Propranolol : Does anyone know what is lowest... - Thyroid UK

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Propranolol

sobs1962 profile image
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Does anyone know what is lowest dose of propranolol that can slow heart rate without interfering with t4 to t3 conversion too much. Doctor has had me on metropolol but is causing extreme confusion and as have had no adverse reaction to propranolol in the past decided to try taking 10 mg twice daily to see how that works. Any advice greatly appreciated.

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sobs1962
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humanbean profile image
humanbean

Does anyone know what is lowest dose of propranolol that can slow heart rate without interfering with t4 to t3 conversion too much.

I've never taken propranolol or metropolol but I do take bisoprolol, another beta blocker. I started taking 1.25mg per dose in about 2013 / 2014 / 2015 (can't remember exactly), and it worked for me for several years. But eventually I had to raise my dose to 2.5mg per day. It seems that slowly I became slightly resistant to it and my heart wouldn't slow down when I took the lower dose. I don't know if "resistance" is possible, but it is how I interpreted my symptoms.

One thing I did that was against doctor's advice at the time, is I refused to take bisoprolol every day because it slowed my heart down far too much and also reduced my blood pressure dramatically as well, even at half my prescribed dose.

So I started taking it only when I felt I needed it because my HR was high, and that has suited me ever since. It meant that in the early days a single prescription would last me for many months. I still don't take BBs every day, and I do try to keep my dosing to an absolute minimum.

kassie5 profile image
kassie5 in reply to humanbean

I have to say that I get a lot of information from this site and it gives me the confidence to 'fight my corner' with various doctors. I hope my experience helps others.

I was experiencing heart flutters for a while and put it down to stress that I was under. Then they got worse and I felt very lightheaded and an ecg showed extra ventricular beats. End of 2019 I was put on a calcium channel blocker 2.5mg which I really couldn't tolerate as my blood pressure is normally on the low side of normal (I presumed).

I kept telling them that it only seemed to happen when I was hungry or just eaten. My gallbladder was investigated as I'd had a severe pain in the middle of the night and I do have a 2 cm gallstone. Heart man would not agree that there is a vagus nerve association!

Middle of 2020 he put me on Bisoprolol 2.5 which I couldn't tolerate either and it was reduced to 1.25 which was still bad. Thanks to this site I realized it was stopping the conversion to T3 and the cold and tiredness were due to this.

Another ecg also showed a-fib so was put on blood thinner, Edoxaban.

Around this time the penny dropped in my foggy brain. Mid 1019 the GP had reduced my Thyroxine from 1.25 through 1micg to 75! I had put on a stone! He agreed to put it back to 1micg as I had put on weight. I then pushed this back to 1.25 citing replacement guidelines.

Crux of this story is that the heart man agreed that the beta-blocker or Bisoprolol were only to make me feel more comfortable, not any therapeutic value, and he was happy for me to manage my 'comfort' with diet (not allowing myself to skip meals) and the vagal maneuver to limit the palpitations.

Another tip from this site. The weight would not shift even following a carb limiting diet until I tried HCL. It improves the gallstone symptoms and the weight is coming down. I understand that low stomach acid causes the gall bladder problems and is common in hypothyroidism. As was said here, it goes full circle and comes back to the thyroid every time.

Flecmac profile image
Flecmac in reply to humanbean

I’ve just started Propranalol for Migraines and raised BP. I take T4/T3 combo and I’m now worried about this affecting conversion.I don’t fancy the confusion with Metropolol. Would Bisoprolol be any better and would it help with migraines, which Propranalol does?

Any advice would be appreciated.

Thankyou.

humanbean profile image
humanbean

I forgot to ask...

What are the beta blockers you take actually for? In my case it was for tachycardia.

sobs1962 profile image
sobs1962 in reply to humanbean

Yes for tachycardia, which is apparently being caused by being "over-replaced" They reduced my levo from 100mcg to 87.5mcg and I felt dreadful as well as put me on metropolol at the same time. Very bad idea and have agreed to my levo going back to 100mcg and like I said have decided to start taking propranolol again at 10mg twice daily. Took one about 2 hours ago and heart rate has slowed. I know it'll have an affect on my conversion but their priority is my heart not my thyroid, so will do it to keep them happy.

SeasideSusie profile image
SeasideSusieRemembering in reply to sobs1962

Why haven't they suggested Bisoprolol? It's what I take.

There is a lot of information about Propranolol affecting conversion but I have looked and haven't found anything to say that Bisoprolol does. I have been prescribed this for tachycardia.

sobs1962 profile image
sobs1962 in reply to SeasideSusie

To be honest, I don't want to try another beta blocker after the hell this one has put me through. If I have to take propranolol, then so be it. Just have to accept I'll always feel ill.

helbell profile image
helbell

My GP prescribed me propropanol as a pull in the pocket, saying that if I needed another prescription he'd need a closer look at my heart function. I used those and later had some of my mums bisoprolol, which I felt better on. I still only take very occasionally when tachy or palping. Now I want someone to look at my heart... can't get in!I didnt realise propropanol was the strongest thyroid hormone beta blocker. This article states that it is and that metoprolol has the least impact. rejuvagencenter.com/hypothy...

sobs1962 profile image
sobs1962 in reply to helbell

I had no idea that taking a beta blocker could cause such severe confusion, so metropolol not for me ,so looks like I will have to take propranolol now whether I like it or not and irrespective of it's affect on thyroid hormone conversion, it's about weighing up the priorities and think that heart is probably more important.

sobs1962 profile image
sobs1962

Don't want to appear pedantic but it's t4 to t3 conversion and I don't think I've got much choice unless of course I want to risk having a heart attack due to heart constantly over working and eventually running out of steam and failing. I think I just have to accept that I'm always going to feel, exhausted and cold.

sobs1962 profile image
sobs1962

Don't want to risk going through what this last week has been like , genuinely was like being in my eighties and having a severe UTI.

Barrister profile image
Barrister

I’ve had sinus tachycardia for as long as I can remember ( long before being diagnosed with hypothyroidism). When it was consistently above 130 beats per minute at rest, ( about 2 years ago) it became extremely uncomfortable and my GP finally prescribed Bisoprolol 2.5mg and it has worked beautifully. My heart rate is usually around 79 now. Clemmie

waveylines profile image
waveylines

Actually there is an alternative to beta blockers: channel calcium blocker. I have tachycardia and P-Afibulation caused by sucessful cancer treatment. All beta blockers made me exceedingly unwell as they affected my thyroid hormone conversion making my symptoms worse.......the cardiologists answer was to keep increasing dose or change beta blocker. I felt like I was dying. Calcium channel blocker changed that and my heart has settled and my thyroid hormones are happy bunnies too. I take Verapamil in a SR form. Beta blockers are always the first line of defense that cardiologists use but yours needs to change tack!! The other thing Id suggest is asking to be referred to an EP they specialise in heart annyrthymias and are far far more knowledgeable. Hope you get sorted soon.Dont accept poor treatment!!

sobs1962 profile image
sobs1962 in reply to waveylines

Sorry what is,an EP, never heard of that.

waveylines profile image
waveylines in reply to sobs1962

Apologies EP= Electrophysiologist. Think I've spelt it right! 🤞. They are consultant medics who special in abnormal rhythms of the heart. I asked my cardiologist to refer me to one.

haggisplant profile image
haggisplant

I spent a long time researching this but got no where. I had to take slow release propanolol for years for anxiety which I now think is also due to hypermobility; research shows it’s v helpful for those with hypermobility. I felt better at the end of the day, often nothing to do with anxiety!

I did have to on a slightly higher dose of thyroxine.

I asked a dr recently and he had no idea it interfered.

SlowDragon profile image
SlowDragonAdministrator

ncbi.nlm.nih.gov/pmc/articl...

Propranolol hydrochloride (>160 mg/d), atenolol, and metoprolol tartrate produce small reductions in total T3 levels.

It’s possible your high heart rate is due to being under medicated especially if have low Ft3

pubmed.ncbi.nlm.nih.gov/303...

sobs1962 profile image
sobs1962 in reply to SlowDragon

Thanks for that, have read that article and have no intention of taking over 160mg a day of propranolol, in fact plan to take 10mg 3x daily if that keeps my heartrate down. Don't really understand why they are diagnosing tachycardia anyway, it's classed as a heartrate over 100 bpm and mine isn't ,just about 90.

Poniesrfun profile image
Poniesrfun

I had a pretty-existing tachycardia related to lung cancer treatment for which I take Corlanor (ivabradine). Beta blockers severely impacted my breathing and calcium channel blockers dropped my blood pressure to the point of being totally unable to function. Corlanor only affects the sinus node of the heart and does not have a direct effect on either breathing or blood pressure. It has been approved for years in Europe for sinus tachycardia but not in the US so I have to source mine from Canada. I thought it was also approved in the UK for tachycardia. I also worked with a cardiologist, not an endocrinologist, to find my dosing “window”. Too much T4 (levothyroxine) will put my heart into overdrive while taking extra T3 (anywhere from 5 to 10 or 15 mcg above my base dose) does not have any noticeable negative effects.

Patti in AZ

MauraWheeler profile image
MauraWheeler

Advice is to take thyroxine first thing in morning on an empty stomach and at least one hour before any caffeine. However much better to avoid all caffeine, and grains if possible.

sobs1962 profile image
sobs1962 in reply to MauraWheeler

Don't drink any caffeine haven't done for years

MauraWheeler profile image
MauraWheeler

Change your diet.no caffeine and possibly no yeast in any form.

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