Split dosing/blood tests, may I check please?

[turquoisea7]

Quick check please:

planning to try and get a bt sent on 3rd Jan.

Currently dosing levo 50mcg 1am (bedtime dose moved back to time that usually seems to help me sleep) and 75mcg 8am.

So to do a bt on Tuesday am:

I take my usual 50mcg Sat night/Sunday 1am.

I take my usual 75mcg Sun 8am.

Sunday night/Monday I do NOT take 50mcg at 1am.

Monday morning I take 125mcg 8am.

Nothing until after bt.

Then take 75mcg after bt;

and 50mcg again Tues night/Weds 1am.

Does that all sound right, to keep in line with usual nothing-for-24-hours results to date?

[Regenallotment]

yep that is what I would do 🦋💚🦋 😊

[turquoisea7 in reply to Regenallotment]

brilliant thanks

[jimh111]

Taking levothyroxine before a blood test makes little difference. I wouldn't bother with this complex manoeuvre. If you are worried: on the day of the blood test just delay your 75 mcg dose until after the blood has been taken.

[turquoisea7 in reply to jimh111]

hallo, it's not that I'm worried, I just want consistent testing conditions for comparison with previous bloods. The one time I did take half a split dose about 16 hours before a test, it made a big difference, so I'm just aiming for comparison. This will be the test before I start adding T3 so I don't want to have to drop more T4 than is necessary at the start.

The one time I did and NHS test a few hours after a dose, it looked like I was doing really well, when in fact I felt more like death then than I do now; so my experience is that dosing at all within 24 hours definitely shows in my bloods.

[jimh111 in reply to turquoisea7]

Levothyroxine has a seven day elimination half-life. So, if you leave 24 hours between the last dose and blood draw your fT4 will have fallen about 10% and this will show up in the blood test (as well as an effect on TSH).

[tattybogle]

i wouldn't bother with that much fiddling about ....we leave 24 hrs to avoid measuring the peak which happens between approx 2-6 hrs after taking a full daily dose in one hit .

You've already evened it out quite a lot by splitting your dose. and so as long as the last dose is more than , say , 6 hrs before blood test , then i'd leave your routine as it is apart from delaying that mornings 75mcg until after the test .Much less faff and much easier to remember what you did so you can be cosistent for future tests .

[turquoisea7 in reply to tattybogle]

Thanks tatty. And herein lies the difficulty with a forum!

[tattybogle in reply to turquoisea7]

ah . now i've read you post more carefully ( sorry ) i see you wanted to keep it in line with your previous 24hr results 'to date'. i thought it was just a general 'policy' question when i answered .

so yes ,, if you want to compare accurately with your previous, then your suggested timing sounds right to me .

[turquoisea7 in reply to tattybogle]

thanks for getting back to my tatty. Yes, definitely wanting to keep it in line with previous. As I mention above, the one time I did take half a split dose about 16 hours prior to testing my results looked completely out of whack.

[Regenallotment]

if I’ve always left 24 hours, I’d want to continue that consistently as otherwise I won’t know what my level is compared to all previous occasions. I split my dose 25/100 and would skip both night / morning and take after the appointment.