Levothyroxine Challenge: Sensitive to Tablet Ingredients

Start at a lower starting dosage and increase the dosage every 4 to 6 weeks as needed based on clinical and laboratory response. 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). This means that this hack probably has far more utility for the average thyroid patient even if it is less effective compared to other thyroid medications. Thepotential to cause problems (3) with the absorption and utilization of thyroid hormone in thyroid patients. Both levothyroxine and Synthroid still contain inactive fillers and binders, that’s for sure, but the 50mcg strength tablets contain the fewest of all other doses. I’ve spent the last 8 years of my life reading, researching, and helping people with thyroid problems, hormone imbalances, and weight loss resistance.

Pregnancy

Consumption of certain foods may affect levothyroxine absorption thereby necessitating adjustments in dosing. Soybean flour (infant formula), cotton seed meal, walnuts, and dietary fiber may bind and decrease the absorption of levothyroxine sodium from the GI tract. Prothrombin time should be closely monitored to permit appropriate and timely dosage adjustments (see Table 2). In patients with secondary or tertiary hypothyroidism, additional hypothalamic/pituitary hormone deficiencies should be considered, and, if diagnosed, treated (see PRECAUTIONS – Autoimmune polyglandular syndrome for adrenal insufficiency).

Storage Conditions

The diagnosis of hypothyroidism is confirmed by measuring TSH levels using a sensitive assay (second generation assay sensitivity ≤ 0.1 mIU/L or third generation assay sensitivity ≤ 0.01 mIU/L) and measurement of free-T4. A portion of the conjugated hormone reaches the colon unchanged and is eliminated in the feces. Closely monitor infants during the first 2 weeks of SYNTHROID therapy for cardiac overload and arrhythmias. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes.

Soybean flour, cottonseed meal, walnuts, and dietary fiber may bind and decrease the absorption of SYNTHROID from the gastrointestinal tract. Grapefruit juice may delay the absorption of levothyroxine and reduce its bioavailability. Biotin supplementation may interfere with immunoassays for TSH, T4, and T3, resulting in erroneous thyroid hormone test results.

Should You Use Iodized Salt If You Have Hypothyroidism?

Stop biotin and biotin-containing supplements for at least 2 days before assessing TSH and/or T4 levels see Drug Interactions (7.10). 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. For some individuals, especially those with thyroid conditions like hypothyroidism, eating gluten can cause adverse reactions.

Certain foods such as soybean flour, cottonseed meal, walnuts, dietary fiber, and grapefruits or grapefruit juice may affect the way that your body absorbs TIROSINT. Tell your healthcare provider if you regularly eat these foods, as they may require your dose of din synthroid TIROSINT to be adjusted. 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. Therefore, the dose of SYNTHROID used for TSH suppression should be individualized based on the specific disease and the patient being treated. Inadequate levothyroxine dosage will produce or fail to ameliorate the signs and symptoms of hypothyroidism.

PRECAUTIONS

• Titrate the dosage (every 2 weeks) as needed based on serum TSH or free-T4 until the patient is euthyroid see Dosage and Administration (2.2).
• Concurrent use of sympathomimetics and SYNTHROID may increase the effects of sympathomimetics or thyroid hormone.
• If, after 30 days, the serum TSH is elevated above 20 mU/L, the diagnosis of permanent hypothyroidism is confirmed, and full replacement therapy should be resumed.
• Consider the potential for food or drug interactions and adjust the administration or dosage of SYNTHROID as needed see Dosage and Administration (2.1), Drug Interactions (7.1), and Clinical Pharmacology (12.3).
• Hypersensitivity reactions to inactive ingredients have occurred in patients treated with thyroid hormone products.
• We are going to discuss the gluten content of the thyroid medication Synthroid and discuss various reasons why you may not be tolerating your thyroid medication which may help explain why you are still suffering from certain symptoms.

The recommended starting daily dosage of SYNTHROID in adults with primary, secondary, or tertiary hypothyroidism is based on age and comorbid cardiac conditions, as described in Table 1. For patients at risk of atrial fibrillation or patients with underlying cardiac disease, start with a lower dosage and titrate the dosage more slowly to avoid exacerbation of cardiac symptoms. Dosage titration is based on serum TSH or free-T4 see Dosage and Administration (2.2).

1 Pregnancy

Approximately eighty-percent of circulating T3 is derived from peripheral T4 by monodeiodination. The liver is the major site of degradation for both T4 and T3, with T4 deiodination also occurring at a number of additional sites, including the kidney and other tissues. Approximately 80% of the daily dose of T4 is deiodinated to yield equal amounts of T3 and reverse T3 (rT3).

As you can see from the image above, the researchers were able to break down the individual ingredients of Synthroid to test each batch to see if they were gluten-free. They found that Synthroid contains less than 3.0 parts per million of gluten in all of the various ingredients that are used to make the Synthroid medication. And, as you probably know, Celiac disease is an autoimmune disease in which your body reacts negatively to gluten (3) (from any source). Store at 25°C (77°F); excursions permitted to 15°-30°C (59°-86°F) see USP Controlled Room Temperature.

Foods that decrease absorption of levothyroxine, such as soybean infant formula, should not be used for administering levothyroxine sodium tablets (see PRECAUTIONS – Drug-Food Interactions). Because of the increased prevalence of cardiovascular disease among the elderly, levothyroxine therapy should not be initiated at the full replacement dose (see WARNINGS, PRECAUTIONS, and DOSAGE AND ADMINISTRATION). The initial dose of levothyroxine varies with age and body weight (see DOSAGE AND ADMINISTRATION – Table 3). Dosing adjustments are based on an assessment of the individual patient’s clinical and laboratory parameters (see PRECAUTIONS – Laboratory Tests). The goal of treatment in pediatric patients with hypothyroidism is to achieve and maintain normal intellectual and physical growth and development.