Definitive therapy reasonable for this patient
Dear Dr. Roach: What is the endgame of hyperthyroidism? I am a 54-year-old female, diagnosed in September 2020 with hyperthyroidism due to Graves' disease. My endocrinologist started me on 10 mg of methimazole and 100 mg of metoprolol daily (my heart rate was above 100 beats per minute).
I have bloodwork done quarterly. My thyroid-related results fluctuate, so my doctor has me either go up to 15 mg of methimazole or back down to 10 mg, accordingly. The last time I had bloodwork, all the values were low again, which I suspected, because I was feeling like a zombie again, but with added double vision, not fun.
I am under the impression that this up and down business is how it goes, in hopes the hyperthyroidism goes into remission by the end of the second year of taking methimazole, because that drug can negatively affect the liver. If it does not, surgery will be recommended to remove the thyroid and I'd have to take a replacement hormone for the rest of my life.
I am feeling unwell on 15 mg, and the double vision is frustrating. I have not seen an ophthalmologist.
I would like to just get the thyroid removed and be done with it so I can feel normal again. Are there other options I am not aware of? -- A.C.
Answer: The thyroid regulates virtually every system in the body, so abnormal thyroid levels have many different possible effects. High thyroid levels from any cause present problems, but Graves' disease adds an additional complication: In Grave's disease, antibodies stimulate the thyroid to make excess hormone, but they also can cause a unique eye condition.
The same antibody that stimulates the thyroid to grow (causing a goiter, an enlarged thyroid) can also stimulate the fat and connective tissue in the back of the eye to grow, which may push the eyeball forward, causing people to look like they are staring. This can cause problems to the eye, even threatening sight. So I strongly advise seeing the ophthalmologist. Radioactive iodine treatment of Graves' is less likely to improve eye disease than surgery.
Many people with hyperthyroidism from any cause have lots of energy, and when the thyroid hormone level in the blood is brought down to normal, they may feel fatigued or run down until the body gets used to running normally again. The metoprolol slows down the heart rate down, and methimazole prevents formation of thyroid hormone. Most experts have their patients on methimazole for one to two years, as many cases of Graves' disease will remit in that time. Unfortunately, not all do, so patients have the option to remain on medication treatment long term, or get definitive treatment, meaning surgery or radioactive iodine.
You've been dealing with this for a year and a half; if you want definitive therapy now, it's entirely reasonable for you to discuss this with your endocrinologist. Although with both radioactive iodine therapy and surgery, we try to get the amount of thyroid tissue left just right, many people will still need to take thyroid replacement hormone.
Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or send mail to 628 Virginia Dr., Orlando, FL 32803.
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