Dosing & Administration

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. Published studies report that levothyroxine is present in human milk following the administration of oral levothyroxine. No adverse effects on the breastfed infant have been reported and there is no information on the effects of levothyroxine on milk production.

Patient Information for Synthroid

• Titrate the dosage (every 2 weeks) as needed based on serum TSH or free- T4 until the patient is euthyroid see Important Considerations For Dosing.
• You are encouraged to report negative side effects of prescription drugs to the FDA.
• Dr. Frieze suggests educating patients on the importance of consistent therapy & precise dosing with Synthroid.

In pregnant patients with primary hypothyroidism, maintain serum TSH in the trimester-specific reference range. For adult patients with primary hypothyroidism, titrate until the patient is clinically euthyroid and the serum TSH returns to normal see Recommended Dosage And Titration. Because of the increased prevalence of cardiovascular disease among the elderly, initiate SYNTHROID at less than the full replacement dose see DOSAGE AND ADMINISTRATION and WARNINGS AND PRECAUTIONS. Atrial fibrillation is the most common of the arrhythmias observed with levothyroxine overtreatment in the elderly. Thyroid hormone increases metabolic clearance of glucocorticoids. Initiation of thyroid hormone therapy prior to initiating glucocorticoid therapy may precipitate an acute adrenal crisis in patients with adrenal insufficiency.

In order for Synthroid to be effective, it should always be taken the same way every day. This is important because the amount of medicine you need is very precise. And even the way you take Synthroid can affect how much medicine your body is getting.

ELDERLY PATIENT*

Tell your doctor about all your current medicines and any medicine you start or stop using. Levoxyl treats hypothyroidism (low thyroid hormone) and treats or prevents goiter. NP Thyroid is used for hashimoto’s disease, hypothyroidism, after thyroid removal, thyroid cancer … By visiting Synthroid.com, patients can access additional support and resources to understand and manage their hypothyroidism. Biotin supplementation is known to interfere with thyroid hormone immunoassays that are based on a biotin and streptavidin interaction, which may result in erroneous thyroid hormone test results.

Thyroid hormones are also metabolized via conjugation with glucuronides and sulfates and excreted directly into the bile and gut where they undergo enterohepatic recirculation. 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 wiki synthroid is present. Thyroid hormones exert their physiologic actions through control of DNA transcription and protein synthesis.

Use the serum free-T4 level to titrate SYNTHROID dosing until the patient is clinically euthyroid and the serum free-T4 level is restored to the upper half of the normal range see Recommended Dosage And Titration. Absorption of orally administered T4 from the gastrointestinal tract ranges from 40% to 80%. The majority of the SYNTHROID dose is absorbed from the jejunum and upper ileum. The relative bioavailability of SYNTHROID tablets, compared to an equal nominal dose of oral levothyroxine sodium solution, is approximately 93%. T4 absorption is increased by fasting, and decreased in malabsorption syndromes and by certain foods such as soybeans.

If cardiac symptoms develop or worsen, reduce the SYNTHROID dose or withhold for one week and restart at a lower dose. Concurrent use of ketamine and SYNTHROID may produce marked hypertension and tachycardia. Closely monitor blood pressure and heart rate in these patients. The peak therapeutic effect of a given dose of SYNTHROID may not be attained for 4 to 6 weeks.

Dr. Frieze suggests educating patients on the importance of consistent therapy & precise dosing with Synthroid. Armour Thyroid is used for hashimoto’s disease, hypothyroidism, after thyroid removal, thyroid … Your child’s dose needs may change if the child gains or loses weight. You may not be able to take Synthroid if you have certain medical conditions.

Toxic effects may include increased risk of cardiac arrhythmias and central nervous system stimulation. Administration of sertraline in patients stabilized on SYNTHROID may result in increased SYNTHROID requirements. Many other medicines can be affected by your thyroid hormone levels.

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 hormone. Many drugs and physiologic conditions affect the binding of thyroid hormones to serum proteins see DRUG INTERACTIONS. Thyroid hormones do not readily cross the placental barrier see Use In Specific Populations. SYNTHROID increases the response to oral anticoagulant therapy. Therefore, a decrease in the dose of anticoagulant may be warranted with correction of the hypothyroid state or when the SYNTHROID dose is increased.