As I said in the other topic, there are many, many choices out there for meds for neuropathic pain, if one doesn't work for you, or the side effects are worse than the problem, get your primary to start you on a different one.
I've been on over 20 different ones now myself, as most didn't work, worked somewhat but had bad side effects. For migraines though the Gabapentin I am on atm does work, and it cured my IBS as well to boot, and I have no side effects at all from it. It doesn't do anything for my CPPS or Sciatica though, so I will still be cycling through different ones, just will be keeping the Gabapentin as long as my primary is ok with that.