T4 starting dose of 50mcg or 100?

[Guest guest]

Hi all. I'm interested to know peoples' experiences of starting on T4. My doctor

has agreed to start me on levo, at 50mcg daily. However, I was just reading the

following by Dr Kerbel, on the talkhealth forum, and have encountered this

idea elsewhere as well:

'Starting treatment and getting to a therapeutic dose:

Many doctors were taught to start levothyroxine (T4) at 50mcg. This supplements

your natural thyroxine but often will not block production. The pituitary picks

up that there is now adequate T4 in system so slows its own production -

negative feedback. Your Dr checks TFTs and finds you need more T4 so increases

by 25mcg - this intensifies negative feedback and lowers your own T4 production

further...

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