Some meds like sudafed make me very nervous and jittery, doc recommended mucinex yesterday for bronchitis, this is regular mucinex, 600 mg. package says to take 1 or 2 pills, I took 1 early this morning, it did not seem to have much effect, Can I take two without having side effects. I am also on Flecainide for irregular heart beat. I want to clear up this mucus in lungs, but don't want to feel crazy side effects.