Was taking four 6.25 doses of Coreg six hours apart. Doctor now wants to change to 20 mg Coreg CR TWICE a day. I have many serious problems with hypertensive RXs but have been able to tolerate Coreg. Also take 3 doses daily of Vasotec; 10 mg morning, 10 mg. mid-day and 20 mg at night. I Understand about the differences in dosing, but very worried about 2 doses. Have taken 3 days of morning (only) dose......feeling the effects somewhat. Am trying to establish safety overall, and how safe w/Vasotec too??