Re: T4 starting dose of 50mcg or 100?

[Guest guest]

I can see the logic behind the " block and replace " idea, but it is not the only

factor involved.

What if you are only able to partially convert the T4 to T3, for example? They

you might be feeling " wired " because of T4 toxicity, before you had enough T3 to

fully meet your needs.

If you can't convert T4 to T3 at all then any dose of thyroxine will be too

much.

Supposing someone was suffering from some degree of cellular resistance to

thyroid hormone? Then they would need to keep their levels of T3 high to give

the T3 the best possible chance of penetrating the cells. There aren't any lab

tests which measure cellular resistance, so you could only discover this by

trial and error. If you were treating such a person with thyroxine only, and

assuming they didn't have a conversion problem, to get their T3 levels up high

enough they would need high levels of thyroxine and might suffer from some

degree of T4 toxicity.

What about the fact that the more body fat people carry, the more oestrogen they

produce? That is another complicating factor which will influence how effective

any dose of thyroid hormone is for any particular person.

A friend of mine who is low thyroid was taking 200 mcg thyroxine, yet her Free

T4 and Free T3 were lower than the reference ranges. What is going on there?

There are so many complicating factors that it seems simplistic to believe that

thyroid dosage can be calculated in relation to body weight.

Miriam

> It should now be standard practice to " block and replace " . This means using a

large enough dose of T4 to block the bodies own production and provide enough

for the body. The trouble is that we are all different with different T4

requirements.

> Current standard practice & teaching is to start at 100mcg of T4 - in BNF

(British National Formulary) now, unless patient has angina or is elderly when

should start at 50mcg for 2w & increase to 100mcg after 2w.'

>

> My husband is worried that 100mcg will be too much for me as I'm only 5'2 " ,

and he's currently on the same dose and even wondering if it's too high for him

(because he was feeling wired and sleepless, so dropped it to 75 for a few

days).

[Guest guest]

my personal experience of T4 is as follows. I was prescribed 50 mcg which I

took daily, after about 2 weeks I began to get sharp pains in my chest, which

was possibly my heart. I ignored it, it came and went at odd times when sitting

or resting as well as walking about, it didn't get better or worst with

exercise. After 6 weeks it was a nuisance and I got palpitations quite bad,

still scared to go to the gp in case I was taken off them. I was getting lots

better and feeling more well than in a long long time. I spent one day in bed

terrified with the palpitations, and then it went away and I was ok at around 6

weeks. I should have cut the dose but did not have the sense to think of it! I

managed on this dose for ages until I started to use thyroid-s which suited me

well and also got treatment for the adrenals too. It is easy enough to take

charge of your dose and to slowly test out how it will affect you, don't be like

me and be blindly obedient and too brain fogged to adjust the dose.

love janet

[Guest guest]

Thanks Miriam, good points. Any idea whether it's preferable for me to start on

50 or 100mcgs?

>

> I can see the logic behind the " block and replace " idea, but it is not the

only factor involved.

[Guest guest]

Thanks for your account, Janet, that's helpful. x

>

>

> my personal experience of T4 is as follows.

[Guest guest]

I am currently reading " Your guide to metabolic health " by Dr Lowe, and

came across this on page 150.

" When hypothyroid patients use T4-containing products such as dessicated

thyroid, they can expect the therapeutic effects from a newly increased dose

from one-to-two weeks later. It's reasonable, then, for them to wait about two

weeks before reevaluating the intensity of their symptoms. "

Thyroxine is also a " T4-containing product " so presumably this applies to it

just as well. Also it ties in with my experience of noticing benefits about 10

days after an increase of thyroxine.

So if you haven't been taking any thyroid hormone before you could start with 25

mcg, but increase by 25 mcg after 2 weeks unless you get any adverse reactions.

If you react badly, either drop back to your previous dose or have a few days

off and go back to a dosage on which you had no adverse reactions.

I have read something similar in one doctor's treatment plan.

Miriam

> Thanks Miriam, good points. Any idea whether it's preferable for me to start

on 50 or 100mcgs?

[Guest guest]

There are many doctors (usually in other countries and not the

UK) who believe in starting their patient on 100mcgs levothyroxine straight off

and titrating the dose upwards and downwards depending upon the patient's

reaction to it. If you don't have any problem with your heart, and you are

worried about starting with 100mcgs, start with 50mcgs, but this will depend on

whether your doctor is in agreement to you starting on that dose. Dr Kerber

makes a good point here.

The average dose is between 125mcgs and 150mcgs with many people

taking much higher doses and many taking less.

Luv - Sheila

'It should now be standard practice to

" block and replace " . This means using a large enough dose of T4 to

block the bodies own production and provide enough for the body. The trouble is

that we are all different with different T4 requirements.

Current standard practice & teaching is to start at 100mcg of T4 - in BNF

(British National Formulary) now, unless patient has angina or is elderly when

should start at 50mcg for 2w & increase to 100mcg after 2w.'

My husband is worried that 100mcg will be too much for me as I'm only

5'2 " , and he's currently on the same dose and even wondering if it's too

high for him (because he was feeling wired and sleepless, so dropped it to 75

for a few days). He's 6ft and quite solid. Is he right to worry? Or is it,

anyway, better to start too high and then reduce - or should I do what he did,

and start at 50mcg, and increase as necessary? It's all a bit daunting...

x H

No

virus found in this message.

Checked by AVG - www.avg.com

Version: 2012.0.1901 / Virus Database: 2109/4772 - Release Date: 01/28/12