Thyrotoxicosis

[elsiev32]

Went to the Dr's because l had palpitations. Woke up with a racing heart revving at 160bpm. He said it was nothing to do with my 100mg daily of Thyroxine even though my TSH is 0.01. T3=4 & T4=28... Told me to carry on being well suppressed as l had Papillary Thyroid Cancer. Had a letter from the hospital yesterday telling me l have Thyrotoxicosis caused by too much medication. How the heck can a Dr not know. If not sure why don't they read up on it.. Not happy at all...

[jimh111]

It's a difficult judgement as to whether you have thyrotoxicosis, I don't think either side can be certain. It's certainly a possibility and there are sensible steps they can take to avoid risk. I'm a patient but let me give three possible actions:

1. Prescribe a beta-blocker to protect the heart, making sure it's not one that affects thyroid function. This is a simple option. You (presumably) need a suppressed TSH at the moment and so protecting the heart is perfectly reasonable.

2. Contact the surgeon / cancer specialist who is looking after you and ask how suppressed your TSH needs to be. There have been advances in thyroid cancer care in recent years and it is now accepted that many patients do not need to have their TSH suppressed indefinitely. This is very specific to the patient, what type of cancer they had. The cancer can be graded and TSH suppression adjusted accordingly. Find out how much your TSH needs to be suppressed and for how long.

3. You will probably do better with some T3 (liothyronine) replacing some of your T4 (levothyroxine). This may give you more stable hormone levels and you will feel better. When fT4 levels are high patients hormone levels tend to be unsable (just personal observation). An endocrinologist will need to prescribe liothyronine initially. It is appropriate that you are referred back to an endocrinologist because you are having problems and your GP is unable to deal with them. If your endocrinologist is still around you might try contacting their office directly and asking for an appointment. Once you have been referred to a specialist you don't need another GP referral to go back to them later.

[elsiev32 in reply to jimh111]

Hi, I do have a supply of T3 which has been sourced by a friend but I have never taken them as I hadn't a clue what dose to take, so may things involved I got quite lost to be honest. I have got Propanalol 10mg which I take if my heart rate doesn't go down quickly. My TSH is 0.01 but the Consultant says he is happy for it to go to 1. I had the TT in May 2018. Sadly my Endo is in india for a few Months and yes no one to stand in for him x

[jimh111 in reply to elsiev32]

I don't have expertise on cardiac care, so my knowledge is limited in this area. As far as I know ... 10 mg propranalol is a very low dose. Propranalol is used in thyrotoxicosis because it not only acts as a beta blocker it can reduce T4 to T3 conversion. So, it may not be the best beta blocker to use in your case where you are receiving levothyroxine.

[greygoose in reply to jimh111]

It's a difficult judgement as to whether you have thyrotoxicosis, I don't think either side can be certain.

I would have thought that looking at her FT3 level would have been enough to ascertain that she didn't have thyrotoxicosis. Surely the definition of thyrotoxicosis - in the real world - is very high thyroid hormones - especially T3 - with suppressed TSH. Not just suppressed TSH with thyroid hormones any old where. If it were the latter, I've had thyrotoxicosis for about 10 years!

I must say, I'm very disappointed by your response. I expected a more considered reply coming from you.

[jimh111 in reply to greygoose]

Thyrotoxicosis is not just the numbers, some like me were still hypothyroid with very high hormone levels. Her fT3 is average, TSH low and fT4 high. It's difficult to know if the high heart rate is due to thyrotoxicosis and I can understand different doctors giving different opinions. The test would be if her dose is reduced a little does the tachycardia resolve? We shouldn't take much notice of the low TSH because it can take several months to recover after long term suppression and sometimes doesn't recover.

With thyroid cancer it's important to prevent it returning and this usually involves supressing TSH to some extent for a period of time. It's good not to supress your TSH for longer than is necessary (it can 'downregulate the axis' - won't go into detail). Whether or not there is thyrotoxicosis should be judged by clinical response not just serum hormone levels. Thus, I feel the jury is out at the moment and I wouldn’t criticise either doctor on this specific point.

[greygoose in reply to jimh111]

Yes, well, I know about thyroid cancer and keeping TSH suppressed and all that. What I'm questioning is the definition of thyrotoxicosis. And, if you can't go by numbers, what do you go by? Seems like the hospital were just going by the TSH. Heart problems can be caused by not enough T3.

[jimh111 in reply to greygoose]

Go by clinical response, see if a reduction in levothyroxine stops the tachycardia.

[greygoose in reply to jimh111]

But surely thyrotoxicosis isn't just about tachycardia, is it?

[elsiev32 in reply to greygoose]

Getting more confused by the minute 😁

[greygoose in reply to elsiev32]

Me too!

[greygoose in reply to greygoose]

diogenes , can you shed any light on thyrotoxicosis, please?

[diogenes Remembering in reply to greygoose]

Thyrotoxicosis and hyperthyroidism are two different entities. Hyperthyroidism is always accompanied by above range FT3 and suppressed TSH. FT4 may remain normal for a while, in cases of T3-specific hyperthyroidism. Thyrotoxicosis factitia is caused by overdosing on T4, giving rise to elevated FT3. It does not include situations of normal FT3, though symptoms of overdose might be believed to occur because of the total hormone load (if TSH was used as the sole determinant of the condition). When I first analysed the clinical trial of the first FT3 test, in 1983, placement of patients in the assessment frame was done from measuring FT4, FT3 and TSH together. I had no role in assessing and placing patients in their categories - the doctors did all that. I merely analysed what they told me. The upshot was for patients on T4 only, that FT3 was the best test to use to discriminate proper from over-treatment. The diagnosis of overtreatment was always accompanied by high FT3. So by patient presentation only ,the doctors had first ascribed thyrotoxicosis factitia without knowing the FT3 value, and this was independently confrmed by the FT3 result.

[greygoose in reply to diogenes]

Thank you, diogenes, that's what I was thinking.

[jimh111 in reply to greygoose]

Just one sign, one of many. For elsiev32 the issue is whether her rapid pulse will stop if her levothyroxine is reduced a little. It doesn't matter about an academic definition of thyrotoxicosis, is the rapid pulse due to fT4 being too high or caused by something else. Simply reducing levo a little and seeing what happens will clarify.

It may be that she will do much better on some liothyronine and a little less levothyroxine. Dr Skinner used to point out that levothyroxine can 'backstack', it can build up in the system and cause brief periods of thyrotoxicity. This doesn't happen with liothyronine.

elsiev32 sorry for the complexity. Just see if your rapid pulse is related to your levothyroxine dose and if so try and persuade your endocrinologist to give you a little liothyronine instead. Also, your GP could prescribe a better beta blocker to protect your heart (even if you do not continue to experience rapid heart beats).

[elsiev32 in reply to jimh111]

Thanks. I have a supply of T3 but wouldn't have a clue how much to take... I still have Propanalol left from before my TT and use this if my heart rate doesn't seem to drop. On Saturday morning it was 160bpm on waking x

[jimh111 in reply to elsiev32]

Liothyronine (L-T3) is about 3x as potent as levothyroxine (L-T4). A factor of 4x or 5x is sometimes quoted but this relates to fT3 and fT4 levels in the blood, the doctors forget that the two drugs have different half lives. So, you would reduce your levo by about 30 mcg and add in 10 mcg lio. I would reduce the levo for a week or so first because it hangs around in the body for much longer. However, I would try and get an endo to prescribe for you, or at least agree to monitor you.

If you find you are alert when going to bed and experience anxiety then it is more likely to be due to too much levothyroxine. Really there are two issues. Whether the levothyroxine is causing the rapid heart rate and how do you solve your hypothyroid symptoms.

[greygoose in reply to jimh111]

Well, I think that the definition of thyrotoxicosis does matter, and the hospital misused the term. And I think that is reprehensible. What is the point of having a vocabulary if we don't all use the same words to use the same thing? How the hell are we supposed to communicate if it means one thing to one person, and something else for another. Accuracy in diagnosis goes completely out of the window!

Did you see what diogenes wrote above? Thyrotoxicosis factitia is caused by overdosing on T4, giving rise to elevated FT3. It does not include situations of normal FT3 And, in elsiev32's case the FT3 was normal.

[elsiev32 in reply to greygoose]

I had my TT in June last year. I really haven't learned much. I have never seen the same endo more than once. Never seen an Oncologist. The ENT explained the Cancer. Nothing ever mentioned since 🤦‍♀️

[greygoose in reply to elsiev32]

I think that's the way it normally is. I don't think they actually know enough to do much explaining.

[elsiev32 in reply to greygoose]

Shame isn't it. Feel like l have been kinda thrown in the trash ☹️

[greygoose in reply to elsiev32]

I know how you feel.

[jimh111 in reply to greygoose]

Purely a technical response to greygoose, I’ll give a general reply later.

If you have a heart rate of 160 bpm you really don’t care about a precise definition of thyrotoxicosis. My pulse is 72 and I’m not bothered about it. My preferred terms are ‘hypothyroidism’ for insufficient thyroid hormone activity and ‘hyperthyroidism’ for excess thyroid hormone activity, regardless of the cause. Unfortunately, we must use thyrotoxicosis if the hyperthyroidism arises from exogenous hormone intake. I strongly dislike the term thyrotoxicosis because thyroid hormone is not a toxin. Using ‘thyrotoxicosis’ tends to engender a negative attitude to treating hypothyroidism.

Thyrotoxicosis is usually defined as excess thyroid hormone or (better) the clinical effects of excess thyroid hormone. Sometimes it is defined as hyperthyroidism! It’s generally accepted that hyperthyroidism is a subset of thyrotoxicosis, when the patient is not taking exogenous hormone. Pop a single levo tablet and your hyperthyroidism becomes thyrotoxicosis!

@diogenes comments are valid. In most cases fT3 will be elevated. In Graves’ or thyroiditis a lot of T3 comes from the thyroid. High levels of T4 will increase type-1 (D1) and type-3 (D3) deiodinase activity leading to elevated circulating T3 and rT3. Thyrotoxicosis is usually accompanied by high T3.

elsiev32 appears to have impaired deiodinase (T4 to T3 conversion):

TSH is 0.01. T3=4 & T4=28

T3 is 2.9, range is 3.1 - 4.9 ...... T4 is 14, range 9 - 19 (from her previous post).

She had a thyroidectomy following cancer, so the high T3 secretion associated with Graves’ or thyroiditis cannot occur. Nor can thyroidal deiodinase take place. Even so her fT3 is still low for her fT4 level.

There are two issues: -

1. Does the tachycardia arise from excess levothyroxine?

2. Does she have signs and symptoms of thyrotoxicosis?

We can’t answer the second question because elsiev32 has not described any signs or symptoms other than her heart rate.

The heart expresses type-2 deiodinase (D2) but very little is known about it, how much or how it is regulated. We know little about how the heart responds to elevated circulating T4 (with normal T3). We do know that both hypo and hyperthyroidism are bad for the heart, they cause reversible (to some extent) structural changes. We also know that elevated circulating thyroid hormone causes changes in the ‘wiring’ of the heart that lead to tachycardia and atrial fibrillation. I have no cardiac knowledge so that’s as much as I can say. Thus, it’s possible that during the thyroid cancer and follow-up hormone treatment there were elevated thyroid hormone levels that have made the heart susceptible to small levels of excess hormone. As I noted earlier the heart can recover from this.

It’s possible that elsiev32 is thyrotoxic, either in the true definition sense or her heart is susceptible to minor hormone elevations. This can be established by seeing how her heart responds to a levothyroxine reduction. If this is the case an informed decision can be made about future hormone treatment, is it reduced or perhaps maintained with monitoring and beta blockers. Or combined levothyroxine / liothyronine therapy used. If the tachycardia does not respond to reduced levothyroxine, then the doctors need to fully investigate why her heart beats so fast. A pulse of 160 bpm is not normal, it should be investigated.

We are in danger of getting bogged down with an academic definition of ‘thyrotoxicosis’, even worse a definition based on numbers. Clinical response should always take precedence over the numbers. The hospital might have incorrectly used the term ‘thyrotoxicosis’ which I would consider a minor faux pas. Unless they are dealing with expert patients, I'd prefer they avoid technical jargon and explain things in plain English. Most thyroid patients come away from their consultations with little understanding of what went on.

@diogenes - the link I put in the above text doesn't want to work!

[greygoose in reply to jimh111]

I strongly dislike the term thyrotoxicosis because thyroid hormone is not a toxin.

At least we agree about something. But, not only that, just putting in a letter that someone has thyrotoxicosis with no explanation, and scaring the proverbial out of them, is a bit more than a minor faux pas. But, I would have thought that our purpose here was to explain, support and reassure, not just say we-ell, either doctor could be right, when it's highly unlikely that she actually does have thyrotoxicosis as such, just maybe a little to much T4 or T3 for her needs.

[Lora7again in reply to greygoose]

I have that written on my medical records from 10 years ago ... so wrong imho

[elsiev32 in reply to Lora7again]

I had never ever heard of it to be honest, I think that is why I freaked a little bit

[elsiev32]

It says ::: The Thyroid function indicates Thyrotoxicosis which is contributing to palpitations and racing heart I recommend the patient reduces the Levo from 100mg to 50mg and to have another Thyroid check in 4 weeks time. I would accept TSH level up to 1, we need to keep a close eye on the Thyroglbulin antibodies as the bloods are showing a steady rise since Dec 2018 of 3.0, 5.0 and now 6.0. We will discuss this in the Thyroid MDT x

[elsiev32]

No I am tall and fat. Haha, no I am 5' 6" and weigh 68 kg. 62 years young (feel 92 though) My T4 was 28 x

[elsiev32 in reply to elsiev32]

Yes both Thyroglobulin tests are rising sadly

[FedupofOldW]

Good luck getting liothyronine. I used to on it and was fine but a new endocrinologist took my prescription away, no discussion. Nice don't want it used anymore too expensive.

[SlowDragon Administrator in reply to FedupofOldW]

Liothyronine now has green light ....you should push to get your T3 prescription reinstated

[FedupofOldW in reply to SlowDragon]

I have decided to go back onto natural thyroid, fed up of dealing with Drs who don't listen or just go off blood tests

[SlowDragon Administrator]

Your conversion of FT4 to FT3 looks poor

Can you add the ranges on those FT3 and FT4 results

FT4 and FT3 should be roughly equal % through range

Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .

Last dose of Levothyroxine 24 hours prior to blood test. (taking delayed dose immediately after blood draw).

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

Is this how you do your tests?

Low vitamin levels can affect conversion of FT4 to FT3 so it's important to test vitamin D, folate, ferritin and B12 too

Frequently it's the combination of low FT3 causing hypothyroid symptoms and high FT4 due to poor conversion

You need to get vitamins tested if not done do

Reducing Levothyroxine dose will lower FT4, but would also lower FT3 too, possibly making symptoms worse

Frequently after TT patients need the addition of small doses of T3 alongside Levothyroxine

20% Patients with no thyroid can not regain full health on just Levothyroxine

ncbi.nlm.nih.gov/pmc/articl...

Ask GP to test vitamin levels or get full Thyroid and vitamin testing privately via Medichecks or Blue Horizon

Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine,

"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.

In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l.

Most patients will feel well in that circumstance. But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."

You can obtain a copy of the articles from Thyroid UK email print it and highlight question 6 to show your doctor

please email Dionne at

[e-mail]

Professor Toft recent article saying, T3 may be necessary for many. Note especially his comments on current inadequate treatment following thyroidectomy

rcpe.ac.uk/sites/default/fi...

Reducing Levothyroxine down by 50mcg is a MASSIVE dose reduction. Even 25mcg dose reduction is likely too much

[elsiev32 in reply to SlowDragon]

FT3 is 4.9....the range is 3.5 - 6.8

FT4 is 28 .... the range is 12 - 22

[elsiev32 in reply to elsiev32]

Vit D is 50 .... range 50 - 175

Vit B12 is 200 ... range 190 - 885

Folate is 7 .....range 4.8 - 19

Ferritin is 25.... range 13 - 150

[SlowDragon Administrator in reply to elsiev32]

All vitamin levels are low, getting these optimal should help improve conversion of FT4 to FT3. This would reduce high FT4 and increase low FT3

Vitamin D

GP will only prescribe to bring vitamin D up to 50nmol. Aiming to improve by self supplementing to at least 80nmol and around 100nmol may be better .

Once you Improve level, you may need on going maintenance dose to keep it there.

Retesting twice yearly via vitamindtest.org.uk

Vitamin D mouth spray by Better You is good as avoids poor gut function.

It's trial and error what dose each person needs.

Government recommends everyone supplement October to April

gov.uk/government/news/phe-...

B12 and folate on the low side.

B12 is very low

Do you have any low B12 symptoms?

b12deficiency.info/signs-an...

If you do ask GP to test for Pernicious Anaemia before starting on any B vitamin supplements

You may need B12 injections or daily Sublingual B12

Once tested.....Supplementing a good quality daily vitamin B complex, one with folate in not folic acid may be beneficial.

chriskresser.com/folate-vs-...

B vitamins best taken in the morning after breakfast

Igennus Super B complex are nice small tablets. Often only need one tablet per day, not two. Certainly only start with one tablet per day after breakfast. Retesting levels in 6-8 weeks

Or Thorne Basic B or jarrow B-right are other options that contain folate, but both are large capsules

If you are taking vitamin B complex, or any supplements containing biotin, remember to stop these 7 days before any blood tests, as biotin can falsely affect test results

endo.confex.com/endo/2016en...

endocrinenews.endocrine.org...

If vitamin D is low, B vitamins may be too. As explained by Dr Gominack

drgominak.com/sleep/vitamin...

healthunlocked.com/thyroidu...

Ferritin is very low. Ask GP for full iron panel test for Anaemia

Eating liver or liver pate once a week, plus other iron rich foods like black pudding, prawns, spinach, pumpkin seeds and dark chocolate, plus daily vitamin C can help improve iron absorption

Links about iron and ferritin

healthunlocked.com/thyroidu...

healthunlocked.com/thyroidu...

drhedberg.com/ferritin-hypo...

restartmed.com/hypothyroidi...

Post about iron supplements

healthunlocked.com/thyroidu...

Selenium supplements can help improve conversion of FT4 to FT3

Only start one supplement at a time and wait at least ten days to assess results before adding another

[SlowDragon Administrator in reply to elsiev32]

How long before blood test did you take Levothyroxine ?

FT3 is only 48% through range

Useful calculator for working out % through range

chorobytarczycy.eu/kalkulator

[Angel_of_the_North]

Hard to say without ranges, but your Free T3 looks low and that causes adrenaline rushes and palpitations. You can also get racing heart from low iron. You are probably taking too much T4 and not enough T3.

[elsiev32]

I was just enquiring about a private ultrasound to be honest but they say I have to be referred by the Dr, not happy about that as they are not going to agree it, a bit odd my surgery, I thought £290 didn't sound too bad, no Lymph nodes removed and no RAI as they said the Cancer was encapsulated, I have a lump in my neck but the Doc said if it hurts thats ok x

[elsiev32]

Never seen an Oncologist Janey 😳

[elsiev32]

Yes the Dr did. I have a lump that hurts but he said if it hurts that's OK x

[diogenes Remembering]

This isn't an easy one to solve. First of all, you are by these results a very poor converter of T4 into the necessary T3 (FT4/FT3 ratio nearly 6.1/1). So because of this, the amount of T4 you have to take to get even a half reasonable FT3 is so high that the two hormones together are suppressing your TSH. But being a poor converter it's likely that taking even more T4 will make matters worse. FT3 wouldn't respond and you would simply produce useless reverse T3. I would say you are a clear candidate for joint therapy with T4 and T3. In this way, the total hormone load will be lowered, because the T3 would immediately help directly. Lowering the T4 dose won't help because that will then lower your FT3. I think your palpitations are caused by the excess total hormone load and combined therapy should be considered rather than monotherapy with T4 only.

[jimh111 in reply to diogenes]

I would agree with this with the caveat that they really should find out whether your rapid heartbeat is instigated by the levothyroxine dose or not. Whilst I don't have a problem with two doctors having different opinions they should not express them with full certainty until they have taken steps to confirm their diagnosis. Either way they should find out why your heartbeat is so rapid, it warrants investigation.

I also agree that the heart may be responding to the total hormone load. It is generally accepted the heart converts T4 to T3 but nobody really knows much about how it is regulated and to what extent.

elsiev32 your hospital doctor is happy for your TSH to go as high as 1.0. This is based on your thyroid cancer, in the early post-operative stages they like to keep TSH very low because there is a possibility that TSH will stimulate the cancer to come back.

The other issue is whether you are now hypo, euthyroid or hyper. You haven't described your signs and symptoms so it's difficult to know how you are doing. Given your blood tests you are likely to do better on combined therapy, as diogenes said it should allow a lower overall dose whilst improving symptoms. From this viewpoint we would need to know what symptoms you have.

[elsiev32]

Not sure if this makes any difference at all but my Thyroglobin levels are rising also which concerns them...

[jimh111 in reply to elsiev32]

I believe thyroglobin levels are used to monitor the possible reoccurance of thyroid cancer. I believe this is a complex issue that requires specialist knowledge which I certainly don't have, there can be factors such as antibodies that can interfere with the results. I suspect they are monitoring this and a little concerned. As I say I have no knowledge in this area, I would suggest you question them carefully about it and make sure they present the information in a form you understand. Don't let them dither, keep them on their toes.

[elsiev32 in reply to jimh111]

Thanks Jim, dither they certainly know how to do

[elsiev32]

Actually I just rang the Dr and said I received a letter on Nov 1st, just wondered if by any chance I should be receiving a call from them, she said it hasn't been read yet but if you don't hear by November the 10th call back