Thyroid Hormone Replacement Therapy

Consider changes in TBG concentration when interpreting T4 and T3 values. Measure and evaluate unbound (free) hormone and/or determine the free-T4 index (FT4I) in this circumstance. Pregnancy, infectious hepatitis, estrogens, estrogen-containing oral contraceptives, and acute intermittent porphyria increase TBG concentration. Nephrosis, severe hypoproteinemia, severe liver disease, acromegaly, androgens, and corticosteroids decrease TBG concentration.

• Additionally, TSH goal achievers incurred significantly lower average medical and total all-cause and hypothyroidism-related costs than non-achievers.
• SYNTHROID® (levothyroxine sodium) tablets, for oral use is a prescription, man-made thyroid hormone that is used to treat a condition called hypothyroidism in adults and children, including infants.
• The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for SYNTHROID and any potential adverse effects on the breastfed infant from SYNTHROID or from the underlying maternal condition.
• Note that this list is not all-inclusive and includes only common medications that may interact with Synthroid.

Associated Data

As you get older, you might not need as much Synthroid to keep your thyroid hormones in balance. If you are elderly and are just starting treatment for hypothyroidism, your doctor may start you on a lower dose of medicine. Concurrent use of tricyclic (e.g., amitriptyline) or tetracyclic (e.g., maprotiline) antidepressants and SYNTHROID may increase the therapeutic and toxic effects of both drugs, possibly due to increased receptor sensitivity to catecholamines.

Drug-Food Interactions

Costs are reported per patient and were adjusted to 2017 USD price levels using the medical care index provided by the Bureau of Labor Statistics. Secondary outcomes were measured in a subset of matched patients from the primary objective with complete pharmacy cost capture. Thyroid hormones, including SYNTHROID, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss.

• HypothyroidismSYNTHROID® (levothyroxine sodium) tablets, for oral use is indicated as a replacement therapy in primary (thyroidal), secondary (pituitary), and tertiary (hypothalamic) congenital or acquired hypothyroidism.
• Closely monitor infants during the first 2 weeks of SYNTHROID therapy for cardiac overload and arrhythmias.
• Compared with patients who received GL, significantly fewer patients in the Synthroid treatment group had TSH levels outside the recommended range (0.3 to 4.12 mIU/L) and a smaller proportion was undertreated 9, 10.
• Whereas no significant difference between the two groups in all-cause pharmacy fills was observed, the Synthroid cohort had significantly more hypothyroidism-related prescription fills per patient than the GL cohort.
• Published studies report that levothyroxine is present in human milk following the administration of oral levothyroxine.

If this SPL contains inactivated NDCs listed by the FDA initiated compliance action, they will be specified as such.

NP Thyroid is used for hashimoto’s disease, hypothyroidism, after thyroid removal, thyroid cancer … Tirosint is used for hashimoto’s disease, hypothyroidism, after thyroid removal, myxedema coma … It may take several weeks before your body starts to respond to Synthroid. You may not be able to take Synthroid if you have certain medical conditions. Tell your doctor if you have an untreated or uncontrolled adrenal gland disorder, a thyroid disorder called thyrotoxicosis, or if you have any recent or current symptoms of a heart attack.

Administer thyroid hormone products formulated for intravenous administration to treat myxedema coma. Dosage titration is based on serum TSH or free-T4 see Dosage and Administration (2.2). For secondary or tertiary hypothyroidism, serum TSH is not a reliable measure of SYNTHROID dosage adequacy and should not be used to monitor therapy.

Data Availability Statement

Levothyroxine monotherapy (Synthroid® or multiple generic levothyroxine GL formulations) is standard treatment for hypothyroidism. Our objective was to compare effectiveness (as measured by achievement of thyroid-stimulating hormone TSH levels) and economic outcomes of Synthroid vs. any one of multiple GLs in patients with hypothyroidism. Rapid restoration of normal serum T4 concentrations is essential for preventing the adverse effects of congenital hypothyroidism on cognitive development as well as on overall physical growth and maturation. Therefore, initiate SYNTHROID therapy immediately upon diagnosis. Levothyroxine is generally continued for life in these patients see WARNINGS AND PRECAUTIONS. Levothyroxine is generally continued for life in these patients see Warnings and Precautions (5.1).

Monitor serum free-T4 levels and maintain in the upper half of the normal range in these patients. Inquire whether patients are taking biotin or biotin-containing supplements. If so, advise them to stop biotin supplementation at least 2 days before assessing TSH and/or T4 levels see Dosage and Administration (2.4) and Drug Interactions (7.10). In a subpopulation with at least 2 TSH values recorded over 12months follow-up, we found directionally consistent results that were not statistically significant. In this analysis, the sample size was considerably reduced (containing only 21% of the base case cohort), which may contribute to statistical uncertainty.

Antidepressant Therapy

Many drugs and physiologic conditions affect the binding of thyroid hormones to serum proteins see Drug Interactions (7). Thyroid hormones do not readily cross the placental barrier see Use in Specific Populations (8.1). Published studies report that levothyroxine is present in human milk following the administration of oral levothyroxine.

In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction. Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects. Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects.

Circulating thyroid hormones are greater than 99% bound to plasma proteins, including thyroxine-binding globulin (TBG), thyroxine-binding prealbumin (TBPA), and albumin (TBA), whose capacities and affinities vary for each hormone. The higher affinity of both TBG and TBPA for T4 partially explains the higher serum levels, slower metabolic clearance, and longer half-life of T4 compared to T3. Protein-bound thyroid hormones exist in reverse equilibrium with small amounts of free synthroid indications hormone.