Oral levothyroxine is approved for use as a replacement therapy in hypothyroidism. Use the serum free-T4 level to monitor adequacy of therapy in this patient population. Measure and evaluate unbound (free) hormone and/or determine the free T4 index (FT4I) in this circumstance. In patients on a stable and appropriate replacement dose, evaluate clinical and biochemical response every 6 to 12 months and whenever there is a change in the patient's clinical status.In patients with congenital hypothyroidism, assess the adequacy of replacement therapy by measuring both serum TSH and total or free-T4. This hormone nuclear receptor complex activates gene transcription and synthesis of messenger RNA and cytoplasmic proteins.The physiological actions of thyroid hormones are produced predominantly by T3, the majority of which (approximately 80%) is derived from T4 by deiodination in peripheral tissues.Oral Levothyroxine sodium is a synthetic T4 hormone that exerts the same physiologic effect as endogenous T4, thereby maintaining normal T4 levels when a deficiency is present.Absorption of orally administered T4 from the gastrointestinal tract ranges from 40% to 80%. COVID-19 is an emerging, rapidly evolving situation. [see Dosage and Administration (2.3), Warnings and Precautions (5)Primary Hypothyroidism in Adults and in Adolescents in Whom Growth and Puberty are CompletePediatric Dosage - Congenital or Acquired Hypothyroidism[see Dosage and Administration (2.4) and Use in Specific Populations (8.4)] .TSH Suppression in Well-differentiated Thyroid Cancer[see Warnings and Precautions (5.1) and Use in Specific Populations (8.4).5.1 Cardiac Adverse Reactions in the Elderly and in Patients with Underlying Cardiovascular Disease[see Dosage and Administration (2.3), Use in Specific Populations (8.5).5.3 Acute Adrenal Crisis in Patients with Concomitant Adrenal Insufficiency5.4 Prevention of Hyperthyroidism or Incomplete Treatment of Hypothyroidism[see Drug Interactions (7.9) and Clinical Pharmacology (12.3).5.6 Decreased Bone Mineral Density Associated with Thyroid Hormone Over-Replacement[see Warnings and Precautions (5), Overdosage (10)]7.1 Drugs Known to Affect Thyroid Hormone PharmacokineticsDisease-Associated Maternal and/or Embryo/Fetal RiskDose Adjustments During Pregnancy and the Postpartum PeriodTable 6. Thyroid hormones exert their physiologic actions through control of DNA transcription and protein synthesis. Levothyroxine sodium tablets may accelerate the onset of action of tricyclics. There are many brands and forms of levothyroxine available. conditional upon your acceptance of our user agreement.Endocrine Web is a Remedy Health Media, LLC web property.How Does Biotin Impact Laboratory Results and Influence Management of Endocrine Disorders?Given the Risks Associated with Environmental Chemical Exposure, What Should Clinicians Do?Levothyroxine: More Leeway In Timing of Administration?Time to Redefine Obesity as Adipose-Based Chronic Disease (ABCD)?
Each Levothyroxine sodium tablet contains the inactive ingredients Magnesium Stearate, NF; Microcrystalline Cellulose, NF; Colloidal Silicone Dioxide, NF; and Sodium Starch Glycolate, NF. eCollection 2019.
Titrate the dose of Levothyroxine sodium tablets carefully and monitor response to titration to avoid these effects Addition of Levothyroxine therapy in patients with diabetes mellitus may worsen glycemic control and result in increased antidiabetic agent or insulin requirements. Adequate Levothyroxine treatment during lactation may normalize milk production in hypothyroid lactating mothers.
Protein bound thyroid hormones exist in reverse equilibrium with small amounts of free hormone. Typically, patients are instructed to take their levothyroxine in the morning for optimal bioavailability.
Closely monitor blood pressure and heart rate in these patients.Concurrent use may of sympathomimetics and levothyroxine may increase the effects of sympathomimetics or thyroid hormone.