Try looking around. I have never tried fentanyl for my pain, but do currently take the ir version of Opana. I have chronic pain from a broken vertabre and arthritis throughout my spine. It rocks for my pain. Being yours is a ER, I would think that these two opiates would be safe to take together, however, both seem high on the addiction scale. That would be my main concern if I were in your shoes. Did you discuss your concerns with your doctor? I would do that.