What happens when you can’t tolerate Levothyroxine? Is there another medication out there? I started Synthroid (brand name) two weeks ago and since then I have now experience two episodes of NSVT (non sustained ventricular tachycardia - it’s not related to SVT; that’s complexly different) this week, one Tuesday one last night, both caught and confirmed by my internal loop recorder. They aren’t completely sure if it was the medication but for the time beginning I was told to stop. Now I’m wondering exactly what options there are if my heart doesn’t tolerate this medication? My TSH is too high (96.2) to not be treating but I also can’t be going in and out of NSVT either. I feel stuck between a rock and a hard place.
What happens when...: What happens when you can’t... - Thyroid UK
What happens when...
Written by
Tiffw28
To view profiles and participate in discussions please or .
Read more about...
64 Replies
•
Perhaps you should try a different brand?
Thanks for the response!
I did ask that because that was the first thing that came to my mind, but they were thinking it could be the treatment all together so the Endo and the Cardio want to speak about it this week. Is the active ingredient the same in all those medications or does It vary? I thought it was all Levothyroxine just under different brands and manufacturers. I apologize about being clueless I’m still trying to learn, I google quite a bit though!
No apologies necessary. The reason I am on this forum is to learn. There are different brands some can be by the same manufacturer. I am unable to tell you which is which. Read the written info on the one you have had a possible reaction and compare with another. Your chemist will help you with this.
That’s one thing I’m grateful for here all the knowledgeable people! I’m very slowly getting it. thanks again for the help!
I did reach out to the pharmacist today to discuss what was going on and he was leaning more towards the active ingredient than anything but said we could try different manufacturers just Incase it is an inactive. I’m a bit nervous to go through that roller coaster! It’s funny I originally got the brand name because I thought it would be the easiest! Guess not lol
Maybe you need to try another brand, problem could be the fillers.
thyroiduk.org/treatment-opt...
But it sounds possible that you simply do not tolerate Levo and your heart is reflecting this
Therefore, if you can visit a cardiologist...they may recommend a trial of T3 only
Unlike most endos cardios seem to better understand T3.....or so I've heard
The joint discussion will hopefully result in a way forward
Just a few thoughts, I'm not a medic I've just had to learn along my thyroid journey
Good luck
DD
Hey! Thanks for the response. So it’s funny you mention the T3 because a while back I asked my endo about it and she was like no the T4 is the best.... but I remember reading on here that T3 is also directly connected with the heart. So it’s all very interesting. I’m curious what they are going to say to me tomorrow and how they want to move forward.
Hey! So I discussed with my doctor the T3 and they felt that may work up my heart even more. So they are thinking about sticking with a Levothyroxine type med but knock it down to a half dose. I suggest if I had to stay on that type of med, which I’m dreading, I would like to try the tirostint, probably spelled that wrong.
OK.....did she make that decision without carrying out a Full Thyroid Panel?
Most importantly FT4 and FT3
What does "a half dose" consist of?
I hope starting with a small dose and slowly increasing works for you
Good luck....members are always here to help.
DD
Hey.
Yeah She has always pulled Ft4 it was the Ft3 that she hasn’t done. She just pulls the regular t3. When I see her on Monday I plan on asking for the free t3.
She mentioned possibly taking half a 25mg dose. Essentially cutting it in half. But I know there’s the one brand that makes a 13mg dose. So we discussed that as well. Since I had the arrhythmia the manufacturing literature actually says to stop for one week and then restart at a lower dose so I haven’t started anything back up again yet. Plus I asked to stop the pill till we figure out our next step. Which worked out because I see her in her Monday. I just know the thought of restarting any Levothyroxine scares the crap out of me!!
Good idea to push for FT3 rather than Total T3 which I guess is what you refer to as regular.
FT3 is the important reading....
Hope it works well
DD
I have tachycardia on synthroid as well.
I do not have tachycardia on cytomel unless I take too much.
looking at previous post's, you mention having some nsvt's prior to starting the thyroid hormone replacement, so that makes me think it would not be the thyroxine, (whatever brand) itself that caused them.
But obviously you must have become extremely Hypo by now with that TSH result. I assume they only gave you a very small dose of thyroxine to start ,with your complicated cardiac history ?
Hey! Thanks for the response. Yeah I had the one run of NSVT a year and so ago (none prior to that) until this Tuesday and the last night. I guess where their issue is It looks completely different than what I had last year and I went so long without an issue. They felt that one run last year may have been an isolated incident that’s why I think they are questioning what’s happening now and why. I keep asking if the hypo itself could be causing this and I keep getting “we’ll not really, it tends to be the atrial stuff like Afib etc” so they seem resistant. Personally I think it’s all connected- the hypo/high TSH and arrhythmia. I have no clue about the medication and how that plays a role. I’m wondering if it can help make my heart more irritable and maybe that’s why. Who knows. I just didn’t know what they did if someone really legitimately couldn’t take Levo.
i don't know what people on here mean when they talk about 'palpitations'....... however, i hear lots of examples here of specialists who don't recognise common Hypo symptoms which i hear, can include 'palpitations'.
But i assume your problem is something more serious to have an 'internal loop recorder'
Doctors are very quick to associate LOW TSH with Afib
(My instinct is that you are on the right track, in thinking they are a hypo thing, )
people with heart conditions should be started on a low dose and increased gradually,
What dose did they put you on for the last couple of weeks , 25mcg ?
'helvella' (admin) has a list of all the brands of thyroxine,and which fillers are used in them.
Sorry can't be more help .
So yeah I started at 25mg and was on it until today when they told me to hold it for now it’s going to be interesting what they want to do.
I will be honest I haven’t felt good since I started it. First few days I felt wiped out, brain fog, exhausted. I didn’t even want to talk and the rest of the time I’ve felt super emotional-crying at the drop of a hat and just generally off. My heart has also been off. My resting rate is lower than normal and now I’m having these crazy beats. I did not feel like this before even with the crazy TSH. This all started after I started the medication. I know the dose isn’t a therapeutic dose but it’s still enough to get in your system and act up. All of this would just be one heck of a coincidence if it’s not related!
So I have the loop recorder because my doctors and I knew something was up and we didn’t know what so we figured we would catch it sooner or later. So now all the information is rolling in from it part of me wishes I didn’t know.
If you cannot tolerate levo then T3 may be the way to go but we really need results of a comprehensive test (below) to evaluate your thyroid status
Your gut feeling is probably correct- hypo!
For a different reason I don't respond well to levo.....like many others here.
I am T3-only ...you may need to push for a a trial because with a TSH of 96.2, as you know, you need to be medicated correctly...asap
Have you had the following tested together
TSH
FT4
FT3
folate
ferritin
Vit D
Vit B12
All need to be optimal to support thyroid function....not just "in range"
Do you have any other hypo symptoms
thyroiduk.org/signs-symptom...
I might suggest that the irregular heart beat may be resolved by correct thyroid medication
You may find this interesting
verywellhealth.com/thyroid-...
Thanks for the information!!
So the last four (b12,D...) are either right under range or barely in it. I’m working right now to try and get them up but I’ve always had issues with my levels. So annoying. I don’t think I’ve ever had my folate checked but I could be wrong. I get so much blood work regularly done it may have been slipped in somewhere! I actually still have a cortisol test I need to get done I don’t know where that fits in with all of this.
I’ve had the TSH, the FT4 done but I’ve only had the T3 not free T3. When I asked about it my doctor said she doesn’t like the free T3 and thinks the regular T3 is more reliable. She didn’t say why though. I’ve also had my antibodies checked numerous times because I have Hashimotos.
I thankfully don’t suffer from too many of the hypo symptoms but I may just be so used to them I don’t even notice anymore. I have had some recent weight gain which is annoying especially since I haven’t changed my diet at all. I notice it’s more belly related which is not a place I normally gain. I also have the swollen thyroid and nodule which you can see looking at my neck.
So I have a large nodule I have to get a biopsy for. It’s part fluid and solid and continuously gets bigger every year when I get my ultrasound. How much does that play into all of this? If I was to get that removed and it’s not cancer could all of this possibly turn around? I never think to talk about that aspect. I didn’t know if that was more a symptom or a cause.
I swear there are so many pieces to this hypo puzzle. How is it this field hasn’t come further along at this point!
I'm afraid your medic is wrong to focus on TT instead of FT results....
"she doesn’t like the free T3 and thinks the regular T3 is more reliable." .
By "regular" T3 I assume she means TT3.
The following explains why she is wrong...
"Note that the TT3 and TT4 tests have largely been superseded by the FT4 and FT3
measurements. Only the free thyroid hormones are biologically active and they represent only about two tenthousandth of total T4 and three thousandths of total T3. This makes the assessment of FT4 levels from the TT4 levels very inaccurate."
Ex ...
thyroiduk.org/getting-a-dia...
Re cortisol
yourhormones.info/hormones/...
I suggest you work on the nutrients mentioned above and get some comprehensive testing done. You appear to be wrongly medicated but if medics don't look for problems they won't find them!
Can you access private testing many of us here go down that route because NHS generally only test TSH and sometimes FT4.....no wonder people are ill!
Agree....it is scandalous that thyroid disease is treated so badly often by medics whose knowledge is limited. That is why over 100,000 people have arrived here looking for help!
So I’ll have to talk to her about the ft3 because there’s no reason she can’t test for it even if she’s not a fan. I know she does watch my ft4. Thats the one I always get tested. Last ft4 was 0.81 the “normal” range is 0.76-1.46
I’m so frustrated and scared. Frustrated because of the hypo stuff and scared because of the cardiac stuff. I had a feeling about this medication before I even started it but I want so desperately to fix things I jumped in. I have no idea how they plan to move forward now. I didn’t take my Synthroid yesterday like they told me to do but I know they will have to switch it to something!
And I will have to see. In the states it’s weird how they do things. You can’t go to a lab and get tests without a doctors office ordering them.
It's a horrible position to be in but correct treatment should help.
FT4 - 0.81 (0.76 - 1.46)
This is not a normal result your FT4 is only 7.14% through the reference range, it should be close to 75%? That, combined with a TSH of 96.2 is most likely the reason you feel so unwell.
Your medic needs to check this out
This article might help you prepare for that conversation
thyroid.org/thyroid-functio...
Just a thought but have they suggested checking your pituitary....it might be worth asking for a test. You can search on-line for info.
Hope they get to grips with your problem soon .....please keep us posted.
In the states it’s weird how they do things. You can’t go to a lab and get tests without a doctors office ordering them.
Sorry, but you are mistaken - or at least not totally accurate. It depends on which state you live in.
If you go to this link :
stopthethyroidmadness.com/r...
and scroll down to where it says "PLACES TO ORDER YOUR OWN TESTS"
There are several companies listed that will test people without involving doctors or insurance companies.
Oh wow I’ve never heard of that here. Every lab I’ve been to in my state has never done that but I will have to check that link out. That’s good to know!
So I checked out the link and the labs. Thanks again. So are these labs that send you the tests and you send them back? It looks like it from first glance. I never thought to do those! That’s actually a great idea. In my comment I was referring more to the laboratories you walk into and get tested like at the hospital etc. Those are the places I’ve been told oh no you need a doctors office.
I’m going to look around that website too looks like it’s full of good information.
I can't tell you exactly how they work, I don't live in the US. But if they are like UK labs then they work by people ordering over the interent, being sent a kit to get a finger-prick sample of blood for a test done, then the blood is sent to the lab through the post and results are sent via email.
If the test you order required blood to be extracted from a vein then things get more complicated unless you know a nurse or a phlebotomist or a paramedic or some other suitable professional who can take blood for you. But you'd have to follow that up with the lab you deal with.
It's more likely that you are reacting to the fillers and excipients in your levothyroxine tablets rather than the levothyroxine itself. If you want to find out which ingredients there are in various makes of Levo you can find out from this site :
dailymed.nlm.nih.gov/dailymed/
It covers drugs prescribed in the US. I'm just assuming that is where you live because you take Synthroid.
Hey! Thanks for the response and for the link! I remember using that site before when I was checking out the inactive in my potassium pills so I will have to take a look. The issue though is I don’t know what I would be looking for. Like what would be a red flag for this medication or do I go through them all playing process of elimination? As of right now I dread having to take any thing with Levo in it. After this experience I don’t want to touch it. I haven’t felt right since I started it and knew I dreaded it for a reason. But I also know I have to treat it so rock meet hard place.
I did go directly to the literature for Synthroid where I saw that during and after market arrhythmia was a complaint. So that’s interesting to me. It specifically said it can cause more PVCs which is the foundation to NSVT. I was under the impression it only cause or exacerbated arrhythmia if you go over to far but according to this it can happen right out the gate. So does the hormone act like a stimulant? I don’t understand why it would do this and I don’t get why doctors don’t say this when it’s literally written from the company.
Another option that no-one has mentioned yet is to try NDT (natural desiccated thyroid). It's what I use, although it's almost impossible to find a doctor that will prescribe it due to cost. I source it myself. My GP's comment was "whatever you're doing, it seems to be working. So keep doing it."
I HATED synthroid (had weird skippy heart issues, water retention, hives) to the point I thought I couldn’t take T4 meds at all and for years was on this forum posting about T3 only meds (and was on a LOT)... I was taking 300 T3 a day (Cytomel)).
And then, in May I found a doctor who said God, no, try Tirosint. Tirosint is T4, like Synthroid, but without fillers.
So I switched to Tirosint and just a little bit of T3 and my goodness my life has changed! I thought I knew everything there was to know about thyroid meds. But I knew nothing. In just two months I have put on 5 lbs muscle (I lost all my muscle on T3) lost 5 lbs fat, my skin no longer itches, I am running!!!! Miles and miles, 5 miles at a time, FAST, whereas I had had to give up running, my crazy appetite has gone back to normal, I’m sleeping, I can easily curl 20 lbs with each bicep (vs 8 in May) and on and on. I’m a 46 yr old woman. The loss of muscle had been a real issue.
And I’m on 1/10th the dose I was on in May.
Not saying Tirosint is the answer, though it may be. But brands matter. And Tirosint is the only one without fillers. I tried every brand of NDT without success too (Armour, Nature Throid, NP throid, WestP throid, all gave me hives and heart issues). A TSH that high must be treated.
Hey! Thank you for your reply! Someone else mentioned this med below. I’m going to have to talk to my doctor about it today. I’m so terrified to try anything with Levo in it now but I know I have to do something. They told me not to take my dose yesterday and see what they want to do today and I noticed (and it could be a coincidence) but I started having massive anxiety by last night. All I know is I don’t like Synthroid. I haven’t felt right since I started it. My thyroid felt better untreated.
Honestly I was angry when she suggested it. I told her I was allergic to it. She was so kind and said ‘just try it’ I’m so so so glad I did. Has truly changed my life.
That’s awesome. I just wonder if it’s actually the Levo, which is in both products, that’s stimulating my heart and then in turn causing the arrhythmias. I don’t know how inactives would play a factor in this but now you have told me about it I can discuss it with my doctors. And to be honest I would much rather take a medication that has less extra nonsense. Why put it in our bodies if we don’t need it! I like this medication doesn’t have all that.
SlowDragonAdministrator
As you are EXTREMELY hypothyroid it’s likely you have very low vitamin levels
Essential to regularly test vitamin D, folate, ferritin and B12
These need to be optimal for good conversion of levothyroxine (Ft4) into Ft3
Standard starter dose of levothyroxine is 50mcg
Starting too low can cause increased symptoms
50mcg levothyroxine is only a starter dose, and it needs increasing up as fast as tolerated until on FULL Replacement dose (1.6mcg levothyroxine per kilo of your weight)
Bloods should be retested 6-8 weeks after each dose increase in levothyroxine
If you really can’t tolerate then one option is to steady heartbeat with beta blockers until on adequate dose levothyroxine and all four vitamins are optimal
Hey thanks for the response.
I take 200mg of Toprol XL which is Quite a bit plus the max dose of that beta blocker. My vitamin levels are low which I’m currently working towards normal. And yeah I wondered about it causing extra symptoms because it was too low but with my cardiac stuff there was no way they were starting me on 50. They actually had me stop the pill yesterday till they figure out what to do. After I started it not only did I have the NSVT but my heart rate started going into the 50s which it didn’t do prior. I have also felt off since day one. They are having me go today to get blood work done just to see if that TSH jumped again. I’m interested to see what they will say when they all call me since this was all decided over the weekend. All I know is I don’t want my heart rhythm doing this stuff.
I’m going to make a new post but I just got new blood work done and this is where I’m at
TSH 32.50 range- 0.36-3.74
FT4 1.03 range-0.76-1.46
And that’s after almost two weeks on 25mg of Synthroid. Which I stopped yesterday. One of my cardiologist believes the Synthroid is aggravating my heart but said I have to take it. What a mess.
So I also had low potassium prior to all of this. Now my potassium is on the higher side of the normal range. And I have three doses to still take today. My body is a mess. And none of my doctors are talking to each other.
Malabsorption of levothyroxine is complex and common issue
academic.oup.com/edrv/artic...
Often the other problem can be due to starting on too low a dose of levothyroxine
Standard starter dose of levothyroxine is 50mcg and dose increased upwards as fast as tolerated
Retesting 6-8 weeks after each dose increase
I started taking generic levothyroxine and had all sorts of bad reactions (hot flushing, increased b/p, increased heart rate, severe anxiety, and palpitations). My endo said it was most likely the fillers and started me on Tirostint liquid ampules. It is pure levothyroxine with zero fillers/dyes. I had zero reactions and have been doing great.
I do wish you the best as it is very scary and frustrating.
Hey! Thanks for the reply. I will have to look into that I didn’t know that was even an option.
I am switching to tirosint next month and hoping this helps me too!
Did u start at a lower dose, etc?
My tsh was 11.5 and I was also positive for Hashimoto antibodies. The tirosint is way better absorbed than any other. drug. They have the studies to show this. They started me on 25mcg dose and my tsh dropped to normal range and symptoms subsided. The endocrinologist said he could tweek it to 50 mcg - but I feel great and didn't want to risk the tsh going to low. We made a mutual decision to stay at 25mcg. Every 6 months we will do a blood draw to check the level. It took several months before my palpitations completely left, but I felt way better and the severe anxiety completely left as well. I hope you feel better with the med.
You had severe anxiety? With high TSH? How about your sleep?
Hi,iv had a lot of problems with levo, my doc doesn't believe me, not as bad as yours, I take alternative medication, they recommend it for people who can't tolerate levo, I cal it poison, I will tell you what I take them you can look them up and decide for yourself, two are by higher nature, one is thyroid support formula with iodine and selenium, the other one is ocean kelp , also selenium with vitamins ,a, c, and e,you can get them off any vitamin supplier ,I get mine from woods, you get a year's supply, I also take vitamin bcomplex, that's all the vitamin ds ,I also take ashwagandha ,that's suppose to be very good for thyroid problems.
T Ake a look on the internet there are a few good sites, hope it gets you looking for something that helps , anything has to be better than levo, good luck ,and take care in these difficult times,😷😷😷
Hey! That’s for your reply. I referred to it as poison too. I just felt off since day one of taking it. I’m so disappointed with it all. The field, the medication, the doctors. I don’t get it.
So with all that you take how are your levels?
After after reading everything, some people think maybe you're reacting to fillers? If so, have you thought about trying tirosint?
Hey! Thanks for the response. So yeah a few have mentioned that medication and I plan on talking to my doctor about it. I have a feeling it’s more associated with the actual active ingredient less with the fillers. If the hormone is stimulating my already irritable heart not sure how I would get around this.
I can only tolerate activis levolthyroxine, other brands make me feel sick or give me indigestion. It's important to let the chemist know your preferences. Good luck.
Thank you!
Hi Tiffw28, i see you’ve had lots of replies and maybe some has mentioned this already as I haven’t read all of them but i thought i could offer some useful info. A while back i read a research paper detailing how women esp have difficulty tolerating Levothyroxine, when they were given a ferrous sulfate supplement, regardless of their iron levels, they had few side effects and were able to raise their dose accordingly. I could try to find the link or just Google ‘anemia and hypothyroidism’ . I’m not clear on your full situ so maybe this is not relevant but worth a mention I thought. Good luck
Hey! Thanks for the reply. So I currently take iron supplements and I’ve been able to get my iron up thankfully. So If they help that makes me curious how much worse it would be without them! Oh boy.
Oh well perhaps that’s not it! Unless it’s an absorption issue? Are you taking actual iron ( not so easily absorbed) or a ferrous sulfate or similar and with a vit c supplement to aid absorption, just a thought...hope you find a solution soon.
A ferrous sulfate. I drink it with orange juice but not a vit C supplement.
Tirosint-it’s the latest generation thyroid replacement and has only water, glycerin and hormone so it’s much better absorbed and that tolerated. It is made in Switzerland and should be available in Europe.
Hey! Thanks for the reply. I plan on switching to it if they decide to keep me on some sort of Levo. My endo is thinking about having me take half tablet of the 25mg dose and this company actually has a 13mg dose so perfect! Thanks for the suggestion.
I have heart palps in hypo and when adjusting my synthroid dose.
Synthroid always gave me tachycardia since the day I was put on it. With a TSH of 96, I don’t think dropping your dose is the answer. But don’t take my word, I’m not well versed in thyroid, just going by my personal experience.
Maybe a beta blocker to help your adjustment?
Hey! Thanks for the response what kind of palpitations do you have? I know benign PACs and sinus tachycardia are very common with hypo. I already take 200mg of a beta blocker which normally helps outside of this. Right now the doctors have taken me off the Synthroid since my thyroid is still some what functioning on it’s on own and we need to figure out how to move forward with this. While my TSH is high my ft4 is still “normal” as of now but for how long who knows.
The issue is the medication is setting off non sustained ventricular arrhythmia (PVCs that happen in runs) which is riskier than anything coming from the atrial (Afib, SVT etc) so they trying to figure out how to not set it off. We may try the 13mg dose of the tirostint. But to be honest I’m pretty scared to want to get back on anything right now. My cardio feels it’s ok if it does some cause some arrhythmia but I’m not ok with that and my endo doesn’t like the idea either. So I’m in the process of getting a second opinion to see what I can do.
Random increases in HR are my
Palps!
Whatever you and your dr deem fit for your case seems to be the best 
Not what you're looking for?
You may also like...
What happens to your body when you adjust dose?
sensation in my brain. I have been getting these episodes ever since I have tried to make...
What is happening to me now :<
What happens to the thyroid 
Whats happening to me!!! Help!!
What is happening with Goldshield?
