Post Script: I was the instigator for John using the patches. I had read here about the good pain relief fentanyl provided and I wanted something that would stop the debilitating headaches he was having and help with the mouth pain. Interestingly, the headaches disappeared while he was on the patch,and to date, have not come back. My uneducated guess is that the patch stopped a cycle of pain that was maybe tension and stress related. Am keeping my fingers crossed. amy