Trial of Levothyroxine: what is being tested ex... - Thyroid UK

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Trial of Levothyroxine: what is being tested exactly?

Hoop1888 profile image
12 Replies

I’m into week 4 of a 50mg trial of Levothyroxine, which I had to insist on getting.

I’m just wondering what the doctors or I should be looking for in a trial? I’ve read that the levo pill replaces thyroid hormones with the dose given so it’s possible to feel worse on the pills or no better. How will the doctor know whether to increase dose or might they suggest I discontinue taking them if no change?

For info, I have felt some change although I’m a lot moodier and a bit depressed still. Energy levels could be better too.

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SlowDragon profile image
SlowDragonAdministrator

8 months ago your thyroid results showed you were clinically hypothyroid with below range Ft4 and TSH of 8

healthunlocked.com/thyroidu...

Yet you have only just started on levothyroxine?

50mcg is only the standard starter dose levothyroxine

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

Typically dose is increased SLOWLY Upwards in 25mcg steps over 6-12 months

Looking at previous posts you have been hypothyroid a long time

Have you had thyroid antibodies tested, or vitamin D, folate, ferritin and B12

If not request these are tested at next blood test

Levothyroxine doesn’t top up failing thyroid, it replaces it

Guidelines on dose levothyroxine by weight is that you are likely to EVENTUALLY be on approx 1.6mcg levothyroxine per kilo of your weight per day

ESSENTIAL vitamins are maintained at optimal levels

Hoop1888 profile image
Hoop1888 in reply toSlowDragon

I had thyroid antibodies tested (I think) about 5 years ago and the result came back with ‘slightly elevated’ but nothing was done or deduced from it.

I suspect that I won’t be moved up on these pills once I get tested. The trial was done to appease me, I reckon.

SlowDragon profile image
SlowDragonAdministrator in reply toHoop1888

If thyroid antibodies result was over range this confirms autoimmune thyroid disease…..even if they subsequently drop below range you still have autoimmune thyroid disease

You will need to push and argue for dose increase in levothyroxine over coming months

Levothyroxine doesn’t top up failing thyroid it replaces it

Almost everyone on levothyroxine will eventually need to be on full replacement dose

Always test thyroid levels early morning and last dose levothyroxine 24 hours before test

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.

If GP only tests TSH you will need to test privately

cheapest option for just TSH, FT4 and FT3 - £29 (via NHS private service ) and 10% off down to £26.10 if go on thyroid uk for code

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

monitormyhealth.org.uk/

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...

Only do private testing early Monday or Tuesday morning. 

Watch out for postal strikes, probably want to pay for guaranteed 24 hours delivery 

Comprehensive list of references for needing LOW TSH on levothyroxine 

healthunlocked.com/thyroidu....

TSH should be under 2 as an absolute maximum when on levothyroxine 

gponline.com/endocrinology-...

NHS England Liothyronine guidelines July 2019

 

sps.nhs.uk/wp-content/uploa...

Page 9 

Test for Deficiency of any of the following: Vitamin B12, Folate,  Vitamin D, Iron

See page 13 

1. Where symptoms of hypothyroidism persist despite optimal dosage with levothyroxine. (TSH 0.4-1.5mU/L)

Graph showing median TSH in healthy population is 1-1.5

web.archive.org/web/2004060...

Persevere - have all guidelines printed and be ready to quote them 

healthunlocked.com/thyroidu...

Jaydee1507 profile image
Jaydee1507Administrator

50mcgs is still a low dose so no wonder you don't feel much benefit and possibly worse.

The 'trial' thing in my book is a lot of nonsense. It's doctor speak for 'we are being very cautious'. Looking back at your results your TSH was over 9 so there is no doubt you require Levo but doctors like to cover their backs.

They are looking for results in that you feel benefit from Levo treatment. Thing is, they are so slap dash and have a tendency to abandon thyroid patients once their TSH is within the normal range and make zero effort to actually returning them to their pre hypo health. That's where this group comes in to coach yourself and your GP (!) to get you well.

You should have another blood test 6-8 weeks after starting Levo. Do this first thing at 9am, fasting and having taken your last Levo 24hrs before. Then the doctor will decide if you need an increase. Again you may have to push them to do this.

Hoop1888 profile image
Hoop1888 in reply toJaydee1507

how do you think I could ‘convince’ the gp that TSH levels should be at around 1 rather than just in range?

Jaydee1507 profile image
Jaydee1507Administrator in reply toHoop1888

There is a good list of references in this thread. healthunlocked.com/thyroidu....

Cross that bridge when it comes to it. Perhaps try a different GP within the same practice.

PurpleNails profile image
PurpleNailsAdministrator

The doctor should be looking to resolve your symptoms - but they are often of the opinion that an “in range TSH” will equal good thyroid level and therefore good health. 

Most feel well with FT4 & FT3 in upper part of range & TSH around 1. 

As your doctor didn’t treat you when you had 2 plus above range TSH I would predict they are the type of doctor that will be saying your are well once your TSH is “normal”. 

Usually what happens is initially the replacement does “top up” thyroid levels & you feel better but the TSH drops in response causing less thyroid out put. So by week 6 your TSH may be a little lower but still not low in range.  

You need a dose increase because the FT4 & FT3 (if tested) are still not good in range.  

Sometimes the TSH can to go very low, which isn’t always due to high thyroid levels, just because the TSH is unreliable your doctor may conclude a Trial dose “over replaces” you and say you don’t need it.

Hoop1888 profile image
Hoop1888

ah okay, this seems like a difficult one. The only reason a trial was agreed to was when I referred him to the NICE guidelines on sub clinical hypo, which he hadn’t noticed before.

I’m worried that I won’t be given the treatment that I need now and there will be no way to convince the doc.

humanbean profile image
humanbean in reply toHoop1888

You could tell doctors that you have noticed some improvements on Levo, and you'd like more please. Decide in advance what improvements you want to claim, but don't exaggerate too much. I would suggest saying you felt better for a couple of weeks then started to feel worse, and you want to try a higher dose.

The section on Initiation and Titration of Levo in the NICE guidelines might be helpful :

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

The dose of levothyroxine (LT4) should be individualized on the basis of clinical response and thyroid function test (TFT) results. Treatment must be monitored regularly to determine an adequate dose and to avoid both under- and over-treatment.

The NICE clinical guideline recommends:

Consider starting LT4 at a dosage of 1.6 micrograms per kilogram of bodyweight per day (rounded to the nearest 25 micrograms) for adults under 65 years of age with primary hypothyroidism and no history of cardiovascular disease.

Consider starting LT4 at a dosage of 25–50 micrograms per day with titration for adults aged 65 years and over, and adults with a history of cardiovascular disease.

The British National Formulary (BNF) recommends:

For adults aged 18–49 years — initially 50–100 micrograms once daily; adjusted in steps of 25–50 micrograms every 3–4 weeks, adjusted according to response; maintenance 100–200 micrograms once daily.

For adults aged 50 years and over, with cardiovascular disease, or severe hypothyroidism — initially 25 micrograms once daily; adjusted in steps of 25 micrograms every 4 weeks, adjusted according to response; maintenance 50–200 micrograms once daily.

Advise the person to take LT4 medication on an empty stomach in the morning before other food or medication.

Note that it suggests adjusting dose in the above every 3 - 4 weeks, but patient experience suggests every 6 - 8 weeks is better.

tattybogle profile image
tattybogle in reply toHoop1888

Since GP was unaware of NHS guideline for treating subclinical hypothyroidism.. he may not have paid much attention to the other bits of NHS information for GP's ... so . following the blood test on 50mcg if he is unwilling to raise dose following blood test results because "TSH is in range now" or "it made no difference/ made you feel worse", point him to this bit of the Clinical Knowledge Summary for Hypothyroidism :

cks.nice.org.uk/topics/hypo... (hypothyroidism/management/subclinical-hypothyroidism-non-pregnant)

"Review the person and recheck TSH levels every 3 months after initiation of LT4 therapy, and adjust the dose according to symptoms and TFT results. Consider checking FT4 in addition if the person has ongoing symptoms on treatment.

Aim to resolve symptoms and signs of hypothyroidism.

Aim to maintain serum TSH and FT4 levels to within or close to the normal reference range.

If symptoms persist, consider adjusting the dose of LT4 further to achieve optimal wellbeing, taking care to avoid over-treatment.

Once the TSH level is stable (2 similar measurements within the reference range 3 months apart), check TSH annually."

~The NHS wording for the bit about a trial, (and stopping it) says:

"If symptoms persist when the TSH is within the reference range, consider stopping LT4 therapy, and assess for alternative causes of symptoms." ...so .. be careful what you say and how you say it ... present your case as "there was some improvement but i'd like to see if trying a higher dose would bring more improvements " rather than "i feel worse" and then point to this list of references that advise GP's to keep TSH betwen about 0.5 to 2/ 2.5 when treating with Levo .

If stopping the trial is suggested .. point out that in order for it to be a reasonable trial and not a waste of time , they need to have tried treated it 'properly' ie TSH 0.5-2 ish .... not just a half assed attempt at treatment to get TSH 'just into range' .

SlowDragon profile image
SlowDragonAdministrator

You should have been started on levothyroxine 5 years ago

healthunlocked.com/thyroidu...

Starting levothyroxine - flow chart 

gps.northcentrallondonccg.n...

ESSENTIAL To test vitamin D, folate, ferritin and B12

SlowDragon profile image
SlowDragonAdministrator

when GP retests thyroid levels request they also test vitamin D, folate, ferritin and B12 levels as per guidelines

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