possible AF: Hi there I’ve recently had a blood... - Thyroid UK

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possible AF

wolthebuilder profile image
26 Replies

Hi there

I’ve recently had a blood test that has led to my thyroxin dose being reduced from 200 mcg to 175 mcg with the possibility of it being reduced further. This is due to my increased risk of AF.

I’ve been on 200 mcg for 17 years now after having thyroid removed due to Thyroid cancer and not sure why all of a sudden my levels are out.

Is this a common issue? Also I’ve heard of far more case of thyroid issues over the last couple of years. Is it on the increase

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wolthebuilder
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26 Replies
SlowDragon profile image
SlowDragonAdministrator

You haven’t posted on here for around 4 years

Are you just taking levothyroxine or also NDT?

NEVER agree to dose reduction based just on low TSH

Which brand of levothyroxine do you take for 200mcg

You need FULL thyroid and vitamin testing before even considering reducing dose levothyroxine

Many (most?) people when adequately treated will have Ft3 and Ft4 at least 60-70% through range…..frequently that will result in low/suppressed TSH

As long as no hyperthyroid symptoms or Ft3 is not over range you’re not over treated

For full Thyroid evaluation you need TSH, FT4 and FT3 tested

Very important to test vitamin D, folate, ferritin and B12 at least once year minimum

what vitamin supplements are you taking

Recommended that all thyroid blood tests early morning, ideally just before 9am, only drink water between waking and test and last dose levothyroxine 24 hours before test

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip)

On T3 or NDT day before test split T3 as 2 or 3 smaller doses spread through the day with last dose 8-12 hours before test

Private tests are available as NHS currently rarely tests Ft3 or all relevant vitamins

List of private testing options and money off codes

thyroiduk.org/getting-a-dia...

Medichecks Thyroid plus antibodies and vitamins

medichecks.com/products/adv...

Blue Horizon Thyroid Premium Gold includes antibodies, cortisol and vitamins

bluehorizonbloodtests.co.uk...

Only do private testing early Monday or Tuesday morning.

Link about thyroid blood tests

thyroiduk.org/getting-a-dia...

Symptoms of hypothyroidism

thyroiduk.org/wp-content/up...

Tips on how to do DIY finger prick test

healthunlocked.com/thyroidu...

Medichecks and BH also offer private blood draw at clinic near you, or private nurse to your own home…..for an extra fee

Just TSH, Ft4 and Ft3 test - £32

monitormyhealth.org.uk/thyr...

10% off code here

thyroiduk.org/getting-a-dia...

Monitor My Health also now offer thyroid and vitamin testing, plus cholesterol and HBA1C for £65

(Doesn’t include thyroid antibodies)

monitormyhealth.org.uk/full...

10% off code here

thyroiduk.org/getting-a-dia...

wolthebuilder profile image
wolthebuilder in reply to SlowDragon

Hi Slow Dragon

Thanks so much for your quick reply.

I didn’t go down the NDT route in the end

My new 75mcg Levo is made by M A HOLDER TEVA UK LTD and my 100mcg ( which I was taking 2 of ) is made by accord.

I’ll probably take your advice and get bloods re done. I’m due another blood test to see if they have sorted out levels in a few weeks. They may reduce my dose again it seems.

I’m not taking any vit supplements but definitely open to suggestions for them if you have any ?

Thanks in advance.

SlowDragon profile image
SlowDragonAdministrator in reply to wolthebuilder

Test thyroid and vitamin levels now

Then see what your vitamin levels are before starting any supplements

Many people find Levothyroxine brands are not interchangeable.

Most easily available (and often most easily tolerated) are Mercury Pharma or Accord

Mercury Pharma make 25mcg, 50mcg and 100mcg tablets 

Mercury Pharma also boxed as Eltroxin. Both often listed by company name on pharmacy database - Advanz

Accord only make 50mcg and 100mcg tablets. Accord is also boxed as Almus via Boots, 

Wockhardt is very well tolerated, but only available in 25mcg tablets. Some people remain on Wockhardt, taking their daily dose as a number of tablets 

Lactose free brands - currently Teva or Vencamil only

Teva makes 25mcg, 50mcg, 75mcg and 100mcg

Many patients do NOT get on well with Teva brand of Levothyroxine.

Teva is lactose free.But Teva contains mannitol as a filler instead of lactose, which seems to be possible cause of problems. Mannitol seems to upset many people, it changes gut biome 

Teva is the only brand that makes 75mcg tablet.

So if avoiding Teva for 75mcg dose ask for 25mcg to add to 50mcg or just extra 50mcg tablets to cut in half

But for some people (usually if lactose intolerant, Teva is by far the best option)

Aristo (currently 100mcg only) is lactose free and mannitol free.

March 2023 - Aristo now called Vencamil

healthunlocked.com/thyroidu...

List of different brands available in U.K.

thyroiduk.org/if-you-are-hy...

Posts that mention Teva

healthunlocked.com/search/p...

Teva poll

healthunlocked.com/thyroidu...

Once you find a brand that suits you, best to make sure to only get that one at each prescription.

Watch out for brand change when dose is increased or at repeat prescription.

Government guidelines for GP in support of patients if you find it difficult/impossible to change brands

gov.uk/drug-safety-update/l...

If a patient reports persistent symptoms when switching between different levothyroxine tablet formulations, consider consistently prescribing a specific product known to be well tolerated by the patient.

academic.oup.com/jcem/artic...

Physicians should: 1) alert patients that preparations may be switched at the pharmacy; 2) encourage patients to ask to remain on the same preparation at every pharmacy refill; and 3) make sure patients understand the need to have their TSH retested and the potential for dosing readjusted every time their LT4 preparation is switched (18).

Discussed here too

healthunlocked.com/thyroidu...

SlowDragon profile image
SlowDragonAdministrator in reply to wolthebuilder

100mcg is low dose for a bloke

75mcg obviously even lower

Chronic fatigue…..suggests you’re under medicated

guidelines on dose levothyroxine by weight

Even if we frequently start on only 50mcg, most people need to increase levothyroxine dose slowly upwards in 25mcg steps (retesting 6-8 weeks after each increase) until eventually on, or near full replacement dose

NICE guidelines on full replacement dose

nice.org.uk/guidance/ng145/...

1.3.6

Consider starting levothyroxine at a dosage of 1.6 micrograms per kilogram of body weight per day (rounded to the nearest 25 micrograms) for adults under 65 with primary hypothyroidism and no history of cardiovascular disease.

Also here

cks.nice.org.uk/topics/hypo...

pathlabs.rlbuht.nhs.uk/tft_...

Guiding Treatment with Thyroxine:

In the majority of patients 50-100 μg thyroxine can be used as the starting dose. Alterations in dose are achieved by using 25-50 μg increments and adequacy of the new dose can be confirmed by repeat measurement of TSH after 2-3 months.

The majority of patients will be clinically euthyroid with a ‘normal’ TSH and having thyroxine replacement in the range 75-150 μg/day (1.6ug/Kg on average).

The recommended approach is to titrate thyroxine therapy against the TSH concentration whilst assessing clinical well-being. The target is a serum TSH within the reference range.

……The primary target of thyroxine replacement therapy is to make the patient feel well and to achieve a serum TSH that is within the reference range. The corresponding FT4 will be within or slightly above its reference range.

The minimum period to achieve stable concentrations after a change in dose of thyroxine is two months and thyroid function tests should not normally be requested before this period has elapsed.

wolthebuilder profile image
wolthebuilder in reply to SlowDragon

Hi again

Apologies, my mistake I’m not making it clear

I was in 200mcg but they have lowered me to 175 mcg with a view to lowering it possible again. I’m 2 different makes of Levo.

Thanks again

SlowDragon profile image
SlowDragonAdministrator in reply to wolthebuilder

So have you already reduced to 175mcg

Only change one thing at a time ….dose or brand

Otherwise you won’t know if any issues are brand change or dose change

How much do you weigh in kilo approximately

Presumably you have quite a physical job and out in cold

wolthebuilder profile image
wolthebuilder in reply to SlowDragon

Hi again

Yes they have reduced me to 175 mcg. Im a builder with a physical job. I think the issue is one of my test results was very low, almost negligible which apparently puts me at risk for AF. Also my current tablet maker is Accord who dont do 75mcg hence the 2 types of tablet. Im 93 kgs

wolthebuilder profile image
wolthebuilder in reply to SlowDragon

Hi again Slow Dragon.

I’ve found my thyroid blood results and think I know what has caused them to lower my Levo. My serum TSH level is 0.01 and serum free TSH level is 35.8. The first is really low and the second is high which is why (I think) they are concerned about me having possible AF issues.

Does this mean anything to you ?

Thanks in advance

SlowDragon profile image
SlowDragonAdministrator in reply to wolthebuilder

I think you mean

TSH 0.01

Ft4 35.8

What’s the range on Ft4 (figures in brackets after each result)

Ft4 range is often 12-22

Was test done early morning with last dose levothyroxine 24 hours before test?

How long have you been on 175mcg daily now

Retest 6-8 weeks after dose was reduced

all thyroid blood tests early morning, ideally just before 9am, only drink water between waking and test and last dose levothyroxine 24 hours before test

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip)

Also request they test vitamin D, folate, ferritin and B12

wolthebuilder profile image
wolthebuilder in reply to SlowDragon

0.20 to 4.27 is normal range for TSH. I’ve been on the lower dose of 175 for around 3 weeks now.

I will probably get private blood tests and show them my results. I’m due another test in around 4-6 weeks

SlowDragon profile image
SlowDragonAdministrator in reply to wolthebuilder

no range for Ft4?

Don’t test until at least 6 weeks after dose reduction

wolthebuilder profile image
wolthebuilder in reply to SlowDragon

Thank you for your advice. It’s been very informative

I’ll keep you posted

wolthebuilder profile image
wolthebuilder in reply to SlowDragon

Apologies I didn’t realise I hadn’t answered

Test range for Ft4 is 12-22

pennyannie profile image
pennyannie in reply to wolthebuilder

You would appear to have stopped converting the T4 into T3 - 4 years ago your conversion was good - has anything else medically happened in this time frame ?

4 years ago - T3 came in at the top of it's range 6.70 with a T4 at 89% through the range with TSH at 0.01 :

Personally I think your issues will improve adding in a little T3 - Liothyronie alongside with a slightly reduced T4 dose or switching to NDT - you have't a thyroid and running your own business which must be both financially and physically challenging.

wolthebuilder profile image
wolthebuilder in reply to pennyannie

Sorry I didn’t see this reply only the one below. There concerns are the TSH at 0.01 which, as you pointed out, was that 4 years ago. I’ll get a blood test and put results on here when I get them

Thanks again

wolthebuilder profile image
wolthebuilder in reply to pennyannie

Forgot to mention I’m now type 2 diabetic ( only just though) and 2 months ago i was put on statins for raised cholesterol, which is odd as it’s always previously been good. Are you more prone to these things if you have no thyroid?

pennyannie profile image
pennyannie in reply to wolthebuilder

As I understand things a raised cholesterol can happen when hypothyroid and not optimally medicated -

and yes - I think statins can interfere with thyroid hormone uptake -

I'm going to try and link in Slow Dragon as I'm out of my comfort zone here :

 SlowDragon is the fastest Dragon I know and in fact a wizard and much better placed to give you the low down on your ' Forgot to mention ' and ' only just ' type 2 diabetic message above :

SlowDragon profile image
SlowDragonAdministrator in reply to wolthebuilder

For GOOD conversion of Ft4 (levothyroxine) to Ft3 (active hormone) we need GOOD Vitamin Levels

Poor conversion results in high Ft4 but low Ft3

Low Ft3 leads to higher cholesterol

nhs.uk/conditions/statins/c...

If you have an underactive thyroid (hypothyroidism), treatment may be delayed until this problem is treated. This is because having an underactive thyroid can lead to an increased cholesterol level, and treating hypothyroidism may cause your cholesterol level to decrease, without the need for statins. Statins are also more likely to cause muscle damage in people with an underactive thyroid.

Thyroid patients need to supplement to maintain GOOD vitamin levels

Important to test vitamin D, folate, ferritin and B12

Statins tend to increase blood sugar and may increase risk of developing type 2 diabetes

bhf.org.uk/what-we-do/news-...

cdc.gov/diabetes/library/fe....

SlowDragon profile image
SlowDragonAdministrator in reply to wolthebuilder

So Ft4 at 35.8 was much higher than 22

ALWAYS test early morning and last dose levothyroxine 24 hours before test

But also very important to test Ft4 and Ft3 together

High Ft4 but Low Ft3 would mean poor conversion

pennyannie profile image
pennyannie

Hey there again Wolthe builder :

It is essential that you are dosed and monitored on your T3 and T4 results and ranges and not a TSH though fully understand in primary care a TSH is seen as the only test necessary with the odd T4 thrown in from time to time.

You have not got a thyroid - your TSH does not give reliable measures of anything as your HPT axis - the Hypothalamus - Pituitary -Thyroid feedback loop on which the TSH relies on as working well - no longer gives accurate readings as your have no thyroid and this circuit loop broken.

The TSH was originally introduced as a diagnostic tool to help diagnose a patient dealing with hypothyroidism and was nevr intended to be used once the patient was taken any form f thyroid hormone replacement.

Your metabolism has been slowed by lowering your dose of T4 - and we need optimal core strength vitamins and minerals - those of ferritin, folate, B12 and vitamin D maintained at optimal levels to help convert the T4 into T3 - and frequently when metabolism is slowed the body struggles to extract key nutrients through food - so sugggest you get these run as they may well be impacting further your health issues.

Your conversion looked good 4 years ago - but we do need to see a FreeT3 and Free T4 drawn from the same bloods and please do not agree to a dose reduction based on just a TSH reading - I fell into this TSH obsession scenerio. believing the doctor knew best and trusting blindly and became increasing unwell over a 2 year period and then referred to as a conundrum - because my TSH was ' in the range ' .

wolthebuilder profile image
wolthebuilder in reply to pennyannie

Thank you so much for your advice. I will Keep you posted.

humanbean profile image
humanbean

I’ve recently had a blood test that has led to my thyroxin dose being reduced from 200 mcg to 175 mcg with the possibility of it being reduced further. This is due to my increased risk of AF.

So you don't actually have AF? You just have a risk of it developing?

This is weird. You probably have a risk of being run over by a bus, but people aren't treated for that in advance of it happening.

If you felt well on the dose you were on you could have said you don't want to reduce your dose.

If you are now under-dosed you are likely to be at greater risk of getting heart problems than you were with the higher dose.

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

thyroidpatients.ca/2018/07/...

verywellhealth.com/thyroid-...

wolthebuilder profile image
wolthebuilder

Thank you. I wasn't aware i could refuse to have your dose reduced. Ive got a blood test in a few weeks for a check up. Ill ask for an appointment with a Dr and ask for the additional bloods ref vitamin D and others mentioned earlier etc as well.

Thanks again

SlowDragon profile image
SlowDragonAdministrator in reply to wolthebuilder

Make sure to book early morning test, before 9am and only water to drink between waking and test and last dose levothyroxine 24 hours before test

You need TSH, Ft4 and Ft3 tested together (unlikely NHS will test Ft3 ) also vitamin D, folate, ferritin and B12

Come back with new post once you get results

humanbean profile image
humanbean in reply to wolthebuilder

I wasn't aware i could refuse to have your dose reduced.

It's worth making a case for not having your dose reduced. However, there is no guarantee that a doctor will agree to leave you on the higher dose.

It would help if you knew what the doctor was worried about with respect to your dose. Does the doctor think your TSH is too low? Or your Free T4 is too high? Or your Free T3 is too high?

Contra21 profile image
Contra21

How do you know you are at risk for af?

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