Levothyroxine sodium

Sodium Levothyroxine. As one of the active principles of the thyroid gland, sodium levothyroxine [55-03-8] (levothyroxine sodium) can be obtained either from the thyroid glands of domesticated animals (10) or synthetically. It should contain 61.6—65.5% iodine, corresponding to 100 3% of the pure salt calculated on an anhydrous basis. Its chiral purity must also be ascertained because partial racemi2ation may occur during synthesis and because dl-T is available commercially. Sodium levothyroxine melts with decomposition at ca 235°C. It is prepared as pentahydrate [6106-07-6] from... 

Levatrom - Clofibrate Levaxin - Levothyroxine sodium Levjcor -Metaraminol Levisul Sulfadimethoxine Levium Diazepam Levius Aspirin... 

Q76 Levothyroxine sodium is the synthetically prepared sodium salt of the natural isomer of thyroid hormone. Levothyroxine sodium tablets are unstable and require administration on an empty stomach. 

For most patients older than 50 years of age or for patients younger than 50 years of age with underlying cardiac disease, an initial starting dose of 25 to 50 mcg/day of levothyroxine is recommended, with gradual increments in dose at 6- to 8-week intervals, as needed. The recommended starting dose of levothyroxine sodium in elderly patients with cardiac disease is 12.5 to 25 mcg/day, with gradual dose increments at 4- to 6-week intervals. 

Synthetic levothyroxine sodium is used most commonly and is the drug of choice. Oral doses are incompletely absorbed. In plasma levothyroxine is for more than 99% bound to proteins, mainly to TBG. Maximal effects are reached in 3 weeks and the activity persists for 1-3 weeks after withdrawal of chronic therapy. It has a half-life of 7 days which permits once-daily administration. Its adverse effects mainly consist of signs and symptoms of hyperthyroidism. 

Levothyroxine sodium (Levothwid, Synthroid, Levoxine) is the sodium salt of the naturally occurring levorota-tory isomer of T4. It is the preparation of choice for maintenance of plasma T4 and T3 concentrations for thyroid hormone replacement therapy in hypothyroid patients. It is absorbed intact from the gastrointestinal tract, and its long half-life allows for convenient once-daily administration. Since much of the T4 is deiodi-nated to T3, it is usually unnecessary to use more expensive preparations containing bothX4 and Tj.The aim is to establish euthyroidism with measured serum concentrations of T4, T3, and TSH within the normal range. 

Liotrix (Euthroid, Thywlar) is a 4 1 mixture of levothyroxine sodium and liothyronine sodium. Like levothyroxine, liotrix is used for thyroid hormone replacement therapy in hypothyroid patients. Although the idea of combining T4 and T3 in replacement therapy so as to mimic the normal ratio secreted by the thyroid gland is not new, it does not appear that liotrix offers any therapeutic advantage over levothyroxine alone. 

Thyroid hormones levothyroxine sodium liothyronine sodium thyroid... 

Lithium Plus Thyroid Supplementation. Treatment-resistant and rapid-cycling bipolar patients may have an increased frequency of thyroid dysfunction. Further, some patients suffer from subclinical hypothyroidism and improve with the addition of thyroid supplementation. In this context, several case reports involving this population found that high doses of the thyroid hormone levothyroxine sodium (T ) were clinically beneficial (122,123 and 124). Kusalic (1.25) found that 6 of 10 rapid cyclers had hypothyroidism, based on their thyrotropin-releasing hormone stimulation tests. Further, the average number of mood episodes per year decreased by more than 75% (i.e., from 9.7 to 2.2) after thyroxine was added to the treatment regimen. 

Bauer et al. (126) entered 11 rapid-cycling, treatment-refractory patients into an open trial of high-dose levothyroxine sodium, added to their previously stabilized medication regimen. The dosage of the levothyroxine was increased by 0.05 to 0.1 mg/day every 1 to 2 weeks, as tolerated, until symptoms improved or adverse effects prevented further increases. Scores on both the depressive and the manic symptom rating scales decreased significantly compared with baseline scores. 

I. Levothyroxine sodium Citric acid, anhydrous Magnesium stearate.. 

---