Confused re Levothyroxine dosage: I am flummoxed... - Thyroid UK

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Confused re Levothyroxine dosage

Knip profile image
Knip
9 Replies

I am flummoxed. I have had hypothyroidism for many years now...it is autoimmune in my case.

Two years ago my T4 went up to 15, towards the top end of normal, and my TSH went down to 0.03... below normal range.

(This was first picked up by my Rheumatologist two years ago who wrote to my GP suggesting that he thought I would need a dose reduction to protect my bones from further thinning. I have osteopenia...the forerunner of osteoporosis).

That's OK as far as it goes but I can't understand why, following my latest check five weeks ago, still with the same results, I have had my Levothyroxine raised from 100mcg to 125mcg. I have queried this twice but without an explanation. I would have expected a lower dose rather than a higher one. I have another test in three weeks time. Feeling confused.

I should probably add that it is not possible, at present, to see, or talk to, a GP on request...messages are passed on via the receptionist who then passes on the response from the doctor.

If anyone can throw any light on this I would appreciate hearing from you.

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Knip
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SeasideSusie profile image
SeasideSusieRemembering

Knip

Can you please post the actual results, along with their reference ranges, as "top end of normal" doesn't actually tell us that much.

Also, for a full picture it's TSH, FT4 and FT3 that are needed, with FT3 being the most important result.

Knip profile image
Knip in reply to SeasideSusie

Thank you for your reply Seaside Susie...I love your name! Ufortunately, I don't have the TF3 result or reference. I was only given the TSH and T4 that I have mentioned...so perhaps the problem lies with the FT3.

My GPs surgery is currently not giving 'print outs' of results or emailing them and our Practice only allows online access to prescription renewals and pre pandemic we could book appointments,. The normal range for T4 has been given to me by both the RA consultanat the receptionist as 4.5 to 16 and the TSH normal range as 0.04 to 4.

Your reply has been very helpful because i had no idea that another factor had been checked...or that it was the important one. I suspect now that T3 might be the culprit. I will try to find out more about what it does online. The underline is unintentional...but I just can't get rid of it! Stay safe and well, and thank you so much for your help.

tattybogle profile image
tattybogle in reply to Knip

If these are NHS results then fT3 is very unlikely to have been tested (or considered) by GP in adjusting your dose We know it's the most important , hence it being recommended , but GP's are taught to use TSH and occasionally fT4 with it. , and it is difficult for them to get the lab to agree to test fT3, even if they request it.

Do you know for certain that the latest result were 'still the same' TSH/fT4 [range] ?

If no other choice you could ask receptionist to read relevant result and [lab range] down phone..

TSH (thyroid stimulating hormone) result 0.00 ? ....range [ ? - ? ]..... date.

fT4 (free T4/thyroxine) .....................................0.00 ? ..................[ ? - ? ]..... ( if done )

fT3 (free T3)..........................................................0.00 ? ..................[ ? - ? ]....(unlikely, but ask if done)

dose decisions where an fT4 has been done are based on Lab reference range : you said range was [4.5 -16 ] a rather unusual one , BUT were both fT4 tests done using this range?

TSH is much less dependant on lab range :

But if TSH result is really still 0.03 it would be very odd for a GP to increase dose. especially if fT4 is in range.

I think it will remain a puzzle until you can get the actual results.

Knip profile image
Knip in reply to tattybogle

Hi Tattybogle. I just love your name! Yes, I do know that the results were the same on each occasion. However, I only asked the Receptionist for the T4 and TSH results. When checking them on the computer she did mention T3 when reading out what had been tested and I remember clearly saying 'no not what I need it's the T4 and TSH results I want'. I had never heard of the T3 before so wrongly assumed that bit wasn't important. What a numpty! I could kick myself for that now. I asked for the lab's normal range of each of these, which she gave me. I did query why I had to have an increase of 25mcg but was told, in a very pleasant way with a chuckle, that she is not a clinician so didn't know. I will try ringing the surgery and ask what the T3 was. I really do appreciate you taking the time and trouble to reply to me. When I get more news, either in the next few days from the surgery, or after the results of my next Thyroid blood test, which is in mid June, I will post what is happening. I really do appreciate your reply. I have a lot to learn! Stay safe. God Bless.

tattybogle profile image
tattybogle in reply to Knip

so .. 2yrs ago you had ;

TSH 0.03 [ 0.04 - 4] ? this range doesn't look right . it might have been [0.4 -4]

fT4 15 [4.5 -16 ] ...an unusual range but it could be right.

Did they reduce you dose as a result of this ?

No further test until 5 weeks ago ?

Then TSH 0.03 [? -?]

fT4 15 [4.5 - 16] ... exactly 15 ? .. as in 15.0 ? results are always reported including first number after the decimal point ie 14.3 / 15.2 / etc

fT3 don't know yet.

And dose increased from 100mcg to 125mcg as a result.

It would be an unusual coincidence to get two exactly the same results for TSH AND fT4 together... Since you have had these reported verbally , it is possible that the receptionist has read you the the results from the wrong date.

TSH ranges would not start at 0.04, but 0.4 is likely ..... so i think since there already seem to be one mistake in reporting, and it is so unusual for pairs of TSH/fT4 results to be exactly the same twice, you really need to double check all these numbers and dates you have been given are correct.

Because it would be extremely unusual for GP to increase dose based on these results because the TSH is below range, and fT4 is top of range. Increased dose would lead to supressed TSH , which GP's are instructed to avoid due to alleged bone and heart risks.

Even if by some chance your fT3 was way below the range ... they would be highly unlikely to care or do anything about it, because raising your Levo dose will lower TSH further.

So i don't know where it is , but i' sure there is a mistake here somewhere . either the receptionist told you the wrong ones, or the decimal point has ben misread , or they are correct and the GP made a mistake and increased dose.

Whatever the fT3 result is, i don't think it explains why your dose has been increased.

Knip profile image
Knip in reply to tattybogle

Since my last post I have now found out, from a different receptionist, that the results I had been given were those from a year ago which explains why they were identical! I know receptionists are busy...and ours are so pleasant, but I never dreamed that they were reading the results from a year ago! I had specifically given the date the test was done. This time they have ONLY tested my TSH which is very high and showing 9.6...normal range is 0.35 -5. Last year it was only 0.03 which is obviously is why it was re-tested in mid April. I double checked the normal range with her. I can see that this is why they upped my Thyroxine to 125mcg from 100mcg. What I can't understand is why this has occurred. Won't the increase, whilst lowering my TSH, increase my T4 even more in the short term? What is a dangerous level of T4 or isn't there one. .. I am being re-tested in ten days time after six weeks on the higher dose but I'm not sure what they will be testing this time. It's so hard since C19 to speak to a doctor about anything at our GP surgery. Thank you for your earlier information.👍

tattybogle profile image
tattybogle in reply to Knip

Ah ha .. i though so !TSH 9.6 definitely needed levo increasing .. i wouldn't worry about the fT4 going over range.... it won't have been anywhere near the top of the range when TSH was 9.6

it is surprising the lab didn't automatically do fT4 when they saw TSH was 9.6.. some labs do this automatically .. called 'reflex testing protocol'.. if TSH is over range they then test fT4 to see it it is under range,, because in order to get TSH as high as 9.6 fT4 would normally be pretty low.

perhaps leave message for GP to request they put note on blood test form for Lab to do an fT4 as well as TSH this time ?

They probably won't be allowed to do an fT3 but there's no harm in asking.

follow usual instructions for next blood test , early AM appointment if possible ( as TSH is highest in middle of night and falls to lowest around 2/3 pm )

If you usually take Levo in morning take that day's dose AFTER the blood test. otherwise make sure blood test is at least 12 hrs after last dose , (but not more than 24hrs ) Because fT4 peaks sharply about 4 ish hours after taking the tablet , so you don' want that 'false' high to show up on the blood test.

Over range fT4 isn't a particular problem anyway, if it was too high for YOU you would probably start to get symptoms of overmedication after a couple of weeks and notice anyway even without a blood test.

As to why it happened ?.. dunno :) could be several reasons,...

Maybe a but more thyroid died off due to immune system attacking it ?,

maybe you had a complete loss of memory and forgot to take Levo for a week or two

... only joking !

maybe 'something else' meant you were talking the usual dose but not absorbing as much as usual.. other medications ? you developed a habit of drinking strong latte coffees half an hour after taking Levo ? started Taking Iron tablets ?

But 'automimmune' just does that sometimes.. ups and downs.

Will hopefully be easier to make sense of when we see what happens next.

Knip profile image
Knip in reply to tattybogle

Thank you for your reassuring reply. It has put my mind to rest. I have Rheumatoid Arthritis and I'm currently having a flare up, as well as Chron's Disease...which is currently not being a problem (fingers crossed)...so yes, I do have auto immune issues which could mean a surge or antibodies. I knew that I would eventually have thyroid problems when the protein was picked up in my blood during RA antibody checks...long before i was on Thyroxine some thirty five years ago. I shall sleep well tonight and bear in mind all you have said above re the testing. I will post the next results when I get them. Take care, God Bless.

tattybogle profile image
tattybogle in reply to Knip

;) sleep well

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