Thyrogen and Its Uses in Thyroid Cancer Follow-Up

How Thryogen Prevents Hypothyroid Symptoms for Thyroid Cancer Follow-Up

Close up of nurse preparing a syringe for an injection
Andrew Brookes/Cultura/Getty

What is thyrogen and why would your doctor recommend this drug as part of your follow-up for thyroid cancer?

What is Thyrogen?

Thyrogen is a synthetic thyroid stimulating hormone (TSH). It is given in a series of injections to the buttocks prior to a whole body scan or ablation. When you are administered Thyrogen, you will continue to take synthetic thyroid hormones and do not experience the ill effects associated with being hypothyroid that occur otherwise as part of follow-up testing.

After receiving the Thyrogen injection, you may experience a headache and/or nausea. Although rare, hives, itching, and flushing have been reported after receiving Thyrogen because of an allergic reaction to the drug.

Thyrogen is not for everyone. Women who are pregnant or breastfeeding should not take Thyrogen. If you are allergic to any of the ingredients, you should avoid it as well. Your doctor may or may not recommend Thyrogen based on your current health and other factors.

Thyroid Cancer Follow-Up Without Thyrogen

For most people who have successfully battled cancer, follow-up care to check for recurrence usually involves relatively simple tests, such as blood and imagery tests. However, for those who have had thyroid cancer, the process is much more complicated. To check for recurrence, there are a few steps a patient needs to take to ensure test results come back accurate.

In a standard follow-up plan for thyroid cancer, you must undergo a whole body radioactive iodine scan.

Before a whole body scan, your doctor will advise you to stop taking your synthetic thyroid hormone medication for 4-6 weeks, forcing the body into a hypothyroid state. The goal is to increase thyroid stimulating hormone (TSH) in the body. Increased TSH promotes maximum absorption of radioactive iodine by any residual thyroid cancer cells.

Radioactive iodine uptake, or absorption, is critical for accurate results.

Becoming hypothyroid is essential for follow-up, but the physical effects of "going hypo" can be difficult for many to tolerate. The physical effects of being hypothyroid can include:

  • moderate to severe fatigue
  • depression
  • weight gain
  • muscle aches
  • thinning hair
  • dry skin
  • mood swings
  • difficulty concentrating
  • delayed reflexes
  • headaches
  • constipation
  • insomnia

For the first week or two of stopping synthetic thyroid medication, you will likely feel relatively normal. Synthetic thyroid hormones have a relatively long half-life, the time it takes for a drug to be eliminated from the body. Once a person stops taking synthetic thyroid hormones, the process of elimination from the body is gradual.

After a week or two, you may begin to feel the effects of being hypothyroid. This experience is different for every person, and varies between testing time for each individual.  Some people may experience only mild physical effects, while others may experience side effects which seriously compromises their quality of life.

   People may hesitate to do their follow-up testing as this wash-out period results in an inability to function normally at work and at play.

In addition to allowing the body to become hypothyroid, you must follow a strict low-iodine diet. Restricting the diet of iodine starves residual thyroid cells - the only cells in the body which absorb iodine. When radioactive iodine is given before a whole body scan, any residual thyroid cancer cells will readily absorb it. Like increased TSH, decreased levels of iodine in the body aid in radioactive iodine absorption.

You May Not Have to "Go Hypo"

The combination of being hypothyroid and a restrictive diet can certainly wreak havoc emotionally and physically. It can be so devastating that some people have avoided follow-up testing. To address these concerns a drug called Thyrogen (thyrotropin alfa for injection) was created by drugmaker Genzyme. Thyrogen allows you to continue taking your prescribed daily synthetic thyroid hormone while preparing for a whole body scan or radioactive iodine ablation. You can avoid the misery of having to go hypothyroid.

Insurance Coverage and Availability of Thyrogen

Many insurance providers do cover Thyrogen, but the co-pay can be quite high depending on the insurance plan. If Thyrogen is not covered under your health insurance plan, it may be covered as a pharmaceutical benefit if you have a prescription drug plan. If either coverage plan does not cover the cost of Thyrogen, check to see if the company has a prescription assistance plan.  Those paying out of pocket can expect to pay between $1,000- $1,500 per injection.

Sources:

Thyrogen (thyrotropin alfa for injection). Safety Information for Patients and Providers. U.S. Food and Drug Administration. Accessed July 15, 2013. http://www.fda.gov/Safety/MedWatch/SafetyInformation/ucm314891.htm

Nuclear Medicine in Thyroid Cancer Management: A Practical Approach. Radioiodine Therapy. International Atomic Energy Agency. http://www-pub.iaea.org/MTCD/publications/PDF/te_1608_web.pdf

Continue Reading