Hi, first post. Dad has been prescribed this drug after HA 10 days ago. He takes 10 mg at 10 am and 10 mg at 1 pm. He is himself without taking the drug but in the afternoon he has severe headaches - it is debilitating for him. It is distressing to see him suffer so badly. We have read that the headaches should become less over time, but so far can’t see any evidence. He is 81 years old. In need of advice
Thank you
Hi. The headache will go away after few days of taking them as this is the most common side affects of these pills but temparery affect within week or so it shouldn't be a problem.
Go back to your doctor and report it .I to had severe headaches for 10 days which I could no longer tolerate and came of Isorbide. Debilitating migraine like headaches .may change to a suitable alternative .
Did you just stop taking them? I'm on them, only day 5 but I feel rubbish. Like the worst hangover, day after day. Want to stop. Trying to call GP but so busy at the moment. I was managing with GTN before, was trying to find a solution to prevent having to use it in the middle of the night but I think I prefer that to this feeling.
Hi Sloopy yes I just stopped taking them after phoning my doctor.Was ill taking them and explained the side effects .Some people might be ok .I was on them 10 days and .I had my GTN spray if needed.Hope this helps
Thank you, yes it did. GP really busy but suggested I speak to the chemist who pretty much said although he couldn't advocate it said just leave the second dose and talk to the GP in the morning. Also suggested the one dose in the morning may be sufficient, maybe I'm on too much for my needs. I've got my GTN handy, but yeah those headaches, feeling sick and hearing my heartbeating in my left ear felt like I'd swapped one debilitating problem for another. xx
Maybe a lower dose will be better for you Sloopy,.Try and see Hope it works for you.let me know how you get on .
Hi, the latest situation, Dad took 10 mg in the morning, and 10 mg in the afternoon. Complained to GP about headache, she told him to stop the afternoon tablet. Anyway 2 weeks later he had bad angina in the morning requiring ambulance. Cardiologist gave him slow release 40 mg, he’s been on it for 2 weeks - still headache but it has stopped the chest pain. The GTN makes him sick so we need something else. Work in progress
Thank you for the update. This forum has been so helpful. Work in progress here too xx
I also had really bad headaches on these but after a couple of weeks they ease off
So sorry to hear this. I took it for 2 weeks and couldn’t tolerate the severe headaches so was taken off it. There are alternative drugs and I am now on Nifedipress with no problems at all x
I just want to say I really do appreciate your helpful replies. Thank you
HiDoes your dad have GTN spray that he uses ?
He has been given a GTN spray as part of his prescription. How long does the GTN spray relieve the pain?
Has any body told you the procedure regarding your spray GTN ????
Spray under tongue. Dad has been stable since the last episode, but reading the moment we may need to use GTN again. He’s passed out most of the time after using it, although it could be that he should take the GTN sooner.
Hi maybe speak to your cardiologist, I take 30mg a day in the evening and I didn't get any headaches.
i take 120mg daily.. had headaches to begin with but luckily settled down after a couple of weeks
First dose Isosorbide Mononitrate 30mg MR
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Isosorbide Mononitrate 
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Isosorbide mononitrate - bad headache
