What Are the Concerns about Levothyroxine in Pregnancy?

Youjiale (Left Thyroxine Sodium Tablets), the indications are: 1. Treatment of non-toxic goiter (normal thyroid function). 2. Prevent goiter recurrence after goiter resection. 3. Alternative treatment for hypothyroidism. 4. Adjuvant treatment of antithyroid drugs for hyperthyroidism. 5. Inhibition treatment for thyroid cancer after surgery. 6. Thyroid suppression test.

Drug Name: Euthyrox

Drug type: Prescription medicines, essential medicines, medicines for medical workers' injuries
Use classification: Thyroid hormones

Ukulele ingredients

The main ingredient of this product is sodium levothyroxine. Its chemical name is sodium 4-oxy- (4-hydroxy-3,5-diiodophenyl) -3,5-diiodo-L-tyrosine.

Molecular formula: C ₁₅ H ₂₅ I ₄ NNaO ₄ · xH ₂ O
Molecular weight: 799 (anhydrous)

Youjiale Traits

This product is white or off-white round tablets. One side is marked with "ten", and the other side is marked with "EM 50" (50g size) or "EM l00" (100g size).

Uniform Indications

1. Treat non-toxic goiter (normal thyroid function).
2. Prevent goiter recurrence after goiter resection.
3. Alternative treatment for hypothyroidism.
4. Adjuvant treatment of antithyroid drugs for hyperthyroidism.
5. Inhibition treatment for thyroid cancer after surgery.
6. Thyroid suppression test.

Youjiale Specifications

50 g; 100 g.

Youjiale usage dosage

The recommended dosage in this item is a general principle. The daily dose of an individual patient should be determined based on the results of laboratory tests and clinical examinations.
Because T4 and fT4 levels rise in many patients, the basal concentration of thyroid stimulating hormone in the serum is a reliable basis for determining the treatment.
In addition to the rapid dose increase that is very important for newborns, thyroid hormone therapy should generally be started from a low dose and gradually increased every 2-4 weeks until a full dose is reached.
For elderly patients, patients with coronary heart disease, and patients with severe or long-term hypothyroidism, special attention should be paid to the stage of starting thyroid hormone therapy. A lower initial dose (such as 12.5 g / day) should be selected and the interval should be longer Slowly increase the dose (eg 12.5 g / day every two weeks). It is also worth noting that if the final maintenance dose given to the patient is below the optimal dose, its TSH level cannot be completely corrected.
Experience has shown that low-dose administration is effective for lighter patients and patients with large nodular goiter.
Daily dosage of levothyroxine sodium 50g dosage 100g dosage method Goiter (normal thyroid function) 75-200g 3 / 2-4 tablets 3 / 4-2 tablets once a day to prevent thyroid recurrence after thyroidectomy 75 -200g 3 / 2-4 tablets 3 / 4-2 tablets once daily hypothyroidism in adults-initial dose 25-50g 1 / 2-1 tablets 1 / 4-1 / 2 tablets once daily (every 2 after the initial dose -4 weeks increase 25-50 g until the maintenance dose)
-Maintenance dose 100-200g 2-4 tablets once a day hypothyroidism in children -Initial dose 12.5-50g 1 / 4-1 tablets 1 / 8-1 / 2 tablets once daily -Maintenance dose 100-150g / m2 body surface area 2-3 tablets / m2 body surface area 1-3 / 2 tablets / m2 body surface area once daily adjuvant treatment of hyperthyroidism 50-100 g 1-2 tablets 1 / 2-1 tablet once daily thyroid cancer surgery After 150-300g-1 and a half-3 tablets once daily thyroid suppression test 200g-2 tablets once daily thyroid cancer suppression treatment (recommended daily dose is 150-300g), in order to precisely adjust the patient's medication dose , 50g of this product can be used with other high-dose tablets.
Levothyroxine sodium tablets should be taken half an hour before breakfast on a fasting day with a suitable liquid (such as half a glass of water) in a single dose.
Infants and young children take the full dose of this product at least 30 minutes before the first daily meal. The tablets can be mashed with a suitable amount of water to make a suspension. But remember that this step needs to be performed temporarily before taking the medicine. The resulting drug suspension can then be taken with an appropriate liquid.
Under normal circumstances, patients with hypothyroidism, patients with partial or complete thyroidectomy, and patients with goiter removal to prevent goiter recurrence should take medicine for life. When combined with this product to treat hyperthyroidism, this product is administered The cycle should be the same as for antithyroid drugs.
For benign goiter, a course of 6 months to 2 years is necessary. In order to avoid recurrence of goiter, it is recommended to use low-dose iodine (100-200 g) for prevention after goiter shrinkage. If these drugs are not enough to relieve goiter, surgery and radioactive iodine treatment should be considered.

Youjiale adverse reactions

This product is used for treatment. If you take the medicine as prescribed by your doctor and monitor the clinical and laboratory indicators, generally no adverse reactions will occur. If the individual's tolerated dose is exceeded or the drug is taken in excess, especially because the dose is increased too quickly at the beginning of treatment, the following clinical symptoms of hyperthyroidism may occur, including: tachycardia, palpitations, arrhythmia, angina, headache, muscle weakness And cramps, flushing, fever, vomiting, menstrual disorders, pseudo-brain tumors, tremors, restlessness, insomnia, sweating, weight loss and diarrhea.
In these cases, the patient's daily dose should be reduced or discontinued for several days. Once these symptoms have disappeared, patients should carefully restart medication.
For some hypersensitivity patients, allergic reactions may occur.

Youjiale taboo

Those who are highly sensitive to this product and its accessories.
Untreated adrenal insufficiency, hypopituitarism, and thyrotoxicosis.
Application of this product should not be started from the acute myocardial infarction period, acute myocarditis and acute pancarditis.
This product is not used in combination with antithyroid drugs to treat hyperthyroidism during pregnancy.

Precautions

Patients must not suffer from or be treated for the following diseases before starting thyroid hormone therapy: coronary heart disease, angina pectoris, arteriosclerosis, hypertension, hypopituitarism, inadequate adrenal function, and autonomous high-functioning thyroid tumor .
For patients with coronary heart disease, cardiac insufficiency, or tachycardia arrhythmia, care must be taken to avoid the use of levothyroxine and even mild hyperthyroidism. Therefore, these patients should often be monitored for thyroid hormone levels.
For secondary hypothyroidism, the cause must be determined before using this product for replacement therapy, and if necessary, supplemental treatment with glucocorticoids should be performed.
If autonomic high-function thyroid tumors are suspected, a TRH test or scintigraphic scan should be obtained before treatment begins.
For postmenopausal women with an increased risk of hypothyroidism and osteoporosis, supraphysiological serum levels of levothyronin should be avoided, and thyroid function should be closely monitored.
This product can be used for concomitant supplementary treatment only when antithyroid drugs are used for hyperthyroidism. Otherwise, levothyroxine cannot be used alone in the case of hyperthyroidism.
Once a levothyroxine treatment has been identified. In the case of changing medicines, it is recommended to adjust the dose according to the clinical response of the patient and the results of laboratory tests.
Rare patients with hereditary galactose intolerance, Lapp lactase deficiency or glucose galactose malabsorption should not take this product.
For patients with diabetes and patients undergoing anticoagulation, see "Drug Interactions".
Taking this product will not affect driving and operating the machine.

Medication for pregnant women and lactating women

Special attention should be paid to the continued use of thyroid hormones during pregnancy and lactation. The dose of this product may increase during pregnancy. So far, although this product is widely used by pregnant women, there have been no reports that this product is harmful to infants. In the case of high-dose levothyroxine treatment, the amount of thyroid hormones released into the milk during breastfeeding is not sufficient to cause infants with hyperthyroidism or suppression of TSH secretion.
During pregnancy, levothyroxine and antithyroid drugs should not be used in combination to treat hyperthyroidism, because the addition of levothyroxine increases the dose of antithyroid drugs.
Unlike levothyroxine, effective doses of antithyroid drugs can pass through the placenta, so combined treatment with levothyroxine requires higher doses of antithyroid drugs, which may cause fetal hypothyroidism. Therefore, breastfeeding women with left hyperthyroidism must be treated with antithyroid drugs alone.

Youjiale medication for children

See "Dosage and Administration."

Youjiale elderly medicine

See "Dosage and Administration."

Youjiale Drug Interaction

[u] Antidiabetic drugs: [/ u]
L-thyroxine may reduce the hypoglycemic effect of this class of drugs. Therefore, when starting thyroid hormone therapy, the patient's blood glucose level should be monitored frequently, and if necessary, the dose of diabetes medication should be adjusted.
[u] coumarin derivatives: [/ u]
Levothyroxine can replace the combination of anticoagulants with plasma proteins, thereby enhancing its effect. Therefore, when starting thyroxine therapy, the coagulation index should be monitored regularly, and the dose of anticoagulant should be adjusted if necessary.
[u] Cholestyramine, Colestipol: [/ u]
Cholestyramine inhibits the absorption of levothyroxine sodium, so levothyroxine sodium should be taken 4-5 hours before taking choline.
Colestipol is the same as cholestyramine.
[u] Aluminum-containing drugs, iron-containing drugs and calcium carbonate: [/ u]
Related literature reports that aluminum-containing drugs (antacids, Weikui Ning) may reduce the effect of levothyroxine. Therefore, levothyroxine-containing drugs should be taken at least 2 hours before taking aluminum-containing drugs.
Iron-containing drugs and calcium carbonate are the same as aluminum-containing drugs.
[u] Salicylates, dicoumarins, furosemide, antamine, and phenytoin: [/ u]
Hydrochloride, dicoumarin, high-dose furosemide (250mg), antrum, phenytoin, etc. can replace the combination of levothyroxine and plasma proteins, resulting in increased fT4 levels.
[u] propylthiouracil, glucocorticoids, -sympathomimetics, amiodarone, and iodine-containing contrast agents: [/ u]
These drugs can inhibit the conversion of peripheral T4 to T3.
Amiodarone has a high iodine content, which can cause hyperthyroidism and hypothyroidism. Special attention should be paid to nodular goiter with unknown autonomy.
[u] sertraline, clotrim / proguanil: [/ u]
These drugs can reduce the effect of levothyroxine and increase serum TSH levels.
[u] Barbiturate: [/ u]
Barbiturates have the property of inducing liver drug enzymes and can increase the liver clearance of levothyroxine.

Youjiale drug overdose

Elevated T3 levels are an effective way to determine drug overdose and are more reliable than elevated T4 or fT4 levels.
Overdose of this product will cause a sharp increase in metabolic rate.
Depending on the extent of the drug overdose, it is recommended to discontinue and check.
Symptoms of overdose include strong beta-sympathomimetic effects such as tachycardia, anxiety, agitation, and hyperkinesia, which can be alleviated with beta blockers. In the case of extreme drug overdose, plasmapheresis can be used.
During the period of poisoning that has occurred (such as attempted suicide), the human body can tolerate 10 mg of levothyroxine without complications. It has been reported that patients with long-term abuse of this product will experience sudden cardiac death.

Youjiale Pharmacology and Toxicology

[u] Pharmacology: [/ u]
This product contains the same synthetic levothyroxine and thyroid hormone naturally secreted by the thyroid. Like endogenous hormones, it is converted to T3 in peripheral organs and then exerts its specific role by binding to the T3 receptor. The human body cannot distinguish between endogenous or exogenous levothyroxine.
[u] Toxicology: [/ u]
Levothyroxine has very slight acute toxicity. Through chronic toxicity studies of different species of animals (rats, dogs), it was found that when high doses of levothyroxine sodium were given to rats, signs of liver disease appeared, the incidence of spontaneous kidney disease increased, and organ weights changed. Only a very small number of ineffective thyroid hormones pass through the placenta. There are sufficient human trial data to show that the application of levothyroxine in different stages of pregnancy has no toxic effects on the fetus and will not cause deformities. There are no reports that this product will damage the fertility of men or women, nor is there any indication that fertility damage is related to this product. No information on the mutagenicity of this product is available. So far, there is no indication that thyroid hormones can cause genomic changes that could harm offspring. Regarding the carcinogenic effects of levothyroxine, no long-term animal tests have been conducted.

Youjiale Pharmacokinetics

After oral administration of levothyroxine sodium, most of it is absorbed in the upper end of the small intestine. With galenical preparation, the absorption of this product can reach more than 80%, and the peak time (t _max ) is about 5 to 6 hours.
This product takes effect 3-5 days after oral administration. The binding rate of levothyroxine to a specific transporter is extremely high, about 99.97%. This protein-hormone binding is not a covalent structure, so the bound and free hormones in the plasma exchange continuously and very quickly.
Due to its high protein-binding rate, levothyroxine cannot be used during hemodialysis and hemoperfusion.
The average half-life of levothyroxine is 7 days. For patients with hyperthyroidism, the half-life of this product is shortened (3-4 days), and for patients with hypothyroidism, the half-life of this product is extended (9-10 days). The distribution volume of this product is about 10-12 liters. The liver contains one-third of the intact levothyroxine secreted by the thyroid, which can be quickly exchanged with levothyroxine in the serum. Thyroid hormones are mainly metabolized in the liver, kidneys, brain and muscle. Metabolites are excreted via urine and feces. The total metabolic clearance of levothyroxine is approximately 1.2 liters of plasma / day.

Youjiale storage

Store in a dry environment below 25 ° C, protected from light.

Youjiale Packaging

Aluminum-plastic packaging.
100 tablets / box

Youjiale validity period

36 months.

Excellent Jiale implementation standards

Import drug registration standard JX20030195

Excellent Jiale Production Enterprise

Merck KGaA, Darmstadt

Youjiale Approval Date

February 20, 2007

Youjiale Revision Date

July 15, 2010