Patch is safest
I have gone through your query. You have already been diagnosed with:
Have Bladder pacemaker
Stage II skin cancer
Now coming to your query. You are already on Fentanyl
Patch for pain. Fentanyl is given to you because it is safe for renal failure patients. Pain pump need Morphine
and ziconotide for direct pumping into fluid around Spinal Cord
. Both of these medicines are contraindicated in renal failure.
So in your case pain pump will not work. If the Fentanyl patch is not working there is no need to stop it suddenly as it will lead to withdrawal symptoms
You should consult your doctor for another route of Fentanyl like sublingual spray or fentanyl lozenges (like Lollipop). It is more effective than present route.
Hope I have answered your query. If you have any further questions I will be happy to help.