Levothyroxine sodium
Levothyroxine, the active substance of Levirox, is a synthetic thyroid hormone used to treat thyroid gland disorders. It has the same effect as the thyroid hormones that occur naturally in the body.
Levirox is used:
Levirox 25 micrograms, 50 micrograms, 75 micrograms, and 100 micrograms are also used to normalize thyroid hormone levels in patients who are taking antithyroid drugs due to excessive thyroid hormone production.
Levirox 100 micrograms and 150 micrograms may also be used in tests to assess thyroid function.
Levirox should not be taken with antithyroid drugs if the patient is pregnant (see "Pregnancy and breastfeeding" below).
Before starting Levirox, tell your doctor or pharmacist if you have any of the following heart conditions:
It is necessary to treat these disorders before starting Levirox or before performing a thyroid suppression test. During Levirox treatment, it is necessary to frequently monitor thyroid hormone levels. Tell your doctor if you are not sure if any of the above conditions apply to you or if you have not yet started treatment for them.
Your doctor will perform tests to check if you have adrenal or pituitary gland disorders or thyroid function disorders with uncontrolled overproduction of thyroid hormones (autonomous thyroid function), as in such cases, appropriate treatment may be necessary before starting Levirox or before performing a thyroid suppression test.
When starting levothyroxine treatment in premature infants with very low birth weight, it is necessary to regularly monitor blood pressure, as a sudden decrease in blood pressure (so-called circulatory collapse) may occur.
Tell your doctor:
Tell your doctor or pharmacist about all medicines you are taking, have recently taken, or might take, as Levirox may affect the way they work:
If you are taking any of the following medicines with Levirox, you must follow the recommended time intervals between taking the medicines:
Tell your doctor or pharmacist if you are taking, have recently taken, or might take any of the following medicines, as they may reduce the effect of Levirox:
Tell your doctor or pharmacist if you are taking, have recently taken, or might take any of the following medicines, as they may enhance the effect of Levirox:
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 way Levirox works:
Tell your doctor if you are taking amiodarone (a medicine used to treat heart rhythm disorders), as it may affect thyroid function.
Tell your doctor if you are taking Levirox and need to undergo a diagnostic or imaging test with a contrast agent containing iodine, as the test may affect thyroid function.
Tell your doctor or pharmacist about all medicines you are taking, have recently taken, or might take, including those obtained without a prescription.
Thyroid hormones should not be used to lose weight. Taking them will not cause weight loss if thyroid hormone levels are normal.
Increasing the dose without consulting a doctor may lead to severe and life-threatening side effects, especially if you are taking other weight loss medicines.
Tell your doctor if you consume soy products, especially if you change the amount of soy products you eat. Soy products may reduce the absorption of Levirox from the gut, and therefore, it may be necessary to adjust the Levirox dose.
During pregnancy, continue taking Levirox. Talk to your doctor, as dose adjustment may be necessary.
If you were taking Levirox with an antithyroid medicine to treat excessive thyroid hormone production, your doctor will advise you to stop taking Levirox after becoming pregnant.
During breastfeeding, continue taking Levirox as advised by your doctor. The amount of levothyroxine that passes into breast milk is too small to affect the baby.
No studies have been conducted on the effects of Levirox on the ability to drive and use machines. It is not expected that Levirox will have any effect on the ability to drive and use machines, as levothyroxine is identical to the hormone that occurs naturally in the body.
This medicine contains less than 1 mmol (23 mg) of sodium per dose, which means it is essentially "sodium-free".
Always take this medicine exactly as your doctor or pharmacist has told you. If you are not sure, ask your doctor or pharmacist.
Your doctor will determine the appropriate dose for you individually, based on clinical evaluation and laboratory tests. Treatment usually starts with a small dose, which is increased every 2 to 4 weeks until the full dose, tailored to each patient, is reached.
In the first weeks of treatment, laboratory tests will be necessary to allow your doctor to adjust the appropriate dose.
If a child is born with a thyroid disorder characterized by insufficient thyroid hormone production, it is essential to supplement them quickly. Therefore, your doctor may recommend a higher initial dose of 10 micrograms to 15 micrograms per kilogram of body weight per day for the first 3 months. Then, your doctor will adjust the dose individually.
Typical dose ranges are presented in the table below. Smaller, individually adjusted doses may be sufficient for:
Levirox administration | Recommended daily dose of Levirox | |
| 75–200 micrograms | |
| 75–200 micrograms | |
| Adults
| Children 12.5 - 50 micrograms
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| |
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| 100 microgram tablets: Start 2 weeks before the test - 200 micrograms (2 tablets). 150 microgram tablets: Start 4 weeks before the test - 75 micrograms (1/2 tablet) for 2 weeks, then 150 micrograms (1 tablet) until the test. |
Method of administration
Levirox is intended for oral use.
The single daily dose should be taken in the morning, on an empty stomach (at least 30 minutes before breakfast), preferably with a small amount of liquid, e.g., half a glass of water.
Infants should be given the entire daily dose of Levirox once a day, at least 30 minutes before the first meal of the day. Immediately before administration, the tablet should be crushed and mixed with a small amount of water. The resulting suspension should be given with a small additional amount of liquid. A fresh suspension of the medicine should be prepared each time before administration.
Duration of treatment
The duration of treatment may vary depending on the reason for taking Levirox. Your doctor will discuss with you individually how long you need to take the medicine.
Most patients need to take Levirox for the rest of their lives.
The tablet can be divided into equal doses.
If you take more than the recommended dose, you may experience symptoms such as rapid heartbeat, restlessness, excitement, or involuntary movements. In patients with neurological disorders, such as epilepsy, single seizures have been observed.
In patients at risk of psychotic disorders, symptoms of acute psychosis may occur.
In patients with heart conditions, cardiac symptoms can be life-threatening. In such cases, you should see a doctor.
Do not take a double dose to make up for a forgotten dose. The next day, take your usual dose of Levirox.
If you have any further questions on the use of Levirox, ask your doctor or pharmacist.
Like all medicines, Levirox can cause side effects, although not everybody gets them.
If you take more than the recommended dose of Levirox or if you have poor tolerance to the prescribed dose (e.g., rapid dose increase), you may experience some of the following side effects:
Irregular or rapid heartbeat, chest pain, headache, weakness or muscle cramps, hot flashes (feeling of heat and facial flushing), fever, vomiting, menstrual disorders, pseudotumor cerebri (increased intracranial pressure), tremors, restlessness, sleep disturbances, sweating, weight loss.
If you experience any of these side effects, contact your doctor. Your doctor may decide to stop treatment for a few days or reduce the daily dose until the symptoms disappear.
Allergic reactions to the ingredients of Levirox are possible (see section 6). Allergic reactions may include facial or throat swelling (angioedema), rash, or hives (frequency not known, cannot be estimated from the available data). If you experience an allergic reaction, seek medical attention immediately.
If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly to the national reporting system:
Department for the Monitoring of Adverse Reactions to Medicinal Products, Medical Devices, and Biocidal Products,
Jerozolimskie Avenue 181C, 02-222 Warsaw,
phone: +48 22 49 21 301,
fax: +48 22 49 21 309,
website: https://smz.ezdrowie.gov.pl
You can also report side effects to the marketing authorization holder.
By reporting side effects, you can help provide more information on the safety of this medicine.
Keep this medicine out of the sight and reach of children.
Do not use this medicine after the expiry date which is stated on the blister or carton. The expiry date refers to the last day of that month.
Do not store above 25°C.
Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. These measures will help protect the environment.
Levirox 25 micrograms, tablets are white or almost white, round tablets with a diameter of 7.5 mm, with "25" embossed on one side and a score line on the other side.
Levirox 50 micrograms, tablets are white or almost white, round tablets with a diameter of 7.5 mm, with "50" embossed on one side and a score line on the other side.
Levirox 75 micrograms, tablets are white or almost white, round tablets with a diameter of 7.5 mm, with "75" embossed on one side and a score line on the other side.
Levirox 100 micrograms, tablets are white or almost white, round tablets with a diameter of 7.5 mm, with "100" embossed on one side and a score line on the other side.
Levirox 125 micrograms, tablets are white or almost white, round tablets with a diameter of 7.5 mm, with "125" embossed on one side and a score line on the other side.
Levirox 150 micrograms, tablets are white or almost white, round tablets with a diameter of 7.5 mm, with "150" embossed on one side and a score line on the other side.
Levirox is available in cartons containing blisters.
Pack sizes: 100 tablets
Orion Corporation
Orionintie 1
02200 Espoo
Finland
Orion Corporation Orion Pharma
Orionintie 1
02200 Espoo
Finland
Orion Corporation Orion Pharma
Joensuunkatu 7
24100 Salo
Finland
To obtain more detailed information on this medicine, please contact the local representative of the marketing authorization holder:
Orion Pharma Poland Sp. z o. o.
contact@orionpharma.info.pl
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