Jan 05, 2011 - 4:24 am
I had a TT in May 2010 and was treated with RAI in the end of July 2010 after about 5 weeks without thyroxine (T4). After I started taking T4 again (125 mcg/day) I had my fT4 measured after 4, 5 and 11 weeks. The results showed fT4 14-14,5 (lab ref area 9-22 pmol/l), fT3 3,4-3,6 (ref 3,5-7,8) and TSH 19-27 (ref 0,2-4).
The dosage was increased to 175 mcg/d and after 4 weeks the results were fT4 15, fT3 5 and TSH 3,5.
The dosage was increased again to 175 mcg/d four times a week and 200 mcg/d three days a week. I also started taking 10 mcg/d liothyronine (T3). After four weeks the fT4 was still 14,6 but TSH was now acceptable 0,07 and fT3 6,2.
My question is: Why is fT4 more or less constant even though I have increased the dosage by almost 50%. Is it due to bad uptake from the intestines? I take the dosage in the morning before breakfast. Does the increased dosage also increase the binding proteins? I have always been slim, my current weight is 65 kg and my height is 180 cm. Does this mean that I need more T4 then others? I have read that the average dose of T4 is 2mcg/kg/day. I am now on 2,86 mcg/kg/day.
Do any of you have some of the same experiences?