What were you doing on Valentine’s Day this year? Normally it skips right past me but this year it marked quite an important moment in my journey to treat my POTS symptoms. So this February 14th, rather than anticipating an exciting date night with my husband, I was in hospital to trial the drug Ivabradine, which my cardiologist has been using to treat most of his POTS patients.
You can watch the video below to hear about my personal experiences with Ivabradine and beta-blockers. But if you prefer written rather than spoken word, you can skip down to read about it instead.
I was quite excited to try Ivabradine as I was told that it has helped a lot of other POTS patients. However, I did not want to set my hopes too high as some patients had experienced more severe side effects and had to stop taking it. In my history of taking medication, I tend to collect side effects in abundance and I was a bit concerned that most of the side effects are to do with eyesight. I have also not had the best experience with other medications that slow down the heart-rate.
Prior to Ivabradine, I was taking a beta-blocker known as Bisprolol (1.25mg daily) because, although my first cardiologist was not entirely sure what was wrong, one thing she did know was that my heart was beating much faster than it should do. She also misdiagnosed me with another condition (supra-ventricular tachycardia) which is often treated with beta-blockers. However, Bisprolol and me did not get on well! In fact, taking it seemed to make many of my symptoms worse including dizziness, tinnitus, brain-fog and fatigue. I also started to develop uncontrolled blood pressure while on Bisprolol, and began to faint as my blood pressure would drop suddenly. Prior to Bisprolol, most of my issues with POTS were to do with tachycardia, nausea, palpitations, extreme breathlessness and chest pain rather than issues around inadequate blood supply to the brain like dizziness and brain-fog, and of course the fainting. Since Bisprolol is often used to treat hypertension, it is perhaps not surprising that it affected my blood pressure negatively. Although I contribute a lot of my physical decline at that time to doing ‘all the wrong things’ and the anxiety of being so unwell without a diagnosis, looking back I can see that beta-blockers were perhaps doing me more harm than good.
So how do beta-blockers work? Beta-blockers act on the beta-receptors responding to stress hormones, which stimulate the sympathetic nervous system (our fight/flight response). This means that they lower the activity of the heart by blocking the action of hormones like noradrenaline. They also tend to lower blood pressure, as they reduce the force at which blood is pumped around the body, and can be used to treat anxiety by turning down the volume on how the body responds to stress. The most common side effects are dizziness, cold extremities, fatigue, nausea and disturbed sleep. Notice how many of those side effects are also symptoms of POTS!
Ivabradine, on the other hand, slows the heart rate down through a completely different mechanism. It selectively inhibits the cardiac pacemaker current known as the ‘funny channel’. This current affects the spontaneous action of pacemaker activity in the sinoatrial node, which is the part of the heart tissue that controls ‘normal’ beating of the heart. It therefore slows down the heart rate in a completely different way to beta-blockers, and tends to have fewer side effects. The most common side effect is luminous phenomena, or phospenes, which presents as bright vision. It is thought that the reason for this is that the funny channel is similar to an electrical current in the eyes (see this study for more details). While it is contraindicated in patients with very low blood pressure, it is not thought to affect blood pressure as much as beta-blockers. It was designed to treat stable angina pectoris and chronic heart failure, so it was not designed with POTS in mind. However, there have been a few studies that have shown Ivabradine can be beneficial for POTS patients (see further reading below).
I will not lie, I was certainly quite anxious about trying Ivabradine. However, the trial itself went well – my resting heart rate did drop to the low 60s but I felt fine – and I was let out of the hospital in the afternoon. I was told to take the usual starting dose which is 2.5mg three times a day at intervals of four hours, and at the same time I was told to stop taking my beta-blocker. My biggest worry was that taking Ivabradine would set me back after months of hard work to get better. So you can imagine my concern when a few days after taking it, I started to feel my breathlessness, dizziness and palpitations creeping back.
I go into this in more detail in the video, but in short my body was struggling with me not taking Bisprolol and it not yet being used to the Ivabradine. After consulting my GP, I reduced the Bisprolol gradually and was able to wean myself off it. However, as soon as I thought I was out of the woods, I began to develop quite bad vertigo and nausea. Again, I go into this in more detail in the video so I won’t repeat myself here! But, simply put, the Ivabradine was too strong for me so I reduced my dose.
I now take 2.5 mg twice a day, leaving a gap of around 7 hours. I often find I only need to take one 2.5mg tablet in the morning depending on how I am feeling that day and how active I will be.
What you would probably really like to know is, has it helped?
Yes, it definitely has. These are the improvements that I have noticed:
- NO FAINTING EPISODES!
- No more tinnitus
- No more tremors
- Drastically reduced dizziness and brain fog
- Reduced fatigue
- Reduced blurry vision and hearing/visual disturbances
- Reduced breathlessness and palpitations
- Reduced nausea
- Better memory and concentration
- Dramatically reduced exercise and heat intolerance
- Less problems with reduced sweating
- Fewer issues with cold extremities and blood pooling
- Fewer low moods (I would not say I felt depressed but I did find myself feeling overwhelmed and down at times)
- Better sleep and fewer nightmares
I am sure some of these improvements are down to stopping the Bisprolol, but the Ivabradine has made a huge difference to my health even compared to how I felt before developing more severe symptoms of POTS. I have struggled with fatigue and exercise intolerance for a very long time and this is considerably better now.
The greatest change is that I have not fainted at all since taking Ivabradine. Although I had managed to improve this considerably I still had a few faints and much more pre-syncopy while taking Bisprolol. I now rarely feel like I am going to faint, and if I do it is mild and transient. I also have a much more active life. I exercise three times a week, commute into and out of London after a full day of work, and still have energy to cook dinner, clean and do anything else I need to do that day. I can even stand still on the train for up to 20 minutes! My body works more efficiently and I am almost living like a ‘normal’ person again. I still have good and bad days, but the bad days are nothing like as bad as they used to be.
The only two side effects I seem to get with Ivabradine are that occasionally my heart does beat quite slowly, in which case I stick to one dose of 2.5mg. I also do experience luminous phenomena (phosphenes) on occasion, but it is transient and does not really bother me at all. I see this as a brighter field of vision and ‘sparkly lights’ – it can actually be quite pretty!
All in all, I think my experience so far with Ivabradine has been a success. I still need to see how I will be with it long term, but it has allowed me to improve my fitness enough that it might be possible for me to reduce taking it in future. I’ll let you know how it goes and if there are any changes to my health along the way.
Thank you for reading and I hope it has helped you in some way. Please feel free to comment or message me if you have any questions or would like someone to talk to. I’d also love to know if you have tried Ivabradine for POTS, or are about to take it. Take care xx
Strange fact: One of the things you cannot consume when taking Ivabradine is grapefruit!
NICE guidelines: Ivabradine for treating chronic heart failure (http://www.nice.org.uk/guidance/TA267)
Ivabradine in the treatment of Orthostatic Intolerance (http://europace.oxfordjournals.org/content/13/3/306.full.pdf)
Single centre experience of Ivabradine in Postural Orthostatic Tachycardia Syndrome (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3043639/)
Package Leaflet for Procoralan/Ivabradine (http://www.servier.com/sites/default/files/pil_procoralan_0.pdf)