Does anybody here take Isosorbide Mononitrate 60 mg twice a day ?

[Leszo]

Had a 3 X CABG 7 years ago, I’m now a 64 years old, male. Everything since then has been fine, until recently, as I've now started to get angina attacks in the early mornings whilst asleep, and if I exert myself (like walking to the shops).

I had to go to A&E when using my GTN spray did not work on me that well. After a few hours in A&E I was told I'd had a heart attack but luckily no damage. It was very mild. Had an angiogram, and they didn't find anything unusual. So I'm now on medical management.

The cardiologist put me on Isosorbide Mononitrate 90 mg once a day, Ranolazine 375 mg twice a day, and Ticagreior 90 mg twice a day, I was then sent home.

I found the team in Hospital very pleasant, helpful and very efficient. And the food was quite good. I stayed in for 4 nights.

When I got home after the first night I started to get the angina attacks again in the early morning, and started to get a bit anxious that the same thing is going to happen, have yet another a succession of angina attacks but next time a fatal heart attack.

This went on for 3 nights, waking up about 3 am feeling tightness in my chest with burning sensation (I don't mind having an angina attack as one uses the GTN spray) but they started to be reoccurring and if it's 3 times one has to dial 999, which I don't know what they can do as they found nothing.

So here’s the thing, the cardiologist said that the Isosorbide Mononitrate (90 mg) can only be taken once a day due to how it works. And I felt at the time that 2 doses a day would work better (that is, stopping my angina attacks whilst sleeping) His advice was not to take twice a day.

When I got home and started to get these reoccurring attacks after a few days, I spoke to my GP. And they agreed that I should be taking Isosorbide Mononitrate 60 mg twice a day. Which I am doing, and I can say they are working. It took a few days for my body to adjust.

I don't think this is a good situation, as I'm on the maximum dosage. I take my meds 12 hours apart.

According to medicine website Isosorbide Mononitrate last 17 hours and Ranolazine only lasts 7 hours, so there is supposed to be a gap of the body being drug free, which for me is not helpful, as I've got CHD.

Anybody with similar experience.

[Milkfairy Heart Star]

Hello,

I take 120mgs of isosorbide mononitrate extended release tablets a day.

60mgs at 6pm and 60mgs at 11pm.

This is because I experience most of my chest pain at night.

It also allows a long enough break between the isosorbide mononitrate doses to reduce the chance of tolerance.

I live with vasospastic angina, my coronary arteries are unblocked however my coronary arteries go into transient contrictions causing angina.

A severe vasospasm in the coronary arteries can cause a heart attack.

Known as Myocardial Infarction non obstructive coronary arteries, MINOCA.

One of the classic symptoms of vasospastic angina is chest pain at rest, in particular between midnight and 6am.

I suggest you ask your Cardiology team to consider whether coronary vasospasms are causing your night time angina episodes.

The usual treatment is with calcium channel blockers.

academic.oup.com/eurheartj/...

[Leszo in reply to Milkfairy]

Thanks for your reply. Even though I do get angina when exerting oneself, all I do is stop, and it goes away instantly, however I also get them mostly at night about 4 am, and they are dull and linger into quite a scary feeling. I've contacted my GP who has sent an urgent email to the cardiologist, and I'm hoping for a reply or invite to see him soon. At the mo, whatever I'm doing is working, but it's really taking the wind out of me, I'm still waking up at 4 am but not having any attacks. I believe that this med causes insomnia. I do think that I'm taking them too far apart 12 hours, that is 8 am and 8 pm. Thanks again for your reply.

[Milkfairy Heart Star in reply to Leszo]

I hope you get the answers you need soon.

I also use GTN patches which I put on in the late afternoon to help manage my chest pain at rest and in the night.

[Steve_G]

I’m not taking either drug but maybe can explain something about drugs in general (I worked in drug development for many years). Drugs have what is called an elimination half life which is how long it takes the body to remove 50 percent or half of a dose from the system. There is an accepted principle that it takes five half lives to completely remove a drug from the body (this is 50+25+12.5+6.25+3.125 or 96.875 percent of a given dose). The half life of isosorbide is 5 hours and for Ranolazine it is 7 hours which means that it takes 25 and 35 hours respectively for each to be completely removed. This is why your GP could prescribe isosorbide twice daily (or use a sustained release formulation as a single dose as an alternative) but wouldn’t do the same for ranolazine. The goal of treatment is to maintain a therapeutic level of the drug in the blood at all times without hitting levels that are toxic by prescribing too high a dose that is taken too often. So 90mg couldn’t be given twice a day but 60mg can. The ranolazine dose will be one that ensures there is still a therapeutic level of drug in your blood when you take the next dose but that there will be no problems caused by the levels getting too high.

I wish you well and hope this helps to explain thing for you.

[Leszo]

I was initially on 90 mg of Isosorbide Mononitrate in the morning, but still got angina at 4 am. However, taking 60 mg 12 hours apart appears to be working, but I'm becoming an insomniac. Ta for your info..