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

However, elderly patients are more likely to have age-related heart or blood vessel problems, which may require caution and an adjustment in the dose for patients receiving levothyroxine. Synthroid is also used in patients who need surgery and radioiodine therapy to manage a type of thyroid cancer called well-differentiated thyroid cancer. A study titled “Symptoms in temporomandibular joints dysfunction in adult patients with thyroid diseases” reported that hypomobility of temporomandibular joints (TMJ) was typical for patients with hypothyroidism. This means patients with hypothyroidism are more likely to experience limited movement in their jaw joints. Hypothyroidism is frequently accompanied by various musculoskeletal symptoms ranging from myalgia and joint pain to myopathy and osteoarthritis.

• Synthroid works best if you take it on an empty stomach, 30 to 60 minutes before breakfast.
• Closely monitor infants during the first 2 weeks of SYNTHROID therapy for cardiac overload and arrhythmias.
• The peak therapeutic effect of a given dose of SYNTHROID may not be attained for 4 to 6 weeks.
• Hypothyroidism can cause muscle stiffness, joint pain, and overall inflammation, all of which may contribute to the development of TMJ problems.
• It is meant to replace a hormone that is usually made by your thyroid gland.

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). 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.

Administration of sertraline in patients stabilized on SYNTHROID may result in increased SYNTHROID requirements. 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. Initiate SYNTHROID therapy in this population at lower doses than those recommended in younger individuals or in patients without cardiac disease see Dosage and Administration (2.3) and Use in Specific Populations (8.5). 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. The signs and symptoms of overdosage are those of hyperthyroidism see WARNINGS AND PRECAUTIONS and Adverse Reactions.

• One lesser-known symptom of hypothyroidism is the development of TMJ problems.
• Using alcohol or tobacco with certain medicines may also cause interactions to occur.
• This includes prescription and over-the-counter medicines, vitamins, and herbal products.
• Assess compliance, dose of medication administered, and method of administration prior to increasing the dose of SYNTHROID see WARNINGS AND PRECAUTIONS and Use In Specific Populations.
• Synthroid is a thyroid medicine that replaces a hormone normally produced by your thyroid gland to regulate the body’s energy and metabolism.
• 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.

What happens if I miss a dose?

You may have to take this medicine at a different time of day from when you eat these foods. This medicine will need to be taken for the rest of your life or your child’s life. Do not stop taking this medicine or change your dose without first checking with your doctor.

Drug Label Info

Stop biotin and biotin-containing supplements for at least 2 days prior to thyroid testing. 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. 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.

Administer SYNTHROID at least 4 hours before or after drugs known to interfere with SYNTHROID absorption see Drug Interactions (7.1). 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.

Carefully monitor glycemic control, especially when thyroid therapy is started, changed, or discontinued see Warnings and Precautions (5.5). Carefully monitor glycemic control after starting, changing, or discontinuing SYNTHROID see Drug Interactions (7.2). Assess compliance, dose of medication administered, and method of administration prior to increasing the dose of SYNTHROID see Warnings and Precautions (5.1) and Use in Specific Populations (8.4). 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. 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.

Your child’s dose needs may change if the child gains or loses weight. Although this study did not directly focus on the connection between TMJ disorder and hypothyroidism, it provided insights into the relationship between autoimmune thyroid diseases and TMJ disorders. The study “Prevalence of temporomandibular disorders in patients with Hashimoto thyroiditis” found a significantly elevated prevalence of TMJ disorder in patients with Hashimoto’s thyroiditis. The study included 119 women and concluded that all subjects in the Hashimoto’s group had TMJ disorder symptoms. The temporomandibular joint (TMJ) connects the jawbone to the skull.

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. 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 Dosage and Administration (2.3). 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. Children can take the medicine if the tablet is crushed and put into about 1 to 2 teaspoons of water; do not store or delay giving this crushed pill suspension. Doctors often may have to slowly increase the dose; patients should not increase or decrease this medication themselves.

Because some preparations of the drug may contain iodine or lactose, patients should tell their doctors about such allergies or reactions to these components. 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. Adequate levothyroxine treatment during lactation may normalize milk production in hypothyroid lactating mothers with low milk supply. SYNTHROID is indicated in adult and pediatric patients, including neonates, as a replacement therapy in primary (thyroidal), secondary (pituitary), and tertiary (hypothalamic) congenital or acquired hypothyroidism. HypothyroidismSYNTHROID® (levothyroxine fluconazole synthroid sodium) tablets, for oral use is indicated as a replacement therapy in primary (thyroidal), secondary (pituitary), and tertiary (hypothalamic) congenital or acquired hypothyroidism.