I haven't even read this yet. But the fact that UK and USA are speaking and writing together represents a major step forward.
Optimizing the treatment of hypothyroidism
Antonio C. Bianco & Peter N. Taylor
Daily levothyroxine (LT4) is the standard of care for the treatment of hypothyroidism; however, a small number of patients experience residual symptoms of hypothyroidism. Guidelines indicate that a trial with LT4 and liothyronine (LT3) could be attempted once other conditions have been addressed or excluded. Even so, currently, treatment of hypothyroidism can still be suboptimal.
The pay wall hits straight away for me. The possibility that someone is considering flexibility in treatment protocols is exciting. But will the powers that be listen?
What immediately stands out is no medical professional will spend their time on ruling all the different things that are listed in latest liothyronine consensus statement for example before initiating a T3 trial, and even if such an exclusion disease/ailment approach was attempted, it would be too time consuming and burdening on the patient. That in itself is cruel.
The one flaw I can see in the UK approach with regards to having a trial of T4 + T3 is that some places limit the amount of T3 in the trial to 5mcg or 10mcg. So it might well be that patients may not notice a difference because the amount of T3 in the trial is insufficient. 5-10mcg is a small amount, especially if T4 is replaced by T3 at a ratio of 5 to 1. For me, I needed a ratio of 3mcg T4 to 1mcg T3.
The restrictive T3 prescribing policy is why my husband and I haven't moved to Devon/Cornwall, despite the amazing waves to body board on (when I have the energy!)
Fortunately, hypothyroidism can be promptly reversed through hormone replacement therapy.
Fortunate indeed (sarcasm). But how unfortunate that getting a diagnosis can take decades!
Initially, the thyroid glands were cooked and then injected subcutaneously ; subsequently, they were desiccated and packed in tablets known as ‘thyroid’ or desiccated thyroid extract (DTE). DTE is mostly porcine thyroglobulin, and contains tetraiodothyronine (T4) and triiodothyronine (T3) at a ratio of approximately 4:1 (ref. 1).
I must admit I always thought that thyroid was eaten raw in sandwiches in the early days (1890s).
For any member who is unaware of this... NDT (Natural Dessicated Thyroid) is the same stuff as DTE (Dessicated Thyroid Extract). Patients generally use the name NDT, doctors use the name DTE, although I wonder if some medical staff hold up a cross and hiss at patients whenever DTE or NDT is mentioned. I don't know when or where the names DTE and NDT originated.
Tablets of LT4 had the advantage of being dosed accurately (DTE had issues with variable potency)
I thought there were shenanigans going on at the time that pharma companies were keen on replacing NDT with Levo, and some companies making NDT were being sent thymus gland instead of thyroid gland.
The "accuracy" of Levo is being oversold. Synthroid, the most expensive and most popular form of Levothyroxine in the USA was withdrawn from sale in 2001 because it turned out it hadn't ever applied for FDA approval :
Note there are two pages in the internet archive for the above article. Anyone with an account to read the NYT can read the whole article without going to the archive (I think).
Quote from the NYT article :
"The drug has had problems with potency, and the agency decided that it needed a formal evaluation. "
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At about the same time, an assay for measuring serum levels of thyroid-stimulating hormone (TSH) was developed and later perfected to become one of the most-used clinical assays. Thus, the standard of care for the treatment of hypothyroidism became daily tablets of LT4 at doses that normalize serum levels of TSH, with the tacit understanding that this approach restores T3 levels and resolves all symptoms of hypothyroidism. The excitement with this new approach was high. It was approved by governmental agencies and recommended by professional societies across the globe without the benefit of a single randomized clinical trial (RCT)
I spent ages looking for RCTs on the introduction of Levo and the replacement of NDT/DTE. No wonder I could never find any.
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In the first full paragraph on page 2 there is reference made to people under 65 years old being offered Levo. I'm not clear if the authors are suggesting that people aged 65+ shouldn't be offered Levo. I can't understand what they are getting at there.
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This focus on LT3 arose, at least in part, owing to increased awareness and issues with LT3 prescriptions and access to LT3 in the UK, which can be traced back to a substantial price spike in 2016, when the NHS cost of a 28-day supply of LT3 increased from about £4.50 to £258.19.
[This is my understanding about T3 prices in the UK. I could have got the wrong end of the stick.]This T3 situation was allowed to happen. The price of T3 in the UK was allowed to rise to the highest in the world because the NHS doesn't shop around. They make manufacturers come to them, and they charge those manufacturers a lot to do so. The NHS doesn't go and seek out drugs at better prices. They wouldn't have been that far away if they'd tried - France and Germany paid a lot less for T3 than the UK, as far as I know.
Prior to 1980, the standard by which the United States Pharmacopeia (USP) assessed the potency of thyroid hormone and thyroid extract tablets was based on their iodine content [43] and products were considered to meet that standard if the iodine content fell within the prescribed limits. Each manufacturer conducted their own manufacturing processes and created formulations to maintain this iodine standard without FDA oversight [9], however this unregulated process resulted in significantly conflicting results when various preparations were compared with one another [45, 69] and even amongst different batches within the same brand [44, 70, 71].
That is, until 1980, DTE really was inconsistent. Iodine content was a hopeless approach. However, we have all seen ideas which persist decades after they were outdated by circumstance, technology, or whatever.
I think that the doctors around in 1980 were still being taught that DTE was inconsistent. And those doctors, especially the ones who had little or no experience of DTE, probably carried on teaching that. So we have had two generations of doctors passing on incorrect information.
I'll not for one moment pretend there haven't been issues with DTE. Nor that the assays in 1980 were as good as the best of today. But I will claim that the older view had been overtaken by reality - at least in those who followed the USP standard.
(The UK BP standard was different - one grain of BP was a different potency to one grain USP and not in a simple way - and, rather than being updated, lapsed.)
As a matter of the greatest seriousness, I nonetheless get a degree of amusement from that same paper I just quoted. For it goes on to discuss that appalling state of levothyroxine potency in 1997:
In 1997, following receipt of 58 adverse drug experience reports indicating that products had failed to maintain potency through the expiration date and the amount of active ingredient of the same dosage and brand varied from lot to lot, the FDA decided that it was of utmost importance to ensure that the amount of available active drug be consistent for a given tablet strength. The FDA declared LT4 products to be new drugs subject to new drug applications (NDA) in order to be distributed in the US. A call for major change in the documentation of the manufacture, quality control, distribution, and use of LT4 products was stipulated by the FDA [49, 50]. Soon after, the NDA procedures were in place, a process of evaluating the potential interchangeability among approved LT4 products ensued.
And this had been the situation (in the USA) since levothyroxine (LT4) was introduced in about 1955 and competitors to Synthroid were allowed. My interpretation is that even Synthroid was poor and the others were in general no better.
For any member who is unaware of this... NDT (Natural Dessicated Thyroid) is the same stuff as DTE (Dessicated Thyroid Extract). Patients generally use the name NDT, doctors use the name DTE, although I wonder if some medical staff hold up a cross and hiss at patients whenever DTE or NDT is mentioned. I don't know when or where the names DTE and NDT originated.
As this has long been a bee in my bonnet...
helvella - Desiccated Thyroid Extract vs Natural Desiccated Thyroid
A discussion on the use of the terms "Desiccated Thyroid Extract" and "Natural Desiccated Thyroid" and the problems with both terms.
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