Blood tests

Hi all,

Background - I take NDT, a slightly larger dose first thing (and then coffee/breakfast minimum of half an hour later, as instructed) and then a slightly smaller dose later in the day (theoretically around lunchtime). That timing varies, I'm not in a good pattern with it (long story mostly involving my weird schedule which thankfully has settled down a bit). Sometimes I get to bedtime and realise that I haven't taken it and take it with my sertraline (microdose as I'm tapering off it at an excruciatingly slow pace) on grounds that it's better to take it imperfectly than not at all. As it happens I've also seen conflicting ideas about whether or not it is necessary to space NDT as much as levothyroxine (my pharmacy says do the same as levo).

Anyway, I'm due a blood test. I'm trying to be better with that second dose of NDT and my life has settled down a lot and it's much easier now. How long do you think I need to be more consistent with the timing of the second dose to get a reliable result? 4 weeks? 6? Or is it less important than I think and I should just go now?

Also, I've seen a lot of different opinions on timing of blood tests - both here and on other forums. One forum (not here, and I left it) insisted on no meds on the day of test until afterward and none on the day before (which struck me as a bad idea and was the primary reason I left that forum). Other places vary and say to take last dose 12-17 hours prior to test, others say test just before meds, so more like 24 hours. I think the last time I took my NDT at about 3pm and blood test place opens at 8am (which I guess is about 17 hours prior or a titch more if I had to wait).

Cheers!

Sim

[greygoose]

Opinions may very on how long you should wait between thyroid hormone and food/coffee, but I doubt the vary about taking NDT with sertraline. That's bound to have an effect.

And, opinions vary about whether or not you can take T3 with food because it's more easily absorbed, etc. But, don't forget that NDT also contains levo. So, if I were you, where maximising absorption is concerned, I would side with your pharmacist. Best not to take any chances, don't you think?

As for what to do before a test, I doubt you'll find any varying opinions on here. With NDT and T3 you should leave a gap of 8 to 12 hours between the last dose and the blood draw.

As for how long you should leave before doing your next blood tests now that your routine has settled down, once again, don't forget that NDT contains T4, and T4 converts to T3, so it would best to leave the full 6 weeks to get the most accurate results.

[Hidden in reply to greygoose]

Argh, I just wrote a response and it was lost.

Thank you @greygoose.

It occurs to me that I'm going to see the pharmacist tomorrow, so I could have planned to ask her then and not posted! I'll ask her anyway.

Re the varying opinions - yes, here!

Re the less than perfect med taking... Yes I know. I find it challenging to take meds at three separate times in the day as well as keeping two of them separated from food, especially over the last few months, however, my life has settled down and it is easier again now.

If I get to bedtime and the second NDT is still in the box with the sertraline (which is a microdose), I've taken them together as the lesser of the evils. I'm not keen to wake and take the other med as my sleep isn't good enough to disrupt. The sertraline can't be skipped.

I'll wait six weeks and work out the timing before the test.

Thank you. Much appreciated.

[greygoose in reply to Hidden]

You don't have to split it into three doses, you know. A lot of people take it all in one go, it's so much easier. But it's a very personal thing.

[Hidden in reply to greygoose]

The third is the sertraline, to keep it - theoretically- away from the ndt. I single dosed the ndt for a long time but with an increased dose I'm preferring two.

[Hidden in reply to greygoose]

Ok good news from the pharmacy, she didn't think that taking them together would be a problem. This may be because she compounds both so knows what's what and may not apply to a regular dose (which is between 12.5 and 40 times greater than I'm taking) , but for me on this occasion it sounds like it is okay. She also thought that the main issue regarding blood tests is not taking the NDT within an hour or so before the blood test to avoid the big peak, so I'll ponder on that one.

[greygoose in reply to Hidden]

OMG no! She's so wrong. All thyroid hormones should be taken on an empty stomach and gaps respected between that and food/medications/supplements. And 8 to 12 hours left between your last dose of NDT and the blood draw. I've always thought it was a bad idea to ask a pharmacist questions like that - she's just proved me right. So many stupid things have been said to me by pharmacist: vit D is dangerous; fluoride is good for you; aspartam is exactly the same as sugar… the list goes on.

[Hidden in reply to greygoose]

This isn't dispenser type of pharmacist. She's a compounding pharmacist.

[greygoose in reply to Hidden]

I still say she's wrong.

[Hidden in reply to greygoose]

Ok, good to know. Cheers.