Dosing & Administration

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. You are encouraged to report negative side effects of prescription drugs to the FDA. 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.

• Levothyroxine injection is used in adults to treat myxedema coma.
• However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule.
• 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 is important as 32% of patients who think they are on SYNTHROID are actually not given this because substitutions are made at the pharmacy.
• In all the scenarios mentioned above, pharmacists should ensure proper dosing and report to the clinician if there is any potential drug-drug interaction or if supplies may dictate a change to a different formulation.

levothyroxine (Rx)

Levothyroxine toxicity is rare; however, it is most likely to occur in the setting of accidental ingestion by children or older adults. Thyroxine (T4) and triiodothyronine (T3) levels rise within 1 to 2 hours of ingestion. In the initial stage of overdose (6 to 12 hours post-ingestion), the common signs of toxicity would be tremulousness, tachycardia, hypertension, anxiety, and diarrhea. Rarely convulsions, thyroid storms, acute psychosis, arrhythmias, and acute myocardial infarction may occur. Laboratory workup usually reveals elevated serum total T4 and T3, suppressed serum TSH, and elevated Free T4 and Free T3.

Onset, myxedema coma

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 share this medicine with another person, even if they have the same symptoms you have. Adding plans allows you to compare formulary status to other drugs in the same class. Enter medications to view a detailed interaction report using our Drug Interaction Checker.

Your doctor may want you or your child to gradually reduce the amount you are using before stopping completely. Do not eat grapefruit or drink grapefruit juice while you are using this medicine. Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding. This medicine is available only with your doctor’s prescription. Administer SYNTHROID as a single daily dose, on an empty stomach, one-half to one hour before breakfast.

2 Antidiabetic Therapy

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. 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.

Check with your physician for additional information about side effects. Notify your doctor if you experience serious side effects of Synthroid including rapid heartbeat, fluttering in your chest, or chest pain. Get medical help right away, if you have any of the symptoms listed above.

Pregnancy

Providing a complete list of medications to the doctor will help with getting the correct dose established for each individual patient. Tell your doctor about all your current medicines and any medicine you start or stop using. If you become pregnant while taking Synthroid, do not stop taking the medicine without your doctor’s advice. Having low thyroid hormone levels during pregnancy could harm both mother and baby. Synthroid is also used in patients who need surgery and radioiodine therapy to manage a type of thyroid cancer called well-differentiated thyroid cancer. Synthroid is a prescription medicine used to treat hypothyroidism (low thyroid hormone).

Tell your doctor if you have an untreated or uncontrolled adrenal gland disorder, a thyroid disorder called thyrotoxicosis, or if you have any synthroid derived recent or current symptoms of a heart attack. Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use levothyroxine only for the indication prescribed. In a medical setting, you are not likely to miss a dose of levothyroxine injection. Taking more than your recommended dose will not make this medicine more effective, and may cause serious side effects. You may not be able to use levothyroxine if you have certain medical conditions.

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. Take levothyroxine tablets and capsules on an empty stomach, at least 30 to 60 minutes before breakfast with a full glass of water.

DISCUSS THE FOLLOWING WITH PATIENTS WHEN PRESCRIBING SYNTHROID

​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. To minimize the risk of hyperactivity, start at one-fourth the recommended full replacement dosage, and increase on a weekly basis by one-fourth the full recommended replacement dosage until the full recommended replacement dosage is reached.