Thyroid Hormone Replacement Therapy

Foods containing soy and cottonseed meal can make Synthroid less effective. Walnuts, grapefruit juice, and dietary fiber can also make Synthroid less effective. If you eat any of these on a regular basis, check with your doctor. This is not a complete list of side effects and others may occur.

• Nephrosis, severe hypoproteinemia, severe liver disease, acromegaly, androgens, and corticosteroids decrease TBG concentration.
• No adverse effects on the breastfed infant have been reported and there is no information on the effects of levothyroxine on milk production.
• For pregnant patients with pre-existing hypothyroidism, measure serum TSH and free-T4 as soon as pregnancy is confirmed and, at minimum, during each trimester of pregnancy.
• Use of oral thyroid hormone drug products is not recommended to treat myxedema coma.
• This is important because the amount of medicine you need is very precise.
• Titrate the dose of SYNTHROID carefully and monitor response to titration to avoid these effects see DOSAGE AND ADMINISTRATION.

Hypothyroidism

• If so, advise them to stop biotin supplementation at least 2 days before assessing TSH and/or T4 levels see DOSAGE AND ADMINISTRATION and DRUG INTERACTIONS.
• Who are otherwise healthy non-elderly and have been hypothyroid for a few months.
• Since postpartum TSH levels are similar to preconception values, the SYNTHROID dosage should return to the pre-pregnancy dose immediately after delivery see DOSAGE AND ADMINISTRATION.
• After joining, patients will receive exclusive benefits including savings, tips, and tools to help your patients make the most of their SYNTHROID treatment.
• Get medical help right away, if you have any of the symptoms listed above.

It may take several weeks before your body starts to respond to Synthroid. synthroid discontinued Synthroid works best if you take it on an empty stomach, 30 to 60 minutes before breakfast. Follow your doctor’s dosing instructions and try to take the medicine at the same time each day.

FDA Drug Information

Grapefruit juice may delay the absorption of levothyroxine and reduce its bioavailability. Monitor serum free-T4 levels and maintain in the upper half of the normal range in these patients. Do not store the crushed tablet/water mixture and do not administer it mixed with foods that decrease absorption of levothyroxine, such as soybean-based infant formula. Synthroid is a prescription medicine used to treat hypothyroidism (low thyroid hormone). Levothyroxine is given when your thyroid does not produce enough of this hormone on its own.

Stop biotin and biotin-containing supplements for at least 2 days prior to thyroid testing. 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 and DRUG INTERACTIONS. You are encouraged to report negative side effects of prescription drugs to the FDA.

Triiodothyronine (T3) and L-thyroxine (T4) diffuse into the cell nucleus and bind to thyroid receptor proteins attached to DNA. 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. Monitor for cardiac arrhythmias during surgical procedures in patients with coronary artery disease receiving suppressive SYNTHROID therapy.

It’s important to always take your medication exactly as your doctor prescribed. Do not share this medicine with another person, even if they have the same symptoms you have.

1 Cardiac Adverse Reactions in the Elderly and in Patients with Underlying Cardiovascular Disease

RxList does not provide medical advice, diagnosis or treatment. A portion of the conjugated hormone reaches the colon unchanged and is eliminated in the feces. SYNTHROID is contraindicated in patients with uncorrected adrenal insufficiency see WARNINGS AND PRECAUTIONS. Long-term carcinogenicity studies in animals to evaluate the carcinogenic potential of levothyroxine have not been performed. Studies to evaluate mutagenic potential and animal fertility have not been performed.

Dosage titration is based on serum TSH or free-T4 see Important Considerations For Dosing. SYNTHROID is indicated in adult and pediatric patients, including neonates, as an adjunct to surgery and radioiodine therapy in the management of thyrotropin-dependent well-differentiated thyroid cancer. 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.

Secondary and Tertiary Hypothyroidism

Administer thyroid hormone products formulated for intravenous administration to treat myxedema coma. The general aim of therapy is to normalize the serum TSH level. TSH may not normalize in some patients due to in utero hypothyroidism causing a resetting of pituitary-thyroid feedback.

Recently diagnosed patient*

Providing a complete list of medications to the doctor will help with getting the correct dose established for each individual patient. Reduce the SYNTHROID dosage or discontinue temporarily if signs or symptoms of overdosage occur. Initiate appropriate supportive treatment as dictated by the patient’s medical status. Biotin supplementation may interfere with immunoassays for TSH, T4, and T3, resulting in erroneous thyroid hormone test results. Stop biotin and biotin-containing supplements for at least 2 days before assessing TSH and/or T4 levels see DRUG INTERACTIONS. Patients The SYNTHROID dosage is based on the target level of TSH suppression for the stage and clinical status of thyroid cancer.