Eferox

Package leaflet: Information for the patient

Eferox, 150 micrograms, tablets
Eferox, 200 micrograms, tablets
Levothyroxinum natricum
Please read this leaflet carefully before using the medicine, as it contains
important information for the patient.

• Keep this leaflet, as you may need to read it again.
• If you have any questions, please consult your doctor or pharmacist.
• This medicine has been prescribed for a specific individual. Do not pass it on to others. This medicine may harm other people, 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.

Table of contents

1. What Eferox is and what it is used for
2. Important information before taking Eferox
3. How to take Eferox
4. Possible side effects
5. How to store Eferox
6. Contents of the pack and other information

1. What Eferox is and what it is used for

Thyroxine is a hormone naturally produced by the thyroid gland. Sodium levothyroxine is a synthetic form of this hormone.
Eferox is used to replace deficient thyroid hormone and/or to manage thyroid diseases and disorders.
Eferox is used:

• to replace thyroid hormone in all forms of hypothyroidism or following thyroidectomy,
• to prevent recurrence of goiter after its removal in patients with normal thyroid function,
• to treat benign (non-malignant) goiter in patients with normal thyroid function,
• in the treatment of malignant thyroid cancers, particularly after surgical procedures to suppress tumor growth and to replace missing thyroid hormone,
• in thyroid suppression tests.

2. Important information before using Eferox

When not to use Eferox

• if the patient is allergic to levothyroxine or any of the other ingredients of this medicine (listed in section 6);
• if the patient has untreated hyperthyroidism (hyperthyreosis, thyrotoxicosis);
• if the patient has adrenal insufficiency (adrenal failure) and is not receiving appropriate replacement therapy;
• if the patient has untreated pituitary insufficiency;
• if the patient has any of the following diseases or conditions:
• acute myocardial infarction
• acute inflammation of the heart muscle (myocarditis)
• acute inflammation of all layers of the heart wall (pancarditis)
• during pregnancy, Eferox must not be taken simultaneously with other antithyroid drugs (thyroid-suppressing drugs).

The following diseases or conditions must be excluded or treated before starting treatment with Eferox:

• coronary heart disease;
• chest pain with pressure (angina pectoris);
• fatty deposits in the arteries (atherosclerosis);
• high blood pressure (hypertension);
• conditions in which the pituitary and (or) adrenal glands do not produce sufficient amounts of hormones (pituitary insufficiency and (or) adrenal cortex insufficiency);
• nodules in the thyroid gland producing uncontrolled amounts of thyroid hormone (autonomous thyroid function).

Warnings and precautions
Thyroid hormones are not suitable for weight reduction. Taking thyroid hormones will not lead to weight loss in patients with normal thyroid hormone levels. Taking additional thyroid hormones without medical indication may cause severe, even life-threatening adverse effects, especially when combined with other weight-reducing drugs (see section 2 "Eferox with other medicines").
When switching from one medicine to another containing levothyroxine, thyroid function imbalance may occur. In case of any questions regarding switching medication, please discuss this with your doctor. Patients should be closely monitored (clinically and biologically) during the transition period. Inform your doctor if any adverse effects occur, as this may indicate the need for dose adjustment (increasing or decreasing the dose).
Before starting treatment with Eferox, discuss the following with your doctor or pharmacist:

• if the patient has had hypothyroidism for a long time, for example since birth, or if the disease appeared in childhood;
• if the patient has heart disease, including angina pectoris, coronary heart disease, weakened heart muscle, cardiac arrhythmias, or high blood pressure or atherosclerosis;
• if the patient recently had a heart attack;
• if the patient is taking anticoagulant drugs (e.g. phenprocoumon). The dose of this drug may require adjustment (see section 2 "Eferox with other medicines");
• if the patient is being treated for diabetes. The dose of antidiabetic medication may require adjustment, as levothyroxine may increase blood glucose levels (see section 2 "Eferox with other medicines");
• if the patient is postmenopausal. Thyroid function should be monitored more frequently to avoid elevated levothyroxine levels in the blood, which may lead to osteoporosis (bone fragility);
• if the patient has epilepsy (seizures). Seizures have been reported rarely during initiation of levothyroxine treatment or rapid dose escalation;
• if the patient has myxoedema (skin and subcutaneous tissue swelling), as the dose of Eferox may need to be reduced;
• if the patient has small intestine disease, as it may impair drug absorption (malabsorption syndrome, e.g. coeliac disease, lactose intolerance), which may require treatment to ensure Eferox works properly;
• if the patient has adrenal insufficiency (adrenal failure), pituitary dysfunction, or a certain type of thyroid disorder with uncontrolled overproduction of thyroid hormones, appropriate treatment must be initiated before starting Eferox;
• if the patient is to undergo laboratory tests measuring thyroid hormone levels, the patient should inform the doctor or laboratory staff about current or recent biotin intake (also known as vitamin H, vitamin B7 or vitamin B8). Biotin may interfere with laboratory test results. Depending on the type of test, results may be falsely elevated or falsely decreased due to biotin intake. The doctor may advise the patient to discontinue biotin before laboratory testing. It should also be remembered that other products taken by the patient, such as multivitamin preparations or supplements for hair, skin and nails, may also contain biotin. This may affect laboratory test results. If the patient takes such products, they should inform the doctor or laboratory staff (see information in section 2: "Eferox with other medicines").

Talk to your doctor if the patient experiences symptoms of psychotic disorders.
When initiating levothyroxine treatment in preterm infants with very low birth weight, blood pressure should be monitored regularly, as sudden hypotension (so-called circulatory collapse) may occur.
In elderly patients, e.g. those with heart disease, the dose should be carefully and individually adjusted. The doctor should monitor such patients.

Blood tests
Before starting levothyroxine, the doctor will perform a blood test to determine how much thyroxine the patient's thyroid gland produces and what dose of medicine is needed. After starting treatment, the doctor will recommend regular blood tests to ensure the medicine is working properly.

Eferox with other medicines
Tell your doctor or pharmacist about all medicines the patient is currently taking or has recently taken, as well as any medicines the patient plans to take. This includes medicines without prescription, herbal medicines and vitamin supplements. Many other medicines may affect the action of Eferox. Levothyroxine may also affect the action of other medicines.
Before undergoing imaging tests using iodine-containing contrast agents, inform the doctor about taking Eferox.
If the patient is currently taking or has recently taken biotin, they must inform the doctor and (or) laboratory staff if thyroid hormone tests are to be performed. Biotin may affect laboratory test results (see "Warnings and precautions").

The following medicines may affect the action of levothyroxine:

• antiepileptic drugs such as: carbamazepine, phenytoin, primidone and barbiturates
• medicines containing St. John's wort (some herbal medicines)
• sertraline, lithium – drugs used in depression, mood disorders and anxiety
• statins such as simvastatin and lovastatin (drugs used to treat high blood cholesterol)
• rifampicin – a drug used to treat infections
• imatinib, sunitinib, 5-fluorouracil – drugs used to treat certain types of cancer
• beta-blockers such as: propranolol, atenolol and sotalol – drugs used to treat high blood pressure and heart diseases
• hormonal drugs containing oestrogens, used in hormone replacement therapy and hormonal contraception ("the contraceptive pill")
• hormonal drugs containing androgens, used in hormone replacement therapy in men
• glucocorticosteroids such as: cortisone, hydrocortisone, prednisolone and dexamethasone – drugs used to treat inflammatory conditions
• amiodarone – a drug used to treat irregular heart rhythm
• anti-inflammatory drugs such as: phenylbutazone or acetylsalicylic acid
• methadone – a drug used in opioid substitution therapy
• furosemide – a drug used to treat high blood pressure or oedema
• propylthiouracil – a drug used to treat hyperthyroidism
• potassium iodide – used to protect the thyroid gland from radiation
• oral contrast agents – taken before certain imaging tests to better visualise body parts
• chloroquine or proguanil – used for malaria prophylaxis and rheumatic diseases
• ritonavir – a drug used to control HIV infection and chronic hepatitis C virus infection
• orlistat – a drug used to treat obesity
• proton pump inhibitors (such as omeprazole, esomeprazole, pantoprazole, rabeprazole and lansoprazole) used to reduce stomach acid production, which may impair levothyroxine absorption from the intestine and reduce its effectiveness. If the patient is taking levothyroxine during treatment with proton pump inhibitors, the doctor should monitor thyroid function and, if necessary, modify the dose of Eferox.

Eferox should be taken at least 4 to 5 hours before taking the following medicines:

• calcium, magnesium, aluminium or iron supplements, lanthanum
• cholestyramine, colestipol or clofibrate – drugs used to reduce high blood cholesterol
• sodium polystyrene sulfonate – used in the treatment of kidney diseases
• orlistat – used for weight loss
• cimetidine – used to inhibit excessive gastric acid secretion
• proton pump inhibitors such as: omeprazole, esomeprazole – drugs used to inhibit excessive gastric acid secretion
• sucralfate, antacids – used in the treatment of gastric ulcer.

Eferox may affect the action of the following medicines:

• anticoagulant drugs preventing blood clot formation, such as: warfarin, dicoumarol and phenprocoumon
• drugs used to treat diabetes, such as: insulin and metformin
• tricyclic antidepressants such as: amitriptyline, imipramine and doxepin
• drugs that stimulate the sympathetic nervous system, such as: adrenaline (used to treat severe allergic reactions) or phenylephrine (a drug reducing mucosal congestion found in many cold and flu medicines)
• digoxin – a drug used to treat heart diseases
• phenytoin – a drug used to treat epilepsy.

Eferox with food and drink
Soy-containing products and foods high in fibre may affect levothyroxine absorption. Therefore, dose adjustment of levothyroxine by the treating doctor may be necessary.

Pregnancy and breastfeeding
If the patient is pregnant or breastfeeding, suspects she may be pregnant, or plans to become pregnant, she should consult her doctor or pharmacist before using this medicine.
Continuous thyroid hormone therapy is particularly important during pregnancy and breastfeeding and must therefore be continued under medical supervision.
During pregnancy, the requirement for levothyroxine may increase due to elevated oestrogen (female sex hormone) levels in the blood. Therefore, thyroid function should be monitored both during and after pregnancy, and the levothyroxine dose adjusted accordingly.
Even when treated with high doses of levothyroxine, the amount of thyroid hormone passing into breast milk during breastfeeding is very small and therefore harmless.
Suppression tests must not be performed during pregnancy and breastfeeding.

Driving and using machines
Eferox is not expected to have any influence on the ability to drive and use machines, as the levothyroxine contained in this medicine is identical to the thyroid hormone naturally present in the body.

Eferox contains sodium
The medicine contains less than 1 mmol (23 mg) of sodium per tablet, i.e. the medicine is considered "sodium-free".

3. How to use Eferox

This medicine should always be taken exactly as directed by your doctor or pharmacist.
If in doubt, consult your doctor or pharmacist.
In elderly patients, patients with ischemic heart disease, and patients with severe or chronic
hypothyroidism, thyroid hormone therapy should be initiated with particular caution. In these
patients, treatment should begin with a low starting dose, which should then be gradually increased
at longer intervals, with frequent monitoring of thyroid hormone levels. Experience shows that
lower doses may also be sufficient in patients with low body weight and in patients with large
goiter.

Dosing
For individualized treatment, Eferox tablets are available in graduated strengths from 25 to
200 micrograms, meaning that in most cases only one tablet per day needs to be taken.
Your doctor will determine the individual dose based on clinical evaluation and laboratory test
results. Treatment usually starts with a low dose, which is increased every 2 to 4 weeks until the
full, individually adjusted dose is reached. During the first weeks of treatment, laboratory tests will
be ordered to allow your doctor to adjust the appropriate dose.

Method of administration
The entire daily dose should be taken in the morning on an empty stomach, at least half an hour before breakfast,
because the active substance is better absorbed on an empty stomach than before or after a meal. Tablets should be
swallowed whole, without chewing, with a glass of water.
Infants should receive the entire daily dose at least half an hour before the first meal, preferably with a small amount of water to facilitate swallowing. If necessary, the tablet may be divided.
Crushing the tablet or preparing a suspension in water or other liquids is not recommended,
as this may lead to incorrect dosing.
Eferox tablets may be divided into equal doses.
Instructions for dividing the tablet

Place the tablet on a hard, flat surface with the dividing groove facing upwards. To divide the tablet, press directly on the center of the tablet with your thumb.
Duration of treatment
The medicine should be taken for as long as directed by the physician.
If the patient has hypothyroidism or has undergone surgery for thyroid cancer, they will usually need to take Eferox for life.
In the case of mild goitre and to prevent recurrence, Eferox should be taken for several months or years, and even for life.
In replacement therapy for hyperthyroidism, Eferox should be taken for as long as antithyroid (thyrostatic) medication is being used.
In the treatment of mild goitre with normal thyroid function, the medicine should be taken from 6 months to 2 years. If treatment with Eferox does not achieve the desired results within this period, alternative treatment options should be considered.
For thyroid suppression testing, 150 or 200 micrograms of Eferox should be taken daily for 14 days.
Use of a higher than recommended dose of Eferox
If a patient (or another person) has swallowed more tablets than prescribed, or if there is suspicion that a child has ingested any amount of tablets, contact a doctor, the nearest hospital emergency department, or a poison control center immediately.
Symptoms of overdose may include: excitation, confusion, irritability, fever, chest pain (angina), rapid or irregular heartbeat, rapid breathing, muscle spasms, headache, restlessness, hyperactivity, flushing, sweating, dilated pupils, diarrhea, tremor, difficulty sleeping, anxiety or nervousness, feeling of physical or emotional fatigue, seizures.
These symptoms may last up to 6 days. Bring any remaining tablets and this leaflet with you so that medical personnel know exactly which medicine the patient has taken.
Missed dose of Eferox
If a dose is missed, take the usual dose at the next scheduled time. Do not take a double dose to make up for the missed dose. If in doubt, consult your doctor or pharmacist.
Stopping Eferox treatment
For effective treatment, Eferox must be taken regularly at the doses prescribed by the doctor. Under no circumstances should the prescribed treatment be changed, interrupted, or discontinued without consulting a doctor, as symptoms may return.
If you have any further questions about the use of this medicine, consult your doctor or pharmacist.

4. Possible adverse reactions

Like all medicines, this medicine can cause adverse reactions, although not everyone experiences them.
The patient must stop taking the tablets and go to hospital immediately if any of the following occur:

• allergic reaction such as: swelling of the face, tongue, lips and (or) throat and (or) difficulty swallowing or hives causing breathing difficulties (angioedema), severe itching of the skin with raised lumps, joint pain, increased sensitivity to sunlight, general malaise (frequency unknown). The patient may require urgent medical attention.

Some patients may experience a severe reaction to high levels of thyroid hormone. This is known as "thyroid storm". The patient must immediately stop taking the tablets and go to the nearest hospital if any of the following symptoms occur (frequency unknown):

• very high fever, rapid heartbeat, irregular heartbeat, low blood pressure, heart failure, jaundice, confusion, seizures and coma.

The patient should inform their doctor or pharmacist if any of the following adverse reactions occur,
worsen or if the patient notices any adverse reactions not listed here.
Most adverse reactions resemble symptoms of hyperthyroidism (when the thyroid gland produces too much thyroxine) and are caused by taking too high a dose of the medicine. Symptoms usually resolve after reducing the dose or stopping the tablets. The patient should inform their doctor if any adverse reactions occur. The doctor will decide whether to reduce the daily dose or temporarily discontinue the medicine for a few days. However, the dose of the medicine must not be changed nor treatment discontinued without first consulting the doctor.
Frequency unknown: frequency cannot be estimated from the available data

• increased appetite
• anxiety, restlessness, difficulty sleeping (insomnia)
• tremor, headache, seizures
• chest pain (angina), palpitations, irregular or rapid heartbeat, heart failure, heart attack
• high blood pressure (hypertension), sudden flushing
• shortness of breath (dyspnoea)
• diarrhoea, nausea, vomiting, abdominal pain
• increased sweating, itching, skin rash, urticaria
• muscle cramps, muscle weakness, joint pain
• decreased bone density (osteoporosis), especially in postmenopausal women receiving high doses of the medicine for a prolonged period
• in women: irregular menstruation
• fever (high temperature), swelling, general malaise
• weight loss
• hyperthyroidism.

Additional adverse reactions in children
Rare: may affect up to 1 in 1,000 patients

• increased intracranial pressure in children not caused by tumour or other diseases (benign intracranial hypertension).

Frequency unknown: frequency cannot be estimated from the available data

• slowed or halted growth in children due to changes in bone development
• transient hair loss in children
• skull deformity in infants caused by premature closure of skull sutures in children (craniosynostosis)
• heat intolerance.

In case of hypersensitivity to levothyroxine or any of the other excipients of Eferox, allergic reactions affecting the skin and respiratory tract may occur.
Reporting of adverse reactions
If any adverse reactions occur, including any adverse reactions not listed in this leaflet, the patient should inform their doctor, pharmacist or nurse. Adverse reactions can be reported directly to the Department of Monitoring Adverse Drug Reactions of the Office for Registration of Medicinal Products, Medical Devices and Biocidal Products:
Al. Jerozolimskie 181C, 02-222 Warsaw, tel.: 22 49-21-301, fax: 22 49-21-309,
website: https://smz.ezdrowie.gov.pl
Adverse reactions can also be reported to the marketing authorisation holder.
Reporting adverse reactions helps provide more information on the safety of the medicine.

5. How to store the medicine Eferox

Keep the medicine out of sight and reach of children.
Do not use this medicine after the expiry date stated on the blister pack and the cardboard
box following EXP. The expiry date refers to the last day of the indicated month.
Do not store above 30°C.
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 pack and other information

What Eferox contains

• The active substance in this medicine is levothyroxine sodium anhydrous.

Eferox 150 micrograms tablets
Each tablet contains 150 micrograms of levothyroxine sodium anhydrous.
Eferox 200 micrograms tablets
Each tablet contains 200 micrograms of levothyroxine sodium anhydrous.

• The other ingredients are: microcrystalline cellulose, maize starch, magnesium oxide heavy; sodium carboxymethyl starch (type A) and magnesium stearate.

What Eferox looks like and contents of the pack
Eferox tablets are white, round, uncoated, scored tablets that can be divided by applying pressure, with a dividing line on one side and a numerical imprint corresponding to the strength (i.e. 150 or 200) on the other side. The tablets have a diameter of approximately 7 mm and a height of approximately 3 mm.
Eferox 150 micrograms is available in blister packs containing 20, 25, 30, 50, 60, 90 or 100 tablets in a cardboard carton.
Eferox 200 micrograms is available in blister packs containing 15, 20, 25, 30, 50, 60, 84, 90 and 100 tablets in a cardboard carton.
Not all pack sizes may be marketed.

Marketing Authorisation Holder
Aristo Pharma Sp. z o.o.
Baletowa 30 Street
02-867 Warsaw
Poland
Tel: +48 22 855 40 93

Manufacturer
Aristo Pharma GmbH
Wallenroder Straße 8–10
13435 Berlin
Germany
Lindopharm GmbH
Neustraße 82
40721 Hilden
Germany

This medicinal product is authorised in the European Economic Area (EEA) and the United Kingdom (Northern Ireland) under the following names:
Austria Levothyroxin Aristo 150/200 Mikrogramm Tabletten
Germany L-Thyroxin Aristo 150/200 Mikrogramm Tabletten
Czech Republic Levothyroxine Aristo 150/200 mikrogramů tablety
Finland Levothyroxine Aristo 200 mikrog tablettia
Spain Levotiroxina Aristo 150/200 microgramos comprimidos
Netherlands Levothyroxinenatrium Aristo 200 microgram tabletten
Ireland Levothyroxine sodium Aristo 150/200 microgram tablets
Poland Eferox 150/200 mikrogramów tabletki
Portugal Eferox 150/200 microgramas comprimidos
Sweden Levothyroxine Aristo 150/200 mikrogram tabletter
Italy Levotiroxina DOC 150/200 mikrogrammi compresse