Synthroid Levothyroxine Sodium: Side Effects, Uses, Dosage, Interactions, Warnings

Please consult further with a pharmacist for complete information. Tell your doctor about all your current medicines and any medicine you start or stop using. 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 (7.10). 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).

• Walnuts, grapefruit juice, and dietary fiber can also make Synthroid less effective.
• Follow all directions on your prescription label and read all medication guides or instruction sheets.
• Stop biotin and biotin-containing supplements for at least 2 days prior to thyroid testing.
• Adequate levothyroxine treatment during lactation may normalize milk production in hypothyroid lactating mothers with low milk supply.

Steve is a 50-year-old man with hypothyroidism.

Thyroid hormones, including SYNTHROID, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss. 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 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.

Monitor patients receiving concomitant SYNTHROID and sympathomimetic agents for signs and symptoms of coronary insufficiency. Levothyroxine belongs to a class of medications called hormones. It works by replacing thyroid hormone that is normally produced by the body. There are certain populations where we pay closer attention to thyroid medication dosing.

That is primary, secondary, or tertiary hypothyroidism, either due to congenital synthroid algorithm or acquired state. It is not indicated for the suppression of benign thyroid nodules, or for non-toxic defuse goiter in iodine-sufficient patients. It is also not indicated for the treatment of hypothyroidism during the recovery phase of subacute thyroiditis. There are safety considerations as SYNTHROID should not be used for treatment of obesity or for weight loss.

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 (7). Thyroid hormones do not readily cross the placental barrier see Use in Specific Populations (8.1).

• Synthroid should not be used to treat obesity or weight problems.
• Atrial fibrillation is the most common of the arrhythmias observed with levothyroxine overtreatment in the elderly.
• Tell your doctor about all your current medicines and any medicine you start or stop using.
• Knowing that patient behaviors and consistency of treatment are key factors in treatment success, I educate patients on the process as they begin treatment.

COLORADO THYROID DISEASE PREVALENCE STUDY15

Additional laboratory testing and clinical findings may be necessary. Biochemical assessment incorporated measurement of serum TSH, T3, and T4. TSH lower limit of quantification was 0.2 mIU/L and upper limit of normal was 5.6 mIU/L, as indicated by the shaded area.

Knowing that patient behaviors and consistency of treatment are key factors in treatment success, I educate patients on the process as they begin treatment. The importance of writing “Dispense as Written,” or using the state-specific language for SYNTHROID, is something I discuss with my staff as well. The FDA has determined that drugs that are classified as therapeutically equivalent can be substituted with the full expectation that the substituted product will produce the same clinical effect and safety profile as the reference product.

More about levothyroxine

Enter medications to view a detailed interaction report using our Drug Interaction Checker. You should not use levothyroxine if you are allergic to glycerin or edetate disodium, or if you have an untreated or uncontrolled adrenal gland disorder. Use the drop-down menu below to select your state and see the specific language required to prevent generic substitution.

Follow your doctor’s dosing instructions and try to take the medicine at the same time each day. SYNTHROID is contraindicated in patients with uncorrected adrenal insufficiency see Warnings and Precautions (5.4). Administer SYNTHROID at least 4 hours before or after drugs known to interfere with SYNTHROID absorption see Drug Interactions (7.1). SYNTHROID is contraindicated in patients with uncorrected adrenal insufficiency see WARNINGS AND PRECAUTIONS. Administer SYNTHROID at least 4 hours before or after drugs known to interfere with SYNTHROID absorption see DRUG INTERACTIONS.

Hypothyroid medications require precise

Serum TSH levels should be monitored and the SYNTHROID dosage adjusted during pregnancy. 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 (2.3). Thyroid hormones exert their physiologic actions through control of DNA transcription and protein synthesis. Triiodothyronine (T3) and L-thyroxine (T4) diffuse into the cell nucleus and bind to thyroid receptor proteins attached to DNA.