I am on Neurontin & Buprenorphine pain patches for my RSD. With those two my pain is considered to be "under control". This means that the pain medication is given in a certain amount to attain a certain level of comfort, as they cannot take the pain away fully, it *is* nerve pain. But even then, I have about 1 to 4 moments a day (sometimes more) when the pain increases despite the pain medication regimen. When that happens, the increased pain is called "breakthrough pain", it's the pain enhancing a number of times a day, a night even though your pain is "controlled", as in: treated. Especially for moments like these, I have oral Buprenorphine (tiny tablets). I put one or two (depending how intense the pain has gotten again) under my tongue and it eases the pain a little more.