It's been a while since I posted. I've been extremely busy with my disabled mother, followed by the death of my younger brother. I have had to suffer in silence due to having so much to deal with. Thankfully, I am seeing a light at the end of the tunnel.
I opted for staying on carbimazole long term to control my hyperthyroidism and for the time I have been on 10 mg, things had been OK. For almost two months now I have been suffering with cramps which first started in my legs, then they moved to my arms, chest and at varying times all over my body. I hardly sleep at night because I jump up with cramp, sometimes ten times during the night.
I recently spoke to a Benenden doctor because I couldn't wait for the appointment with my GP who had nothing for two weeks. I was very surprised to learn that it could be the carbimazole causing my cramps as it hadn't even occur to me because I had tolerated it thus far. I was even more surprised when he told me that it is a known fact and many, many people had reported suffering cramps with carbimazole. He suggested asking my Endo team to change it to PTU. It was only the beginning of last week when I spoke to him and since then, I have been trying to get in touch with my Endo team before my next appointment which is not until sometime in August.
Has anyone had the experience of severe cramps whilst on carbimazole? I really don't want to go down the surgery or radioactive iodine route as my Endo team keep offering. Since I have not been able to get anyone from my Endo team, I have been researching the effects of PTU as I know nothing about this drug.
Any advice or comments will be greatly received. Thank you!
LadyA
Written by
LadyAbash
To view profiles and participate in discussions please or .
monitor my T3, T4 and TSH etc. every 6-8 weeks, starting immediately. I had my first blood test before I left the hospital. The next test is already booked for early March. He also advised me to start coming off propanolol in the next week as my heart rate was now back to normal.
When were thyroid levels last tested
Especially important to retest having presumably now stopped propranolol?
Added to that my GP rang me soon after I got home. She had decided to check my folate, ferritin, B12, full blood count and everything that goes with these tests
The changes in the results from 5th - 14th were also due to waiting for my pharmacy to complete my repeat prescription which forced me to take 5 mg tabs instead of the 10 mg, I had been prescribed. I got a right telling off from My Endo. Anyway, I have been taking the 10 mg as I have been told.
Like I said previously, I had never considered carbimazole as a cause of my cramps. I have been on it for quite a long time. I tried to contact my Endo team last week but will try again tomorrow.
My Calcium levels were checked in April: 2.23 mmol/L
Phosphate was also checked: 1.34 mmol/L
My folate, ferritin, transferritin, iron & vit B12 were all checked in January and all within range.
I am still getting used to analysing all my results which sometimes phase me.
Thorne Basic B recommended vitamin B complex that contains folate, but they are large capsules. (You can tip powder out if can’t swallow capsule) Thorne can be difficult to find at reasonable price, should be around £20-£25. iherb.com often have in stock. Or try ebay
IMPORTANT......If you are taking vitamin B complex, or any supplements containing biotin, remember to stop these 7 days before ALL BLOOD TESTS , as biotin can falsely affect test results
In week before blood test, when you stop vitamin B complex, you might want to consider taking a separate folate supplement (eg Jarrow methyl folate 400mcg) and continue separate B12
Post discussing how biotin can affect test results
I used to take B Complex but was told to stop because of the biotin and it's affects on my thyroid. I was not given other suggestion hence taking Vit Bs separately.
Cramps are typically a sign of thyroid hormone imbalance. As you're on carbimazole to control hypERthyroidism, it's possible that your carbimazole dose is no longer appropriate (i.e. you may need the dose increased or reduced).
Best to get a full thyroid blood test done asap to see what your FT4 and FT3 levels are. If you can't get one via your GP soon enough, do consider doing your own via a home testing kit.
Thank you for this link. I have never done my own thyroid test before. This looks very easy to do. I'll try one of the links to help me keep an eye on my results.
I’ve been on carbimazole a while. Had dose tweaked a lot, started on 20, been on 15, 10, 5mg, & back again. So I’ve had a lot of different brands & read a lot of patient information leaflets. I’m going by memory but I don’t recall any of them specifying cramp as a known side affect, although muscle soreness / joint pain is often listed.
Often this is due the abnormal thyroid levels - either still too high or becoming too low, from too high a dose of antithyroid.
You might want to rerun levels and make sure FT4 & FT3 are in range before switching.
Have your key nutrients also been checked?
PTU is 2nd option antithyroid, it works a little differently to carbimazole & and can have greater impact on FT3. The equivalent of carbimazole to PTU is 1:10 so 5mg carbimazole is 50mg in PTU & they are made in 50mg pills so depending on daily dose you might need to make more pills.
To be honest, I also hadn't heard of this but the doctor said he has had patients as he used to work with an Endo team before moving over, hence him suggesting I ask about PTU. He also suggested having my vitamins etc also checked.
I hate changing meds (the truth be known, I hate taking meds, full stop!), but I have to, in order to stay healthy. I'll see what my Endo team says about the cramps. Once they have done another blood test, I'll be clearer about whether I need to change to PTU. I don't have any other symptoms which is a good sign.
Well it’s good they suggest checking nutrients. Hopefully an answer can be found whether it be due to nutrients / levels or the carbimazole. More importantly it can be addressed & you stop having the issue.
So sorry to read about all that is going on - we all need time, reflection and space to recharge ourselves and you are no exception.
I have never heard this comment about cramp when taking Carbimazole - but we do have the option of PTU - so maybe it's worth switching to see if it makes any difference ?
The nature of the AT drug is to restrict thyroid hormone production so maybe your dose of the AT drug needs adjusting - do you have any T3/T4 blood test results and see your T3 dipping ?
What has changed that may have caused these horrible symptoms -
Did you come off the Propranolol - did these symptoms start around the same time ?
I read that this is a hard drug to come off and you must go very very slowly - this drug also slows conversion of T4 into T3 - so may well have a bearing on your T3/T4 readings
Just reading around it suggests keeping well hydrated, and having optimal levels of B12 , vitamin D and potassium and magnesium - so maybe there is something there to look into as well as buying a weekly bunch of bananas !!
My most recent results I put in my reply to SlowDragon.
I was on propanolol but was told to stop at my March appointment with my Endo team. Yes! I think the severe cramps did start around the time I stopped taking it. Again, I had not looked at the link between the two. Certainly something worth discussing with my Endo team.
My Vit D and potassium levels are always high so I had to stop eating bananas or taking vitamin D tabs which I was taking daily at one point but now take vit D once a month. I realised since I eat quite a number of different fruit (blueberries, strawberries, grapes, pomegranate and cranberries.) that my potassium levels will be high as there is potassium in all we eat. I've tried to stick to the foods and fruit low in potassium. I recently started taking magnesium supplements to see if that will help as suggested by my GP, as he said I may be low in salts.
So within 9 days - from March 5th and 14th March -
Your TSH dropped from - 0.23 to 0.12 -
your T4 dropped from - 20.50 to 17.50 -
and your T3 increased from - 6.80 to 7.20 :
so maybe this dovetails in with coming off the Propranolol :
Your T3 appears to be rising and you look a little under medicated now on just the AT drug -
which makes sense as you stay you stopped the Propranolol around this time -and since these are new horrible symptoms I think I see cause and effect - though could be wrong.
Thank you for your analysis. You may well be right.
I never really stop to look at possibilities at the moment because I am dealing with so much. I will definitely be taking a much closer look in the future.
Oh my gosh ! I'm have very severe cramps and didn't even consider that Carbimazole would or could cause it.Thankyou for your post LadyAbash I'm off to my doctor 9am next Wednesday and will ask him about it.
If you've read the responses to my post you will get some ideas as to what to ask/say to your doctor. I have been taking carbimazole for a few years but never related my cramps to that. I initially thought I was over doing things especially recently with all I have been dealing with.
Anyway, I hope you also get a resolution as I hope I will get.
This is what I really enjoy about this forum. Real people with very similar issues to you...meaning, You are not alone! Do continue to post as in my opinion all the responses you get, are valuable!
I been on Carbimazole since December . I started with 30mg then 20 mg . When I was on 10mg I remember having really painful cramps in my legs. It transpired that I was over medicated and after I reduced my dose to 5 mg it stopped.
Funnily, when I first started taking carbimazole, I started on 5 mg for 18 months. A couple of years later when my hyperthyroidism returned they put me on 10 mg because it had come back. SO definitely, something I can discuss with my Endo team.
I have the same experience with severe body cramping but l am not on carbimazole. It'd. happens to me when my body needs more thyroid hormone. It sounds like you have hypothyroid. Or hyperthyroid. You need bloowork checked. I had radioactive iodine. And finally a thyroidectomy which l do not recommend unless absolutely necessary.
I nearly had radioactive iodine two years ago. BUT I am forever, grateful to this forum for helping me see the light! I trusted and believed the doctors and consultants who told me that it would be my best option. I won't have either options as I still feel I need my thyroid despite its current state.
I'd rather have these issues rather than the issues following RAI or thyroidectomy.
I have read that thyroid disease reduces levels of minerals in the body.
In the case of hypothyroidism it is because the condition reduces stomach acid and thus reduces absorption of minerals from food.
In the case of hyperthyroidism it is because the body uses up or excretes minerals at a greater rate than it would in a healthy person because the body is "running fast".
The commonest causes of cramp that I have found myself are low levels of minerals :
Iron and Ferritin (iron stores), Magnesium, Potassium, Sodium
Not a mineral but also a cause of cramp - Low Vitamin D.
I keep vitamin D tablets in stock at home all the time and I keep my level as close to optimal as I can so it rarely gives me cramp.
As for the minerals - I have a box of ferrous fumarate 210 mg (bought from a pharmacy without prescription in the UK) and will take one when I have cramp. Other iron pills are available.
If the iron tablet doesn't fix the cramp within a few minutes then I will take magnesium. Then if that doesn't help, then after a few minutes I will take a potassium supplement, then finally some salt.
The magnesium and potassium supplements I choose to take are magnesium citrate and potassium bicarbonate, both in powder form, bought from Amazon or Ebay. Dose is a level quarter teaspoon in orange juice of each one.
I recently bought Asda's own brand rehydration powder but haven't used it yet due to it's potassium content. But from what you say, I will try it and see and also try some of your links.
I have been on carbimazole off and on for 5 years as I have been in and out of remission. I have had leg cramps primarily due to fibromyalgia and statins but don’t attribute them to carbimazole.
hi, I’m a fellow long term carbimazole user (25yrs+) I haven’t experienced this issue as a symptom of it, but I would suggest that you may need magnesium supplementation a lot of women ‘our age’ certainly experience leg cramps at night.
Thank you for your response. It really made me smile this morning. Sometimes, I forget that I am 'a woman of a certain age', and some things will affect us more than others. Anyway, I am still waiting to get in touch with my Endo team.
I have been taking magnesium supplements for nearly two months since this whole cramp issue started. I am very hopeful.
I’m on Carbimazole (now 2.5mg daily) and didn’t get on well with dose of 10mg daily but since slowly reducing I’ve done a bit better but don’t know if I’m just getting used to all the side effects now or what 😂. anyway … when my thryroid levels were high I had extreme cramps, like you I would wake in the night and then struggle to walk the next day as both legs would cramp up which left me bruised the following day, this moved to thighs upper arms toes and hands whilst riding my motorbike mainly but literally would happen at any time I jut noticed it happening more when cold …I also got a severe shooting pain and pins and needles down my left leg during certain activities which would leave me in agony for half an hour … however since thyroid levels have come down I don’t get any of those things although I do get other side effects instead. Carbimazole for me has been like swapping one evil for another … I’m just choosing to tolerate it as much possible at the minute.
Sorry it’s not much help but that’s my experience so far 😕
Things that I take along side Carbimazole which I think have helped are:
Vit D
B12
B3
L theanine
L carnetine
Magnesium
Selenium
Vit E
I tend to be low gluten but have been for many years as wheat generally doesn’t agree with me, I have traits of adhd so I walk one hour daily (was two but got a leg injury so had to slow down a bit) this helps with depression and stress for me.
Good luck on your journey - I hope you have a speedy remission 🙂
I have been taking high strength Vit D for years now but was told that my levels were too high so I started taking the tabs, first once a month now I take them twice
The same thing with vit B12 where I was told my levels were also too high so I take these every other day. I've also started taking magnesium.
I wasn't taking selenium but started eating Brazil nuts which supposedly contains selenium.
I am in the gym every day as my main form of exercise. Ill have a look at the other vitamins you list and see if I can start taking them.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
Carbimazole feeling terrible
carbimazole and hives 
Graves CARBIMAZOLE and liver
Maximum Carbimazole Dose?
Carbimazole or not
