thyrotropin alfa

Action and Spectrum

Actions and spectrum: 

thyrotropin alfa is a recombinant form of thyroid-stimulating hormone (TSH) which acts as a diagnostic agent in the management of thyroid cancer. It mimics the action of endogenous TSH and stimulates the release of thyroid hormones. thyrotropin alfa is used in conjunction with radioactive iodine (RAI) scanning to detect residual or metastatic thyroid cancer tissue.

The radioactive iodine is taken by the thyroid tissue, and the imaging procedure can identify the location and extent of any remaining thyroid cancer cells. thyrotropin alfa can also be used in patients with hypothyroidism who are being treated with thyroid hormone replacement therapy to evaluate the effectiveness of the treatment. 

Drug Interaction

Adverse Reaction

Frequency defined 

>10% 

Nausea (11%) 

1-10% 

Asthenia (1%) 

Fatigue (2%) 

Dizziness (2%) 

Vomiting (2%) 

Headache (6%) 
Postmarketing Reports 

Erythema 

Pruritus 

Pain 

Bruising 

Black Box Warning

Black Box Warning: 

There are no black box warnings associated with the use of thyrotropin alfa. 

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

thyrotropin alfa is contraindicated in patients with uncorrected adrenal insufficiency or hypersensitivity to any component of the medication. It should also not be used for diagnostic purposes in patients with unexplained elevations of serum thyrotropin (TSH) concentrations as it may result in falsely low serum TSH levels.  

Caution: 

• Adrenal insufficiency – thyrotropin alfa can stimulate the adrenal gland, leading to an adrenal crisis in patients with pre-existing adrenal insufficiency. 
• Cardiovascular disease – thyrotropin alfa may increase the risk of cardiovascular events, such as angina, arrhythmias, and myocardial infarction. 
• History of thyroid cancer – thyrotropin alfa may have an increased risk of recurrence in patients with a history of thyroid cancer. 
• Pregnancy – thyrotropin alfa should be used during pregnancy only if clearly needed and after weighing the potential benefits against the potential risks. 
• Breastfeeding – It is not known whether thyrotropin alfa is excreted in human milk, and caution should be exercised when administering it to a breastfeeding mother.

Comorbidities: 

thyrotropin alfa is primarily used in the treatment of thyroid cancer, particularly in patients who have had their thyroid gland removed. It is not typically used in the treatment of comorbidities, but caution should be exercised in patients with pre-existing heart disease, as thyrotropin alfa may increase the risk of cardiovascular events.

Patients with uncontrolled hypertension or hyperthyroidism should also be monitored carefully during treatment with thyrotropin alfa. Additionally, patients with a history of adrenal insufficiency or pituitary gland disorders should be evaluated carefully before beginning treatment with thyrotropin alfa. 

Pregnancy / Lactation

Pregnancy consideration: Pregnancy Category C 

Lactation: safety and efficacy not established  

Pregnancy category: 

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester. 
• Category B: There is no evidence of risk to the fetus found in animal reproduction studies and there are not enough studies on pregnant women. 
• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for an effect in humans, care must be taken for potential risks in pregnant women. 
• Category D: There is adequate data available with sufficient evidence of human fetal risk from various platforms, but despite potential risks may be used only in emergency cases for potential benefits. 
• Category X: Drugs listed in this category outweigh risks over benefits These category drugs should be prohibited for pregnant women. 
• Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology: 

thyrotropin alfa is a recombinant form of human thyroid-stimulating hormone (TSH) that is used for diagnostic purposes. It has the same pharmacological actions as endogenous TSH.

TSH is produced by anterior pituitary gland and stimulates the thyroid gland to produce and release thyroid hormones, including thyroxine (T4) and triiodothyronine (T3), into the bloodstream. TSH is also important for the growth and function of the thyroid gland. 

thyrotropin alfa acts by binding to the TSH receptor on the surface of thyroid cells, leading to an increase in thyroid hormone synthesis and release. It has a short half-life, with a rapid onset and peak effect within 30 minutes to 2 hours after administration.  

Pharmacodynamics: 

thyrotropin alfa (also known as a recombinant human thyroid-stimulating hormone) acts as a thyroid-stimulating hormone (TSH) analog. It binds to the TSH receptors on the thyroid follicular cells and stimulates the production and secretes of thyroid hormones, thyroxine (T4) and triiodothyronine (T3), by the thyroid gland. thyrotropin alfa is used as a diagnostic agent to differentiate between primary and secondary hypothyroidism, assess thyroid function in patients with thyroid cancer, and enhance the uptake of radioactive iodine in patients with thyroid cancer prior to scanning.  

Pharmacokinetics: 

Absorption 

thyrotropin alfa is administered by intravenous injection, and its bioavailability is 100%. 

Distribution 

The volume of distribution of thyrotropin alfa is not well established. 

Metabolism 

thyrotropin alfa is metabolized by the liver and other tissues. 

Elimination and excretion 

The elimination half-life of thyrotropin alfa is approximately 2.5 hours. It is excreted mainly in the urine and, to a lesser extent, in the feces. 

Adminstartion

Administration: 

thyrotropin alfa is administered as an injection into a muscle (intramuscularly) by a healthcare professional. The dose and frequency of administration may vary depending upon the condition being treated and the patient’s response to the treatment. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: thyrotropin alfa 

Pronounced: (thy-roh-troh-pin al-fuh)   

Why do we use thyrotropin alfa? 

thyrotropin alfa is used in conjunction with radioactive iodine uptake (RAIU) tests to evaluate thyroid function in thyroid gland-removed patients due to cancer or other conditions and in patients with suspected thyroid disease. The RAIU test measures the amount of radioactive iodine taken up by the thyroid gland, which can help determine if the gland is functioning normally or abnormally. thyrotropin alfa is given before the RAIU test to stimulate the thyroid gland and improve the accuracy of the test results. 

thyrotropin alfa is also used in the management of patients with differentiated thyroid cancer (DTC) to help detect any remaining thyroid tissue or cancer cells after thyroidectomy (surgical removal of the thyroid gland). It is given as an adjunct to whole-body scintigraphy (WBS) with radioiodine (iodine-131), which can help identify areas of residual or metastatic cancer in the body.