Is It Safe To Take Nucynta To Relieve Back Pain?

My insurance wants me to try nucynta rather than 30mg. oxycodone that has controlled severe backpain for many years,I also deal with seisure medication.I just got a good combination of meds that works the best for my condition and my insurance put a hold my oxycodone until I try this nucynta. Why cant they leave what works alone?