Index
- Introduction: what is it?
- Dosage: how is it used and how does it work?
- Warnings and Precautions
- Interactions and side effects
- Pregnancy and breastfeeding
- Notes (methods of storage, validity)
Questions and answers
Introduction: what is it?
Eutirox is a drug that is used for the therapy and treatment of various diseases and pathologies such as states of hypothyroidism such as goiter, prophylaxis of relapses after strumectomy (total or partial removal of a goiter), thyroid hypofunction, inflammation of the thyroid gland (thyroiditis) or in course of antithyroid therapy.
Eutirox contains as an active ingredient the sodium salt of Levothyroxine, a compound that belongs to the category of thyroid hormones.
Eutirox can be prescribed with RR Recipe – medicines subject to medical prescription and is available in off-white round tablets containing different amounts of the hormone: 25-50-75-88-100-112-125-137-150-175 or 200 micrograms of Levothyroxine sodium.
Dosage: how is it used and how does it work?
Treatment with Eutirox must be followed carefully by the physician , who may adjust the dosage and duration of therapy according to the needs of the individual patient.
The tablets should preferably be taken with a sip of water in the morning on an empty stomach.
In principle, the dosage schedule is:
- Goiter: Adults: 100-150 (200) micrograms per day;
- Children (up to 14 years): 50-100 (150) micrograms per day;
- Prophylaxis of relapses after strumectomy: 100 micrograms per day.
Thyroid hypofunction :
Adults : Particular caution is required when initiating therapy with thyroid hormones in elderly patients, in patients with coronary artery disease and in patients with severe or long-lasting hypothyroidism.
50 micrograms per day as a starting dose (for about two weeks); increase in the daily dose by 50 micrograms at intervals of approximately 14-15 days, up to the maintenance dose of 100-200 (300) micrograms per day: on average 2-2.5 micrograms / kg body weight per day.
Children : 0-6 months: 10 micrograms / kg body weight per day; 6-12 months: 8 micrograms / kg body weight per day; 15 years: 6 micrograms / kg body weight per day; 5-10 years: 4 micrograms / kg body weight per day. Dissolve the tablets in a little water in order to obtain a suspension to be taken with a further addition of liquid. The suspension should be prepared immediately before each administration and taken immediately.
Thyroid inflammation (thyroiditis) : 100-150 micrograms per day.
During therapy with antithyroid drugs, the administration of 50-100 micrograms per day is sufficient.
Eutirox contains Levothyroxine as a sodium salt . The thyroid (a gland located in the neck, in front of the trachea, just above the breastbone) produces various hormones: (T1, T2, T3, T4 and calcitonin).
Levo-thyroxine (T4, a low active hormone) and triiodothyroxine (T3), two iodinated amino acid derivatives of thyronine (a large thyroglobulin glycoprotein) are produced after stimulation by thyrotropin or thyroid stimulating hormone (TSH) produced by the pituitary (a gland located in the skull). The production of TSH is in turn stimulated by the thyrotropic hormone releasing hormone (TRH) which is produced by the hypothalamus(another gland located in the central area inside the two cerebral hemispheres). The secretion of thyroid hormones follows a circadian rhythm; the highest levels of T3 and T4 are reached during the night and early morning, while the lowest levels are observed in the early afternoon until the evening.
In the blood , the hormones T3 and T4 circulate bound to transport proteins; a smaller amount, on the other hand, called fT3 or fT4 is present in free (unbound) form and can reach peripheral tissues. The levels of T3 in the blood depend (15%) on the secretion by the thyroid, but above all on the action of a specific enzyme , the deiodinase, which removes an iodine molecule from T4 (thyroxine) and converts it to T3 (85%). From a metabolic point of view, this hormone is much more active than T4, but at the same time it is also much less represented in the blood.
Thyroid hormones act by binding to nuclear α and β receptors which in turn bind to specific sequences on the DNA thus modulating the transcription of different genes and therefore also the synthesis of different proteins . Both receptors are present in different tissues but their level of expression varies in various organs.
By acting on these receptors, these hormones play a critical role in cell differentiation during the development of the organism and help maintain thermal and metabolic homeostasis.in the adult. Thyroid hormones regulate metabolism, that is the complex of chemical reactions that take place in our body, indicating to the latter “how fast it must work” and how it must use food substances to produce energy. Thyroid hormones cause an increase in oxygen consumption , metabolism of carbohydrates , fats and proteins , promote the growth and differentiation of the immature organism and inhibit the secretion of pituitary thyrotropin (thus controlling their own secretion).
The thyroid problems arise mainly from autoimmune disorders that can either stimulate aexcessive production of thyroid hormones (thyrotoxicosis) or cause a degeneration of the thyroid gland and consequent deficiency of thyroid hormones (hypothyroidism) .
Thyroid hormones, to ensure the correct functioning of the various physiological functions, must remain within certain limits : T3 1.1-2.6 nmoles / L, fT3 3-8 pmoles / L; T4 60-150 nmoles / L, fT4 10-25 pmoles / L. The values considered normal may vary between the various testing laboratories and in some cases may be expressed as nanograms or micrograms / dL with completely different numbers. It is therefore advisable to refer to the values reported on the clinical findings and ask your doctor for advice.
With “ euthyroidism”Indicates the condition in which thyroid hormones (both T3 and T4) are present in physiological, ie normal, concentrations. The patient who has Eurothyroidism, takes the name of “euthyroid”. Thus, a “euthyroid” person has a normal amount of T3 and T4 thyroid hormones.
Both triiodothyronine and levothyroxine correct the alterations of hypothyroidism and therefore the therapeutic practice of administering hormones that offer the advantages of a direct response in relation to the actual metabolic needs of the patient is now universally widespread.
For the therapy of hypothyroidism it is useful to resort to Levothyroxine(T4), which is available in different concentrations and therefore allows for various dosage levels.
Until 2011 , dry thyroid was available in Italy , produced from dried and pulverized pork thyroid and then formulated in tablets.
Warnings and Precautions
Eutirox is contraindicated in patients with hypersensitivity to the active substance or to any of the excipients and in patients with untreated adrenal insufficiency, untreated pituitary insufficiency and untreated thyrotoxicosis, or untreated hyperthyroidism (overactive thyroid).
Treatment with Eutirox should not be initiated in patients who have had acute myocardial infarction , acute myocarditis or pancarditis (simultaneous inflammation of the three tunics of the heart: endocardium, myocardium and, more rarely, pericardium. Often seen in the acute period of rheumatic disease ) .
The combination of levothyroxine and an antithyroid drug for hyperthyroidism iscontraindicated during pregnancy .
Eutirox should be used with caution and always under close medical supervision .
Before starting thyroid hormone therapy, or before performing a thyroid function inhibition test, the following conditions must be ruled out or treated: coronary insufficiency, angina pectoris , myocardial infarction, myocarditis, heart failure, arteriosclerosis, hypertension , pituitary insufficiency or adrenal, autonomy of the thyroid gland.
When initiating therapy with levothyroxine in patients at risk for psychotic disorders, it is recommended to start with a low dose of levothyroxine and slowly increase the dose at the start of therapy. Monitor the patient carefully. If signs of psychotic disturbance occur, a dose adjustment of levothyroxine should be considered.
Use caution when administering levothyroxine to patients with a known history of epilepsy . Seizures have rarely been reported in association with levothyroxine sodium therapy and may be related to the effect of thyroid hormone on the seizure threshold. Frequent monitoring of thyroid hormone levels
is important in patients with coronary insufficiency, heart failureor tachyarrhythmias so as not to risk inducing hyperthyroidism (even mild).
The overdose can cause side effects severe or even fatal.
Thyroid hormones should not be given for weight reduction. In euthyroid patients, treatment with levothyroxine does not lead to weight reduction. Levothyroxine in high doses should not be combined with substances used for weight reduction, eg. sympathetic-mimetic drugs.
Rare cases of hepatic dysfunction have been reported , therefore it is advisable to reduce the dosage or discontinue treatment if, during the course of therapy, fever, muscle weakness or abnormallaboratory tests for liver function .
Patients with adrenal insufficiency may react unfavorably to Levothyroxine; therefore it is advisable to start corticosteroid therapy before treatment with Eutirox. The cause of secondary hypothyroidism should be established prior to administration of replacement therapy and, if necessary, replacement therapy should be initiated for compensated adrenal insufficiency . In cases where thyroid autonomy is suspected, a TRH test or a scintigraphy should be performed during thyroid suppression before starting therapy.
In postmenopausal women with hypothyroidism and a high risk of osteoporosisan increase in serum levels of levothyroxine above physiological levels must be avoided; therefore, thyroid function must be closely monitored.
Levothyroxine should not be administered in hyperthyroidism except as a concomitant supplement to antithyroid therapy of hyperthyroidism.
After initiating therapy with levothyroxine, in case of switching to another levothyroxine product, it is recommended to adjust the dosage according to the individual clinical response and laboratory tests.
In primary hypothyroidism only TSH levels (measured by a sensitive method) should be used to monitor therapy. The frequency of TSH checks during the dose adjustment phase depends on the clinical situation but is generally recommended at 6-8 week intervals until desired levels are achieved. In particular, in patients with differentiated thyroid carcinoma who start treatment following thyroidectomy and possible radioisotope therapy, TSH dosage is recommended 2 months after the start of treatment to confirm TSH suppression and visits. control after about 6 and 12 months. In individuals judged to be in complete remission of the disease, it is recommended that the level of TSH suppression be adjusted based on medical judgment.
In patients whose TSH levels have reached the desired level and in those whose levothyroxine product or dosage has been changed, the TSH concentration should be checked after 8-12 weeks and the dosage adjusted according to the results. obtained. Once the maintenance dose is reached, clinical and biochemical checks should be repeated every 6-12 months based on medical judgment.
For diabetic patients treated with insulin or oral hypoglycemic agents and in patients on anticoagulant therapy, systematic laboratory checks must be carried out to highlight any phenomena of interaction and therefore adapt the daily dosage.
Pediatric population : Parents of children receiving thyroid medication should be advised that partial hair loss may occur in the first months of therapy, but this effect is generally transient and usually resolves in subsequent regrowth.
Eutirox contains lactose , therefore patients with rare hereditary problems of galactose intolerance, total lactase deficiency, or glucose-galactose malabsorption should not take this medicine.
Eutirox in different strengths contains less than 1 mmol (23 mg) sodium per tablet, i.e. essentially ‘sodium-free’.
There are no known effects on the ability to drive and use machines. However, due to the possible onset of headache , caution is advised when driving vehicles or carrying out activities that require special vigilance .
Interactions and side effects
Antidiabetic drugs : Levothyroxine may reduce the effect of hypoglycemic drugs. Blood glucose levels should be monitored frequently at the initiation of thyroid hormone therapy and the dosage of the antidiabetic drug should be adjusted as necessary.
Proton pump inhibitors : (rabeprazole, esomeprazole, lansoprazole, pantoprazole) In long-term use, proton pump inhibitors may impair the absorption of levothyroxine.
Protease inhibitors (e.g. ritonavir , indinavir , lopinavir): may have an influence on the effect of levothyroxine. Close monitoring of thyroid hormone parameters is recommended. If necessary, the levothyroxine dose should be adjusted.
Phenytoin : Phenytoin may have an influence on the effect of levothyroxine by displacing levothyroxine from plasma proteins resulting in a high fraction of fT4 and fT3. In turn, phenytoin increases the hepatic metabolism of levothyroxine . Close monitoring of thyroid hormone parameters is recommended.
Coumarin derivatives : ( warfarin, acenocoumarol) The effects of anticoagulant therapy may be potentiated, as levothyroxine displaces anticoagulant drugs from plasma proteins and this may increase the risk of bleeding , eg. gastrointestinal or central nervous system bleeding, especially in elderly patients. Therefore, coagulation parameters should be monitored regularly at the beginning and during concomitant thyroid therapy. Where necessary, the dosage of the anticoagulant drug should be adjusted.
Tricyclic antidepressants : Levothyroxine increases receptor sensitivity to catecholamines thus accelerating the response to tricyclic antidepressants (such as amitriptyline, imipramine).
Digitalis preparations: If levothyroxine therapy is initiated in patients treated with digitalis, the digitalis dose may need to be adjusted. As treatment progresses, hyperthyroid patients may require a gradual increase in digoxin dose , as patients are initially relatively sensitive to digoxin.
Sympathomimetic Agents : The effects of sympathomimetic agents (such as adrenaline ) are enhanced.
Some drugs intensify the effect of levothyroxinewhen used in combination: Salicylates, dicumarol, high-dose furosemide (250 mg), clofibrate, phenytoin and other substances can displace levothyroxine from plasma proteins, thus resulting in a high fT4 fraction.
Other drugs can reduce the effect of levothyroxine:
Orlistat. Hypothyroidism and / or reduced control of hypothyroidism may occur when orlistat and levothyroxine are taken together. This may be due to decreased absorption of iodine and / or levothyroxine salts. Patients taking levothyroxine should consult their doctor before starting treatment with orlistat, as orlistat and levothyroxine may need to be taken at different times and the levothyroxine dose may need to be adjusted. In addition, it is recommended to monitor the patient by checking serum hormone levels.
Sevelamer: can reduce the absorption of thyroxine. Therefore, it is recommended that patients be monitored for changes in thyroid function at the start or end of concomitant treatment. If necessary, the levothyroxine dose should be changed.
Tyrosine kinase inhibitors (imatinib, sunitinib): may reduce the efficacy of levothyroxine. Therefore, it is recommended that patients be monitored for changes in thyroid function at the start or end of concomitant treatment. If necessary, the levothyroxine dose should be changed.
Ion exchange resins(cholestyramine): inhibit the absorption of levothyroxine sodium. Levothyroxine sodium should therefore be taken 4-5 hours before the administration of cholestyramine. The same goes for colestipol.
Aluminum, iron and calcium salts : drugs containing aluminum (antacids, sucralfate) can reduce the effect of levothyroxine. For this reason, levothyroxine-containing drugs should be administered at least 2 hours prior to administration of aluminum-containing drugs. The same applies to drugs containing iron and calcium salts .
Propylthiouracil, glucocorticoids, beta-sympatholytics, amiodarone and iodine-containing contrast media: These substances inhibit the peripheral conversion of T4 to T3. Due to the high amount of iodine it contains, amiodarone can trigger both hyperthyroidism and hypothyroidism.
Sertraline, chloroquine / proguanil : These substances decrease the effectiveness of levothyroxine and increase the serum TSH levels.
Medicinal products which induce liver enzymes : Barbiturates and other hepatic enzyme inducing drugs may increase the hepatic elimination of levothyroxine.
Estrogen : Women using estrogen-containing contraceptives or postmenopausal women taking hormone replacement therapy ( raloxifene ) may have an increased requirement for levothyroxine.
Antiepileptic drugs: While taking Eutirox should not be given phenytoin intravenously. Co-administration with carbamazepine may reduce plasma levels of free levothyroxine.
Compounds containing soy : Compounds containing soy may decrease intestinal absorption of levothyroxine. A dose adjustment of Eutirox may therefore be necessary, particularly at the beginning or end of the period of taking soy supplements.
Quinlones : An interval of at least 6 hours is recommended between oral administration of levothyroxine and ciprofloxacin as this may reduce levothyroxine levels. Monitor thyroid function tests closely.
Appropriate clinical and laboratory parameters should be monitored during levothyroxine therapy. When the individual tolerance limit for levothyroxine sodium is exceeded or after an overdose, the following symptoms typical of hyperthyroidism may appear, especially if the dose is increased too quickly at the start of therapy:
Cardiac disorders ( tachycardia , palpitations, cardiac arrhythmias , anginal manifestations, heart failure, myocardial infarction);
Nervous system disorders ( headache , brain pseudotumors, tremor, restlessness, insomnia, agitation. Seizures have rarely been reported in association with levothyroxine therapy);
Vascular disorders (hypertension, hot flashes); Musculoskeletal and connective tissue disorders (muscle weakness, skeletal muscle cramps, craniosynostosis in the infant and premature closure of the epiphysis in the infant); Gastrointestinal disorders (increased appetite, abdominal pain, nausea, diarrhea, vomiting); Respiratory, thoracic and mediastinal disorders (dyspnoea); Metabolism and nutrition disorders (weight loss); Reproductive system and breast disorders (changes in the menstrual cycle);
General disorders and administration site conditions (redness, fever and hyperhidrosis ); Heat intolerance and transient hair loss in children
have also been reported . In such cases the daily dosage must be reduced or the drug must be suspended for a few days. Therapy can be resumed with caution when the adverse reactions have resolved; Immune system disorders (allergic reactions may occur in case of hypersensitivity. Cases of angioedema have been reported ).
It is important to report suspected adverse reactions that may occur after the marketing authorization of the drug, as this allows continuous monitoring of the benefit / risk ratio of the drug. Healthcare professionals, but also patients, are asked to report any suspected adverse reactions via the national reporting system at https://www.vigifarmaco.it/ .
Overdose
A high level of T3 is a more reliable indicator of overdose than high levels of T4. After an overdose, symptoms of a sharp acceleration of the metabolism occur . An overdose of levothyroxine can cause hyperthyroidism and can cause symptoms of acute psychosis , especially in patients at risk for psychotic disorders .
In the event of an overdose, it is advisable to stop treatment with the tablets and carry out the appropriate tests.
Symptoms due to intense beta-sympathomimetic effects (tachycardia, anxiety , agitation and hyperkinesis) can be improved by taking a beta-blocker. Plasmapheresis can help in the case of large doses.
In predisposed patients, isolated cases of seizures have been reported when the individual tolerance limit was exceeded. There have been several reported cases of sudden cardiac arrest death in patients with a history of abuse lasting several years.
Pregnancy and breastfeeding
Levothyroxine treatment should be kept constant , especially during pregnancy and lactation . The necessary dosages may also increase during pregnancy. Because increases in serum TSH can occur as early as the fourth week of pregnancy, pregnant women taking levothyroxine should measure their TSH in each trimester and evaluate the values with their doctor to confirm that these values are within the range. specific reference for that trimester of pregnancy. An elevated serum TSH level must be corrected by increasing the levothyroxine dose. Since postpartum TSH levels are similar to pre-conception values, the levothyroxine dosage should return to pre-pregnancy immediately after delivery. Serum TSH should be checked 6-8 weeks after delivery.
Excessively high doses of levothyroxine during pregnancy can have a negative effect on fetal and postnatal development .
Levothyroxine is secreted into breast milk during lactation but the concentrations reached at the recommended therapeutic doses are not sufficient to cause the development of hyperthyroidism or the suppression of TSH secretion in the newborn. During pregnancy, levothyroxine should not be given in combination with drugs for hyperthyroidism (antithyroid drugs), as the addition of levothyroxine may require a higher dose of antithyroid drug which passes through the placenta thus inducing hypothyroidism in the newborn.
Since antithyroid drugs, in contrast to levothyroxine, can cross the placenta in quantities sufficient to exert pharmacological effects, concomitant therapy with levothyroxine requiring a higher dosage of antithyroid drug could induce hypothyroidism in the fetus .
Consequently, antithyroid drugs should always be administered alone in hyperthyroidism in pregnancy .
Notes (methods of storage, validity)
The tablets of 25, 50, 75, 100, 125, 150, 175, 200 micrograms have a shelf life of 3 years . The 88, 112, 137 microgram tablets are valid for 18 months.
Store below 25 ° C in the original package to protect from light.
Keep this medicine out of the sight and reach of children.
Do not dispose of any medications via wastewater or household waste. Ask your pharmacist how to throw away drugs you no longer use. This will help protect the environment.
Questions and answers
DOES TAKING EUTIROX CAUSE WEIGHT LOSS?
Thyroid hormones should not be given for weight reduction. In patients with normal thyroid hormone levels, treatment with levothyroxine does not lead to weight reduction. Levothyroxine in high doses should not be combined with substances used for weight reduction, eg. sympathetic-mimetic drugs.
WHAT ARE THE SIDE EFFECTS?
When the individual tolerance limit for levothyroxine sodium is exceeded or after an overdose, the following symptoms typical of hyperthyroidism may appear, especially if the dose is increased too quickly at the start of therapy: heart, nervous system, seizures , vascular, musculoskeletal and connective tissue disorders, gastrointestinal or respiratory disorders, metabolism and nutrition disorders, reproductive system and breast disorders, systemic diseases, immune system disorders.
