My insurance has made my doctor try me on different medicines for my chronic pain. the first one was nucynta which did not help nearly as well as the oxycontin I was on and it also gave me really weird side effects like putting things in strange places and talking about strange things with my sister. Now as per my insurance, they still want my doctor to try at least two other medicines before they will preapprove my going back on the oxycontin that does work for my herniated discs. the meds they want my doctor to chose from are Opana ER, MS Contin, and Fentanyl, and I am reluctant because, just like Nucynta, I have never heard of these and I'm afraid that I might have side effects to these also. So are these common meds?