My FT 4 level was 3.79 on 7/18/17. (0.89-1.76)
I started methimazole on 8/4/17 and FT4 was again checked 8/14/17. The level had dropped to 2.64 (0.89-1.76). This reduction happened in 10 days. The doctor told me today, to increase methimazole to 20 mg per day instead of 15 mg per day. She wants to test FT4 in 2 weeks. She wants it to be mid range on the scale. Should I increase methimazole as instructed or reduce it. I have very high reverse T3 and posted my labs in another post. I'm worried that in 2 weeks my FT4 will be too low.

I also don't understand what reverse T3 means. I felt better without methimazole. When I was put on it my symptoms became worse. Needed more propranolol. I have noticed I get colder since being on the meds. Did go off for 5 doses once and had high heart rate more often. I'm wondering if I even need to be on it. It has lowered my FT4 and no other labs have been redone. Should I request current labs of other levels since it's been almost a month? I was told by some doctors I have Graves. Two nodules were found through ultrasound 2mm and 7mm. I have not done an iodine uptake test. I am lost in all of this. Have been to a ER too many times. My biggest symptoms now are anxiety and trouble taking a deep breath and unpredictable heart rate. Still take propranolol as needed, but can only tolerate 5 mg because it lowers my heart rate and blood pressure too much. My heart rate increases mostly at night while sleeping.

Hi,
I'm glad that you clarified that your July labs were at the time of diagnosis. You should have been started on 20 mg then. Your FT4 will not be too low in two weeks, but it should fall within the reference range, and at that time your 20 mg will probably be lowered.

You don't want to stop taking your doses or this can precipitate a sudden rise in thyroid hormone levels, increased cardiac symptoms and a high risk for thyroid storm.

You should have a TSI antibody test to confirm Graves' disease. Graves' disease can occur in conjunction with thyroid nodules. You don't need an uptake test and it can increase your symptoms. A 5 mg propranolol dose may be all you need, and you may no longer need it once your FT4 falls back into range.

Our major thyroid hormones are T4 and T3. In this form they're inactive. they become active when they're cleaved from the protein molecules that transport them to the blood and are in a free form. Thus, free T4 (FT4) and free T3 (FT3) are the best indicators of your thyroid status. T3 can also be cleaved into reverse T3, which is inert and has no actions. this level is high in babies and in illnesses where a high FT3 could be harmful. it's a protective mechanism.
best, elaine