Thyrotropin Alpha

Thyrotropin alpha is used as a diagnostic tool for serum thyroglobulin testing in tracking patients with thyroid cancer. Thyroglobulin is stored in the thyroid gland and is incorporated into thyroid hormone. The amount of thyroglobulin released by thyroid cells is a good marker of thyroid function, and high levels in the blood could indicate cancer. Thyrotropin alpha is used to stimulate the release of thyroglobulin to determine if excessive thyroglobulin is being produced. The Food and Drug Administration approved thyrotropin alpha on November 30, 1998 and it is marketed in the U.S. by Genzyme under the brand name Thyrogen.

The thyroid gland is located in the throat. Thyrotropin alpha stimulates the gland to produce thyroglobulin, a response that is elevated in thyroid cancer. Source: Wikimedia Commons

Other Names

• Thyrotropin
• Recombinant human thyroid-stimulating hormone (rhTSH)

Uses

Thyrotropin alpha is used for the diagnosis, followup, and management of thyroid cancer.^[1][2]

How Thyrotropin Alpha is Taken

Thyrotropin alpha is available at a concentration of 0.9 mg/ml. It is injected into a muscle in two doses administered 24 hours apart.

How Thyrotropin Alpha Works

Thyrotropin alpha is a protein produced by genetic engineering of the naturally-occurring thyroid-stimulating hormone that is produced by the pituitary gland. After injection, thyrotropin alpha circulates throughout the body and binds to thyroid-stimulating hormone receptors on cancerous thyroid cells. The binding stimulates these cancerous thyroid cells to secrete thyroglobulin. Doctors can determine if the thyroid cancer has spread, or metastasized, based on the amount of thyroglobulin secreted after thyrotropin alpha stimulation.

How the Body Affects Thyrotropin Alpha

Peak circulating levels of thyrotropin alpha are reached between three to four hours after injection. The average time needed for the concentration of the drug in the blood to be reduced by half is 25 hours.

Studies suggest that the liver and kidneys may be involved in the metabolism of thyrotropin alpha, but this is unclear at this time.

Side Effects

The most common side effects (occurring in more than 1% of people) are the following:

• Nausea
• Headache
• Fatigue
• Vomiting
• Dizziness
• Tingling
• Weakness
• Insomnia
• Abnormal blood cholesterol levels
• Diarrhea
• Common cold symptoms

Risks and Precautions

Thyrotropin alpha is used with caution in patients who have been treated with, or who are allergic to, bovine thyroid-stimulating hormone.

Thyrotropin alpha can significantly elevate circulating thyroid hormone levels when given to patients who have substantial thyroid tissue remaining after surgery. This spike in thyroid hormone levels may affect heart rhythms. Complications are more likely in patients with existing heart disease or who have significant residual thyroid tissue.

Drug Interactions

There is no evidence of any drug interactions with thyrotropin alpha at this time.

Clinical Trials

The primary issue in tracking thyroid cancer patients is detecting metastatic thyroid cancer. Thyrotropin alpha-stimulated thyroglobulin testing is a tool for detecting metastatic thyroid cancer.

Available clinical trials: ClinicalTrials.gov

References

1. ↑ Emerson CH, Torres MS.Recombinant human thyroid-stimulating hormone: pharmacology, clinical applications and potential uses.BioDrugs. 2003;17(1):19-38. Abstract
2. ↑ Zanotti-Fregonara P, Toubert ME, Taieb D, et al. Overview on the use of recombinant human thyrotropin in thyroid cancer of follicular cell origin. Minerva Endocrinol. 2008 Jun;33(2):53-65. Epub 2008 Mar 11. Abstract | PDF

External Links

FDA: Patient Information Sheet Thyroid Cancer Survivor's Association