Synthroid Uses, Dosage & Side Effects

Larger doses may produce serious or even life-threatening manifestationsof toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects. 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. It is meant to replace a hormone that is usually made by your thyroid gland. Generally, thyroid replacement treatment is to be taken for life. SYNTHROID should not be used to treat noncancerous growths or enlargement of the thyroid in patients with normal iodine levels, or in cases of temporary hypothyroidism caused by inflammation of the thyroid gland (thyroiditis). Absorption of orally administered T4 from the gastrointestinal tract ranges from 40% to 80%.

DAW codes are codes a pharmacy uses when filling your patient’s prescription. DAW-1 indicates that substitution is not allowed, based on the prescriber’s preference, and ensures your patient will receive the treatment you prescribe. It also helps your patient pay the lowest possible price for the product you write if it is billed through insurance.

Related treatment guides

RxList does not provide medical advice, diagnosis or treatment. Closely monitor infants during the first 2 weeks of SYNTHROID therapy for cardiac overload and arrhythmias. Concurrent use of ketamine and SYNTHROID may produce marked hypertension and tachycardia. Closely monitor blood pressure and heart rate in these patients. This document does not contain all possible side effects and others may occur.

Drugs Known To Affect Thyroid Hormone Pharmacokinetics

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. Closely monitor coagulation tests to permit appropriate and timely dosage adjustments. Assess the adequacy of therapy by periodic assessment of laboratory tests and clinical evaluation. Persistent clinical and laboratory evidence of hypothyroidism despite an apparent adequate replacement dose of SYNTHROID may be evidence of inadequate absorption, poor compliance, drug interactions, or a combination of these factors.

  • 54% of prescriptions for SYNTHROID were not protected with a DAW or state-specific language in one study.
  • Grapefruit juice may delay the absorption of levothyroxine and reduce its bioavailability.
  • Tirosint is used for hashimoto’s disease, hypothyroidism, after thyroid removal, myxedema coma …
  • Depending on patient circumstances, cost can sometimes be a concern.
  • Certain other medicines may also increase or decrease the effects of Synthroid.
  • Many drugs and physiologic conditions affect the binding of thyroid hormones to serum proteins see DRUG INTERACTIONS.
  • I go over with the patient there are treatment goals that are very important in the process.
  • In adult patients with primary hypothyroidism, monitor serum TSH levels after an interval of 6 to 8 weeks after any change in dosage.
  • You are encouraged to report negative side effects of prescription drugs to the FDA.
  • 34-week prescription audit of 441 pharmacies (average 41 prescriptions per state) totaling 1908 new and renewed SYNTHROID prescriptions between August 1, 2020 and March 23, 2021.

Language needed to prevent generic substitution varies by state. AbbVie is committed to adhering to CGMP and believes in the integrity of its manufacturing process. AbbVie is dedicated to ensuring that all SYNTHROID products are manufactured at the highest standards. Depending on patient circumstances, cost can sometimes be a concern.

SPECIAL CONSIDERATIONS FOR HYPOTHYROID MEDICATIONS

Many other medicines can be affected by your thyroid hormone levels. Certain other medicines may also increase or decrease the effects of Synthroid. 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. Thyroid hormone increases metabolic clearance of glucocorticoids.

Hypersensitivity reactions to inactive ingredients have occurred in patients treated with thyroid hormone products. These include urticaria, pruritus, skin rash, flushing, angioedema, various gastrointestinal symptoms (abdominal pain, nausea, vomiting and diarrhea), fever, arthralgia, serum sickness, and wheezing. Hypersensitivity to levothyroxine itself is not known to occur. Synthroid is prescribed in tablets that range from 25 to 300 mcg in strength and is usually taken once a day with a full glass of water (about 8 ounces) 30 to 60 minutes before breakfast for best adsorption into the body.

  • It may take several weeks before your body starts to respond to Synthroid.
  • 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.
  • Administer SYNTHROID at least 4 hours before or after drugs known to interfere with SYNTHROID absorption see DRUG INTERACTIONS.
  • 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.

The recommended daily dosage of SYNTHROID in pregnant patients is described in Table 3. Do not administer in foods that decrease absorption of SYNTHROID, such as soybean-based infant formula see DRUG INTERACTIONS. The “optimal dose” was determined for each patient as that dosage of thyroxine being taken when the thyrotropin-releasing hormone (TRH) response was normal (ie, an increase in TSH of between 4.7 and 25 synthroid alli mIU/L). I go over with the patient there are treatment goals that are very important in the process. And the other is to improve the clinical symptoms that they’ve been experiencing. Because the long-acting nature of the medication, I do indicate that it may take several months to see an improvement in both of these levels.

Do not share this medicine with another person, even if they have the same symptoms you have.

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. Stop biotin and biotin-containing supplements for at least 2 days prior to thyroid testing. Patients The SYNTHROID dosage is based on the target level of TSH suppression for the stage and clinical status of thyroid cancer.