/70043

Eutirox 150 micrograms: https://cima.aemps.es/info/64016

Eutirox 175 micrograms: https://cima.aemps.es/info/64017

Eutirox 200 micrograms: https://cima.aemps.es/info/64018

and on the website of the Spanish Agency for Medicines and Health Products (AEMPS) http://www.aemps.gob.es/.

About the medicine

How much does EUTIROX 125 micrograms TABLETS cost in Spain ( 2025)?

The average price of EUTIROX 125 micrograms TABLETS in October, 2025 is around 5.7 EUR. Prices may vary depending on the region, pharmacy, and whether a prescription is required. Always check with a local pharmacy or online source for the most accurate information.

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