I posted recently on here about adverse reaction to Carbimazole after 1 month on 40mg for overactive thyroid. I developed Neutropenic Sepsis, no neutrophils left, week in hospital, and immune system still not right.
I'm continually told this is 'very rare' and doctors seem to have a stock response of only one they personally have encountered in past 10 years. I checked to see if NHS centrally collects this data for thyroid meds/Neutropenia/Agranulocytosis - it does not. I also suspect clinicians are not recording the 'Yellow Card' and it's up to patients to do that if they are aware of this system.
If no one is gathering the data, and the yellow card system is not reflective of the adverse reactions, and pharmaceutical companies are happy to downplay adverse reactions to take drugs to market and keep them on the market, can anyone trust the notion that Carbimazole/Anti-thyroid drugs adverse reaction on immune system is as rare as doctors claim?
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Mancunian_C
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“The incidence is certainly less than one in 500 and is possibly as low as one in 3,000”
The wide discrepancy strongly suggest that data & research isn’t very accurate / up to date.
I think as it’s viewed as such are rare affect it’s not priority research area.
The options for hyper treatment is also very limited. It’s antithyroid (carbimazole / PTU). or on to definitive interventions (surgery / RAI)
No medical professional has ever mentioned yellow card reports to me. The information is in the small print of patient information leaflets. If we don’t realise a symptoms might be connected, have the time / ability to log the report I suspect a huge amount of issues go unreported. I also certain doctors don’t really keep themselves up to date with new information from yellow card reports.
Two years into treatment of carbimazole I developed a neck lump under jawline about 3 cm from my hyper nodule. The GP was very concerned & furious when the hospital declined ultrasound and so put me through for urgent ENT consult - who were equally concerned & booked that scan.
They advised it was a inflamed salivary gland, couldn’t explain cause, couldn’t explain why 1 side only, didn’t want to do a fine needle aspiration because they are tricky / painful & apart from inflammation didn’t look concerning. Suggested plan was to review in 3 months. By then it had disappeared. I had a further consult, dr was only interested in salivary gland and said he couldn’t discuss thyroid because that was a different department & I was discharged. Then I had an unexpected appointment for another scan, which I’m quite certain was arranged because they wanted a training experience (waste of my time).
The reason I mentioned these 5 additional appointments? - I was sent a new brand of carbimazole & decide as it’s a new brand I might read through the information which I’d not done for months. On the list of known side affects is inflamed salivary gland. If it was listed before I had forgotten. & none of the doctors were aware. What a waste of resources!
Amazing that no one connected the drug and the salivary gland issues. Crazy.
The consultant I saw said reaction to Carbimazole is so rare it's 1 in 30,000 which is a very BIG variation on the BTF numbers. I suggest he interpreted 3000 as 30000 which leads me to believe he literally has no idea on the risk or how often this happens.
I registered my own Yellow Card on this one, and suspect you are right that most don't/won't or assume a clinician will.
The BTF link you provided states "This is very rare" in terms of having reaction to both Carbimazole and PTU, yet my clinician told me if I opt for PTU now he has to talk to a family member about the liklihood of my having another immune reaction and dying. I kid you not - that was the conversation.
My immune system is still low but improving so can't start PTU until that is right, and the clinicians are reluctant to give me PTU.
I genuinely believe I am being given bad advice at every step. I'm currently on no meds other than beta blockers so all getting bad again with thyroid going up. It's a very frustrating situation.
I contacted thyroiduk.org but didn't realise there is a British Thyroid Foundation which is bigger, so I might contact them on Monday for a bit of a steer.
I just feel there is an iceberg situation where very little adverse reaction data is ever collected, and little if any collected centrally. There is available data on the number of prescriptions per month, but that's it.
Dr likely quoting wrong figure is pretty worrying!
It’s good you’re improving. It must be very difficult to decide if you should try PTU. I can see why the doctor doesn’t want you to attempt it. Have they suggested an alternative plan (RAI / Surgery)
PTU & carbimazole will likely have different statistics & they grouped them together. The variation of treatment is also going to have an impact. eg level of starting dose & how well managed a patient might also be important factors.
BTF are factual & will go by NHS guidelines. It can be useful to use their information & leaflets because it should be from the perspective of NHS hospitals / doctors. Many of the leaflets are designed to reassure the patient.
Hey, just to say I suffered the same as you. After about 3 weeks on 40 carb I eventually dragged myself to hospital, was in for 10 days in isolation with Agranylucytosis, neutropenic sepsis etc. On a drip for 7 days. My endo told me it was very rare, he had only seen one other case 15 years ago. (working in London and he's senior) My endo did tell me to report it via yellow card system. I was not allowed Ptu after. The only option was Rai or TT. I opted for Rai as I couldn't get my head around the TT.
3 years on, I've been in many thyroid forums looking for advice and learning and I've never read about anyone else that was admitted like I was (and you). With the help of the knowledgeable people on here, I'm finally feeling almost normal (!!) and have learnt so much from this group. Do check your key vitamins and iron if you haven't already as mine were all rock bottom when I was discharged. (all normal previous) Good luck with everything going forward!
Thank you and sorry to hear you had the same. It sounds such a similar story to my own. Can I ask you about the RAI and how long before your thyroid symptoms recovered. And how taking thyroxin is. I'm paddling blindly on this. Happy to do so by DM is you prefer.
I'm annoyed this week that this has happened and wondering why, when so many others sail through.
My immune system still below what it should be so it's going to take a few weeks so thank you on the vitamins advice.
Yes I often googled at the time why me, what are the odds, why me, why me..I still have no answer. I guess I haven't had the easiest of times, so bare in mind not everyone will struggle like I have! Gentle exercise now and eat well to recover from the ordeal.It was an 8 week wait for Rai and I was on propranolol only. My brain was frazzled and my legs hurt during that time, but no real difference than untreated Graves. Rai itself was simple swallow a tablet and keep your distance from people. I kept away from husband and kids and went to work as normal. The real fun started after about 6 weeks. I felt like I was losing the plot, on the verge of a breakdown. It was like a switch was suddenly flicked and I was full blown hypo real quick. Terrible body pains, terrible pms, bleeding, my hair started falling out (although endo said that is likely double whammy reaction from stress of neutropenia hospital stay etc) puffy eyes, exhausted. Quick call to endo, had bloods done and started thyroxine. I'd say it took 4 months to not feel so unwell. I now know that I dont react well to dose changes. So I have suffered badly each time my dose was increased and it takes weeks for the thyroxine to fully build up in your system.
I've had a brilliant endo who has done regular blood tests, I can call or email at any time, but the whole process has taken ages. I've constantly felt unwell, tired, no energy, no spark, it's been horrible. I'm also perimenopausal so dealing that with hormonal imbalance aswell hasn't helped one bit! But I have not just accepted that ( as many do) and have constantly stood my ground and said I'm not feeling right, what are you going to do to help me. Learning what I can from here has been a game changer and ultimately last year starting T3 Liothyronine has been life changing. Feel free to dm. Not everyone has such a tough time though, remember that, some people sail through.. Why me?! 😂
Good on you for standing your ground. Medical misogyny is real and women have to stand firm in the face of that.
Helvella in their post below provides some research links. I've read one so far and it does pose some reasons why some more than others hit issues, including possible genetic component and issues beginning with poor liver synthesis of the drug.
You're information on the RAI and then hitting wall is really helpful. I'm sorry it was that rough and I suspect that may be the roadmap for this journey for me also, so thank you for sharing that.
It's a crazy ride, that's for sure.
Thank you again for flagging this has happened to you and it's good to have your lived experience to work with.
Over the years we have had quite a number of members who have had issues which might have been agranulocytosis, etc.
The advice has always been to get medical support urgently. Just maybe, that has saved a few from the very worst situations.
If so, we do have to wonder what would have happened if they had NOT sought that urgent help? Would your endo perhaps have seen more of the most serious cases if the members had not posted and been pointed at A&E?
At least a few mention the possibility of using lithium, at least in the short term between finding an issue with one of the usual anti-thyroid medicines and "definitive" treatment.
I had hoped to find a clear review paper discussing incidences of all forms. This one is quite interesting but there might be others.
Drug-Induced Idiosyncratic Agranulocytosis - Infrequent but Dangerous.
I strongly agree that the medical professions appear poor at filing Yellow Card reports. I suspect they rarely do so for known adverse reactions. Hence, once it has been identified, few bother. So they are poor at evaluating incidences.
Patient Yellow Card reports have much potential. But only if we do them (as you have). We need to positively encourage all members, all patients, to file Yellow Card reports whenever they have an adverse reaction or side effect that is not ever so clearly understood and known.
Thank you for those links. I'm going to read through that today for some better understanding.
Yes, Yellow Card only works if people complete and currently it's a voluntary option which leaves the field wide open for patients assuming clinicians complete it or for many to just not bother. It's very easy to use.
The lithium idea is interesting.
I have found a published Yellow Card report from only a couple of years back flagging pancreatitis and impact for pregnant women, so the information is filtering out from Yellow Card reports.
To be fair, I'm only aware of Yellow Card reporting as it was mentioned a lot during the COVID pandemic.
Just seems such a lottery as to who the thyroid drug is going to do this to, and about as much scientific determination as the Harry Potter sorting hat.
Thank you again for taking the time to provide your answer. It's genuinely helpful.
I'd very much like to see something like a QR code on all Patient Information Leaflets which would enable us to start a Yellow Card report using a smartphone (optionally). The precise product, batch, expiry, dosage, could all be picked up from that. Or support scan of box-end information. Or, well, something to help patients start their reports.
Although hyperthyroidism is not a rare disease, the incidence is between 0.2 and 1.3% globally and around 0.75% in Europe. Diabetes for example has an incidence of 10% globally, so this is much more prevalent.
Every new medication that comes to the market will have limited adverse events reported, due to the relatively small population the drug has been tested in. All medicines carry a black triangle warning after they come to the market, meaning that they are subject to intense monitoring by the regulatory authorities (post-marketing surveillance). Everyone is encouraged to report any adverse event through the yellow card system, so accurate data can be recorded and if new adverse events come up, these can be added to the label. This AE reporting includes KNOWN adverse events, so for example if the trial showed nausea as an adverse event, and if you are on the medication and experience nausea, you should report this as it is important to keep track of all events - sadly this is not generally known by physicians or patients. And it can be a nuisance, but obviously the side effect profile is only as good as the reporting allows.
As the drug will be exposed to more patients when it is routinely prescribed, new adverse events might come up and should be reported. Pharma companies have the legal and ethical responsibility to document and report information to the regulatory authorities and the label needs to be updated when new safety information comes to light.
Therefore all suspected and unexpected side effect should be reported by physicians and patients to the regulatory authorities.
Thank you. Yes, data is power and if people aren't reporting, then the picture of adverse effects is not correct. It's human nature to not bother or assume someone else will bother, and responsibility to report comes down to those who are aware they should and who are willing to take the time to do that. It's very hit and miss to be fair.
Do you now have access to your medical records and can share your TSH +Free T3 + Free T4 results and ranges at diagnosis -31st January - and which sets of antibodies were found positive and over range in your initial blood test results.
Thank you. I really need to get those original ones from 31st January. Unfortunately now I'm off throid med I'm heading back to square 1! The link you provided on RAI is very interesting, so thank you for that.
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Canary in the Coal Mine: Thyroid Disease 
Overactive Thyroid - Carbimazole and reduced immune system
Reaction to various drugs
Hashimoto's and Adverse Drug Reactions Misery
