carbimazole dosage

[Sean23]

good day, I was diagnosed with hyperthyroidism in July ..my TSH 0.01. T4 31 T3 24 ... so I’m seeing my endo two weeks from now but I had my levels checked again and now my T4 is 16 and Tsh still 0.01 ..I’m on 40mg carbimazole so was thinking of lowering my dosage ...symptoms have reduced and I don’t want to end up being hypo...please advice

[PurpleNails Administrator]

please can you add range? Ranges vary between labs.

It quite usual to start in higher dose of carbimazole then reduced it to stop levels going too low. TSH often stays low for much longer than FT4 & FT3 when you been hyper for a prolonged time it can stop responding long term.

Have doctors tested thyroid antibodies to see if you have hyper Graves autoimmune?

TPO & TG signifies autoimmune, if Graves is suspected TSI or TRab antibodies must be tested.

Hyper can sometimes be transient (autoimmune thyroiditis often called Hashimoto’s) and levels naturally drop carbimazole will drive levels low too fast so doctors should be establishing the cause of your hyper.

[Sean23 in reply to PurpleNails]

I fairly new at this and I can’t remember my first ranges but the second rage for T4 was 7-16 and my T4 was 16 and I can’t remember my TSH range but I will try get my results back from the Doctor... he didn’t test for Tsi or trab (I don’t even know what that is) as it’s a new thing for me and he didn’t test for T3 the second time even though my T3 was 24 at the first test.... so he saying my T4 is within range 16 but Tsh still low but insist I should continue with the 40mg dosage and I’ve noticed that recently I’m having more anxiety than I was getting few weeks back... so I was thinking of switching to 20mg a day

[PurpleNails Administrator in reply to Sean23]

Ranges vary between labs so  FT4 it may be top of range or lower in some ranges.  TSH ranges are very similar but the TSH can remain low.  Even in those with healthy function a TSH can take a while to respond.  

The carbimazole dose should be adjusted by FT4 & FT3. FT3 is free triiodothyronine and it it the more powerful hormone.  It’s usually balanced with FT4, but once thyroid is dysfunctional it can become low or disproportionately high.  So you need to test it.  If lab won’t test there are private options.  You can test at home.  Lots of options available.  From function only (TSH, FT4 & FT3) to one including nutrients & TPO & TG antibodies.  Here’s a links with some companies & discount codes 

thyroiduk.org/help-and-supp...

GP is looking at TSH but not considering FT4 measurement (or including FT3) once it is in range the carbimazole dose should be reduced otherwise the Carbimazole will continue to lower the levels.  Now you to keep them stable.  

Discuss again with doctor, suggest they liase with specialist rather than waiting another 2 weeks.  

Carbimazole works by inhibiting production of new thyroid hormone.  The high existing stores are being used up but unless new hormone it allowed to replenish levels it will become too low.  

Online access to results useful if practice offers it or obtain printed copies via reception, don’t trust verbal or handwritten results. TSI & TRAb are antibodies considered markers for Graves. TRab) TSH receptor antibodies - (measures stimulating, neural & blocking antibodies) Thyroid-Stimulating Immunoglobulin (TSI) It may be that only a specialist can order TSI or TRAb (or GP will say this as they will not want to get involved with diagnosis ect) GPs are able to arrange TPOab (Thyroid Peroxidase antibodies) for Hashimoto’s  autoimmune thyroiditis - this can cause transient hyper in initial stages before immune system damage causes low function (hypothyroid) but these antibodies can also be positive with Graves too.  Thyroid antibodies will help show if a autoimmune condition is affecting you. If TPOab positive TGab (Thyroglobulin antibodies) can also be tested.  

Was the 40mg taken in 2x (20mg) doses?  That can help initially but not always suggested.

[Sean23 in reply to PurpleNails]

I’m going to see a new endo will come back with the results, thank you for taking your time and replying me... carbimazole was taking it 20mg in the morning and 20mg at night

[Sean23]

I will definitely get Trab and Tsi antibodies test done in my next appointment

[pennyannie]

Hello Sean and welcome to the forum :

The antibodies unique to Graves Disease are generally detailed on the print out as either a TSI ( a thyroid stimulating ) and or TR ab ( a thyroid receptor blocking ) antibody :

One or other of these should be positive and over range and the medical proof of diagnosis and on which your treatment plan is based.

Generally we see TRab readings - and with further analysis within this reading there are both stimulating and blocking antibodies vying for control of your thyroid and as you can imagine the extremes of symptoms can be experienced.

The NHS generally allocate around 15-18 month window with the Anti Thyroid drug hoping this time frame is sufficient for your immune system response to calm down and your body reset itself.

The definitive treatment offered by the NHS is either RAI thyroid ablation or a thyroidectomy - neither of which solves the AI disease but flips you to being primary hypothyroid and needing life long mediation in primary care.

These choice options are to ingest a toxic substance or have your throat slip open for an AI disease that you still have, but then considered treated and discharged back out into primary care and on medication life long.

So the AT drug blocks your own thyroid hormone production, and yes, you will likely need your dose titrated as your T3 and T4 come back into range as otherwise you risk falling too far through the T3 and T4 ranges and then experiencing symptoms of hypothyroidism, equally debilitating.

You might like to dip into Thyroid UK the charity who support this forum as there amongst all things thyroid is a list of symptoms of both hyper and hypo and yes, of course, it's not that easy as some symptoms can be experienced when with either an overactive or underactive thyroid. thyroiduk.org

The most recent research is suggesting that the longer the patient is on the AT medication the better the outcome for the patient - pubmed.ncbi.nlm.nih.gov/338... - and I think this has to be the best way forward, and if well on the AT drug should be the first option offered, though it's likely the most expensive treatment option for the NHS to fund.

Graves is an auto immune disease - there is no cure - the thyroid is the victim in all this and not the cause - as the cause is one of your immune system having been triggered to attack your body - and your thyroid is your body's engine and why Graves is considered life threatening by the mainstream medical.

You might like to read around Graves - and the most well rounded website I found is that of the Elaine Moore Grave's Disease Foundation website - and check out the alternative, more holistic and complimentary treatment options and give thought to your life/work balance and why your immune system might have decided to go on the attack.

There is a genetic predisposition to Graves and finding your trigger may help you understand this poorly understood and badly treated AI disease. It can be triggered by a sudden shock to the system - like a car accident or the sudden death of a loved one, or it can simply occur out of the blue and knowing yourself, will help you understand how to manage your Graves.

elaine-moore.com