Block and Replacement Therapy Carbimazole and Thyroxine

Posted , 3 users are following.

Hi I wasn't sure which forum to post on as Carbimazole was prescribed to me for Hyperthyrodism which I think was brought on by underlying Graves disease. Had hypothyroidism for 11ish years, then thyorid went haywire last year due to stress.

Now I am on block and replacement therapy.  30mg Carbimazole and 100mg Thyroxine daily.  Has anyone used this method before and was it successful ?

I am trying to get my head round the benefits of this treatment, found this on the British Thyroid Foundation as they seem contradictory. 

Block and replace: You continue taking CMZ, usually 20-40mg daily, or PTU, usually 200-400mg daily, to stop your thyroid gland producing thyroid hormone; and start taking levothyroxine (usually 100-150mcg daily) to replace the thyroid hormone your body would normally produce

My latest blood tests results: TSH 0.001    FT3 5.1     FT4 14.4 and I feel fine.

Any advice would be greatly appreciated. Thanks 

1 like, 4 replies

4 Replies

  • Posted

    i hope this really works for you.

    i have read a lot of thyroid articles and some say this is also really effective.


    • Posted

      thank you Joanna, I'm doing ok so far, my thyroid levels are within the normal range, still hardly any TSH reading but am told that it could take up to 2 years to get that back.

      I should have been off block and replacement in June, but my endo has asked me to stay on it until November, so watch this space. Then once off block and replacement medication they will see how my thyroid behaves and then treat it.  I've a feeling I will go back to being underactive again, which isn't a problem for me as I was underactive for 11 years and could cope with that.

      What's really been depressing is the weight I've put on, which is nearly 1 and a half stone, since being on Carbimazole.

      Will be glad to see the back of Graves and all my thyroid issues.

      Hope you are ok, as maybe you have Graves and are trying B & R .

      Have a great day biggrin

    • Posted

      Hi Jan

      Which was easier to control - hypo or hyper? Weren on levothyroxine when you were hypo? I have graves but but may become hypo after thyroid surgery (which I must have for a lump). Thanks

    • Posted

      When first diagnosed 11 years ago with hypo it took them 2 and a half years to get my thyroxine at the right dosage then I was ok with no side effects for another 9 years and my weight was stable.

      Going hyper I noticed that I was feeling hotter with night sweats and my heart rate/blood pressure was up. But I was an egnima to my doctor as even though hyper I was putting on weight, thats when I was sent to see the Endo who found out I have graves.

      So for me hypo was not a problem when they got the thyroxine dosage right, no symptoms and stable weight.  In fact thats what I'm hoping is going to happen after I finish block and replacement.  I did however get lots of symptoms when first diagnosed with hypo, then the symptoms settled down.

      I have stressed my concerns to my Endo about coming off block and replacement and if within the first month I get hypo symptoms back, he wiill put me on 100 mg thyroxine as that was what I was on for 9 years without a problem.  I told him I didn't want to go through the process of starting on 25mg, going to 50mg, then to 75mg, then to 100mg which was what I initially had to do and that's why it took so long to get dosage right as they start you off with small amounts and then gradually increase.

      My thyroid when from hypo to hyper after a lot of stress, husband very ill and a house move.

      God luck with your surgery and as said once thyroid under control with correct dosage of thyroxine you'll be fine.

      I hope this helps biggrin


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