LevothyroxinNatrium

LevothyroxinNatrium is a synthetic thyroid hormone replacement medicine. It is the sodium salt of levothyroxine (T4) and functions as a substitute for endogenous thyroid hormones in the body. It is used to treat hypothyroidism of various causes and, in some cases, to suppress thyroid-stimulating hormone (TSH) in differentiated thyroid carcinoma after thyroid surgery or radioiodine therapy.

Administration and dosing are personalized and typically involve lifelong therapy. The medicine is usually taken once daily, preferably on an empty stomach with a full glass of water, at least 30 to 60 minutes before breakfast. Some patients may take it in the evening if a consistent schedule is maintained. The starting dose for adults is commonly 25 to 50 micrograms daily, with gradual increases by 12.5 to 25 micrograms every 3 to 6 weeks until TSH levels normalize. Pediatric dosing depends on age and weight.

Interactions and monitoring are important. Absorption can be reduced by iron or calcium supplements, certain antacids, bile acid sequestrants, and some dietary factors; these should be taken several hours apart. Drugs that induce liver enzymes (for example rifampin, carbamazepine, phenytoin) may increase clearance and require dose adjustments. Regular monitoring of TSH and free T4 is recommended, with adjustments based on laboratory results and clinical status. In pregnancy, thyroid hormone requirements often rise, necessitating dose changes.

Contraindications and safety: LevothyroxinNatrium is contraindicated in untreated thyrotoxicosis and in individuals with hypersensitivity to the drug. Caution is advised in cardiovascular disease, diabetes, and adrenal insufficiency. Common adverse effects at excessive doses resemble hyperthyroidism, including palpitations, tremor, anxiety, heat intolerance, and weight loss.

Pharmacology and storage: The drug has a long half-life and is absorbed in the small intestine, with hepatic metabolism and renal/biliary excretion of metabolites. Store at room temperature away from light and moisture.