LEVOTIROXINE SANOFI 500 micrograms powder and solvent for injectable solution

Introduction

Package Leaflet: Information for the User

Levotiroxina Sanofi 500 micrograms powder and solvent for solution for injection

Levotiroxina

Read all of this leaflet carefully before you start using this medicine because it contains important information for you.

• Keep this leaflet, you may need to read it again.
• If you have any further questions, ask your doctor or pharmacist.
• This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their signs of illness are the same as yours.
• If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. See section 4.

Contents of the pack:

1. What is Levotiroxina Sanofi and what is it used for
2. What you need to know before you use Levotiroxina Sanofi
3. How to use Levotiroxina Sanofi
4. Possible side effects
5. Storage of Levotiroxina Sanofi
6. Contents of the pack and further information

1. What is Levotiroxina Sanofi and what is it used for

Levotiroxina Sanofi belongs to a group of medicines called thyroid hormones.

It is indicated in:

• Treatment of replacement or substitution in case of malfunction of the thyroid gland, or lack of functioning of it, such as in the case of diseases such as: myxedema coma (hypothyroid), cretinism (congenital disease characterized by the cessation of physical and mental development), myxedema (deficient functioning of the thyroid gland that produces a hard edema extended to face and limbs), non-toxic goiter (swelling in the front of the neck due to an increase in the size of the thyroid gland, in this case without excess thyroid hormones) or hypothyroidism in general (lack of thyroid hormones) (including hypothyroid states in the child, during pregnancy or in old age).
• Hypothyroidism (lack of thyroid hormones) resulting from surgical removal of the thyroid gland, or its deficient functioning, such as a result of radiation or treatment with antithyroid agents (medicines for hyperthyroidism).
• Suppression of thyrotropin (thyroid-stimulating hormone) secretion required in the treatment of simple non-endemic goiter (increase in thyroid size) and lymphocytic thyroiditis (inflammation of the thyroid gland).
• Treatment of thyrotoxicosis (excess of thyroid hormones), in combination with antithyroid agents, to prevent hypothyroidism.

2. What you need to know before you use Levotiroxina Sanofi

Do not useLevotiroxina Sanofi

• If you are allergic to the active substance (levotiroxina) or to any of the other components of this medicine (included in section 6).

• untreated excess of thyroid hormones (thyrotoxicosis),
• underactive adrenal gland (adrenal insufficiency) and you do not have adequate replacement treatment,
• untreated hypopituitarism (decreased function of the pituitary gland),
• untreated hyperthyroidism (you are not receiving treatment from your doctor),
• acute myocardial infarction,
• acute inflammation of the heart muscle (myocarditis),
• acute inflammation of all layers of the heart (pancarditis).

During pregnancy, Levotiroxina Sanofi should not be used at the same time as medicines used to treat an overactive thyroid (antithyroid medicines).

Warnings and precautions

Consult your doctor or pharmacist before starting to use Levotiroxina Sanofi, especially in the following cases:

• If you suffer from any cardiovascular disease, including angina pectoris, heart failure, myocardial infarction, arteriosclerosis (disease of the arteries) and hypertension (high blood pressure). In case of worsening of your disease, your doctor may indicate a immediate reduction of the dose of Levotiroxina Sanofi, a lower initial dose, smaller dose increments and a longer time between increments. You will likely need periodic checks.
• If you have goiter (enlargement of the thyroid gland) and are an elderly patient with normal thyroid function and have had a myocardial infarction or have heart failure, angina pectoris or arrhythmias with tachycardia.
• Tell your doctor if you have hypopituitarism (underactive pituitary gland), if you are suffering from underactive adrenal gland (adrenal insufficiency), thyroid autonomy (thyroid nodules that secrete hormones), iodine intolerance, tuberculosis, kidney failure (renal impairment) or extreme thinness (anorexia).
• Thyroid hormone replacement therapy may trigger a decrease in hormone levels (acute adrenal crisis) in patients with adrenal insufficiency or hypopituitarism without adequate corticosteroid coverage.
• Tell your doctor if you are hypothyroid (your thyroid hormone levels are low) or suffer from myxedema (disease due to underactive thyroid gland). In general, people with these diseases are very sensitive to levotiroxina. Therefore, the initial dose prescribed by your doctor will be low, to be gradually increased later. Your doctor will check the response to treatment through blood tests.
• If you are a postmenopausal woman, with a high risk of osteoporosis, and are being treated for hypothyroidism (decreased thyroid hormones), your doctor should adjust the dose to the lowest possible level and may need more frequent checks.
• Tell your doctor if you have hyperthyroidism (very high thyroid hormone levels) and if you are being treated. Treatment with Levotiroxina Sanofi may not be suitable in this case.
• In case you need to undergo surgery with general anesthesia, it is recommended to interrupt treatment with Levotiroxina Sanofi.
• If you have diabetes mellitus or diabetes insipidus (high blood sugar) (see section "Other medicines and Levotiroxina Sanofi").
• If you are an elderly patient with long-standing hypothyroidism.
• If you are being treated with anticoagulants (medicines to prevent the formation of blood clots), since Levotiroxina Sanofi may enhance their effect.
• If a newborn premature baby with low birth weight is being treated. Extreme caution is required when starting treatment with levotiroxina as a circulatory collapse may occur due to immature adrenal function (see section 4 "Possible side effects"). Blood pressure will be periodically monitored when starting treatment with levotiroxina in premature newborns with very low birth weight as a rapid decrease in blood pressure (known as circulatory collapse) may occur.
• If you have a history of epilepsy since the risk of seizures increases when levotiroxina is administered.
• Thyroid hormones are not suitable for weight reduction. Taking thyroid hormones will not reduce your weight if your thyroid hormone level is within the normal range. Serious or life-threatening side effects may occur if the dose is increased without the special advice of your doctor, especially when used in combination with other medicines for weight reduction.
• Thyroid imbalance may occur if you need to change your medicine to another product containing levotiroxina. Consult your doctor if you have any doubts about how to change your medicine. Close monitoring (clinical and biological) is required during the transition period. You should inform your doctor if you have any side effects, as this may indicate that your dose needs to be adjusted upwards or downwards.
• Your doctor should adjust the dose according to thyroid function tests. Patient monitoring should be performed according to clinical symptoms as well as thyroid function tests.
• The doctor should monitor patients who are administered levotiroxina and other medicines (such as amiodarone, tyrosine kinase inhibitors, salicylates and high-dose furosemide) that may affect thyroid function (see section "Other medicines and Levotiroxina Sanofi").
• If you have a situation of protein loss, nephrotic syndrome, as they may increase the need for levotiroxina.
• If you experience an allergic reaction (see section 4 "Possible side effects"). Contact your doctor or healthcare professional immediately or go to the emergency room of the nearest hospital immediately.
• If you are going to have 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 may affect the results of laboratory tests (see "Warnings and precautions").

Other warnings

In the case of myxedema coma, the patient's history and laboratory values, as well as the clinical situation, should be taken into account to confirm the diagnosis of "hypothyroid coma".

The comatose condition should be controlled before starting replacement therapy to treat thyroid hormone deficiency.

Other medicines and Levotiroxina Sanofi

Tell your doctor or pharmacist if you are using, have recently used or might use any other medicines.

The effect of Levotiroxina Sanofi is influenced by other medicines, as indicated below:

• Catecholamines, since levotiroxina may enhance their effect.
• Oral anticoagulants, as it may be necessary to reduce the dose of the oral anticoagulant.
• Antidiabetics: levotiroxina may reduce the hypoglycemic effect of oral antidiabetic medicines such as metformin, glimepiride and glibenclamide, as well as insulin, and therefore it is recommended to monitor blood sugar levels, especially when starting or stopping treatment with thyroid hormone and may be necessary to adjust the dose of the antidiabetic.
• Rifampicin, carbamazepine, phenytoin, barbiturates, products containing hypericum: rifampicin (an antibiotic), carbamazepine (used to treat seizures), phenytoin (used to treat seizures and heart rhythm disorders), barbiturates (used in seizures, for anesthesia; certain sleeping pills) and products containing hypericum (a plant-based medicine) may weaken the effect of levotiroxina.
• Salicylates, dicumarol, high-dose furosemide (250 mg), clofibrate and other substances may displace levotiroxina sodium from plasma proteins, resulting in an elevation of the free T4 fraction (fT4).

Salicylates, especially at doses greater than 2.0 g/day, as well as high-dose furosemide (250 mg), may inhibit the binding of thyroid hormones to transport proteins, which may produce a transient initial increase in free thyroid hormones, followed by a general decrease in total thyroid hormone levels.

• Sertraline, chloroquine, proguanil: these substances reduce the efficacy of levotiroxina and increase the serum concentration of TSH.

• Protease inhibitors, such as lopinavir/ritonavir: cases of loss of therapeutic effect of levotiroxina have been reported when administered together.
• Estrogens, such as in oral contraceptives, as they may lead to diagnostic and therapeutic errors. During treatment with estrogen-containing oral contraceptives or during postmenopausal hormone replacement therapy, it may be necessary to increase the dose of levotiroxina.
• Propylthiouracil, glucocorticoids, beta-sympatholytics (especially propranolol) inhibit the peripheral conversion of T4 to T3 and may result in a reduction of serum T3 concentration.
• Amiodarone and contrast media containing iodine. Amiodarone inhibits the peripheral conversion of T4 (levotiroxina) to T3, resulting in a reduction of serum T3 concentration and an increase in serum TSH levels.
• Medicines containing tyrosine kinase inhibitors (imatinib, sunitinib, sorafenib or motesanib), as they may decrease the efficacy of levotiroxina.
• 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 may affect the results of laboratory tests (see "Warnings and precautions").

Medicines that may decrease the absorption of levotiroxina when administered orally

• Cholestyramine and colestipol (medicines for the treatment of cholesterol), calcium polystyrene sulfate, sevelamer and sodium salts, as these medicines reduce the absorption of levotiroxina by binding to thyroid hormones in the gastrointestinal tract, so these medicines should be administered as far apart as possible from levotiroxina; it is recommended to wait at least 4-5 hours after the administration of levotiroxina before using them.

• Medicines containing calcium carbonate, sucralfate and antacids, as they may reduce the effect of levotiroxina by reducing its absorption in the gastrointestinal tract, so their administration should be separated as much as possible.

• Bile acid sequestrant (colesevelam), binds to levotiroxina and reduces the absorption of levotiroxina in the gastrointestinal tract. Therefore, levotiroxina should be administered at least 4 hours before colesevelam.
• Iron salts reduce the absorption of levotiroxina in the gastrointestinal tract, so their administration should be separated as much as possible.
• Soy: in babies with a soy-based diet and treated with levotiroxina for the treatment of congenital hypothyroidism, an increase in TSH levels has been reported. Unusually high doses of levotiroxina may be required to achieve normal serum TSH and T4 levels. During and after a soy-based diet, close monitoring of serum T4 and TSH levels is required, with the possibility of needing to adjust the dose of levotiroxina.

Pregnancy and lactation

If you are pregnant or breastfeeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before using this medicine.

If you have hypothyroidism and are being treated with Levotiroxina Sanofi, you should not stop treatment during pregnancy. Sometimes, it may be necessary to increase the dose.

Thyroid function should be monitored during and after pregnancy. A dose adjustment may be necessary.

It is essential to maintain normal thyroid hormone levels in pregnant women to ensure good health for both the mother and the fetus.

During pregnancy, the use of Levotiroxina Sanofi as a complement to the treatment of hyperthyroidism with antithyroid medicines is contraindicated. It may increase the necessary dose of these medicines.

Levotiroxina Sanofi can be administered during breastfeeding.

Driving and using machines

No effects of Levotiroxina Sanofi on the ability to drive and use machines have been described.

Levotiroxina Sanofi contains sodium

This medicine contains less than 1 mmol of sodium (23 mg) per 1 ml of solution for injection; i.e., it is essentially "sodium-free".

3. How to use Levotiroxina Sanofi

Follow the administration instructions of this medication exactly as indicated by your doctor. In case of doubt, consult your doctor again.

Your doctor will indicate the duration of your treatment and the most suitable dose for you.

Treatment should be administered, taking into account individual circumstances, during the period when oral hormone administration is not possible.

Levotiroxina Sanofi is administered solely by intravenous or perfusion route (see section 6 "Instructions for healthcare personnel").

Treatment of myxedema coma (hypothyroidism):

Patients suffering from the most severe form of hypothyroidism (myxedema coma) should undergo urgent treatment. The treatment will aim to correct hydroelectrolytic disorders or any potential infection, along with the administration of thyroid hormones.

Levotiroxina Sanofi can be initially administered intravenously for a period of 2-3 minutes at a dose of 500 micrograms of levotiroxina, given that the onset of action may appear after several hours, even with intravenous administration.

It is also possible to administer it by perfusion, using a 50 ml perfusion syringe with an isotonic sodium chloride solution, over 30-60 minutes.

From the second day onwards, 100 micrograms of levotiroxina should be administered daily until the end of the myxedema coma.

• In elderly patients and patients with heart disease:

Treatment should be started with caution, for example, by setting a low initial dose and gradually increasing it at long intervals, with frequent monitoring of thyroid hormones.

Experience has shown that low doses are sufficient in patients with low body weight.

Based on individual circumstances, your doctor will choose the treatment during the period when oral hormone administration is not possible. The administration of oral formulations available for other indications not related to myxedema coma should be considered, taking into account individual circumstances.

If you use moreLevotiroxina Sanofithan you should

Call your doctor, pharmacist, or go to the nearest hospital immediately.

Treatment of overdose will be symptomatic and supportive. Beta-blockers may be useful in controlling some symptoms.

In cases of poisoning with extremely high doses (suicide attempt), plasmapheresis may be useful.

Overdose requires a prolonged follow-up period since symptoms may be delayed up to 6 days.

In case of overdose, no serious complications with a threat to vital functions are expected, except in cases of heart disease.

However, in cases of chronic or massive poisoning, cases of thyrotoxic crisis, muscle spasms, convulsions, cardiac arrhythmias, heart failure, coma, and even death have been reported. Cases of sudden cardiac arrest have also been reported in patients after many years of levotiroxina abuse.

In case of overdose or accidental ingestion, consult your doctor or pharmacist or call the Toxicology Information Service. Phone 91 562 04 20, indicating the medication and the amount used.

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

If you forget to use Levotiroxina Sanofi

Do not use a double dose to make up for forgotten doses.

4. Possible side effects

Like all medications, this medication can produce side effects, although not all people experience them.

Hypersensitivity to the active substance or other components of Levotiroxina Sanofi

In case of hypersensitivity to levotiroxina or any other component of Levotiroxina Sanofi, allergic reactions of the skin and respiratory tract (either immediately or after several days of medication administration) may occur, which can be life-threatening. Symptoms may include skin rash, itching, difficulty breathing, shortness of breath, swelling of the face, lips, throat, or tongue. Contact your doctor or healthcare professional immediately or go to the emergency room of the nearest hospital.

Side effects have been grouped according to their frequency as follows:

Very common: may affect more than 1 in 10 patients

Common: may affect up to 1 in 10 patients

Uncommon: may affect up to 1 in 100 patients

Rare: may affect up to 1 in 1,000 patients

Very rare: may affect up to 1 in 10,000 patients

Frequency not known: cannot be estimated from available data.

These side effects are generally associated with excessive doses and correspond to symptoms of hyperthyroidism.

Disorders of the immune system:

Frequency not known: hypersensitivity.

Disorders of the blood and lymphatic system:

Frequency not known: cases of decreased white blood cell count (leukopenia) have been observed.

Endocrine disorders:

Common: increased thyroid hormones (hyperthyroidism).

Psychiatric disorders:

Very common: insomnia,

Common: nervousness,

Frequency not known: excitability.

Nervous system disorders:

Very common: headache,

Frequency not known: tremors, increased intracranial pressure (benign intracranial hypertension) especially in children.

Cardiac disorders:

Very common: palpitations,

Common: accelerated heart rate (tachycardia),

Frequency not known: chest pain that sometimes extends to the left arm (angina pectoris), alteration of heart rhythm (cardiac arrhythmias).

Vascular disorders:

Frequency not known: hot flashes, circulatory collapse in premature newborns with low birth weight (see section 2. "Warnings and precautions").

Gastrointestinal disorders:

Frequency not known: vomiting and diarrhea.

Disorders of the skin and subcutaneous tissue:

Frequency not known: allergic skin reactions (e.g., angioedema [difficulty breathing or swelling of the face, lips, throat, or tongue], skin rash, urticaria, sweating).

Musculoskeletal and connective tissue disorders:

Frequency not known: muscle weakness and cramps, osteoporosis especially in postmenopausal women, mainly when treated for a long period.

Disorders of the reproductive system and breast:

Frequency not known: menstrual irregularities.

General disorders and administration site conditions:

Frequency not known: fever, heat intolerance.

Investigations:

Frequency not known: weight loss.

All these reactions usually disappear when the dose is reduced or treatment is temporarily suspended.

If the initial dose of levotiroxina is too high, it may precipitate heart rhythm disorders (atrial or ventricular fibrillation), especially in sensitive patients.

Reporting of 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 the prospectus. You can also report them directly through the Spanish Medication Pharmacovigilance System for Human Use: https://www.notificaram.es. By reporting side effects, you can contribute to providing more information on the safety of this medication.

5. Storage of Levotiroxina Sanofi

Keep this medication out of sight and reach of children.

Store in the refrigerator (between 2°C and 8°C).

Store in the original packaging to protect it from light.

Protect the prepared solution for use from direct light.

Expiration date

Do not use this medication after the expiration date shown on the packaging after CAD. The expiration date is the last day of the month indicated.

Validity period of the reconstituted solution:

• for intravenous administration: 24 hours at room temperature
• for perfusion administration: 2 hours at room temperature

From a microbiological point of view, unless the opening method excludes the risk of microbiological contamination, the product should be used immediately. If not used immediately, the storage time and conditions are the responsibility of the user.

Medications should not be thrown down the drain or into the trash. Ask your pharmacist how to dispose of the packaging and medications you no longer need. This will help protect the environment.

6. Package contents and additional information

Composition ofLevotiroxina Sanofi 500 micrograms powder and solvent for injectable solution

• The active substance is levotiroxina sodium. Each package contains 1 vial with 514 micrograms of levotiroxina sodium (equivalent to 500 micrograms of levotiroxina).
• The other components are:

Powder: disodium hydrogen phosphate dihydrate, sodium chloride, mannitol (E-421), phosphoric acid, and sodium hydroxide (for pH adjustment).

Solvent: water for injectable preparations.

Appearance of the product and package contents

Vial: contains white powder.

Solvent ampoule: contains a colorless solution.

Each Levotiroxina Sanofi pack contains 1 vial of powder and 1 ampoule of solvent.

Instructions for healthcare personnel

Administer intravenously after reconstitution.

The powder should be dissolved in 5 ml of water for injectable preparations (included in the packaging).

For short-term intermittent perfusion, an isotonic sodium chloride solution (50 ml-250 ml) should be added.

Marketing authorization holder

sanofi-aventis, S.A.

C/ Rosselló i Porcel, 21

08016 Barcelona

Spain

Manufacturer

SANOFI WINTHROP INDUSTRIE

30 – 36, avenue Gustave Eiffel

37100 Tours

France

Or

sanofi-aventis, S.A.

Ctra. C-35 (La Batlloria-Hostalric, Km. 63,09)

17404 Riells i Viabrea (Girona)

Spain

Date of the last revision of this prospectus: March 2023

Detailed information about this medication is available on the website of the Spanish Agency for Medicines and Health Products (AEMPS) http://www.aemps.gob.es/.