Ivabradine - Could It Be Causing My Blurry Vision And Nightmares?

[Batik]

I've been on ivabradine for two years or so now. It's helped the POTS considerably. I still have severe ME, and I still have a fair amount of POTS symptoms, including heart rate spikes now and then (I wear a Fitbit Charge HR which is a heart rate monitor as well as a step counter), but I'm not blacking out from things like standing up.

However, I've been getting regular nightmares since, hmm, probably around the time I started it. I'm really not sure. I was already getting regular nightmares when I met my partner in July 2015, and I don't think I'd been on the meds for more than six months at that point. They are around five nights a week and they range from pretty bad to absolutely terrifying. A bad night will leave me with a painfully tight chest, anxiety and total exhaustion (i.e. bedbound) for two days. I should note that I have PTSD, but I've had that for fifteen years, it's gradually improved over time, and the nightmares never used to be that bad. I've also been getting increasing anxiety symptoms, which again are relatively new for me at this level. Apart from this my life is generally going very well, so it's not as if I am under work stress or in a bad relationship or something which might account for it. I've been wondering whether there could be a medication change behind it, though the GP says nothing stands out as a cause. I'm told that PTSD nightmares are different to normal nightmares, and that they are associated with a rush of adrenaline.

The other noticeably worsening problem is blurry vision. Every morning my vision has been blurry, whether just very mildly and for a short time, or more noticeably and for several hours. I've been tested for diabetes, nope, not that. I went for an eye test on Tuesday (I am still absolutely exhausted from that) and even though it was only a year since my last prescription, my eyesight had worsened considerably. I'd lost a dioptre in my better eye and the astigmatism is markedly worse in the other eye. (At the age of 37, my myopia shouldn't suddenly be getting worse like this.) So new specs are being made up. The optometrist said the new prescription will be what's causing the blurry vision. I just found "blurred vision" on a side effects list for ivabradine today. If that is the cause, I suspect I shouldn't be having an eye test just yet, that I should come off it and see what my eyes do then. The other possible culprit is that I was wearing a sleep mask that was a bit on the tight side, but while I think that might have made it slightly worse, I doubt it created the problem to this extent out of nothing. Now I've got a looser eye mask (for, hmm, a week or two), I haven't had as bad an episode in the morning, but I still have problems with blurry vision.

Anyway, I've been snooping about this forum recently, and in, erm, I think it was the thread about hormones, someone talked about low blood pressure at night causing adrenaline surges. Ivabradine is known to cause low blood pressure as a side effect, and some sites say it shouldn't be prescribed if you had low blood pressure to begin with. My daytime blood pressure has actually risen since starting ivabradine, but I have no idea what it's doing at night. I've never in my life found a medical professional who thinks low blood pressure is ever a problem, so I have no idea how often it's been low and they haven't mentioned it. (The most common comment I get from someone taking my blood pressure is, "That can't be right," and a close second is, "Well, aren't you lucky not to have high blood pressure!") So if the ivabradine is making my blood pressure drop at night, and that is causing adrenaline surges, am I right in thinking that could be causing the nightmares?

Random thing: for years I've had an occasional problem where I wake up at night with total amnesia, no idea of who or where I am, plus my heart pounding, pouring with sweat, often with sleep paralysis. I've been told here that it might be caused by low blood pressure. I still have no idea what it is or what causes it. Does anyone know more about this?

I am planning to stop the ivabradine, without talking to my GP, as she won't have a clue and doesn't seem to realise how horrendous nightmares like these can be. So I'll take the morning dose for three days, then stop it altogether. I'd rather be passing out again. Anyway, I'll see what happens then, and if there's any sort of result I will talk about it to the GP. I only saw the cardiologist once and was thoroughly unimpressed, so goodness only knows what will happen then. (I was told that I didn't have POTS because I fainted before my HR had jumped more than 26 during the 24 hour ECG; and with the tilt table test I was full of mast cell meds and didn't faint, though my BP was 96/84 at one point and I was thoroughly symptomatic, so I was told that was normal too. And as a result, couldn't get a referral to the out-of-district ME specialist I've been trying to get referred to for years. I don't know if they'd take my Fitbit data as evidence of HR spikes, though. I had a 40bpm spike yesterday caused by a short, slightly stressful phone call, while sitting down, and that's after it's been averaged out over five minutes for each data point! It must have been a much bigger spike when taken on a minute-by-minute, or second-by-second, basis. And yes, that's when I'm on ivabradine.)

Apologies if I sound anxious, last night's nightmare was really horrendous, and it's left me very shaken.

Eta: yesterday's HR log. Each data point represents 5 min, averaged out. https://www.dropbox.com/s/3eda1m5nnvrtsbp/Screenshot_2015-02-28-14-35-21.png?dl=0

[corina]

As far as I know Ivabradine is considered to not lower bp which is why It could be a good choice for POTS patients. It has a half life of 12 hours, so may be you could just take it in the morning? I'd suggest strongly not to stop this med by yourself as it could cause you more problems. I do think your doctor (cardio/gp) is the one to help you tapering down! I'm sorry you are experiencing the nightmares and amnesia problems, hope you will find some answers as that can be so frightening!

[Batik]

I've found plenty of sources saying it shouldn't be used in patients who already have hypotension, which I did at that point.

http://www.nps.org.au/publications/health-professional/nps-radar/2013/december-2013/ivabradine

"Ivabradine may influence retinal function in humans through interaction with hyperpolarisation-activated currents (Ih) in the retina.3,11 These visual disturbances* usually resolve spontaneously." (What does that first bit mean?)

"consider stopping therapy in patients experiencing any unexpected deterioration in vision."

I'm waiting for the RNIB to ring me back, and will talk to the optometrist as soon as I can.

[SarahA33]

How unfortunate that you are going through so much, I know you've mentioned in some of your other posts sleep difficulties so I'm sure the sleep deprivation adds an extra layer of stress to everything. You sound really overwhelmed, I'd suggest calling your doctor.. I know its the weekend, but my doctor always has someone on call for him. I'm really sorry to hear your going through so much.

My EP/POTS specialist recommended Ivabradine for me. I know each case is specific, however, he was more worried about Bradycardia rather than hypotension. If you think it's causing swings in your blood pressure then maybe the prescribing doctor could order a 24 hour ambulatory blood pressure monitor.

How long have you been taking the Ivabradine? I know I've read in a ton of research articles about the Visual side effects it causes for about %10-15 of patients called "Luminous Phenomenon" which is thought to be a result of the medication altering a channel in the retinal cells (similar to the same way it works on the I/f-channel in the heart). Have you discussed this side effect with your physician yet?

Please take extra good care of yourself,

Sarah

[Batik]

Thanks. The sleep difficulties you mention are the nightmares, and I've already spoken to the doctor about them. No help, and no meds. My partner is being great, and I have a good support network of friends. Also a kittycat! She always glues herself to my lap when my health's worse. Crisis services wouldn't be able to offer anything anywhere near as good as what I have already, and I do have experience of them. Thanks for suggesting it, though. The main problem today was that I'm having a fibro pain flare, and together with hugely overdoing it when I went out for that eye test on Tuesday (turns out the specs are already completed, by the way), I am absolutely exhausted and have been too zonked from pain meds to be able to risk further sedatives. I'm doing a bit better this evening, at least, though I have no idea when I'll next be fit to shower, let alone leave the house. More awake than earlier, and I think starting to get Restless Leg Syndrome, so I might risk 2mg diazepam.

Oh yes, and I'm not exactly sleep deprived, I'm sleeping about nine hours a night. But it's very poor quality sleep.

I've been on ivabradine for two years. I don't think I'm getting luminous phenomena. I mean, I get episodes where darkness and brightness are patchy and odd, but I think I've had that for a lot longer, probably as long as I've had migraine (22 years) and certainly since I developed ME. The blurry vision is what's new, along with a significant change in my myopia and astigmatism. I feel like a bit of a noodle for not checking that before I went to the optometrist, but I am on a lot of meds and there are so many possible side effects for each. If it turns out this prescription is wrong, I hope I don't get charged twice for specs, they were expensive!

Anyway, we are curled up watching a Star Trek film, we've had a nice dinner, and my partner is tootling at the ocarina in the other room while I type. I think it's the Harry Potter theme tune.

I would still like to know more about ivabradine! It doesn't seem to be commonly used. It's the first medication I've ever been on where the dose has been half a tablet twice a day, where the doctor can't just order in a tablet of the right dose. Googling has revealed that there's one person on record as getting nightmares on ivabradine. They stopped and started it a bit, which made the pattern clear. For all I know, there could be many others who didn't report it. Anyway, the blurry vision alone is enough reason to come off it for now, so I'll see what that does to my sleep.

[Batik]

Sorry, clarification from earlier: the nightmares are having a severe impact on my mental health, and due to what I assume is spending a substantial period of the night struggling to breathe and/or having an adrenaline surge or whatever is going on, it's also affecting my physical health dramatically too. Dealing with this is far worse than dealing with tachycardia or near-syncope, so it's taking priority. Not to mention that I honestly hadn't clocked how bad my vision has got (I'm having trouble seeing across the room, about nine feet), and I'm concerned about limiting damage to my eyes. I'm familiar enough with emergency health services to be able to assess whether they're worth contacting or not, and I have my partner to help give me some sense of perspective. The thing that is bothering me is that I do not have any doctors who know a thing about POTS. They didn't even know how to interpret the TTT or 24 hour ECG. If it were simply a matter of asking the GP, I'd be sorted by now! This is why I'm trying to find out what other people's experiences with ivabradine have been.

OK, let's take the known visual side effects of ivabradine, luminous phenomena and blurry vision. Does anyone have any idea why ivabradine might cause those, and how it would tie in with POTS?