Package Leaflet: Information for the User
Thyrofix 13 micrograms tablets
Thyrofix 25 micrograms tablets EFG
Thyrofix 50 micrograms tablets EFG
Thyrofix 62 micrograms tablets
Thyrofix 75 micrograms tablets EFG
Thyrofix 88 micrograms tablets EFG
Thyrofix 100 micrograms tablets EFG
Thyrofix 112 micrograms tablets EFG
Thyrofix 125 micrograms tablets EFG
Thyrofix 137 micrograms tablets EFG
Thyrofix 150 micrograms tablets EFG
Thyrofix 175 micrograms tablets EFG
Thyrofix 200 micrograms tablets EFG
Levothyroxine sodium
Read all of this leaflet carefully before you start taking this medicine because it contains important information for you.
Contents of the pack:
Levothyroxine, the active substance in this medicine, is a synthetic thyroid hormone used to treat diseases and disorders of the thyroid gland. It has the same effect as the natural hormone produced in the thyroid gland.
This medicine is used to:
Thyrofix 13 micrograms, 25 micrograms, 50 micrograms, 62 micrograms, 75 micrograms, 88 micrograms, and 100 micrograms will also be used to balance thyroid hormone levels when hyperthyroidism is treated with antithyroid medications.
Thyrofix 75 micrograms, 100 micrograms, 150 micrograms, and 200 micrograms will also be used for thyroid function tests.
Do not take Thyrofix if you have any of the following conditions:
Do not take Thyrofix with antithyroid medications if you are pregnant (see Pregnancy and lactation section later).
Warnings and precautions
Talk to your doctor or pharmacist before taking this medicine if you have any of the following heart conditions:
You should be under medical control beforeyou start taking this medicine or before you undergo a thyroid suppression test. You mustundergo frequent checks of your thyroid hormone levels while taking this medicine. If you are not sure if you have any of the diseases described, or if you are not receiving treatment, contact your doctor.
Your doctor will investigate if you have adrenal gland or pituitary dysfunction or thyroid gland dysfunction with uncontrolled thyroid hormone overproduction (thyroid autonomy), as this must be medically controlled before starting treatment or before undergoing a thyroid suppression test.
Blood pressure will be monitored periodically when starting treatment with levothyroxine in premature newborns 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.
Talk to your doctor:
The treatment with thyroid hormones is not indicated 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, especially without consulting your doctor, you may experience serious or even potentially life-threatening side effects. You should not take high doses of thyroid hormones with certain weight loss medications, such as amfepramone, catherine, and phenylpropanolamine, as this may increase the risk of serious side effects and even potentially life-threatening effects.
Other medicines and Thyrofix
Tell your doctor or pharmacist if you are taking, have recently taken, or might take any of the following medicines, as Thyrofix may affect their effect:
This medicine may reducethe effect of the medicines you take to control diabetes, so you may need to undergo additional checks of your blood sugar levels, especially at the start of treatment. While taking Thyrofix, you may need to adjust the dose of your diabetes medicine.
Thyrofix may increasethe effect of these medicines, which may increase the risk of bleeding events, especially in elderly patients. When starting and during treatment with Thyrofix, you may need to frequently check your blood coagulation values. While taking Thyrofix, you may need to adjust the dose of coumarin you take.
Make sure to respect the recommended time intervals if you need to take any of the following medicines:
Make sure to take Thyrofix 4-5 hours beforethese medicines, as they may block the absorption of Thyrofix from the intestine.
Make sure to take Thyrofix at least 2 hours before these medicines, as otherwise, they may reduce the effect of Thyrofix.
Tell your doctor or pharmacist if you are taking, have recently taken, or might take any of the following medicines, as they may reducethe effect of this medicine:
Tell your doctor or pharmacist if you are taking, have recently taken, or might take any of the following medicines, as they may increasethe effect of this medicine:
Tell your doctor or pharmacist if you are taking, have recently taken, or might take any of the following medicines, as they may affect the effect of this medicine:
You may need to frequently check your thyroid hormone levels. You may need to adjust your Thyrofix dose.
Tell your doctor if you are taking amiodarone (medicine used to treat irregular heartbeats), as this medicine may affect your thyroid function and activity.
If you need to undergo a diagnostic test or procedure with iodinated contrast media, tell your doctor that you are taking this medicine, as you may need to be given an injection that may affect your thyroid function.
If you are taking or have recently taken biotin, you should inform your doctor or laboratory staff when they are going to perform laboratory tests to check your thyroid hormone levels. Biotin can affect laboratory test results (see Warnings and precautions).
Tell your doctor or pharmacist if you are taking or have recently taken any other medicine, including those obtained without a prescription.
Taking Thyrofix with food and drinks
Tell your doctor if you consume soy products, especially if you often vary the amount you consume. Soy products may reduce the absorption of Thyrofix from the intestine and, therefore, you may need to adjust your Thyrofix dose.
Pregnancy and lactation
If you are pregnant, continue taking this medicine. Talk to your doctor, as you may need to adjust your dose.
If you are taking Thyrofix with a thyroid medicine to treat thyroid hormone overproduction, your doctor will advise you to stop Thyrofix treatment when you become pregnant.
If you are breastfeeding, continue taking this medicine according to your doctor's instructions. The amount of medicine that is excreted in breast milk is so small that it will not affect the baby.
Driving and using machines
No studies have been performed on the ability to drive and use machines.
This medicine is not considered to have any influence on the ability to drive and use machines, as levothyroxine is identical to the natural thyroid hormone.
Thyrofix contains sodium
This medicine contains less than 1 mmol of sodium (23 mg) per tablet, i.e., it is essentially "sodium-free".
Follow exactly the administration instructions of this medication as indicated by your doctor or pharmacist. In case of doubt, consult your doctor or pharmacist again.
Your doctor will determine the individual dose based on exams and laboratory tests. Generally, it starts with a low dose that is increased every 2 - 4 weeks, until reaching the complete individual dose. During the initial weeks of treatment, laboratory tests will be required to adjust the dose.
If your baby is 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 3 months. After that, your doctor will adjust the dose individually.
The normal dose range is shown in the following table. A lower individualized dose may be sufficient:
Use of Thyrofix | Recommended daily dose of Thyrofix | |
| 75 - 200 micrograms | |
| 75 - 200 micrograms | |
| Adults 25 -50 micrograms* 100 - 200 micrograms | Children 13-50 micrograms* 100-150 micrograms per m2 of body surface |
| 150 - 300 micrograms | |
| 50 - 100 micrograms | |
| 100 micrograms: 200 micrograms (2 tablets) from 2 weeks before the test 150 micrograms: From 4 weeks before the test 75 micrograms (1 tablet of 75 micrograms) for two weeks, and then 150 micrograms (1 tablet) until the test 200 micrograms: 200 micrograms (1 tablet) from 2 weeks before the test |
Administration
Thyrofix is used orally. Take one daily dose 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.
Infants can receive the complete daily dose of Thyrofix at least half an hour before the first meal of the day. Crush the tablet and mix it with a little water immediately before use, and give it to the child with a little more water. Always prepare the mixture at the time of taking it.
Duration of treatment
The duration of treatment may vary depending on the indication for which it is used. Your doctor will inform you about the duration of treatment. Most patients need to take this medication for life.
If you take more Thyrofix than you should
If you took a higher dose than prescribed, you may experience symptoms such as palpitations, anxiety, agitation, or involuntary movements. In patients with neurological disorders such as epilepsy, convulsions may occur in isolated cases. In the case of patients at risk of psychotic disorders, symptoms of acute psychosis may occur. If this happens, consult your doctor.
If you forget to take Thyrofix
Do not take a double dose to make up for the forgotten dose; take the normal dose the next day.
If you interrupt treatment with Thyrofix
For the treatment to be effective, this medication must be taken regularly, with the dose prescribed by your doctor. Do not change, interrupt, or stop treatment without consulting your doctor. Stopping treatment definitively or temporarily may cause symptoms to recur.
If you have any other questions about the use of this medication, ask your doctor or pharmacist.
Like all medications, this medication can cause side effects, although not everyone experiences them.
You may experience one or more of the following side effects if you take more than the prescribed amount or if you do not tolerate the prescribed dose (for example, if 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 changes, sweating, weight loss, and diarrhea.
If you experience any of these side effects, contact your doctor. He will decide if you need to interrupt treatment for a few days or reduce the daily dose until the side effects disappear.
You may experience allergic reactions to any of the ingredients in this medication (see section 6. 'Composition of Thyrofix'). Among the allergic reactions you may experience are rash, hives, and swelling of the face or neck (angioedema). If this happens, contact your doctor immediately.
Reporting side effects
If you experience any type of side effect, consult your doctor or pharmacist, even if it is a possible side effect that does not appear in this prospectus. You can also report them directly through the Spanish Pharmacovigilance System for Human Use Medicines. Website: www.notificaRAM.es. By reporting side effects, you can contribute to providing more information on the safety of this medication.
Keep this medication out of the sight and reach of children.
Do not use this medication after the expiration date that appears on the blister pack after EXP and on the box after CAD. The expiration date is the last day of the month indicated.
This medication does not require special storage conditions. Keep the blister packs in their box to protect them from moisture.
Medications should not be thrown away through the sewers or in the trash. Deposit the packaging and medications you no longer need at the SIGRE point in the pharmacy. If in doubt, ask your pharmacist how to dispose of the packaging and medications you no longer need. This way, you will help protect the environment.
Composition of Thyrofix
Appearance of the product and package contents
The Thyrofix tablets of 13, 25, 50, 62, 75, 88, 100, 112, 125, 137, 150, 175, 200 micrograms are white, biconvex, uncoated, with a diameter of 6.5 mm and an average thickness of 3.5 mm, marked with '13', '25', '50', '62', '75', '88', '100', '112', '125', '137', '150', '175', '200' on one side.
Thyrofix is available in packages of 30, 50, 60, or 100 tablets, and in blister packs of 15 or 25 tablets.
Only some package sizes may be marketed.
Marketing authorization holder and manufacturer
Uni-Pharma Kleon Tsetis Pharmaceutical Laboratories S.A.
14th km National Road 1,
GR-145 64 Kifissia
Greece
This medication is authorized in the member states of the European Economic Area with the following names:
Netherlands: Thyrofix 13/25/50/62/75/88/100/112/125/137/150/175/200 micrograms tablets
Denmark: Medithyrox
France: Thyrofix 13/25/50/62/75/88/100/112/125/137/150/175/200 micrograms tablets
Portugal: Thyrofix 13/25/50/62/75/88/100/112/125/137/150/175/200 micrograms tablets
Spain: Thyrofix 13/25/50/62/75/88/100/112/125/137/150/175/200 micrograms tablets
Cyprus: Thyrofix 13/25/50/62/75/88/100/112/125/137/150/175/200 micrograms tablets
Poland: Medithyrox
Finland: Medithyrox 13/25/50/62/75/88/100/112/125/137/150/175/200 micrograms tablets
Sweden: Medithyrox 13/25/50/62/75/88/100/112/125/137/150/175/200 micrograms tablets
Malta: Thyrofix 25/50/75/100/150 micrograms tablets
Date of the last revision of this prospectus:September 2024
Detailed and updated information on this medication is available on the website of the Spanish Agency for Medicines and Health Products (AEMPS) http://www.aemps.gob.es