my mother has type 2 diabetes, thyroid problems,copd,sleep apnea, high blood pressure/blood sugar. she takes metformin 1000mg ,glipizide 5mg,synthroid 175mg,mevacor 20mg,prinivil 40mg, and insulin shots,, she also wears a cpap at night and has to be on oxygen during the day, a new doctor prescribed coreg 25mg. i don't think it is safe.. please help...