Carbimazole

[Sappy95]

So I was diagnosed with Graves’ disease in 2020 when I had all the typical symptoms and my free t4 level was 37 which my consultant was shocked about and immediately put me on 60mg dose of carbimazole. I then found out I was pregnant changed to PTU cos it’s safer. Fast forward I had a safe pregnancy, birth etc and was told to allow my hormones to level out. I had a blood test recently (6 months after giving birth) and my free t4 level was 59?! BUT my consultant has given me a prescription of carbimazole only 10mg a day? I’m really confused as to why it is such a low dose when my levels are so high? I’ve been feeling so unwell and I didn’t question my consultant at the time but now I’m not seeing her for 8 weeks. Any advice gratefully appreciated

[Hollins]

Hi Sappy95

Fwiw my FT4 went from 49 to 20 in 4 weeks on 15mg carbimazole daily

[Sappy95 in reply to Hollins]

Ahhhh that’s good to know. Thank you

[PurpleNails Administrator]

Depends on the knowledge of doctor.

Is it definitely 1 x 10mg per day? Not 10mg 2 or 3 times daily? Just checking.

Usually a higher starting dose of carbimazole is given, 60mg being a high dose. Then regular frequent testing and appropriate carbimazole adjustment means the dose is usually lowered until a level is found which keeps FT4 & FT3 in range.

10mg might be the longer term dose you remain on but starting on this dose will take longer to get in range.

When levels are high often doctors view it as urgent to bring down levels, but when opposite occurs & levels are low, even very low they tend to be risen very gradually. So the body adjusts. I never cope well with dose change so there is some argument slow & steady treatment might be better for you, but many would feel it’s better to bring levels down.

I think you do need higher starting dose eg 40mg and you should have a thyroid function test 6 weeks after starting to adjust dose. GP can arrange function between consultants appointments.

Was your TSH & FT3 tested. Your TSH is likely low but if it’s low but not undetectable you doctor might incorrectly concluding you don’t need a high dose. Your FT3 may also not be as high in proportion, although few doctors test & correctly account for FT3.

[Sappy95 in reply to PurpleNails]

Yeah I double checked myself cos I was on 60mg when it was bad last time so confused at 1x10mg daily. Yeah my TSH is <0.04 miu/L and my t3 level was 4.2 nmol/L. Not entirely sure what these mean as it’s never explained to me by consultant she always seems I’m a rush… it just annoys me that I can never get in contact with anyone until my next appt they give me a number that doesn’t accept calls

[PurpleNails Administrator in reply to Sappy95]

Do you know range on FT3. Doesn’t seem high by most ranges. I had borderline FT3 23 but FT3 was nearly double normal range. I was started on 20mg per day. In 2 months my FT4 was 13.

How you respond to carbimazole is individual. Because it works by reducing the production of new hormone.

Everyone produces an a unique level, & metabolises existing stores at a unique amounts. So you can’t calculate x carbimazole reduces FT4 by y.

Because you’ve taken in past you do have an idea 10mg isn’t going to be high enough.

Terrible you were rushed & can’t get through to specialist. Keep trying.

[pennyannie]

Hello Sappy and congratulations on the birth of your baby :

The anti thyroid drug semi- blocks your own, new daily production of thyroid hormones and slowly your T3 and T4 will fall back down into range - it's a bit like being kept in a holding position - like an aeroplane waiting for a landing slot.

Your dose of Carbimazole should be titrated down as your levels fall into range so your T3 and T4 do not fall too far through the ranges and you start experiencing the equally disabling symptoms of hypothyroidism.

When metabolism is running too fast as in hyper or too slow as in hypo - the body struggles to extract key nutrients through food, no matter how well and ' clean ' you eat ;

It's advised that you get your ferritin, folate, B12 and vitamin D run as these tend to nose dive and need to be optimal to support you through this health issue rather than compound your health issues further.

We now have some research papers you might like to keep in case needed further down the road :-

pubmed.ncbi.nlm.nih.gov/338...

ncbi.nlm.nih.gov/pubmed/306...

For all things Graves Disease I found the website and books of Elaine Moore the most well rounded - particularly the sections on alternative and more holistic treatment options and looking at ways of managing one's life as everyone's journey with Graves is unique to them but stress and anxiety tend to be common triggers.

elaine-moore.com