Pharmacokinetics of NDT uptake

[diogenes]

I wrote this two years ago, from a Medscape site. After all this time and the advances in knowledge since the I'm repeating it here, Note the difference in half-life of NDT T3, consderably longer than synthetic T3 (2.5 days versus 1 day). This is the ammunition which shows that NDT T3 is mostly protein bound and this causes delay in uptake until the protein thyroglobulin has been almost entirely degraded to release the T3 for uptake in cells. This is a secret weapon that Bianco would wish to bury, because his artifiical compound of T3 works little better.

Pharmacokinetics of NDT (DTE)diogenes•2 years ago•9 RepliesI discovered some useful information on NDT pharmacokinetics (rate of uptake, time to achieve peak level in blood, and loss rate). Note that >99% is protein bound, mainly onto thyroglobulin, so it will take time for the hormones to be released from the protein in the stomach/intestine and explains the delay in initial effect and the time it takes to achieve peak level, especially T3. Also we know that T3 taken on its own has a halflife of 1 day, yet it takes 2-.5 days to reach peak level. again indicating slower pharmacokinetics than T3 alone. T4-NDT half-life doesn't seem to differ from T4 alone. The different bioavailability also suggests slower uptake of NDT.Mechanism of ActionNatural thyroid hormone from animals; increase basal metabolic rate, increase utilization and mobilization of glycogen store, promotes gluconeogenesisPharmacokinetics

Onset: Initial effect: 3hr

Bioavailability: 48-80%Protein Bound: >99%

Metabolism: Hepatic; also in kidney and intestinal walls

Metabolites in NDT: Levothyroxine (T4), liothyronine (T3)

Excretion: Urine (major), feces (partially)

Time to peakT4: 2-4 hr

T3: 2-3 days

Half-LifeT4: 6-7 days (euthyroid); T3: 2.5 days

[jimh111]

A cynical view. If liothyronine is preferred on the basis of being easier and cheaper to make I don't see why it can't be bound to thyroglobulin so that it is slow release. The only reason I can think of is that it is a natural compound and so couldn't be patented. Presumably the process would be simple and so would not obtain a patent either. Whilst private enterprise gives some benefits we need a public sector pharmaceutical industry also to develop cheap and effective medicines.

[SlowDragon Administrator in reply to jimh111]

Here’s a great example of pro active steps to produce medication in-house saving NHS millions

imperialendo.com/price-gouging

Imperial College commissioned the synthesis of low strength hydrocortisone from Genesis Pharma, who then launched the drug on the open market. Until then, there was no competition. The study, funded by the NIHR (the research arm of the NHS), required a modest investment of approximately £100,000 to initiate the process. This contributed to a reducing trend in hydrocortisone prices, from over £147.50pcm to £3.55pcm between 2017 and March 2021.

imperialendo.com/price-goug...

unfortunately pitifully small number of people bothered to sign the petition to expand this project

petition.parliament.uk/peti...

[1tuppence in reply to SlowDragon]

Such a shame so few signed it. I am amongst those who didn't, because I didn't know it was there. Is there a way of being notified in future?

[TSH110 in reply to SlowDragon]

OMG 😳😱🤬 big pharma really are ripping us off big time

[TSH110 in reply to jimh111]

totally agree

[TiggerMe Ambassador]

Perfect timing 👏, I've just been discussing this with  Hidden

[amala57]

I'm a classic example of this. I have no thyroid gland & cannot tolerate synthetic T3. When I tried it I got palpitations & dreadful insomnia. With NDT I sleep all night & never palpitate. Such a serious need for slow release t3.The worst thing is my gp would prescribe synthetic t3 but won't prescribe ndt.

[tattybogle]

a juicy nugget indeed...Thanks for reminding us.

i'd have a lot more respect for Bianco, if he'd investigated this innate 'slow release ' property of NDT ( does NDT get much of a mention in his book ?)... since it's already pretty well known amongst patients who've had the opportunity to compare it to synth T3 ... Very nice to see the evidence in black and white rather than 'anecdote' though .

I'm in the same cynical camp as Jim ... sure Bianco knows this stuff all too well, but he also knows you can't patent 'a pig' .

[TSH110 in reply to tattybogle]

he’d rather reinvent the wheel nature gave us and patent his version for profit

[nightingale-56]

Thank you for confirming what I have found out  diogenes . On about the third day of beginning NDT, my mood most definitely lifted and has stayed fairly bouyant since 2018. My best NDT was WP Thyroid and I could not take Armour and Erfa, due to their excipients. I am now taking a compounded NDT from Germany. I feel WP Thyroid was so good for me because it contained mostly food-state excipients.

[Tythrop in reply to nightingale-56]

I've been taking Armour but stopped for a couple of weeks as GP ,who doesn't know I'm taking it wants me to have a "routine" Thyroid blood test .His idea is that if T4 low and TSH high ,I will qualify for free T4 on prescription .He won't test for T3 and won't prescribe it due to NHS protocols blah blah . My question is whether,if I qualify for NHS T4 I should take it or go back to Armour NDT .The former would be free but the latter costs me money . The article referred to above confuses me because I don't know if its better to have stuff that takes a longer time to convert for use ( Armour NDT) or a shorter time T4.Also with ref to Nightingale what are "excipients" ? and what harm did they do,,?

Thanks

[TSH110 in reply to Tythrop]

I didn’t feel well on T4 monotherapy but close relatives do. However I tend to think taking the closest thing to what my thyroid once made (NDT) is going to be a better option than t4 alone, even for my Levothyroxine loving relatives! T4 doesn’t seem to normalise the hormone levels to what they were in health with a properly functioning thyroid gland. That has to have health consequences especially in the long term.

[Tythrop in reply to TSH110]

Thankyou.I wonder if in Olden Days people ate animal thyroid glands (sweetbreads?) for health

[TSH110 in reply to Tythrop]

I think they have always been removed as eating a whole one might not be so healthful! I know the Chinese used them quite early on to treat thyroid disorder a lot earlier (centuries) than the west twigged it.

Sweetbreads are only the thymus and pancreatic glands and occasionally the parotid glands, sublingual glands, the ovaries and testes, but not the thyroid.

[FancyPants54 in reply to Tythrop]

sweetbreads is pancreas.

[Tythrop in reply to FancyPants54]

Ahh mystery solved

[jimh111 in reply to Tythrop]

If your doctor prescribes you have the option of taking a mix of levothyroxine and Armour. This could give you a better T3 / T4 balance and save a lot of money.

[Tythrop in reply to jimh111]

Thanks,this is extremely interesting

[nightingale-56 in reply to Tythrop]

If you were fine on Armour, then I would go back on it. My excipient problem was caused by Levothyroxine being changed in 2010 from Goldshield Eltroxin to Mercury Pharma Levothyroxine. I believe it was to do with the Acacia Powder, but since then I have to go very careful with what excipients I take now. Excipients are all other ingredients of a medication apart from the active ingredient, i.e: Levothyroxine or the actual NDT. NDT works quicker for me and better. The Mercury Pharma Levothyroxine caused bad skin problems that have yet to abate with whatever I try. Better on some NDTs than others.

[Tythrop in reply to nightingale-56]

Ta

[helvella in reply to Tythrop]

Excipients means "all the ingredients other than the Active Pharmaceutical Ingredient".

Also sometimes referred to as "other ingredients", "inactive ingredients", etc.

It is a good word to use as it is well-defined and is shorter than most other ways of saying the same thing.

[TSH110]

this is very interesting, thanks for posting. Did you by any chance look at dosing at different times of day? I know Levothyroxine is supposed to be better absorbed if taken at night but I wondered if this was also the case with t3, that’s t3 in NDT that I’m referring to.

[Tythrop in reply to TSH110]

Again ,interesting , but I thought that it has to be taken on an empty stomach ,so night time mot good if you eat in evening????

[TSH110 in reply to Tythrop]

I think two hours plus after food is ok

[Tythrop in reply to TSH110]

Ta, I'll give it a go.In particular ,thankyou gor taking an interest .

[Poniesrfun]

Do you have a reference link for the study (either Medscape or the actual study)?

Thank you.

Patti in AZ

[waveylines]

Diogenes this is fantastic....sorry only just found out about your post from another member. It totally reflect my experience of the difference between ndt and Liothyronine/levo. Is there a research document linked to this I can download and keep. Patients like me prescribed ndt on the NHS are subject to the argument that we should switch to a levo/lio combination. But that I find isn't nearly as smooth as my ndt.....I dont get highs lows on ndt but I do on the synthectics. I feel so much better on a ndt.

I think you've just explained why!!

[tattybogle in reply to waveylines]

related post re. how to find the Medscape article : healthunlocked.com/thyroidu... rerun-medscape-and-dte-ndt