Thyroxine and blood test query

[Headandneck72]

Good morning hope all is well with you guys....

So basically these are all of my results over the past few years - I finished treatment for right tonsil cancer September 2018. I’ve always thought that my thyroid was sluggish due to having a nodule but this was tested by FNB in 2014 and came back as benign and doctored never gave me any medication even though I was symptomatic.

I’m just concerned and worried that due to the radiation treatment my thyroid will never repair or turn malignant- I’m hoping for any advice from you guys my doctors only test the bloods below so basically these are all of my results over the past few years. I finished treatment for right tonsilla cancer September 2018 and the result clearly show this change below. I’m now only on 25mmg thyroxine and feel so rubbish.

I’m struggling getting any support right now from gp.

10 Sep 2020

Serum TSH level

5.79 mu/L

0.27 - 4.2

Abnormal

28 Jul 2020

Serum TSH level

N/A

N/A

Abnormal

6 Sep 2019

Serum TSH level

4.67 mu/L

0.27 - 4.2 mu/L

Abnormal

2 Nov 2017

Serum TSH level

2.34 mu/L

0.27 - 4.2 mu/L

Normal

23 Mar 2016

Serum TSH level

2.17 mu/L

0.27 - 4.2 mu/L

Normal

24 Mar 2015

Serum TSH level

2.2 mu/L

0.27 - 4.2 mu/L

Normal

25 Jul 2014

Serum TSH level

2.28 mu/L

0.27 - 4.2 mu/L

Normal

5 Jun 2014

Serum TSH level

2.25 mu/L

0.27 - 4.2 mu/L

Normal

[Lora7again]

The Levothyroxine 25mcg is less than a starter dose and usually it is 50mcg and then a blood test after 6 weeks and a further increase of 25mcg. This continues until your TSH is 1 or lower and your T4 and and T3 are in the upper third of the range and you feel well.

[waveylines]

There seems to be a clear trend of your TSH rising over the years. In other countries a TSH over three would be regarded as needing treatment for an underactive thyroid. In the uk they wont treat until over 10.

25mcg is neglible so you need your dose tiltrating upwards every 6-8weeks usually done with 25mcg increases, until your tsh is under one and your thyroid hormones (ft4 & ft3) are in the top third, many needing them to be hear the top of the range. So bottom line is your are under treated.

[SlowDragon Administrator]

See/contact GP for next 25mcg dose increase in levothyroxine

Aim is to increase dose levothyroxine up in 25mcg steps until TSH is under 2

Bloods should be retested 6-8 weeks after each dose increase

Also request that vitamin D, folate, ferritin and B12 are tested

These are frequently very low when hypothyroid

Supplementing to improve low levels can improve symptoms

guidelines on dose levothyroxine by weight

Even if we don’t start on full replacement dose, most people need to increase levothyroxine dose slowly upwards in 25mcg steps (retesting 6-8 weeks after each increase) until on 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.

gp-update.co.uk/Latest-Upda...

Traditionally we have tended to start patients on a low dose of levothyroxine and titrate it up over a period of months.

RCT evidence suggests that for the majority of patients this is not necessary and may waste resources.

For patients aged >60y or with ischaemic heart disease, start levothyroxine at 25–50μg daily and titrate up every 3 to 6 weeks as tolerated.

For ALL other patients start at full replacement dose. For most this will equate to 1.6 μg/kg/day (approximately 100μg for a 60kg woman and 125μg for a 75kg man).

If you are starting treatment for subclinical hypothyroidism, this article advises starting at a dose close to the full treatment dose on the basis that it is difficult to assess symptom response unless a therapeutic dose has been trialled.

A small Dutch double-blind cross-over study (ArchIntMed 2010;170:1996) demonstrated that night time rather than morning dosing improved TSH suppression and free T4 measurements, but made no difference to subjective wellbeing. It is reasonable to take levothyroxine at night rather than in the morning, especially for individuals who do not eat late at night.

BMJ also clear on dose required

bmj.com/content/368/bmj.m41

bestpractice.bmj.com/topics...