Thanks reallyfedup,I have an endo. appointment next week and am just wondering when to stop T3/T4 meds. So feel I can stop T4 48hrs. before then T3 24hrs. and not feel as if I'm cheating.x
Make sure the TFT consists of TSH, FT4, FT3 and also ask for TPO and TgAB antibody check. She will probably baulk at the antibody check, but tell her that this check is very important; if you had positive autoantibodies (either TPO or TgAB), then that alone would be diagnostic for autoimmune thyroiditis - regardless of any TFT figures, as with autoimmune thyroiditis (Hashimoto's disease) the TSH as well as both the FT's can fluctuate violently.
"So feel I can stop T4 48hrs. before then T3 24hrs. and not feel as if I'm cheating.x "
Usually not taking your Levo on the morning of the blood draw (which means ~24 hours since last ingestion) would be the correct thing to do (it's not cheating at all - it is the correct procedure) - but if you have good reason to make your figures look a little lower, then leave it for up to 48 hours .... it's still within the recommended procedure)
Sorry - I overlooked that you are taking T3 as well.... that complicates things a bit (and changes the whole picture of the TFT result) - personally I would not stop the T3 for 24 hours - 12 hours would be acceptable, but all in all with the proposed procedure your TFT result would most likely come back quite a bit lower than it really is - except if you had autoantibodies which might (or might not - depending on AA attacking your thyroid gland) change the picture again.
I would not suggest that anyone stops taking their thyroid medication for 48 hours, even for a blood test. Many people (including myself) would feel very unwell by doing so, and for no good reason. 24 hours without medication is plenty long enough in my opinion to ensure that there is no misleading FT4/FT3 reading due to the temporary peak that occurs from ingesting exogenous thyroid hormone.
It's not a good idea to stop for more than 24 hours. Even if it doesn't make you feel ill, doing this can result in the patient being labelled as 'non-compliant', (i.e. being accused of not taking your meds!). So the doctor won't increase your dose for this reason.
If you have the opportunity to choose what time you get tested, then early morning is best, because that is when TSH is at it's highest.
Ideally, you would skip your 10pm dose the night before, get your test done as soon as the phlebotomy dept or surgery opens (say 8-9am) and then take the dose that you skipped the previous night. Then, you can still also take your dose as usual that evening.
Doing it this way ensures you don't actually have to 'miss out' any of your doses. You simply postpone one dose until after the blood is drawn.
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