From Carbimazole to PTU due to hive

Posted , 7 users are following.

Me again...

I was on 20mg Carbimazole since 5 weeks ago following Graves diagnosis. The medicine was working really nicely on my hyperthyroidism symptoms up until 2 days ago when I developed a nasty hive and a very sore stomach. For one day I was lethargic, completely unable to do anything else then be in bed (which was a massive change from the hyperthyroid life I had! I haven't slept in the afternoon in years!). Today I feel much better but the endocrinologist by email suggested this is an allergic reaction to Carbimazole and told me to stop immediately.

When I told her how disappointed I was, she suggested I could start PTU straight away instead.

I am here looking for experiences of people going form Carbimazole to PTU. As well I would like to know how can I be sure this reaction was induced by Carbimazole and not by something else?

Thank you

0 likes, 33 replies

33 Replies

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  • Posted

    Hey Rita have you had a recent blood test? Sounds like you're swinging to hypo x

    • Posted

      Why do you say that? The lethargic feeling was not simple exhaustion, was a full blown allergic reaction drowsiness, I was seriously afraid of falling asleep in the office so I had to leave. I am the usual person full of life today, ran 10k and will go to the gym now. So I don't think it's thyroid relate but rather allergy/stamin related.

      I have taken a blood test yesterday but I won't have results until tomorrow or the day after.

    • Posted

      Apart from the hives I suddenly started feeling like this when by ranges were swinging towards the bottom end!
    • Posted

      Hi there yes i feel very poorly at the moment. I have doctor calling me today as i want bloods taken again as i suspected i coud be hypo now. I have only been on carbi fir 2 weeks now and fellt no improvement.
  • Posted

    Hello rita,

    I'm in the US and had an allergy to methimazole twice. The first time 2 months ago I was taking 20mg and broke out in a rash and had itching all over so they lowered my dose to 10mg it went away. Then I stopped taking methimazole and resumed again 2 weeks ago on 10mg. Guess what l? A week later I got the itch and hives. So I've been off it for a week and doctor wants to switch me to ptu and I really don't want to take it.

    So my only advice is maybe lowering the dose would help you because it helped me the first time.

    • Posted

      Please update us on whether you will be taking the PTU. I'm in the same predicament and am considering other options because of the scary black box warning on this drug. How long have you had graves disease?

    • Posted

      I have been diagnosed in January but i reckon it started in October/November.

      Can you please tell me more about the black box warning? I know nothing about it.

      I will update this post or open a new one when I have decided/taken it.

    • Posted

      If you are allergic to methimazole your chance of being allergic to PTU is 50%. If you take it for 12-18 months possibility of remission is 40%. Most serious side effects occur in first 3 months but they can happen any time to any one. Rare complication is liver failure 1 in 10,000 which does not depend on dose or age or physical condition. Another side effect is agranulocytosis. This is from the thyroid org site " A rare but serious complication of antithyroid medications is known as agranulocytosis. Researchers have yet to discover what exactly causes agranulocytosis, but they do know that is a reaction characterized by attacking immune cells, called granulocytes. These cells protect the body from outside "invaders," such as bacteria. Without granulocytes, the body is defenseless against bacteria and infection.

      Agranulocytosis occurs more in patients taking PTU than Tapazole—twice as often, in fact. Regardless of their dosage, patients taking PTU have the same risk of developing the condition. With Tapazole, on the other hand, the risk is likely dependent on the dosage. The lower the dose, the lower the risk."

      So while these side effects are rare this is something to think about. PTU does not cure the disease but gives you an opportunity to go into remission.

       

    • Posted

      Thank you... I most likely already have a mild form of Agranulocytosis from Carbimazole since my neutrophils count has more than halved and is now at the bottom range level. Tomorrow I should have my blood tests results from 3 days ago to see what the story is...
  • Posted

    I have heard from many people on this Board and other Boards like this that they get similar reactions to Carbimazole/Methimazole, especially at the higher dosages.  I was never on a dose higher than 10 mg and I did not get full blown hives, however, I did have a recurrent welt across my forehead which went away when i rubbed it with cotton pads soaked with Betamethasone scalp lotion.  Did the hive or hives go away when you stopped the Carbimazole?  If it did and it starts again when you start taking it, then you know that is what they are from.

    Were you on antibiotics recently?  There is a similar reaction that happens to some people when they take certain antibiotics.  

    Please keep us posted on your condition.

    • Posted

      Hi Linda, no I was not on antibiotics (I am allergic to many antibiotics molecules thou, since I was a child).

      I haven't stopped taking Carbimazole yet, I took it this morning and received the email from endocrinologist suggesting I stopped just 3 hours ago. So I will stop tonight by not taking my evening dose. The hive is all over my chest and arms, I notice it on my neck too just now. It is a lot less red/inflamed than yesterday and the day before but it is still there.

    • Posted

      If the hives do not disappear after 24-48 hours after you have stopped taking it, I would then go to an Emergency Department.  While I have heard of many patients who have had this reaction to Carbimazole/Methimazole, I have also had a condition called Serum Sickness with hives all over my body not abating until I was given a week's worth of steroids to take.  Many docs even do not know about this condition.  I have had it twice, once due to a bee sting and second time due to antibiotics I had finished taking 2 weeks prior.

    • Posted

      I also wanted to add that I had to take an over the counter antihistamine in order for the itching to stop last week. You might need something stronger at the ER.
    • Posted

      Same I have never taken more than 10 mg and that made me feel awful!

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