Isosorbide - how long does it take to get this dreadful drug out of your system? the side effects?

I hope your doctor has changed the medication, You should not just stop it and not be on something. You don't say which one your were on but THE side effects should go away fairly soon after discontinuing this medication. at most 7 to 10 days but they well get easier after a few days without it. Very Important that you have talked with the doctor prior to stoping this medication.