Is It Safe To Take Opana Instead Of Oxycontin As A Pain Reliever?

Thank you, since being assaulted blinded for life in my left eye, 9 broken bones in my face, splenectomy, i have had pain issues. I was on 10- 80 mg oxycontin for 4 years, down to 3, but just going on medicare, turning 65, the insurance company doesn t want to cover oxycotin and will cover opana I have just had the Opana filled, and it seems not to work as far as taking the edge off, as well, What would the proper cross over be, from oxycotin 80 mg to Opana er on a daily basis, and what do you feel the difference is?