Levothyroxine getting less effective? - Thyroid UK

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Levothyroxine getting less effective?

firearcade profile image
5 Replies

Hi all

I've written before and found it very useful so hoping you can help again. I have just switched doctors surgeries and as such lost access to my online account with all my detailed results, so hope this limited information is enough to go on.

At the start of last year I was overmedicated at 50mcg, dropped down to 25mcg and although my TSH was only 0.22 I felt rubbish and my doctor agreed to up my dosage.

Since then my TSH has risen despite dose changes and I'm worried that body seems to have stopped responding? On 75mcg my TSH was 3.7, on 100mcg it was 3.1. My goal is under 2 for fertility reasons so I am now on 125mcg, which seems a massive jump given how much my body reacted to 50mcg.

I tolerate mercury pharma well but since we started upping my dosage again I've only able to access 25mcg tablets, so am taking 5 of those tablets a day - are they weaker in some way?

Thanks for all thoughts.

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firearcade
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SlowDragon profile image
SlowDragonAdministrator

Levothyroxine replaces your own thyroid output

50mcg is only the standard starter dose

As dose levothyroxine increases your own thyroid takes a holiday and eventually stops working

So your experience is to be expected

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

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.

Bloods should be retested 6-8 weeks after each dose change or brand change in levothyroxine

Please add your results from 125mcg

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

Also both TPO and TG thyroid antibodies tested at least once

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

About 90% of primary hypothyroidism is autoimmune thyroid disease, usually diagnosed by high thyroid antibodies

Autoimmune thyroid disease with goitre is Hashimoto’s

Autoimmune thyroid disease without goitre is Ord’s thyroiditis.

Both are autoimmune and generally called Hashimoto’s.

Low vitamin levels are extremely common when hypothyroid, especially with autoimmune thyroid disease

20% of autoimmune thyroid patients never have high thyroid antibodies and ultrasound scan of thyroid can get diagnosis

In U.K. medics hardly ever refer to autoimmune thyroid disease as Hashimoto’s (or Ord’s thyroiditis)

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)

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

Testing options and includes money off codes for private testing

thyroiduk.org/testing/

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/testing/thyro...

Link about Hashimoto’s

thyroiduk.org/hypothyroid-b...

Symptoms of hypothyroidism

thyroiduk.org/signs-and-sym...

Tips on how to do DIY finger prick test

support.medichecks.com/hc/e...

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

SlowDragon profile image
SlowDragonAdministrator

previous posts show cause of your hypothyroidism is hashimoto’s

Essential to test vitamin levels at least annually

NICE guidelines that if hypothyroid or subclinical you should see endocrinologist BEFORE TTC

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

See pages 7&8

btf-thyroid.org/Handlers/Do...

Also here - dose increase in levothyroxine as soon as pregnancy test confirms conception

cuh.nhs.uk/patient-informat...

thyroidpharmacist.com/artic...

Low ferritin, low thyroid levels and miscarriage

preventmiscarriage.com/iron...

Low iron and hypothyroid

endocrineweb.com/news/thyro...

Folate and B12 and Neural tube defects and autism

healthunlocked.com/thyroidu...

greygoose profile image
greygoose

At the start of last year I was overmedicated at 50mcg, dropped down to 25mcg and although my TSH was only 0.22 I felt rubbish and my doctor agreed to up my dosage

Oh dear. Your doctor doesn't know much about thyroid, does s/he. Very, very unlikely that you were over-medicated on just a starter dose of 50 mcg, whatever the TSH. What time of day did you have the blood draw for that test? Because TSH levels vary throughout the day, and therefore having the blood draw before 9 am gives you the best chance of having an in-range TSH and avoiding a reduction in dose.

If you felt rubbish, it had nothing to do with the TSH, because the TSH doesn't make you feel anything. You felt rubbish because your thyroid hormone levels were too low on that tiny dose.

You are only over-medicated if your FT3 is well over-range. Did they test that?

Since then my TSH has risen despite dose changes and I'm worried that body seems to have stopped responding?

Responding to what? TSH? Only a healthy thyroid can respond to that, and you haven't got one.

Or did you mean responding to levo? That's doubt full. Levo is a hormone, not a drug. I should imagine that either you are under-medicated - 125 mcg is not a large dose - or you are a poor converter of T4 to T3. Or maybe both. The fact that your TSH is rising suggests that. TSH and thyroid hormones have an inverse relationship - the higher the TSH, the lower the thyroid hormones, and vice versa. But, at best, the TSH is only a rough guide to thyroid status.

My goal is under 2 for fertility reasons so I am now on 125mcg, which seems a massive jump given how much my body reacted to 50mcg.

It would be better if your goal was 1 or under, because that is a 'healthy' level. 2 is actully too high for good health.

But, you body didn't react to 50 mcg, only your pituitary did. And, as you have Hashi's, it might not have had anything to do with your dose, but more to do with a slight Hashi's attack, where the dying cells deposit their stock of hormones into the blood, causing FT4/3 levels to rise sharply, and the TSH to therefore drop.

So, to know more about what is going on, you need full thyroid testing: TSH, FT4 and FT3. And then we might be able to help. :)

firearcade profile image
firearcade

Thank you for responses. I got my latest results this morning and on 125 my TSH is 0.68 and FT4 is 19, my new (excellent) GP says both are where we would like them to be.

Going to follow up with a referral request and some private antibody and FT3 testing... thanks again this is all very helpful.

helvella profile image
helvellaAdministrator

Taking five tablets should be almost identical to taking, say, 100 + 25.

However, you are effectively taking considerably more of the excipients (inactive ingredients).

And we have seen many cases where multiple lower dosage tablets have not felt the same as fewer higher dosage tablets.

It isn't likely to be that big a difference, but best to be aware that if you do change, you might need another dose adjustment afterwards.

Always remember that you can adjust dose by smaller amounts such as 12.5 micrograms. Either by alternate day dosing or splitting tablets. I was not impressed when I say your 50 dose reduced to 25 - and 50% reduction. (And a return to 50 would be a 100% increase.)

In general, when you are being treated, small changes, over a longer time are a better approach.

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