Trileptal ® or Oxcarbazepine is an anti-epileptic drug (AED) which is very similar in chemical structure and activity to Tegretol®. Tegretol is the only FDA approved medication for trigminal neuralgia. Tegretol, however, was approved during a period of time when FDA approval was not as difficult and I find it unlikely it would be approved today without additional information. Because Trileptal and Tegretol are very similar in their mechanism of action, it is presumed that Trileptal works in a similar manner to Tegretol for neuropathic pain.
With the development of gabapentin (neurontin), pregabalin (lyrica), and duloxetine (cymbalta), the use of trileptal and other medications in the same class has decreased for neuropathic pain. I still find it quite useful for those that do not get sufficient relief with other medications.