Isosorbide mononitrate
"I take a whole host of medication for high blood pressure  - and some narrowing of arteries (as determined by an angiogram). I also cycle quite a lot - 50-100 miles/week.

I found that when I took the isosorbide mononitrate, I would get very much out of breath and it would make me very weak. I effectively stopped taken them over time and feel much better with no symptoms of angina"