I need to stop taking diltiazem XR 120 mg -- my sweet elderly cardiologist agrees and wants me to start lisinopril after dc of diltiazem, but isn t sure how to safely wean me off the diltiazem -- last time I tried to stop on my own, my BP spiked 36 hrs after last dose (I m a slow metabolizer, insufficient cyp450 system, hence the need to quit diltiazem) -- now I see that tapering is urged, but how do you taper off an exteneded release formulation? Thanks! Annie