Weight and levothyroxine dose

[xJJx]

Is weight and size taken in to consideration when the gp set your levothyroxine dosage?

[Spareribs]

No - mine is 25mcg and not enough for a budgie (I have that in authority).

A vet would prescribe me at least 200mcg per weight (Ok not to start, incremental).

and I wouldn't have to say a word.

[karenmyring]

I was weighed and height taken but my dose was too low x

[Hidden]

My weight is about 7 stone and when I told my nurse what dose of Levothyroxine I was on I said 75mcg and she said "but you're too little to be on that size dose."

I've gained about 5 inches on my waist since then and I hardly have any appetite or energy to eat anything.

[greygoose in reply to Hidden]

Your nurse is so wrong! That's got nothing to do with it. The point of taking thyroid hormone replacemant is to increase the dose until all symptoms have gone regardless of how much it takes to get to that point. You need what you need and that's all there is to it. Despite what the medical profession thinks you should need!

[Clutter]

xjjx, no they base it on TSH. Weight/dose ratio may be calculated for thyroidectomised patient's initial dose and thereafter adjusted according to TSH. Having said that, I was considerably overmedicated if they used a weight/dose ratio. I think it was more a case of bung 'er on 200mcg.

[helvella Administrator]

There is only one situation in which weight is really of much use. That is for estimating how much levothyroxine someone might need after a total thyroidectomy. The medical literature contains many formulas which could be used for that - and many arguments about which one should be used. I have assembled a number of them in a spreadsheet:

dl.dropboxusercontent.com/u...

As soon as you are taking levothyroxine, the weight calculation should be almost entirely ignored. What then matters is how well you are - with blood tests to help back that up.

About the only use I can think of for the formulas longer term is as a "sanity check" for dosing. That is, if the formula suggested someone needs 150 micrograms, then it is unlikely they will have enough if they are only taking 75 micrograms. And it is worth asking questions if they are taking 300 micrograms.

Things like differing absorption, other health issues (iron deficiency, vitamins, etc.), variations between tablets/makes, etc., all make their contributions to how much people need - not just weight.

Rod

[Marz]

Ironic that you should have a Doggie picture My dog is Hypo and her dose was calculated according to her weight !! She seems fine but has improved even more with doses of B12 and VitD !! We just observe her as she is not able to tell us how she is feeling....

[Treepie]

When diagnosed my GP used body mass index to estimate I would eventually be on about150mcg, still25mcg short as other problems have arisen and another GP will not increase until other tests are carried out.Annoying.

[Thyroidmeg]

After tt a few years ago I was put on 100 levo a day. My after op tsh came back at 30. The doctor phoned me and said take 200 a day from now on.

5 years later and stones heavier I'm still on 200 a day. They don't care as my tsh is fine at 1.3.

[Hidden]

Um no, unfortunately mine only monitor by the TSH only, which led to me self-medicating. My normal weight was around 7 and three quarter stones, I am now 9st and cant bear to look at the scales (I have digital scales). Having had anorexia maybe 15 years ago, weight will always be a major issue for me and I am not happy being anymore than I need to be, and would love to be a perfect size 8 (currently size 10) again and fit into certain clothes, like my 'firetrap jeans' that were quite expensive and can no longer wear due to weight gain grrr.