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

Another concern is the many factors that can influence thyroxine absorption and availability to your body. There is variation in the thyroxine content among the various approved preparations with the same stated dose on the tablet, in some cases greater than 10%. This is a potential problem if a patient switches thyroxine preparations.”“Generic Levothyroxine.” The Medical Letter on Drugs & Therapeutics September 27, 2004. Initiation or discontinuation of therapy with levothyroxine in diabetic patients may create a need for an increase or decrease in the required dose of insulin and/or antidiabetic drug, (for example, glyburide Micronase). The signs and symptoms of overdosage are those of hyperthyroidism see WARNINGS AND PRECAUTIONS and Adverse Reactions.

Short-Term Effects

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. This hormone nuclear receptor complex activates gene transcription and synthesis of messenger RNA and cytoplasmic proteins. The physiological actions of thyroid hormones are produced predominantly by T3, the majority of which (approximately 80%) is derived from T4 by deiodination in peripheral tissues. Reduce the SYNTHROID dosage or discontinue temporarily if signs or symptoms of overdosage occur.

What other drugs will affect levothyroxine?

It works by replacing thyroid hormone that is normally produced by the body. A 2019 study published in Advances in Therapy compared 9,925 adults who consistently used Synthroid to 9,925 adults who switched from Synthroid to a generic. What the researchers found was that people who switched were 15% more likely to have their thyroid hormones fall out of the “normal” range than those who stuck with Synthroid. Not all of the concerns about generic levothyroxine have been allayed. For example, if you are taking Synthroid and thinking about switching to save costs, there is synthroid vegan evidence that doing so may not be the best idea.

• Follow your doctor’s dosing instructions and try to take the medicine at the same time each day.
• NP Thyroid is used for hashimoto’s disease, hypothyroidism, after thyroid removal, thyroid cancer …
• But there is some controversy about whether it’s as effective and reliable as the brand-name versions.

And even though the difference is not big, it may actually matter to certain people (especially those who are sensitive). By Mary ShomonMary Shomon is a writer and hormonal health and thyroid advocate. The problem, the AACE and ATA state, becomes even greater if a patient switches between generics or between a generic and Synthroid. These standards must be documented and approved by the FDA before a generic manufacturer can produce and sell the drug. In addition to Synthroid, there are seven generic versions licensed in the U.S. Enter medications to view a detailed interaction report using our Drug Interaction Checker.

Oral levothyroxine

• Dangerous side effects or death can occur from the misuse of this medicine, especially if you are taking any other weight-loss medications or appetite suppressants.
• In some situations, you may find that switching from Synthroid to Levothyroxine (or vice versa) still doesn’t help remove all of your symptoms.
• Generally, generic medications are less expensive compared to brand medications.
• 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.

Initiate appropriate supportive treatment as dictated by the patient’s medical status. 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. Concurrent use of tyrosine-kinase inhibitors such as imatinib may cause hypothyroidism.

As a means of illustration, here is how Synthroid matches up to two of the leading generic levothyroxine products, Levo-T and Levoxyl. If you’re feeling good and your blood tests are stable on a generic form of levothyroxine, by all means, continue to use that preparation. You are more likely to experience ill effects by changing to a brand-name product. When some people try to switch from a brand name to a generic (often to save money), they experience fatigue, numbness or tingling in their hands, whole-body soreness, or dry skin.

Even so, ongoing concerns about the safety and efficacy of generic levothyroxine have altered the prescribing practices of some healthcare providers. As such, if the early findings were correct, it would suggest that generic levothyroxine works “less well” in managing thyroid disease. During their follow-up, the final TSH lab outcomes were “out of range” for 22.6% of patients who took the generic levothyroxine and 20.9% for those who took Synthroid. If you become pregnant while taking Synthroid, do not stop taking the medicine without your doctor’s advice.

What are the side effects of levothyroxine sodium?

Below you will find the average cost of a 30-day supply of 100mcg of each of the Thyroxine medications. To further complicate this, some pharmacists can even alter medications given to patients for insurance and cost purposes. Inactive ingredients are known as fillers, dyes, and binders which help hold the active medication in place. Levothyroxine is considered a “generic” version of the thyroid medication Synthroid.

For secondary or tertiary hypothyroidism, serum TSH is not a reliable measure of SYNTHROID dosage adequacy and should not be used to monitor therapy. 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. Do not administer in foods that decrease absorption of SYNTHROID, such as soybean-based infant formula see DRUG INTERACTIONS. Many drugs can inhibit Synthroid’s adsorption by the body; other medications may increase or decrease its effectiveness once it is adsorbed.

Avoid use in patients with large thyroid nodules or long-standing goiters, or low-normal TSH levels. Do NOT generally use levothyroxine sodium preparations interchangeably, due to narrow therapeutic index. There are no known effects of drug abuse of thyroid hormone in synthetic form. Thyroid hormones, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss.