# Qustion- what does methimazole suppress?



## poohbear61 (Oct 11, 2010)

Hi, just got back more test results, TSH has gone from 5x normal to almost 10x normal, Free T4 still well below normal. Is this result of methamazole? Does meth suppress the stuff measured by fREE T4 test, and not the TSH, which I understand is produced by the pituitary not the thyroid? Thanks so much, I am having a heckuva time trying to understand how all these things interface.


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## Andros (Aug 26, 2009)

poohbear61 said:


> Hi, just got back more test results, TSH has gone from 5x normal to almost 10x normal, Free T4 still well below normal. Is this result of methamazole? Does meth suppress the stuff measured by fREE T4 test, and not the TSH, which I understand is produced by the pituitary not the thyroid? Thanks so much, I am having a heckuva time trying to understand how all these things interface.


Methimazole is an antithyroid medication that can help bring high thyroid levels under control. It works to disrupt the production of thyroid hormone by preventing the oxidation of iodine. Methimazole prevents further production of thyroid hormones.

It exerts its actions by decreasing thyroid hormone synthesis, and by blocking the conversion of thyroxine (T4) to triiodothyronine (T3).

So (and I am not an expert), I am visualizing that it is blocking the TSH receptor site as well as the conversion of T4 to T3. More than one action is taking place; I believe.


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## poohbear61 (Oct 11, 2010)

Thank you Andros, very understandable- so I guess regardless of how high TSH goes,since meth does not block production of TSH, if TSH receptors and synthesis to T3 are blocked, don't worry too much unless the T3/T4 goes above normal eh? I shoulda gone to pharmacy school when I had the chance


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## GD Women (Mar 5, 2007)

poohbear61 said:


> Hi, just got back more test results, TSH has gone from 5x normal to almost 10x normal, Free T4 still well below normal. Is this result of methamazole? Does meth suppress the stuff measured by fREE T4 test, and not the TSH, which I understand is produced by the pituitary not the thyroid? Thanks so much, I am having a heckuva time trying to understand how all these things interface.


TSH comes from the driving force of brain hormones, the pituitary, a little gland in the brain. F/T4 is produced by the thyroid gland in the neck. They are two different things made by two different organs, connected to bring a balance to thyrpod metabolism, i.e thyroid levels.

Adjusting by brain TSH tells the F/T4 thyroid gland which direction for levels to go according to thyroid med. adjustment. That is, for thyroid levels to go up or down per med. dose adjustment.

Methimazole inhibit thyroid hormone production. However, their effects aren't immediate. The stores of thyroid hormone present in the thyroid must be used up before symptoms subside. After several weeks, when these hormone stores are depleted, effects become noticeable.

In addition, PTU decreases 5'-deiodination of T4 in peripheral tissues. ATDs may also interfere with T3 binding to nuclear thyroid hormone receptors (TRs). However, the effect of ATDs on the transcriptional activities of T3 mediated by TRs has not been studied

Hope that answers your question.


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## Andros (Aug 26, 2009)

poohbear61 said:


> Thank you Andros, very understandable- so I guess regardless of how high TSH goes,since meth does not block production of TSH, if TSH receptors and synthesis to T3 are blocked, don't worry too much unless the T3/T4 goes above normal eh? I shoulda gone to pharmacy school when I had the chance


According to my thinking that is correct. I wish I had gone to schoo period! LOL!!


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## lavender (Jul 13, 2010)

poohbear61 said:


> Thank you Andros, very understandable- so I guess regardless of how high TSH goes,since meth does not block production of TSH, if TSH receptors and synthesis to T3 are blocked, don't worry too much unless the T3/T4 goes above normal eh? I shoulda gone to pharmacy school when I had the chance


TSH is thyroid stimulating hormone. When you are hyperthyroid, T3/T4 are really high, and the pituitary stops producing TSH in an attempt to slow the production of T3/T4. However in Graves, the antibodies are telling the thyroid to keep producing T3/T4 in crazy high amounts. When you are hypothyroid, T3/T4 are low, and the pituitary starts producing more TSH to try to get the thyroid to do it's job.

Since TSH react to T3/T4, it moves slowly. therefore, your T3/T4 can be normal, but it may take the TSH level 4-6 weeks to adjust.

Assuming that you don't have a pituitary problem as well, high TSH would indicate to me that you have gone hypothroid. Perhaps you are on too high a dose of methimazole, or you may be a candidate for block and replace therapy where you take the methimazole to put the breaks on the Graves and some type of thyroid replacement hormone (synthroid or armour) to maintain eurothyroid (normal) function. I can't give you a lot of details about this, but I have heard other people advocate for it.

Hope this helps.


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## AZgirl (Nov 11, 2010)

Lavender, since my T3 and T4 are finally normal but my TSH is understill, i have tried and tried to reread your information above, and for some reason, i just dont understand the whole "lab results" to me its kinda like TAXES, you can tell me over and over things to understand it, but i just cant seem to get a grip on , GD LABS, TAXES AND UNDERSTANDING FOOTBALL. And honestly, im usually pretty smart... idk, maybe im choosing not to understand,,,hehe


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## lavender (Jul 13, 2010)

AZgirl said:


> Lavender, since my T3 and T4 are finally normal but my TSH is understill, i have tried and tried to reread your information above, and for some reason, i just dont understand the whole "lab results" to me its kinda like TAXES, you can tell me over and over things to understand it, but i just cant seem to get a grip on , GD LABS, TAXES AND UNDERSTANDING FOOTBALL. And honestly, im usually pretty smart... idk, maybe im choosing not to understand,,,hehe


I know it's confusing. I am trying to explain it in a way that makes sense to me, but it may not make sense to you.

I had a doctor draw me a picture years ago that helped me understand the whole thing. Here are some links to images that may help:
http://www.beliefnet.com/healthandhealing/getcontent.aspx?cid=165014
http://www.thyroidawareness.com/hyper.php
http://www.news-medical.net/health/Hypothyroidism.aspx
http://www.differencebetween.net/sc...e-between-hypothyroidism-and-hyperthyroidism/

So, here is your thyroid:explodeit makes T4. T4 is converted to T3 elsewhere in your body. (T3 is your active thyroid hormone).

And here is your pituitary (it's in your brain):. It makes TSH (thyroid stimulating hormone)

TSH (made in the pituitary) tells your thyroidexplodehow much T4 to make. T4 is then converted into T3 (your active thyroid hormone). T3 goes out into your body and stimulates it to work.

Your pituitary:rolleyes: senses how much T3 and T4 are in your body, and then adjusts how much TSH is it making. Since it responds to T3/T4 levels, it acts more slowly, TSH can take 4-6 weeks to respond to changes in T3/T4 levels.

This is assuming that everything is working the way it should. (eurothyroid)

If you are hyperthyroid explode, your thyroid continues to make T3/T4, even when your pituitary has stopped producing TSH. TSH is low while T3/T4 are high/

If you are hypothyroid, your thyroid does not make enough T3/T4 no matter how much TSH your pituitary:rolleyes: produces. TSH is high while T3/T4 are low.

Some people have pituitary problems which do not recognize how much T3/T3 their thyroid is making.
Since the pituitary makes TSH, TSH is not an accurate indicator of thyroid function in these individuals.
TSH may be high while T3 and T4 are high or
TSH may be low and T3 and T4 are also low.

I hope this helps. I did my best.


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## AZgirl (Nov 11, 2010)

Lavender, Yes, although i read it at least 6 times, and drew it on paper! i think i might of gotten it! Prolly tomorrow ill forget again, but i think i got it! So basically, because T3 and T4 are good right now, and TSH is still low, it just might take a little bit longer to understand, (kinda like me) haha..... now if only i can get football down, i might be satisfied! thanks so much, i think ill print this out, and h ave my husband understand too, so tomorrow when i have a brain mishap, he can tell me it again! haha


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## lavender (Jul 13, 2010)

AZgirl said:


> Lavender, Yes, although i read it at least 6 times, and drew it on paper! i think i might of gotten it! Prolly tomorrow ill forget again, but i think i got it! So basically, because T3 and T4 are good right now, and TSH is still low, it just might take a little bit longer to understand, (kinda like me) haha..... now if only i can get football down, i might be satisfied! thanks so much, i think ill print this out, and h ave my husband understand too, so tomorrow when i have a brain mishap, he can tell me it again! haha


Sounds like you got it. TSH is a bit slow to catch on! Takes 4-6 weeks after a med adjustment to catch up.


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