Levothyroxine sodium
Levothyroxine, the active substance of Levirox, is a synthetic thyroid hormone used to treat thyroid diseases and disorders. It has the same effect as the thyroid hormones that occur naturally in the body.
Levirox is used:
Levirox at a strength of 25 micrograms, 50 micrograms, 75 micrograms, and 100 micrograms is also used to adjust thyroid hormone levels in patients who are taking antithyroid medications due to excessive thyroid hormone production.
Levirox at a strength of 100 micrograms and 150 micrograms may also be used in tests to assess thyroid function.
Levirox should not be taken at the same time as antithyroid medications if the patient is pregnant (see "Pregnancy and breastfeeding" below).
Before starting treatment with Levirox, the patient should inform their doctor or pharmacist if they have any of the following heart diseases:
It is necessary to treat these disorders before starting treatment with Levirox or before performing a thyroid suppression test. During treatment with Levirox, it is necessary to frequently monitor thyroid hormone levels. The patient should tell their doctor if they are not sure if any of the above diseases apply to them or if they have not yet started treatment for them.
The doctor will perform tests to check if the patient has adrenal or pituitary disorders or thyroid dysfunction with uncontrolled excessive thyroid hormone production (autonomous thyroid function), as in such cases, appropriate treatment may be necessary before starting treatment with Levirox or before performing a thyroid suppression test.
When starting treatment with levothyroxine in premature infants with very low birth weight, blood pressure should be regularly monitored, as a sudden decrease in blood pressure (so-called circulatory collapse) may occur.
The patient should discuss with their doctor:
The patient should tell their doctor or pharmacist about all medicines they are currently taking or have recently taken, as well as any medicines they plan to take, as Levirox may affect the action of these medicines:
If the patient is taking any of the following medicines at the same time as Levirox, they should strictly follow the recommended time intervals between taking the individual medicines:
The patient should tell their doctor or pharmacist if they are currently taking, have recently taken, or plan to take any of the following medicines, as they may reduce the effect of Levirox:
The patient should tell their doctor or pharmacist if they are currently taking, have recently taken, or plan to take any of the following medicines, as they may enhance the effect of Levirox:
The patient should tell their doctor or pharmacist if they are currently taking, have recently taken, or plan to take any of the following medicines, as they may affect the action of Levirox:
The patient should tell their doctor if they are taking amiodarone (a medicine used to treat heart rhythm disorders), as it may affect thyroid function.
The patient should tell their doctor about taking Levirox if it is necessary to perform a diagnostic or imaging test with a contrast agent containing iodine, as this test involves an injection that may affect thyroid function.
The patient should tell their doctor or pharmacist about all medicines they are currently taking or have recently taken, including those available without a prescription.
Thyroid hormones should not be used to reduce weight. Taking them will not lead to weight loss if thyroid hormones are maintained at the proper level.
Increasing the dose of the medicine without consulting a doctor may lead to serious and life-threatening side effects, especially if the patient is taking other weight loss medicines at the same time.
The patient should tell their doctor if they consume soy products, especially if they change the amount of these products they consume. Soy products may reduce the absorption of Levirox from the small intestine, and therefore, it may be necessary to modify the dose of Levirox.
During pregnancy, the patient should continue taking Levirox. They should discuss this with their doctor, as it may be necessary to adjust the dose.
If Levirox was taken at the same time as an antithyroid medicine to treat excessive thyroid hormone production, the doctor will recommend stopping Levirox after becoming pregnant.
During breastfeeding, the patient should continue taking Levirox as recommended by their doctor. The amount of levothyroxine that passes into breast milk is too small to affect the baby.
No studies have been conducted on the effect 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.
This medicine contains less than 1 mmol (23 mg) of sodium per dose, which means it is considered "sodium-free".
This medicine should always be taken exactly as prescribed by the doctor or pharmacist. If the patient has any doubts, they should consult their doctor or pharmacist.
The doctor will determine the appropriate dose for each patient individually, based on clinical assessment and laboratory tests. Treatment usually starts with a small dose, which is increased every 2 to 4 weeks until the full dose, adjusted individually for each patient, is reached.
In the first few weeks of treatment, laboratory tests will be necessary to allow the doctor to adjust the appropriate dose.
If a child is born with a thyroid disease characterized by insufficient hormone production, it is essential to supplement them quickly. Therefore, the 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, the doctor will adjust the dose individually.
Typical dose ranges are presented in the table below. Smaller, individually adjusted doses may be sufficient for:
Use of Levirox | Recommended daily dose of Levirox | |
| 75–200 micrograms | |
| 75–200 micrograms | |
| Adults
| Children 12.5 - 50 micrograms
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| Tablets of 100 micrograms: Start 2 weeks before the test - 200 micrograms (2 tablets). Tablets of 150 micrograms: Start 4 weeks before the test - 75 micrograms (1/2 tablet) for two weeks, and 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 half an hour 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 at one time, at least half an hour 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 an additional small 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. The doctor will discuss with each patient how long they should take the medicine.
Most patients need to take Levirox for the rest of their lives.
The tablet can be divided into equal doses.
If a higher dose than recommended is taken, symptoms such as rapid heartbeat, restlessness, excitement, or involuntary movements may occur. 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 disease, cardiac symptoms may be life-threatening. In such cases, the patient should consult a doctor.
The patient should not take a double dose of the medicine to make up for a missed dose. The next day, they should take their usual dose of the medicine.
If the patient has any further doubts about taking Levirox, they should consult their doctor or pharmacist.
Like all medicines, Levirox can cause side effects, although not everybody gets them.
If a higher dose of Levirox than recommended is taken or if the prescribed dose is not well tolerated (e.g., if the dose is increased too quickly), some of the following side effects may occur:
Irregular or rapid heartbeat, chest pain, headache, weakness or muscle cramps, hot flashes (feeling of heat and facial flushing), fever, vomiting, menstrual disorders, pseudo-tumor cerebri (increased pressure in the head), tremors, restlessness, sleep disturbances, sweating, weight loss, diarrhea.
If any of the above side effects occur, the patient should contact their doctor. The doctor may decide to stop treatment for a few days or reduce the daily dose until the symptoms disappear.
It is possible to have allergic reactions to the ingredients of Levirox (see section 6. "What does Levirox contain").
Allergic reactions may include swelling of the face or throat (angioedema), rash, or hives (frequency not known, cannot be estimated from available data). If such an allergic reaction occurs, the patient should immediately consult a doctor.
If side effects occur, including any side effects not listed in this leaflet, the patient should tell their doctor or pharmacist. Side effects can be reported directly to the Department of Monitoring of Adverse Reactions to Medicinal Products of the Office for Registration of Medicinal Products, Medical Devices, and Biocidal Products:
Jerozolimskie Avenue 181C, 02-222 Warsaw
tel.: +48 22 49 21 301
fax: +48 22 49 21 309
Website: https://smz.ezdrowie.gov.pl
Side effects can also be reported to the marketing authorization holder.
Reporting side effects will help gather more information on the safety of the medicine.
The medicine should be stored out of sight and reach of children.
Do not use this medicine after the expiry date stated on the blister or carton. The expiry date refers to the last day of the month.
Do not store above 25°C.
Medicines should not be disposed of via wastewater or household waste. The patient should ask their pharmacist how to dispose of medicines they no longer use. This will help protect the environment.
Levirox, 25 micrograms, tablets are white or almost white, round tablets with a diameter of 7.5 mm, with the inscription "25" on one side and a dividing line on the other side.
Levirox, 50 micrograms, tablets are white or almost white, round tablets with a diameter of 7.5 mm, with the inscription "50" on one side and a dividing line on the other side.
Levirox, 75 micrograms, tablets are white or almost white, round tablets with a diameter of 7.5 mm, with the inscription "75" on one side and a dividing line on the other side.
Levirox, 100 micrograms, tablets are white or almost white, round tablets with a diameter of 7.5 mm, with the inscription "100" on one side and a dividing line on the other side.
Levirox, 125 micrograms, tablets are white or almost white, round tablets with a diameter of 7.5 mm, with the inscription "125" on one side and a dividing line on the other side.
Levirox, 150 micrograms, tablets are white or almost white, round tablets with a diameter of 7.5 mm, with the inscription "150" on one side and a dividing 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 about this medicine, the patient should contact the local representative of the marketing authorization holder:
Orion Pharma Poland Sp. z o. o.
kontakt@orionpharma.info.pl
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