With all of the anti-seizure meds (gabapentin, Tegretol,
Trileptal, etc) you have to increase the
dose slowly according to your doctor's instructions to get pain relief.
That said, I did not do well on Tegretol -- it made me a zombie and did not help my pain. But everyone is different.
I ended up on Trileptal -- it has less side effects than Tegretol. I took 3 doses of 600 mg per day to stop my pain.