I have been an IP patient for 2 years. I had to switch PM doctors and my new doc took me off oxycontin to Methadone. The pain reief is about the same - but when I started the new meds I also started getting huge panic attacks. After one month my resting heart rate is over 100 and it kind of freaks me out. I can make a switch to MS Contin, but my doc says maybe it is still a WD effect. I take a dose of 10 mg 2xday and was on the same w/oxy.with some BT meds. Any ideas or help would be wonderful. I have to decide and let my Dr. know soon. Has anyone had this problem. Thanks for any help..