Hi,
My doctor has just increased my levothyroxine to 100 from 75. He has implied that he won't increase it any further because i was subclinical hypo and my TSH is now 3.17 down from 6.25. I still have symptoms and have to be retested in 6 weeks. I hope 100 is a high enough dose to sort me out. He seems to be afraid of the potential side effects that to high a dose can cause. Should I be concerned?
Maggiv
The aim of a treated hypo patient generally is for TSH to be 1 or below or wherever it needs to be for FT4 and FT3 to be in the upper part of their respective reference ranges when on Levo if that is where you feel well.
See article in Pulse Magazine (the magazine for doctors) by Dr Toft, leading endocrinologist and past president of the British Thyroid Association, where he says
"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.
In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l. Most patients will feel well in that circumstance.
But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.
This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."
You can obtain a copy of the article by emailing Dionne at
tukadmin@thyroiduk.org
print it and highlight question 6 to show your doctor.
Also see pathology.leedsth.nhs.uk/pa... and scroll down to Thyroxine Replacement Therapy in Primary Hypothyroidism and you will see in the box
0.2 - 2.0 miu/L Sufficient Replacement
> 2.0 miu/L Likely under Replacement
I would show this information to your GP to ensure you get the correct amount of Levo which allows you to be symptom free.
When booking thyroid tests, always book the very first appointment of the morning and fast from evening meal the night before, delay breakfast on morning of blood draw (water allowed) . This gives the highest possible TSH which is needed when looking for a diagnosis, an increase in dose or to avoid a reduction. TSH is highest early morning and lowers throughout the day. It also lowers after eating. Also, take your Levo after the blood draw because if you take it before then your FT4 will reflect this and show higher than what is normally circulating. We usually advise 24 hours between last dose of Levo and blood draw so if you take your Levo in the morning then delay until after the test, or if you take it at night then delay that dose until after the test. These are patient to patient tips which we don't discuss with doctors or phlebotomists.
According to my GP, 100mcg is still a low dose! My TSH is 2.13 and he wants it below 1! He’s increasing it again 3 week after my next test as my FT4 is 8. Though he’s only increasing my 25mcg, he suspects I would need 150mcg eventually!
What do I do
TSH Rising with increased dose of Levothyroxine?!
What to do best? 
Do I need t3?
