Understanding Hypothyroidism

Hypothyroidism Occurs when Thyroid Hormone Levels are Low

If you are being treated for thyroid cancer with remnant ablation, after a total thyroidectomy, your doctor may place you on thyroid hormone replacement therapy immediately after surgery. 

What is Hypothyroidism?

Hypothyroidism occurs when a person’s thyroid has been removed or is underactive and does not produce enough thyroid hormone.  Hypothyroidism affects millions of people in the United States.  Some people may experience only minor symptoms, but some may experience more severe symptoms. Symptoms of hypothyroidism may include those shown below.1

Hypothyroidism may occur in thyroid cancer patients when thyroid hormone replacement therapy is stopped in order to elevate TSH levels for testing during initial treatment (see remnant ablation) or long-term follow-up testing

While the presence and severity of the signs and symptoms of hypothyroidism vary by patient, it is important to be aware of these if your doctor decides to withdraw your thyroid hormone replacement therapy at any time.  The common signs and symptoms are shown below.2

Signs and symptoms of hypothyroidism

References

  1. Skugor M. Hypothyroidism and hyperthyroidism. Cleveland Clinic. 2014. http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/endocrinology/hypothyroidism-and-hyperthyroidism/. Accessed Oct 30, 2015.
  2. Norman, J. Endocrineweb. Hypothyroidism: Too Little Thyroid Hormone. 2015. http://www.endocrineweb.com/conditions/thyroid/hypothyroidism-too-little-thyroid-hormone. Accessed December 14, 2015.

Thyrogen® (thyrotropin alfa for injection) 0.9 mg/mL after reconstitution

IMPORTANT SAFETY INFORMATION

There have been reports of events that led to death in patients who not had surgery to have their thyroid gland removed, and in patients with thyroid cancer cells that have spread to other parts of the body.

Patients over 65 years old with large amounts of leftover thyroid tissue after surgery, or with a history of heart disease, should discuss with their physicians the risks and benefits of Thyrogen.

Thyrogen can be administered in the hospital for patients at risk for complications from Thyrogen administration.

Since Thyrogen was first approved for use, there have been reports of central nervous system problems such as stroke in young women who have a higher chance of having a stroke, and weakness on one side of the body.

Patients should remain hydrated prior to treatment with Thyrogen.

Leftover thyroid tissue after surgery and cancer cells that have spread to other parts of the body can quickly grow and become painful after Thyrogen administration.

Patients with cancer cells near their windpipe, in their central nervous system, or in their lungs may need treatment with a glucocorticoid (a medication to help prevent an increase in the size of the cancer cells before using Thyrogen.)

ADVERSE REACTIONS

In clinical studies, the most common side effects reported were nausea and headache.

USE IN SPECIFIC PATIENT POPULATIONS

Pregnant patients: Thyrogen should be given to a pregnant woman only if the doctor thinks there is a clear need for it.

Breastfeeding patients: It is not known whether Thyrogen can appear in human milk. Breastfeeding women should discuss the benefits and risks of Thyrogen with their physician.

Children: Safety and effectiveness in young patients (under the age of 18) have not been established.

Elderly: Studies do not show a difference in the safety and effectiveness of Thyrogen between adult patients less than 65 years and those over 65 years of age.

Patients with kidney disease: Thyrogen exits the body much slower in dialysis patients and can lead to longer high TSH levels.

INDICATIONS AND USAGE

Thyrogen is used to help identify thyroid disease by testing the blood for a hormone called thyroglobulin in the follow up of patients with a certain type of thyroid cancer known as well differentiated thyroid cancer. It is used with or without a radiology test using a form of iodine.

Limitations of Use:

The effect of Thyrogen on long term thyroid cancer outcomes has not been determined.

When Thyrogen is used to help detect thyroid cancer, there is still a chance all or parts of the cancer could be missed.

Thyrogen is also used to help patients prepare for treatment with a form of iodine to remove leftover thyroid tissue in patients who have had surgery to take out the entire thyroid gland for patients with well differentiated thyroid cancer who do not have signs of thyroid cancer which has spread to other parts of the body.

Limitations of Use:

In a study of people being prepared for treatment with a form of iodine after thyroid surgery, results were similar between those who received Thyrogen and those who stopped taking their thyroid hormone. Researchers do not know if results would be similar over a longer period of time.

See full Prescribing Information for more details.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.