My doctor just prescribed methimazole for my thyroid. I have already had radiation to "kill" my thyroid. Why?

Question

Why would my doctor prescribe a thyroid decreasing medicine when my thyroid is "dead"? I noticed when looking at the uses for this medicine that is is used for preparing people for thyroid removal surgery and radiation therapy. Since I already had radiation I dont understand the purpose for prescribing this.

Answer 1

Your doctor will have the best answer for this. Call him/her and ask. If you can't get ahold of your doc, call the nurse.

Answer 2

After I-131 radioablative therapy for a thyroid pathology, if serologic levels indicate that their is some functional tissue, your physician may opt to place you on methimazole instead of subjecting you to more I-131 therapy.

Answer 3

Radiation to the thyroid gland doesn't kill all of it, it kills a portion of it. But reducing the size of the thyroid, you can reduce how much extra hormone it is producing. If they destroy a portion of your thyroid, and find that you are still producing too much in the way of thyroid hormones, they can give you a drug to reduce you the rest of the way down, hopefully.