medications that weathergirl mentioned looking into, will require a large dose
to equal the amount of fentanyl
you are getting through your current dose
. Of course, there is cross tolerance but once you get that far up in strength via fentanyl, you are still more than likely going to require larger doses than normal of morphine, oxymorphone, oxycontin, etc.
There is also an option to ADD another long acting medication in with the fentanyl.