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

The patient should be monitored closely to avoid undertreatment and overtreatment. Undertreatment may result in poor school performance due to impaired concentration and slowed mentation and in reduced adult height. Overtreatment may accelerate the bone age and result in premature epiphyseal closure and compromised adult stature. The list of drug-thyroidal axis interactions in Table 2 may not be comprehensive due to the introduction of new drugs that interact with the thyroidal axis or the discovery of previously unknown interactions. Adequacy of therapy should be assessed by measuring serum free- T4 levels, which should be maintained in the upper half of the normal range in these patients.

• Toxic effects may include increased risk of cardiac arrhythmias and central nervous system stimulation.
• Carefully monitor glycemic control, especially when thyroid therapy is started, changed, or discontinued see WARNINGS AND PRECAUTIONS.
• C. Kendall at the Mayo Foundation (Rochester, MN) isolated thyroxine from unspecified animals.
• It also helps your patient pay the lowest possible price for the product you write if it is billed through insurance.
• TSH may not normalize due to a resetting of the pituitary-thyroid feedback threshold as a result of in utero hypothyroidism.

CLINICAL PHARMACOLOGY

Patients receiving SYNTHROID for appropriate clinical indications should be titrated to the lowest effective replacement dose. 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. Levothyroxine is generally continued for life in these patients see WARNINGS AND PRECAUTIONS.

Hypothalamic/pituitary hormone deficiencies

If this condition is treated, a lower levothyroxine sodium dose (e.g., 1 mcg/kg/day) than that used for full replacement may be adequate to normalize the serum TSH level. synthroid insurance Patients who are not treated should be monitored yearly for changes in clinical status and thyroid laboratory parameters. Since some more severely affected children may become clinically hypothyroid when treatment is discontinued for 30 days, an alternate approach is to reduce the replacement dose of levothyroxine by half during the 30-day trial period.

• Some key points that I discuss with the patients during appointments are, one, is that this is an open conversation.
• Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Synthroid only for the indication prescribed.
• Do not administer in foods that decrease absorption of SYNTHROID, such as soybean-based infant formula see DRUG INTERACTIONS.

TSH Suppression in Well-differentiated Thyroid Cancer and Thyroid Nodules

The signs and symptoms of overdosage are those of hyperthyroidism see WARNINGS AND PRECAUTIONS and Adverse Reactions. Seizures occurred in a 3-yearold child ingesting 3.6 mg of levothyroxine. Symptoms may not necessarily be evident or may not appear until several days after ingestion of levothyroxine sodium.

SYNTHROID has been committed to treating hypothyroidism for 65 years.3

Look to see if the tablets have Synthroid embossed on them to ensure they’re getting the right product. They can have changes in the female hormone status, either going on or off a birth control pill, going through menopause. Knowing that patient behaviors and consistency of treatment are key factors in treatment success, I educate patients on the process as they begin treatment. I go over with them the fact that they should check the label at the pharmacy, on the bottle, to make sure it says brand-name SYNTHROID and not generic levothyroxine. And in many cases, to also pop the top off the bottle while they are at the pharmacy counter and look at the pills and make sure they have SYNTHROID embossed on those tablets. Primary hypothyroidism is basically diagnosed off of a screening TSH, or thyroid stimulating hormone.

Synthroid During Pregnancy and Breastfeeding

Levothyroxine sodium is contraindicated if the serum TSH is already suppressed due to the risk of precipitating overt thyrotoxicosis (see CONTRAINDICATIONS – WARNINGS and PRECAUTIONS). The target level for TSH suppression in these conditions has not been established with controlled studies. In addition, the efficacy of TSH suppression for benign nodular disease is controversial.

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.

Monitor for cardiac arrhythmias during surgical procedures in patients with coronary artery disease receiving suppressive SYNTHROID therapy. Monitor patients receiving concomitant SYNTHROID and sympathomimetic agents for signs and symptoms of coronary insufficiency. 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. In pregnant patients with primary hypothyroidism, maintain serum TSH in the trimester-specific reference range. In the elderly and in patients with cardiovascular disease, SYNTHROID should be initiated at lower doses than those recommended in younger individuals or in patients without cardiac disease.

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. And to adjust the dose based on periodic assessment of the patient’s clinical response and their laboratory values. The second is that Synthroid has a history, as physicians have been treating patients with hypothyroidism with Synthroid for over 65 years. Due to the long half-life of levothyroxine, the peak therapeutic effect at a given dose of levothyroxine sodium may not be attained for 4-6 weeks. Approximately eighty-percent of circulating T3 is derived from peripheral T4 by monodeiodination. Levothyroxine, at doses individualized according to patient response, is effective as replacement or supplemental therapy in hypothyroidism of any etiology, except transient hypothyroidism during the recovery phase of subacute thyroiditis.

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 mIU/L). Personally, I have had experiences where I have written for brand-name SYNTHROID and the patients have been dispensed generic levothyroxine or even another branded levothyroxine product. It’s very important to make sure that you write “Dispense as written,” or whatever state-specific language, on the prescription when you prescribe the medication. 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.