So was diagnosed HyperT in august, been on 20mg carbimazole for 8 weeks

SO I had bloods done 25/09/12 which showed:

Serum TSH 37 (0.5-4.7) HIGH filed as HYPOthyroid biochemistry
Free T4 6.2 (9-24) LOW
Free T3 4.2 (2.5-5.3)

GP requested a retest a week later 02/10/12 results showed:

Serum TSH 17 (0.5-4.7) HIGH filed as HYPOthyroid biochemistry
Free T4 11 (9-24)

In those 7 days between blood tests, I'd taken 20mg carbimazole on every day except the 01/10/12 and 02/10/12 (I forgot!!) so why had my TSH dropped by 20 and my T4 increased by nearly 5, can it fluctuate that much?? I asked my GP who just shrugged his shoulders and said, well if the symptoms return get another blood test!

After my consultations with the Endo on the 02/10/12 (who didn't see the latest blood results) I stopped the carbimazole as he suggested my hyper results in august were because of viral thyroiditis. So now have been off it for 5 days. My pulse has increased from ~60bpm to ~80bpm, I have been getting hot and feel ‘jittery’ inside but I'm sure that its psychosomatic!!!

Any thoughts?

Hello - Unlike thyroid hormone replacement, which actually builds up in the body over time, anti-thyroid drugs like Carbimazole are eliminated from the body fairly quickly. I'm a fellow patient, not a doc, but it seems that those two missed days could certainly have had an impact.

Another consideration is whether you had the labs drawn at different times of day, as TSH levels can fluctuate.

As for your symptoms, *you* know your body, so definitely take any major changes seriously, and contact your doc for a quicker set of labs if you feel your hypER symptoms coming back.

Take care!

Hi thank you for your reply.
I didn't realise that anti-thyroid drugs were eliminated quickly, so a week of no medication now would probably mean everything in my body is purely from my own body?
The bloods were taken at 9am and 11:30am so I guess that may also affect the variability, I will try to have all remaining blood tests at the same time from now on.
Interestingly my husband commented that since stopping the meds, I've changed, like i'm ‘off the planet’!! I don't know if I was like this before though? I certainly felt a bit psycho before first being diagnosed. I am certainly going to keep an eye out, afterall its only a blood test to find out.
xxx