Each Synthroid pill consists of: levothyroxine sodium, 25, 50 or 100 mcg. Milk sugar, kollidon, talc, magnesium stearate, calcium hydrogen phosphate.
Form of issue:
- Thyroid hormone for replacement therapy.
Pharmacodynamics and pharmacokinetics:
- The drug Levothyroxine is a synthetic levorotatory form of the hormone thyroxine (T4), which is identical to the hormone produced by the thyroid gland. After metabolism in the liver is converted into an active form of T3, which already affects the metabolism and development of tissues. Mechanisms of effects are due to binding to the genome, the change in metabolism in the mitochondria. In small doses has an anabolic effect. Taking Levothyroxine in medium doses stimulates growth, metabolism, increases the activity of the central nervous system and the CCC. This increases the need for oxygen. The use of levothyroxine in high doses reduces the production of thyroid-stimulating hormone. It is used to treat hypothyroidism. The effect of hypothyroidism occurs after 3-4 days. With diffuse goiter the thyroid gland decreases in 3-6 months.
- When taken on an empty stomach, it is absorbed by 70-80%. Absorption decreases after eating. The maximum concentration is determined after 6 hours. It binds to proteins by 99%.
- Metabolism with the formation of triiodothyronine occurs in the liver, as well as muscles. Triiodothyronine has a more pronounced hormonal effect. The elimination half-life is about 6-8 days. 15% of the dose is excreted in urine and bile.
Indications for use:
- Deficiency of thyroid hormones;
- Euthyroid goiter;
- Condition after resection;
- Malignant formation (replacement therapy after removal of the thyroid gland);
- Autoimmune thyroiditis and Graves’ disease.
With caution is prescribed for diseases of SSS, insufficiency of the adrenal cortex, diabetes, thyrotoxicosis, severe hypothyroidism, malabsorption syndrome.
- Itching, skin rash;
- Thyrotoxicosis (dysmenorrhea, diarrhea, chest pain, tachycardia, fever, arrhythmia, tremor, irritability, headache, lower extremity cramps, nervousness, weight loss);
- Pseudotumor brain;
- Hypothyroidism (at effective doses).
- Levothyroxine, instructions for use (Method and dosage)
- Doses of levothyroxine depend on the clinical picture and severity of hypothyroidism. They are selected individually by a doctor after the investigation of thyroid hormones. Treatment begins with small doses, gradually increasing to an effective dose.
How to take Levothyroxine?
- Tablets are taken orally, on an empty stomach with a small amount of water. The dose is taken once in the morning. In some cases, on the recommendation of a doctor, the dose is divided in half and taken up to 11-12 hours a day.
- In hypothyroidism, the initial dose is 50-100 μg, with the transition to the supporting dose – 125-250 μg.
- With congenital hypothyroidism – at 6 months – 8-10 mkg per kg of weight per day, 6-12 months – 6-8 mkg per kg of weight per day.
- When endemic goiter – first 50 mcg per day, bringing to 100-200 mcg.
Euthyroid goiter – 100-200 mcg per day.
- Overdose manifests thyrotoxic crisis.
- With moderate signs of an overdose, the dose of the drug decreases, and if signs are expressed, gastric lavage is performed, colestyramine, beta-adrenoblockers, cardiac glycosides, oxygen therapy, GCS are prescribed. You can not prescribe antithyroid drugs.
- Kolestyramin, preparations of aluminum and colestipol reduce intestinal absorption and concentration in the plasma.
- Phenytoin reduces the amount of active substance associated with the protein. Estrogens reduce effectiveness.
- The metabolism of the drug is affected by amiodarone, PASK, ethionamide, beta-adrenoblockers, chloral hydrate, carbamazepine, levodopa, diazepam, dopamine, lovastatin.
- The active substance reduces the effect of insulin, cardiac glycosides and enhances the effect of tricyclic antidepressants.
- When used with salicylates, furosemide, clofibrate, the plasma concentration of the drug increases.
Terms of sale:
- Without recipe.
- Temperature up to 25 ° С.
- 2 years.